diff --git a/build-logic/conventions/src/main/kotlin/com/datadoghq/native/config/ConfigurationPresets.kt b/build-logic/conventions/src/main/kotlin/com/datadoghq/native/config/ConfigurationPresets.kt index 06bd64d4d..8ec470b07 100644 --- a/build-logic/conventions/src/main/kotlin/com/datadoghq/native/config/ConfigurationPresets.kt +++ b/build-logic/conventions/src/main/kotlin/com/datadoghq/native/config/ConfigurationPresets.kt @@ -1,3 +1,18 @@ +/* + * Copyright 2026, Datadog, Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ package com.datadoghq.native.config diff --git a/ddprof-lib/src/main/cpp/counters.h b/ddprof-lib/src/main/cpp/counters.h index fc98ddfa3..79e89045b 100644 --- a/ddprof-lib/src/main/cpp/counters.h +++ b/ddprof-lib/src/main/cpp/counters.h @@ -71,13 +71,19 @@ X(AGCT_NATIVE_NO_JAVA_CONTEXT, "agct_native_no_java_context") \ X(AGCT_BLOCKED_IN_VM, "agct_blocked_in_vm") \ X(SKIPPED_WALLCLOCK_UNWINDS, "skipped_wallclock_unwinds") \ - X(WC_SIGNAL_SUPPRESSED_SAMPLED_RUN, "wc_signals_suppressed_sampled_run") \ X(WC_PRECHECK_REGISTRY_LOOKUPS, "wc_precheck_registry_lookups") \ X(WC_PRECHECK_CANDIDATES_REJECTED, "wc_precheck_candidates_rejected") \ X(WC_PRECHECK_LOOKUP_BUDGET_EXHAUSTED, "wc_precheck_lookup_budget_exhausted") \ + X(WC_SIGNAL_SUPPRESSED_OWNED_BLOCK, "wc_signals_suppressed_owned_block") \ X(WC_UNOWNED_BLOCKED_SUPPRESSED, "wc_unowned_blocked_suppressed") \ X(WC_UNOWNED_BLOCKED_RECORDED, "wc_unowned_blocked_recorded") \ X(WC_SIGNAL_QUEUE_FULL, "wc_signals_queue_full") \ + X(TASK_BLOCK_EMITTED, "task_block_emitted") \ + X(TASK_BLOCK_SKIPPED_TRACE_CONTEXT, "task_block_skipped_trace_context") \ + X(TASK_BLOCK_SKIPPED_TOO_SHORT, "task_block_skipped_too_short") \ + X(TASK_BLOCK_STACK_CAPTURE_FAILED, "task_block_stack_capture_failed") \ + X(TASK_BLOCK_RECORD_FAILED, "task_block_record_failed") \ + X(TASK_BLOCK_DROPPED_ROTATION, "task_block_dropped_rotation") \ X(UNWINDING_TIME_ASYNC, "unwinding_ticks_async") \ X(UNWINDING_TIME_JVMTI, "unwinding_ticks_jvmti") \ X(CALLTRACE_STORAGE_DROPPED, "calltrace_storage_dropped_traces") \ diff --git a/ddprof-lib/src/main/cpp/event.h b/ddprof-lib/src/main/cpp/event.h index 67ff97b38..ece568fd1 100644 --- a/ddprof-lib/src/main/cpp/event.h +++ b/ddprof-lib/src/main/cpp/event.h @@ -58,7 +58,7 @@ class ExecutionEvent : public Event { OSThreadState _thread_state; ExecutionMode _execution_mode; u64 _weight; - u32 _call_trace_id; + u64 _call_trace_id; ExecutionEvent() : Event(), _thread_state(OSThreadState::RUNNABLE), _execution_mode(ExecutionMode::UNKNOWN), @@ -123,13 +123,13 @@ class WallClockEpochEvent { u32 _num_failed_samples; u32 _num_exited_threads; u32 _num_permission_denied; - u64 _num_suppressed_sampled_run; + u64 _num_suppressed_owned_block; WallClockEpochEvent(u64 start_time) : _dirty(false), _start_time(start_time), _duration_millis(0), _num_samplable_threads(0), _num_successful_samples(0), _num_failed_samples(0), _num_exited_threads(0), - _num_permission_denied(0), _num_suppressed_sampled_run(0) {} + _num_permission_denied(0), _num_suppressed_owned_block(0) {} bool hasChanged() { return _dirty; } @@ -168,10 +168,10 @@ class WallClockEpochEvent { } } - void addNumSuppressedSampledRun(u64 n) { + void addNumSuppressedOwnedBlock(u64 n) { if (n > 0) { _dirty = true; - _num_suppressed_sampled_run += n; + _num_suppressed_owned_block += n; } } @@ -182,7 +182,7 @@ class WallClockEpochEvent { void newEpoch(u64 start_time) { _dirty = false; _start_time = start_time; - _num_suppressed_sampled_run = 0; + _num_suppressed_owned_block = 0; } }; @@ -207,4 +207,14 @@ typedef struct QueueTimeEvent { u32 _queueLength; } QueueTimeEvent; +typedef struct TaskBlockEvent { + u64 _start; + u64 _end; + u64 _blocker; + u64 _unblockingSpanId; + Context _ctx; + u64 _callTraceId; + OSThreadState _observedBlockingState; +} TaskBlockEvent; + #endif // _EVENT_H diff --git a/ddprof-lib/src/main/cpp/flightRecorder.cpp b/ddprof-lib/src/main/cpp/flightRecorder.cpp index 1f3b04b29..60d5671ec 100644 --- a/ddprof-lib/src/main/cpp/flightRecorder.cpp +++ b/ddprof-lib/src/main/cpp/flightRecorder.cpp @@ -1978,6 +1978,21 @@ void Recording::recordMethodSample(Buffer *buf, int tid, u64 call_trace_id, flushIfNeeded(buf); } +void Recording::recordTaskBlock(Buffer *buf, int tid, TaskBlockEvent *event) { + int start = buf->skip(1); + buf->putVar64(T_TASK_BLOCK); + buf->putVar64(event->_start); + buf->putVar64(event->_end - event->_start); + buf->putVar64(tid); + buf->putVar64(event->_blocker); + buf->putVar64(event->_unblockingSpanId); + buf->putVar64(event->_callTraceId); + buf->put8(static_cast(event->_observedBlockingState)); + writeContextSnapshot(buf, event->_ctx); + writeEventSizePrefix(buf, start); + flushIfNeeded(buf); +} + void Recording::recordWallClockEpoch(Buffer *buf, WallClockEpochEvent *event) { int start = buf->skip(1); buf->putVar64(T_WALLCLOCK_SAMPLE_EPOCH); @@ -1988,7 +2003,7 @@ void Recording::recordWallClockEpoch(Buffer *buf, WallClockEpochEvent *event) { buf->putVar64(event->_num_failed_samples); buf->putVar64(event->_num_exited_threads); buf->putVar64(event->_num_permission_denied); - buf->putVar64(event->_num_suppressed_sampled_run); + buf->putVar64(event->_num_suppressed_owned_block); writeEventSizePrefix(buf, start); flushIfNeeded(buf); } @@ -2251,6 +2266,21 @@ void FlightRecorder::recordQueueTime(int lock_index, int tid, } } +bool FlightRecorder::recordTaskBlock(int lock_index, int tid, + TaskBlockEvent *event) { + OptionalSharedLockGuard locker(&_rec_lock); + if (locker.ownsLock()) { + Recording* rec = _rec; + if (rec != nullptr) { + Buffer *buf = rec->buffer(lock_index); + rec->addThread(lock_index, tid); + rec->recordTaskBlock(buf, tid, event); + return true; + } + } + return false; +} + void FlightRecorder::recordDatadogSetting(int lock_index, int length, const char *name, const char *value, const char *unit) { diff --git a/ddprof-lib/src/main/cpp/flightRecorder.h b/ddprof-lib/src/main/cpp/flightRecorder.h index 7e3efacc1..2311fa00d 100644 --- a/ddprof-lib/src/main/cpp/flightRecorder.h +++ b/ddprof-lib/src/main/cpp/flightRecorder.h @@ -337,6 +337,7 @@ class Recording { void recordWallClockEpoch(Buffer *buf, WallClockEpochEvent *event); void recordTraceRoot(Buffer *buf, int tid, TraceRootEvent *event); void recordQueueTime(Buffer *buf, int tid, QueueTimeEvent *event); + void recordTaskBlock(Buffer *buf, int tid, TaskBlockEvent *event); void recordAllocation(RecordingBuffer *buf, int tid, u64 call_trace_id, AllocEvent *event); void recordMallocSample(Buffer *buf, int tid, u64 call_trace_id, @@ -438,6 +439,7 @@ class FlightRecorder { void wallClockEpoch(int lock_index, WallClockEpochEvent *event); void recordTraceRoot(int lock_index, int tid, TraceRootEvent *event); void recordQueueTime(int lock_index, int tid, QueueTimeEvent *event); + bool recordTaskBlock(int lock_index, int tid, TaskBlockEvent *event); bool active() const { return _rec != NULL; } diff --git a/ddprof-lib/src/main/cpp/javaApi.cpp b/ddprof-lib/src/main/cpp/javaApi.cpp index 1e6ffb9ae..bd53fb880 100644 --- a/ddprof-lib/src/main/cpp/javaApi.cpp +++ b/ddprof-lib/src/main/cpp/javaApi.cpp @@ -32,6 +32,7 @@ #include "otel_process_ctx.h" #include "profiler.h" #include "threadLocalData.h" +#include "taskBlockRecorder.h" #include "tsc.h" #include "vmEntry.h" #include @@ -68,7 +69,8 @@ class JniString { }; extern "C" DLLEXPORT jboolean JNICALL -Java_com_datadoghq_profiler_JavaProfiler_init0(JNIEnv *env, jclass unused) { +Java_com_datadoghq_profiler_JavaProfiler_init0( + JNIEnv *env, jclass unused, jboolean delegateMonitorWaitEvents) { Error error = Profiler::instance()->init(); if (error) { throwNew(env, "java/lang/IllegalStateException", error.message()); @@ -76,7 +78,20 @@ Java_com_datadoghq_profiler_JavaProfiler_init0(JNIEnv *env, jclass unused) { } // JavaVM* has already been stored when the native library was loaded so we can pass nullptr here - return VM::initProfilerBridge(nullptr, true); + ProfilerBridgeInitResult result = + VM::initProfilerBridge(nullptr, true, delegateMonitorWaitEvents); + if (result == ProfilerBridgeInitResult::MONITOR_EVENTS_DELEGATION_CONFLICT) { + throwNew(env, "java/lang/IllegalStateException", + "Monitor-event ownership conflicts with the profiler's " + "process-wide initialization"); + return JNI_FALSE; + } + if (result != ProfilerBridgeInitResult::SUCCESS) { + throwNew(env, "java/lang/IllegalStateException", + "Failed to initialize the profiler bridge"); + return JNI_FALSE; + } + return JNI_TRUE; } extern "C" DLLEXPORT void JNICALL @@ -93,6 +108,12 @@ Java_com_datadoghq_profiler_JavaProfiler_getTid0(JNIEnv *env, jclass unused) { return OS::threadId(); } +extern "C" DLLEXPORT jboolean JNICALL +Java_com_datadoghq_profiler_JavaProfiler_monitorWaitEventsDelegated0( + JNIEnv *env, jclass unused) { + return VM::monitorWaitEventsDelegated(); +} + extern "C" DLLEXPORT jstring JNICALL Java_com_datadoghq_profiler_JavaProfiler_execute0(JNIEnv *env, jobject unused, jstring command) { @@ -136,32 +157,6 @@ Java_com_datadoghq_profiler_JavaProfiler_getSamples(JNIEnv *env, return (jlong)Profiler::instance()->total_samples(); } -// some duplication between add and remove, though we want to avoid having an extra branch in the hot path - -static ThreadFilter::SlotID ensureCurrentThreadFilterSlot( - ThreadFilter *thread_filter, ProfiledThread *current) { - int tid = current->tid(); - if (unlikely(tid < 0)) { - return -1; - } - - ThreadFilter::SlotID slot_id = current->filterSlotId(); - if (likely(slot_id >= 0)) { - if (likely(thread_filter->activeSlotForId(slot_id, tid) != nullptr)) { - return slot_id; - } - current->setFilterSlotId(-1); - } - - // Startup can register this TID centrally, but it cannot update another - // pthread's TLS. registerThread(tid) reuses that existing slot. - slot_id = thread_filter->registerThread(tid); - if (slot_id >= 0) { - current->setFilterSlotId(slot_id); - } - return slot_id; -} - // JavaCritical is faster JNI, but more restrictive - parameters and return value have to be // primitives or arrays of primitive types. // We direct corresponding JNI calls to JavaCritical to make sure the parameters/return value @@ -183,7 +178,7 @@ JavaCritical_com_datadoghq_profiler_JavaProfiler_filterThreadAdd0() { return; } - int slot_id = ensureCurrentThreadFilterSlot(thread_filter, current); + int slot_id = thread_filter->ensureCurrentThreadSlot(current); if (unlikely(slot_id < 0)) { return; // Failed to register thread } @@ -358,43 +353,56 @@ Java_com_datadoghq_profiler_JavaProfiler_recordQueueEnd0( Profiler::instance()->recordQueueTime(tid, &event); } -extern "C" DLLEXPORT void JNICALL -Java_com_datadoghq_profiler_JavaProfiler_parkEnter0(JNIEnv *env, jclass unused) { +extern "C" DLLEXPORT jboolean JNICALL +Java_com_datadoghq_profiler_JavaProfiler_parkEnter0( + JNIEnv *env, jclass unused, jthread thread) { + if (!JVMSupport::isPlatformThread(env, thread)) { + return JNI_FALSE; + } ProfiledThread *current = ProfiledThread::initCurrentThreadSignalSafe(); if (current == nullptr) { - return; + return JNI_FALSE; } - bool first_park = current->parkEnter(); - ThreadFilter *tf = Profiler::instance()->threadFilter(); - if (first_park && tf->registryActive()) { - ThreadFilter::SlotID slot_id = ensureCurrentThreadFilterSlot(tf, current); + Context context = ContextApi::snapshot(); + if (!current->parkEnter(TSC::ticks(), context)) { + return JNI_FALSE; + } + + Profiler *profiler = Profiler::instance(); + ThreadFilter *tf = profiler->threadFilter(); + if (context.spanId == 0 && tf->registryActive() && + (profiler->taskBlockEnabled() || tf->enabled())) { + ThreadFilter::SlotID slot_id = tf->ensureCurrentThreadSlot(current); if (slot_id >= 0) { - current->setParkBlockToken( - tf->enterBlockedRun(slot_id, OSThreadState::CONDVAR_WAIT)); + current->setParkBlockToken(tf->enterBlockedRun( + slot_id, OSThreadState::CONDVAR_WAIT, BlockRunOwner::JAVA)); } } + return JNI_TRUE; } extern "C" DLLEXPORT void JNICALL Java_com_datadoghq_profiler_JavaProfiler_parkExit0( - JNIEnv *env, jclass unused, jlong blocker, jlong unblockingSpanId) { + JNIEnv *env, jclass unused, jthread thread, jlong blocker, + jlong unblockingSpanId) { + if (!JVMSupport::isPlatformThread(env, thread)) { + return; + } ProfiledThread *current = ProfiledThread::initCurrentThreadSignalSafe(); if (current == nullptr) { return; } - + u64 start_ticks = 0; u64 park_block_token = 0; - if (!current->parkExit(park_block_token) || park_block_token == 0) { + Context context{}; + if (!current->parkExit(start_ticks, context, park_block_token) || + park_block_token == 0) { return; } - ThreadFilter *tf = Profiler::instance()->threadFilter(); - if (tf->registryActive()) { - ThreadFilter::SlotID slot_id = ThreadFilter::tokenSlotId(park_block_token); - if (tf->activeSlotForId(current->filterSlotId(), current->tid()) != nullptr && - current->filterSlotId() == slot_id) { - tf->exitBlockedRun(slot_id, ThreadFilter::tokenGeneration(park_block_token)); - } - } + finishTaskBlockAtExit(current, Profiler::instance()->threadFilter(), thread, + 1, park_block_token, start_ticks, context, + static_cast(blocker), + static_cast(unblockingSpanId)); } static bool decodeJavaBlockState(jint state, OSThreadState &decoded) { @@ -408,31 +416,34 @@ static bool decodeJavaBlockState(jint state, OSThreadState &decoded) { extern "C" DLLEXPORT jlong JNICALL Java_com_datadoghq_profiler_JavaProfiler_blockEnter0( - JNIEnv *env, jclass unused, jint state) { + JNIEnv *env, jclass unused, jthread thread, jint state) { OSThreadState decoded; - if (!decodeJavaBlockState(state, decoded)) { + if (!decodeJavaBlockState(state, decoded) || + !JVMSupport::isPlatformThread(env, thread)) { return 0; } ProfiledThread *current = ProfiledThread::initCurrentThreadSignalSafe(); if (current == nullptr) { return 0; } - ThreadFilter *tf = Profiler::instance()->threadFilter(); - if (!tf->registryActive()) { + if (ContextApi::snapshot().spanId != 0) { return 0; } - ThreadFilter::SlotID slot_id = ensureCurrentThreadFilterSlot(tf, current); - if (slot_id < 0) { + Profiler *profiler = Profiler::instance(); + ThreadFilter *tf = profiler->threadFilter(); + if (!profiler->taskBlockEnabled() && !tf->enabled()) { return 0; } + ThreadFilter::SlotID slot_id = tf->ensureCurrentThreadSlot(current); + if (slot_id < 0) return 0; return static_cast(tf->enterBlockedRun(slot_id, decoded)); } extern "C" DLLEXPORT void JNICALL Java_com_datadoghq_profiler_JavaProfiler_blockExit0( - JNIEnv *env, jclass unused, jlong token) { + JNIEnv *env, jclass unused, jthread thread, jlong token) { u64 block_token = static_cast(token); - if (block_token == 0) { + if (block_token == 0 || !JVMSupport::isPlatformThread(env, thread)) { return; } ProfiledThread *current = ProfiledThread::initCurrentThreadSignalSafe(); @@ -450,6 +461,60 @@ Java_com_datadoghq_profiler_JavaProfiler_blockExit0( } } +extern "C" DLLEXPORT jlong JNICALL +Java_com_datadoghq_profiler_JavaProfiler_beginTaskBlock0( + JNIEnv *env, jclass unused, jthread thread) { + if (!JVMSupport::isPlatformThread(env, thread)) { + return 0; + } + ProfiledThread *current = ProfiledThread::initCurrentThreadSignalSafe(); + Profiler *profiler = Profiler::instance(); + if (current == nullptr || !profiler->isRunning() || + !profiler->taskBlockEnabled()) { + return 0; + } + ThreadFilter *tf = profiler->threadFilter(); + if (!tf->unfilteredWallTrackingActive()) return 0; + ThreadFilter::SlotID slot_id = tf->ensureCurrentThreadSlot(current); + if (slot_id < 0) return 0; + + Context context = ContextApi::snapshot(); + if (context.spanId != 0) { + Counters::increment(TASK_BLOCK_SKIPPED_TRACE_CONTEXT); + return 0; + } + u64 token = tf->enterBlockedRun( + slot_id, OSThreadState::SLEEPING, BlockRunOwner::JAVA); + if (!current->taskBlockEnter(token, TSC::ticks(), context)) { + if (token != 0) { + tf->exitBlockedRun(slot_id, ThreadFilter::tokenGeneration(token)); + } + return 0; + } + return static_cast(token); +} + +extern "C" DLLEXPORT jboolean JNICALL +Java_com_datadoghq_profiler_JavaProfiler_endTaskBlock0( + JNIEnv *env, jclass unused, jthread thread, jlong token, jlong blocker, + jlong unblockingSpanId) { + u64 block_token = static_cast(token); + ThreadFilter::SlotID slot_id = -1; + u64 generation = 0; + if (!ThreadFilter::decodeBlockRunToken(block_token, slot_id, generation) || + !JVMSupport::isPlatformThread(env, thread)) { + return JNI_FALSE; + } + ProfiledThread *current = ProfiledThread::initCurrentThreadSignalSafe(); + if (current == nullptr) return JNI_FALSE; + + bool recorded = recordTaskBlockAtExit( + current, Profiler::instance()->threadFilter(), thread, 1, block_token, + slot_id, generation, static_cast(blocker), + static_cast(unblockingSpanId)); + return recorded ? JNI_TRUE : JNI_FALSE; +} + extern "C" DLLEXPORT jlong JNICALL Java_com_datadoghq_profiler_JavaProfiler_currentTicks0(JNIEnv *env, jclass unused) { diff --git a/ddprof-lib/src/main/cpp/jfrMetadata.cpp b/ddprof-lib/src/main/cpp/jfrMetadata.cpp index 4064ba241..ddbcf22a6 100644 --- a/ddprof-lib/src/main/cpp/jfrMetadata.cpp +++ b/ddprof-lib/src/main/cpp/jfrMetadata.cpp @@ -176,8 +176,8 @@ void JfrMetadata::initialize( "Number of Exited Threads Before Handling Signal") << field("numPermissionDenied", T_INT, "Number of Permission Denied Errors") - << field("numSuppressedSampledRun", T_LONG, - "Signals suppressed by the wall-clock once-per-run filter")) + << field("numSuppressedOwnedBlock", T_LONG, + "Signals suppressed for lifecycle-owned blocked intervals")) << (type("datadog.ObjectSample", T_ALLOC, "Allocation sample") << category("Datadog", "Profiling") @@ -229,6 +229,20 @@ void JfrMetadata::initialize( << field("localRootSpanId", T_LONG, "Local Root Span ID") || contextAttributes) + << (type("datadog.TaskBlock", T_TASK_BLOCK, "Task Block") + << category("Datadog") + << field("startTime", T_LONG, "Start Time", F_TIME_TICKS) + << field("duration", T_LONG, "Duration", F_DURATION_TICKS) + << field("eventThread", T_THREAD, "Event Thread", F_CPOOL) + << field("blocker", T_LONG, "Blocker Identity Hash") + << field("unblockingSpanId", T_LONG, "Unblocking Span ID") + << field("stackTrace", T_STACK_TRACE, "Stack Trace", F_CPOOL) + << field("observedBlockingState", T_THREAD_STATE, + "Observed Blocking State", F_CPOOL) + << field("spanId", T_LONG, "Span ID") + << field("localRootSpanId", T_LONG, "Local Root Span ID") || + contextAttributes) + << (type("datadog.HeapUsage", T_HEAP_USAGE, "JVM Heap Usage") << category("Datadog") << field("startTime", T_LONG, "Start Time", F_TIME_TICKS) diff --git a/ddprof-lib/src/main/cpp/jfrMetadata.h b/ddprof-lib/src/main/cpp/jfrMetadata.h index 4d3f2a86e..7df1be690 100644 --- a/ddprof-lib/src/main/cpp/jfrMetadata.h +++ b/ddprof-lib/src/main/cpp/jfrMetadata.h @@ -81,6 +81,7 @@ enum JfrType { T_UNWIND_FAILURE = 126, T_MALLOC = 127, T_NATIVE_SOCKET = 128, + T_TASK_BLOCK = 129, T_ANNOTATION = 200, T_LABEL = 201, T_CATEGORY = 202, diff --git a/ddprof-lib/src/main/cpp/jvmSupport.cpp b/ddprof-lib/src/main/cpp/jvmSupport.cpp index b6277a6be..e3614f5e4 100644 --- a/ddprof-lib/src/main/cpp/jvmSupport.cpp +++ b/ddprof-lib/src/main/cpp/jvmSupport.cpp @@ -6,6 +6,7 @@ #include "jvmSupport.inline.h" #include "asyncSampleMutex.h" +#include "common.h" #include "frames.h" #include "os.h" #include "profiler.h" @@ -16,16 +17,50 @@ #include +#include + +using JniFunction = void (JNICALL*)(); +using IsVirtualThreadFunction = jboolean (JNICALL*)(JNIEnv*, jobject); + +static constexpr jint JNI_VERSION_19_VALUE = 0x00130000; +static constexpr int IS_VIRTUAL_THREAD_INDEX = 234; + +static_assert(sizeof(JniFunction) == sizeof(void*), + "JNI function table entries must be pointer-sized"); volatile JVMSupport::JMethodIDLoadStats JVMSupport::jmethodID_load_state = JVMSupport::No_loaded; Mutex JVMSupport::_initialization_lock; - // This method must be called after JVM has been properly initialized, e.g. after JVMTI::VMinit() // callback. // Currently, there are two paths lead to this call // - JVMTI::VMInit() callback (vmEntry.cpp) // - JavaProfiler.getInstance() via JNI down call - JVM must have been initialized +bool JVMSupport::isPlatformThread(JNIEnv* jni, jthread thread) { + if (jni == nullptr || thread == nullptr) return false; + jint jni_version = jni->GetVersion(); + if (jni_version <= 0) return false; + if (jni_version < JNI_VERSION_19_VALUE) return true; + + const JniFunction* functions = + reinterpret_cast(jni->functions); + if (functions == nullptr) return false; + IsVirtualThreadFunction is_virtual_thread = + reinterpret_cast( + functions[IS_VIRTUAL_THREAD_INDEX]); + if (is_virtual_thread == nullptr) { + static std::atomic warning_emitted{false}; + bool expected = false; + if (warning_emitted.compare_exchange_strong(expected, true, + std::memory_order_relaxed)) { + LOG_WARN("JNI version 19 or later does not expose IsVirtualThread; " + "JVM producer callbacks will be ignored"); + } + return false; + } + return is_virtual_thread(jni, thread) == JNI_FALSE; +} + bool JVMSupport::initialize() { MutexLocker locker(_initialization_lock); diff --git a/ddprof-lib/src/main/cpp/jvmSupport.h b/ddprof-lib/src/main/cpp/jvmSupport.h index 8d652fed8..e8d7a8a46 100644 --- a/ddprof-lib/src/main/cpp/jvmSupport.h +++ b/ddprof-lib/src/main/cpp/jvmSupport.h @@ -47,6 +47,10 @@ class JVMSupport { static bool isInitialized(); public: + // Java-owned profiler state is carrier-local and may only be used by platform threads. + // IsVirtualThread was added to the JNI function table in JDK 19. + static bool isPlatformThread(JNIEnv* jni, jthread thread); + // Initialize JVM support - check JVM related resources are available. // Return false if any critical resource is not available, which should // result in disabling profiling. diff --git a/ddprof-lib/src/main/cpp/profiler.cpp b/ddprof-lib/src/main/cpp/profiler.cpp index a332ac79f..685b9b1e0 100644 --- a/ddprof-lib/src/main/cpp/profiler.cpp +++ b/ddprof-lib/src/main/cpp/profiler.cpp @@ -35,6 +35,7 @@ #include "stackFrame.h" #include "stackWalker.h" #include "symbols.h" +#include "taskBlockRecorder.h" #include "tsc.h" #include "utils.h" #include "wallClock.h" @@ -48,6 +49,7 @@ #include #include #include +#include #include #include #include @@ -152,6 +154,8 @@ int Profiler::registerThread(int tid) { } #ifdef UNIT_TEST static std::atomic g_test_last_unregistered_tid{-1}; +static std::atomic + g_test_task_block_record_override{nullptr}; int Profiler::lastUnregisteredTidForTest() { return g_test_last_unregistered_tid.load(std::memory_order_relaxed); @@ -159,6 +163,11 @@ int Profiler::lastUnregisteredTidForTest() { void Profiler::resetUnregisterObservableForTest() { g_test_last_unregistered_tid.store(-1, std::memory_order_relaxed); } + +void Profiler::setTaskBlockRecordOverrideForTest( + TaskBlockRecordOverride override) { + g_test_task_block_record_override.store(override, std::memory_order_release); +} #endif void Profiler::unregisterThread(int tid) { @@ -771,6 +780,92 @@ void Profiler::recordQueueTime(int tid, QueueTimeEvent *event) { _locks[lock_index].unlock(); } +Profiler::TaskBlockRecordResult Profiler::recordTaskBlock( + int tid, jthread thread, int start_depth, TaskBlockEvent *event) { +#ifdef UNIT_TEST + TaskBlockRecordOverride override = + g_test_task_block_record_override.load(std::memory_order_acquire); + if (override != nullptr) { + return override(tid, thread, start_depth, event); + } +#endif + CriticalSection cs; + u32 lock_index = getLockIndex(tid); + if (!_locks[lock_index].tryLock() && + !_locks[lock_index = (lock_index + 1) % CONCURRENCY_LEVEL].tryLock() && + !_locks[lock_index = (lock_index + 2) % CONCURRENCY_LEVEL].tryLock()) { + return TaskBlockRecordResult::RECORD_FAILED; + } + + // Lightweight recordings intentionally encode an absent stack trace as + // constant-pool ID 0, as the regular CPU and wall-clock sample paths do. + if (!_omit_stacktraces) { + if (_max_stack_depth <= 0 || _calltrace_buffer[lock_index] == nullptr) { + _locks[lock_index].unlock(); + return TaskBlockRecordResult::STACK_CAPTURE_FAILED; + } + + CallTraceBuffer *buffer = _calltrace_buffer[lock_index]; + ASGCT_CallFrame *frames = buffer->_asgct_frames; + jvmtiFrameInfo *jvmti_frames = buffer->_jvmti_frames; + jint num_frames = 0; +#ifdef COUNTERS + u64 stack_start = TSC::ticks(); +#endif + jvmtiError error = VM::jvmti()->GetStackTrace( + thread, start_depth, _max_stack_depth, jvmti_frames, &num_frames); + if (error != JVMTI_ERROR_NONE || num_frames <= 0) { + _locks[lock_index].unlock(); + return TaskBlockRecordResult::STACK_CAPTURE_FAILED; + } + + copyJvmtiFrames(frames, jvmti_frames, num_frames); + u64 call_trace_id = + _call_trace_storage.put(num_frames, frames, false, 1); +#ifdef COUNTERS + u64 stack_duration = TSC::ticks() - stack_start; + if (stack_duration > 0) { + Counters::increment(UNWINDING_TIME_JVMTI, stack_duration); + } +#endif + if (call_trace_id == 0) { + _locks[lock_index].unlock(); + return TaskBlockRecordResult::STACK_CAPTURE_FAILED; + } + + event->_callTraceId = call_trace_id; + } + bool recorded = _jfr.recordTaskBlock(lock_index, tid, event); + _locks[lock_index].unlock(); + return recorded ? TaskBlockRecordResult::RECORDED + : TaskBlockRecordResult::RECORD_FAILED; +} + +bool Profiler::tryEnterTaskBlockActivity() { + if (_task_block_rotation.load(std::memory_order_acquire)) return false; + _task_block_inflight.fetch_add(1, std::memory_order_acq_rel); + if (_task_block_rotation.load(std::memory_order_acquire)) { + _task_block_inflight.fetch_sub(1, std::memory_order_acq_rel); + return false; + } + return true; +} + +void Profiler::leaveTaskBlockActivity() { + _task_block_inflight.fetch_sub(1, std::memory_order_release); +} + +void Profiler::beginTaskBlockRotation() { + _task_block_rotation.store(true, std::memory_order_release); + while (_task_block_inflight.load(std::memory_order_acquire) != 0) { + std::this_thread::yield(); + } +} + +void Profiler::endTaskBlockRotation() { + _task_block_rotation.store(false, std::memory_order_release); +} + void Profiler::recordExternalSample(u64 weight, int tid, int num_frames, ASGCT_CallFrame *frames, bool truncated, jint event_type, Event *event) { @@ -1397,12 +1492,33 @@ Error Profiler::init() { return Error::OK; } +void Profiler::setTaskBlockEnabled(bool enabled) { + if (enabled) { + // Keep callback admission closed until native setup has either completed + // or rolled back, so partial event enablement cannot create paired state. + bool monitor_events_enabled = + VM::nativeMonitorEventsAvailable() && + VM::setNativeMonitorEventsEnabled(true); + _task_block_monitor_events_enabled.store(monitor_events_enabled, + std::memory_order_release); + _task_block_enabled.store(true, std::memory_order_release); + return; + } + + _task_block_enabled.store(false, std::memory_order_release); + if (_task_block_monitor_events_enabled.exchange( + false, std::memory_order_acq_rel)) { + VM::setNativeMonitorEventsEnabled(false); + } +} + Error Profiler::start(Arguments &args, bool reset) { MutexLocker ml(_state_lock); Error error = checkState(); if (error) { return error; } + _task_block_enabled.store(false, std::memory_order_release); // Sanity checks run at most once per process, across start and stop cycles. // Profiler::start() sets sanity_checked to true before it checks @@ -1633,6 +1749,7 @@ Error Profiler::start(Arguments &args, bool reset) { _libs->stopRefresher(); return error; } + initializeTaskBlockDurationThreshold(); int activated = 0; if ((_event_mask & EM_CPU) && _cpu_engine != &noop_engine) { @@ -1726,6 +1843,8 @@ Error Profiler::start(Arguments &args, bool reset) { // Paired with drainInflight() on the stop side. _cpu_engine->enableEvents(true); + setTaskBlockEnabled( + (activated & EM_WALL) && args._wall_precheck && track_unfiltered_wall); _state.store(RUNNING, std::memory_order_release); _start_time = time(NULL); __atomic_add_fetch(&_epoch, 1, __ATOMIC_RELAXED); @@ -1750,6 +1869,7 @@ Error Profiler::stop() { if (state() != RUNNING) { return Error("Profiler is not active"); } + setTaskBlockEnabled(false); // Order matters: disable engines first so the _enabled check inside signal // handlers will fail for any new signal delivered from now on. drain() then @@ -1767,6 +1887,11 @@ Error Profiler::stop() { return Error("signal handlers did not drain; teardown skipped, retry stop()"); } + // Prevent existing paired intervals from recording during teardown. New + // intervals were disabled above; this also drains endTaskBlock calls that + // already entered their snapshot-and-record activity. + beginTaskBlockRotation(); + if (_event_mask & EM_ALLOC) _alloc_engine->stop(); if (_event_mask & EM_NATIVEMEM) @@ -1838,6 +1963,7 @@ Error Profiler::stop() { _thread_info.reportCounters(); rotateDictsAndRun([&]{ _jfr.stop(); }); + endTaskBlockRotation(); // Unpatch libraries AFTER JFR serialization completes // Remote symbolication RemoteFrameInfo structs contain pointers to build-ID strings @@ -1928,11 +2054,15 @@ Error Profiler::dump(const char *path, const int length) { // rotateDictsAndRun rotates the dictionaries, takes lockAll() around the // dump (fences ASGCT/JNI writers to CallTraceStorage), then clearStandby()s // the rotated buffers. StringDictionary's RefCountGuard protocol handles - // its own writer/reader coordination. + // its own writer/reader coordination; #527's classMapSharedGuard readers + // (deferred vtable receiver resolution) are coordinated through + // _class_map_lock. + beginTaskBlockRotation(); rotateDictsAndRun([&]{ err = _jfr.dump(path, length); __atomic_add_fetch(&_epoch, 1, __ATOMIC_SEQ_CST); }); + endTaskBlockRotation(); _thread_info.clearAll(thread_ids); _thread_info.reportCounters(); diff --git a/ddprof-lib/src/main/cpp/profiler.h b/ddprof-lib/src/main/cpp/profiler.h index a6f8b13ab..7c460d1d1 100644 --- a/ddprof-lib/src/main/cpp/profiler.h +++ b/ddprof-lib/src/main/cpp/profiler.h @@ -132,6 +132,10 @@ class alignas(alignof(SpinLock)) Profiler { alignas(DEFAULT_CACHE_LINE_SIZE) volatile u64 _sample_seq; alignas(DEFAULT_CACHE_LINE_SIZE) u64 _failures[ASGCT_FAILURE_TYPES]; bool _wall_precheck = false; + std::atomic _task_block_enabled{false}; + std::atomic _task_block_monitor_events_enabled{false}; + std::atomic _task_block_rotation{false}; + std::atomic _task_block_inflight{0}; SpinLock _class_map_lock; SpinLock _locks[CONCURRENCY_LEVEL]; @@ -182,6 +186,9 @@ class alignas(alignof(SpinLock)) Profiler { void lockAll(); void unlockAll(); + void setTaskBlockEnabled(bool enabled); + void beginTaskBlockRotation(); + void endTaskBlockRotation(); // Rotate all three dictionaries, then run jfr_op under lockAll(). // @@ -235,6 +242,15 @@ class alignas(alignof(SpinLock)) Profiler { for (int i = 0; i < CONCURRENCY_LEVEL; i++) { _calltrace_buffer[i] = NULL; } + + // Protects wall-clock unowned-block fallback tail traces (cached in + // ThreadFilter::Slot) from being dropped by a chunk rotation before + // flushUnownedBlockedTail() emits them. ThreadFilter is process-lifetime, + // so this is registered once rather than per-recording. + registerLivenessChecker([this](CallTraceIdSet& buffer) { + _thread_filter.collectUnownedBlockedTraceIds( + [&buffer](u64 call_trace_id) { buffer.insert(call_trace_id); }); + }); } static inline Profiler *instance() { @@ -451,6 +467,28 @@ class alignas(alignof(SpinLock)) Profiler { void recordWallClockEpoch(int tid, WallClockEpochEvent *event); void recordTraceRoot(int tid, TraceRootEvent *event); void recordQueueTime(int tid, QueueTimeEvent *event); + enum class TaskBlockRecordResult { + RECORDED, + STACK_CAPTURE_FAILED, + RECORD_FAILED, + }; + TaskBlockRecordResult recordTaskBlock(int tid, jthread thread, + int start_depth, + TaskBlockEvent *event); +#ifdef UNIT_TEST + using TaskBlockRecordOverride = TaskBlockRecordResult (*)( + int tid, jthread thread, int start_depth, TaskBlockEvent *event); + static void setTaskBlockRecordOverrideForTest( + TaskBlockRecordOverride override); +#endif + bool tryEnterTaskBlockActivity(); + void leaveTaskBlockActivity(); + bool taskBlockEnabled() const { + return _task_block_enabled.load(std::memory_order_acquire); + } + bool nativeMonitorTaskBlockEnabled() const { + return _task_block_monitor_events_enabled.load(std::memory_order_acquire); + } void writeLog(LogLevel level, const char *message); void writeLog(LogLevel level, const char *message, size_t len); void writeDatadogProfilerSetting(int tid, int length, const char *name, @@ -474,6 +512,15 @@ class alignas(alignof(SpinLock)) Profiler { static void unregisterThread(int tid); #ifdef UNIT_TEST + void beginTaskBlockRotationForTest() { beginTaskBlockRotation(); } + void endTaskBlockRotationForTest() { endTaskBlockRotation(); } + bool taskBlockRotationActiveForTest() const { + return _task_block_rotation.load(std::memory_order_acquire); + } + int taskBlockInflightForTest() const { + return _task_block_inflight.load(std::memory_order_acquire); + } + // Returns the tid most recently passed to unregisterThread(), or -1 if it // has never been called (or since the last resetUnregisterObservableForTest). // Used by integration tests to assert that cleanup_unregister wired diff --git a/ddprof-lib/src/main/cpp/taskBlockRecorder.cpp b/ddprof-lib/src/main/cpp/taskBlockRecorder.cpp new file mode 100644 index 000000000..34492f205 --- /dev/null +++ b/ddprof-lib/src/main/cpp/taskBlockRecorder.cpp @@ -0,0 +1,85 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +#include "taskBlockRecorder.h" + +#include + +static const u64 kMinTaskBlockNanos = 1000000; +static std::atomic g_min_task_block_ticks{0}; + +static u64 computeMinTaskBlockTicks() { + return (TSC::frequency() * kMinTaskBlockNanos) / NANOTIME_FREQ; +} + +void initializeTaskBlockDurationThreshold() { + g_min_task_block_ticks.store(computeMinTaskBlockTicks(), std::memory_order_release); +} + +bool exceedsMinTaskBlockDuration(u64 start_ticks, u64 end_ticks) { + u64 min_ticks = g_min_task_block_ticks.load(std::memory_order_acquire); + if (min_ticks == 0) min_ticks = computeMinTaskBlockTicks(); + return end_ticks > start_ticks && end_ticks - start_ticks >= min_ticks; +} + +bool recordTaskBlockAtExit(ProfiledThread* current, ThreadFilter* thread_filter, + jthread thread, int start_depth, u64 block_token, + ThreadFilter::SlotID slot_id, u64 generation, + u64 blocker, u64 unblocking_span_id) { + u64 start_ticks = 0; + Context context{}; + if (!current->taskBlockExit(block_token, start_ticks, context)) { + return false; + } + + if (slot_id != ThreadFilter::tokenSlotId(block_token) || + generation != ThreadFilter::tokenGeneration(block_token)) { + return false; + } + + return finishTaskBlockAtExit( + current, thread_filter, thread, start_depth, block_token, start_ticks, + context, blocker, unblocking_span_id); +} + +bool finishTaskBlockAtExit(ProfiledThread* current, + ThreadFilter* thread_filter, jthread thread, + int start_depth, u64 block_token, u64 start_ticks, + const Context& context, u64 blocker, + u64 unblocking_span_id) { + Profiler* profiler = Profiler::instance(); + bool recording_enabled = profiler->taskBlockEnabled(); + bool activity = profiler->tryEnterTaskBlockActivity(); + + ThreadFilter::SlotID slot_id = ThreadFilter::tokenSlotId(block_token); + u64 generation = ThreadFilter::tokenGeneration(block_token); + ThreadFilter::SlotID current_slot = current->filterSlotId(); + if (current_slot < 0) { + current_slot = thread_filter->slotIdByTid(current->tid()); + } + BlockRunSnapshot snapshot; + bool exited = current_slot == slot_id && + thread_filter->snapshotAndExitBlockedRun(slot_id, generation, &snapshot); + + if (!activity) { + Counters::increment(TASK_BLOCK_DROPPED_ROTATION); + return false; + } + if (!recording_enabled || !exited) { + profiler->leaveTaskBlockActivity(); + return false; + } + if (!snapshot.context_eligible) { + Counters::increment(TASK_BLOCK_SKIPPED_TRACE_CONTEXT); + profiler->leaveTaskBlockActivity(); + return false; + } + + bool recorded = recordTaskBlockIfEligible( + current->tid(), thread, start_depth, start_ticks, TSC::ticks(), context, + blocker, unblocking_span_id, snapshot.active_state, true); + profiler->leaveTaskBlockActivity(); + return recorded; +} diff --git a/ddprof-lib/src/main/cpp/taskBlockRecorder.h b/ddprof-lib/src/main/cpp/taskBlockRecorder.h new file mode 100644 index 000000000..fb11a6155 --- /dev/null +++ b/ddprof-lib/src/main/cpp/taskBlockRecorder.h @@ -0,0 +1,97 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +#ifndef _TASK_BLOCK_RECORDER_H +#define _TASK_BLOCK_RECORDER_H + +#include "context.h" +#include "counters.h" +#include "event.h" +#include "profiler.h" +#include "tsc.h" + +void initializeTaskBlockDurationThreshold(); +bool exceedsMinTaskBlockDuration(u64 start_ticks, u64 end_ticks); + +bool recordTaskBlockAtExit(ProfiledThread* current, ThreadFilter* thread_filter, + jthread thread, int start_depth, u64 block_token, + ThreadFilter::SlotID slot_id, u64 generation, + u64 blocker, u64 unblocking_span_id); + +// Completes ThreadFilter lifecycle cleanup for an already-exited producer and +// records its event only when dump/stop rotation admits the recording work. +// Cleanup is deliberately performed even when admission is rejected so an +// application thread never waits for rotation and suppression cannot be left +// armed. +bool finishTaskBlockAtExit(ProfiledThread* current, + ThreadFilter* thread_filter, jthread thread, + int start_depth, u64 block_token, u64 start_ticks, + const Context& context, u64 blocker, + u64 unblocking_span_id); + +class TaskBlockActivity { + private: + Profiler* _profiler; + bool _active; + bool _owns_activity; + + public: + explicit TaskBlockActivity(bool already_active = false) + : _profiler(Profiler::instance()), + _active(already_active || _profiler->tryEnterTaskBlockActivity()), + _owns_activity(!already_active && _active) { + if (!_active) Counters::increment(TASK_BLOCK_DROPPED_ROTATION); + } + + ~TaskBlockActivity() { + if (_owns_activity) _profiler->leaveTaskBlockActivity(); + } + + bool active() const { return _active; } +}; + +static inline bool taskBlockPassesBasicEligibility(u64 start_ticks, u64 end_ticks, + const Context& ctx) { + if (ctx.spanId != 0) { + Counters::increment(TASK_BLOCK_SKIPPED_TRACE_CONTEXT); + return false; + } + if (!exceedsMinTaskBlockDuration(start_ticks, end_ticks)) { + Counters::increment(TASK_BLOCK_SKIPPED_TOO_SHORT); + return false; + } + return true; +} + +static inline bool recordTaskBlockIfEligible( + int tid, jthread thread, int start_depth, u64 start_ticks, u64 end_ticks, + const Context& ctx, u64 blocker, u64 unblocking_span_id, + OSThreadState observed_state, bool activity_already_held = false) { + TaskBlockActivity activity(activity_already_held); + if (!activity.active() || + !taskBlockPassesBasicEligibility(start_ticks, end_ticks, ctx)) { + return false; + } + TaskBlockEvent event{}; + event._start = start_ticks; + event._end = end_ticks; + event._blocker = blocker; + event._unblockingSpanId = unblocking_span_id; + event._ctx = ctx; + event._observedBlockingState = observed_state; + Profiler::TaskBlockRecordResult result = + Profiler::instance()->recordTaskBlock(tid, thread, start_depth, &event); + if (result == Profiler::TaskBlockRecordResult::RECORDED) { + Counters::increment(TASK_BLOCK_EMITTED); + return true; + } + Counters::increment( + result == Profiler::TaskBlockRecordResult::STACK_CAPTURE_FAILED + ? TASK_BLOCK_STACK_CAPTURE_FAILED + : TASK_BLOCK_RECORD_FAILED); + return false; +} + +#endif // _TASK_BLOCK_RECORDER_H diff --git a/ddprof-lib/src/main/cpp/threadFilter.cpp b/ddprof-lib/src/main/cpp/threadFilter.cpp index c38b9b30e..c0fdc375e 100644 --- a/ddprof-lib/src/main/cpp/threadFilter.cpp +++ b/ddprof-lib/src/main/cpp/threadFilter.cpp @@ -34,6 +34,15 @@ ThreadFilter::ShardHead ThreadFilter::_free_heads[ThreadFilter::kShardCount] {}; +#ifdef UNIT_TEST +std::atomic + ThreadFilter::_block_run_publish_observer{nullptr}; + +void ThreadFilter::setBlockRunPublishObserverForTest(BlockRunPublishObserver observer) { + _block_run_publish_observer.store(observer, std::memory_order_release); +} +#endif + ThreadFilter::ThreadFilter() : _enabled(false), _registry_active(false), _track_unfiltered_wall(false) { // Initialize chunk pointers to null (lazy allocation) @@ -106,6 +115,7 @@ void ThreadFilter::initializeChunk(int chunk_idx) { slot.recording_epoch.store(0, std::memory_order_relaxed); slot.context_window_state.store(0, std::memory_order_relaxed); slot.active_block_state.store(OSThreadState::UNKNOWN, std::memory_order_relaxed); + slot.unowned_blocked_fallback_enabled.store(1, std::memory_order_relaxed); } // Try to install it atomically @@ -145,6 +155,7 @@ ThreadFilter::SlotID ThreadFilter::registerThread(int tid) { slot->lifecycle_generation.fetch_add(1, std::memory_order_acq_rel); slot->recording_epoch.store(0, std::memory_order_relaxed); slot->context_window_state.store(0, std::memory_order_relaxed); + slot->enableUnownedBlockedFallback(); slot->clearActiveBlockRun(OSThreadState::UNKNOWN); slot->tid.store(tid, std::memory_order_release); if (tid >= 0 && !indexSlot(reused_slot, tid)) { @@ -191,6 +202,7 @@ ThreadFilter::SlotID ThreadFilter::registerThread(int tid) { slot->lifecycle_generation.fetch_add(1, std::memory_order_acq_rel); slot->recording_epoch.store(0, std::memory_order_relaxed); slot->context_window_state.store(0, std::memory_order_relaxed); + slot->enableUnownedBlockedFallback(); slot->clearActiveBlockRun(OSThreadState::UNKNOWN); slot->tid.store(tid, std::memory_order_release); if (tid >= 0 && !indexSlot(index, tid)) { @@ -215,6 +227,7 @@ void ThreadFilter::refreshSlotForRecording(Slot* slot, RecordingEpoch epoch) { // payload, then publish the new epoch only after the reset is complete. slot->recording_epoch.store(0, std::memory_order_release); slot->context_window_state.store(0, std::memory_order_relaxed); + slot->enableUnownedBlockedFallback(); slot->clearActiveBlockRun(OSThreadState::UNKNOWN); slot->recording_epoch.store(epoch, std::memory_order_release); } @@ -306,6 +319,45 @@ ThreadFilter::Slot* ThreadFilter::activeSlotForId(SlotID slot_id, return slot; } +bool ThreadFilter::lookupThreadEntry(ThreadEntry& entry, + RecordingEpoch epoch) const { + Slot* slot = epoch != 0 ? lookupByTid(entry.tid, epoch) + : lookupByTid(entry.tid); + if (slot == nullptr) { + return false; + } + entry.slot = slot; + entry.lifecycle_generation = slot->lifecycleGeneration(); + entry.recording_epoch = slot->recordingEpoch(); + return true; +} + +ThreadFilter::SlotID ThreadFilter::ensureCurrentThreadSlot(ProfiledThread* current) { + if (current == nullptr) { + return -1; + } + int tid = current->tid(); + if (unlikely(tid < 0)) { + return -1; + } + + SlotID slot_id = current->filterSlotId(); + if (likely(slot_id >= 0)) { + if (likely(activeSlotForId(slot_id, tid) != nullptr)) { + return slot_id; + } + current->setFilterSlotId(-1); + } + + // Startup can register this TID centrally, but it cannot update another + // pthread's TLS. registerThread(tid) reuses that existing slot. + slot_id = registerThread(tid); + if (slot_id >= 0) { + current->setFilterSlotId(slot_id); + } + return slot_id; +} + void ThreadFilter::initFreeList() { // Initialize the free list storage for (int i = 0; i < kFreeListSize; ++i) { @@ -400,6 +452,7 @@ void ThreadFilter::unregisterThreadLocked(SlotID slot_id, int expected_tid) { slot->recording_epoch.store(0, std::memory_order_release); slot->tid.store(-1, std::memory_order_release); slot->context_window_state.store(0, std::memory_order_release); + slot->enableUnownedBlockedFallback(); slot->clearActiveBlockRun(OSThreadState::UNKNOWN); pushToFreeList(slot_id); } @@ -425,6 +478,7 @@ void ThreadFilter::resetRegistrationsLocked() { slot.recording_epoch.store(0, std::memory_order_release); slot.tid.store(-1, std::memory_order_release); slot.context_window_state.store(0, std::memory_order_release); + slot.enableUnownedBlockedFallback(); slot.clearActiveBlockRun(OSThreadState::UNKNOWN); } } @@ -535,6 +589,24 @@ void ThreadFilter::collect(std::vector& entries) const { } } +void ThreadFilter::collectUnownedBlockedTraceIds(const std::function& visit) const { + int num_chunks = _num_chunks.load(std::memory_order_relaxed); + for (int chunk_idx = 0; chunk_idx < num_chunks; ++chunk_idx) { + ChunkStorage* chunk = _chunks[chunk_idx].load(std::memory_order_acquire); + if (chunk == nullptr) { + continue; + } + + for (const auto& slot : chunk->slots) { + u64 call_trace_id = + slot.unowned_blocked_call_trace_id.load(std::memory_order_acquire); + if (call_trace_id != 0) { + visit(call_trace_id); + } + } + } +} + void ThreadFilter::clearActive() { int num_chunks = _num_chunks.load(std::memory_order_acquire); for (int chunk_idx = 0; chunk_idx < num_chunks; ++chunk_idx) { @@ -543,8 +615,10 @@ void ThreadFilter::clearActive() { continue; } - for (auto& slot : chunk->slots) { + for (int slot_idx = 0; slot_idx < kChunkSize; ++slot_idx) { + Slot& slot = chunk->slots[slot_idx]; slot.exitContextWindow(); + slot.enableUnownedBlockedFallback(); slot.clearActiveBlockRun(OSThreadState::UNKNOWN); } } @@ -556,21 +630,29 @@ void ThreadFilter::resetSlotRunState(SlotID slot_id) { int slot_idx = slot_id & kChunkMask; ChunkStorage* chunk = _chunks[chunk_idx].load(std::memory_order_acquire); if (chunk != nullptr) { - // Clear stale suppression state so a new thread in this slot cannot inherit - // its predecessor's active block or once-per-run sampled marker. + // Clear stale suppression state so a new thread in this slot cannot + // inherit its predecessor's active block. + chunk->slots[slot_idx].enableUnownedBlockedFallback(); chunk->slots[slot_idx].clearActiveBlockRun(OSThreadState::UNKNOWN); } } u64 ThreadFilter::enterBlockedRun(SlotID slot_id, OSThreadState state, BlockRunOwner owner) { + if (state == OSThreadState::UNKNOWN) return 0; Slot* s = slotForId(slot_id); if (s != nullptr) { - u32 generation = 0; - if (!s->trySetActiveBlockRun(state, owner, &generation, - unfilteredWallTrackingActive())) { + u64 generation = 0; + if (!s->tryPrepareActiveBlockRun( + owner, &generation, unfilteredWallTrackingActive())) { return 0; } + s->publishActiveBlockRun(state); +#ifdef UNIT_TEST + BlockRunPublishObserver observer = + _block_run_publish_observer.load(std::memory_order_acquire); + if (observer != nullptr) observer(this, slot_id); +#endif return encodeBlockRunToken(slot_id, generation); } return 0; @@ -583,68 +665,104 @@ void ThreadFilter::exitBlockedRun(SlotID slot_id) { } } -bool ThreadFilter::exitBlockedRun(SlotID slot_id, u32 generation) { +bool ThreadFilter::exitBlockedRun(SlotID slot_id, u64 generation) { Slot* s = slotForId(slot_id); - if (s == nullptr || generation == 0 || s->blockGeneration() != generation) { + if (s == nullptr || generation == 0 || + s->activeBlockState() == OSThreadState::UNKNOWN || + s->activeBlockOwner() == BlockRunOwner::NONE || + s->blockGeneration() != generation) { return false; } s->clearActiveBlockRun(OSThreadState::RUNNABLE); return true; } -bool ThreadFilter::shouldSuppressOwnedBlock(const ThreadEntry& entry) const { - Slot* slot = entry.slot; - if (slot == nullptr || slot->nativeTid() != entry.tid || - slot->lifecycleGeneration() != entry.lifecycle_generation) { +bool ThreadFilter::snapshotAndExitBlockedRun(SlotID slot_id, u64 generation, + BlockRunSnapshot* snapshot) { + Slot* s = slotForId(slot_id); + if (s == nullptr || generation == 0 || + s->activeBlockState() == OSThreadState::UNKNOWN || + s->activeBlockOwner() == BlockRunOwner::NONE || + s->blockGeneration() != generation) { return false; } + if (snapshot != nullptr) *snapshot = s->snapshotBlockRun(); + s->clearActiveBlockRun(OSThreadState::RUNNABLE); + return true; +} - const bool unfiltered_tracking = unfilteredWallTrackingActive(); - RecordingEpoch epoch = 0; - if (unfiltered_tracking) { - epoch = recordingEpoch(); - if (epoch == 0 || entry.recording_epoch != epoch || - slot->recordingEpoch() != epoch) { - return false; - } - } +bool ThreadFilter::activeOwnedBlockGeneration(const ThreadEntry& entry, + u64& generation) const { + return ownedBlockGeneration(entry, generation, false); +} -#ifdef UNIT_TEST - if (_suppression_snapshot_hook != nullptr) { - _suppression_snapshot_hook(_suppression_snapshot_hook_arg); +BlockRunSnapshot ThreadFilter::snapshotBlockedRun(SlotID slot_id) const { + Slot* s = slotForId(slot_id); + return s == nullptr ? BlockRunSnapshot{} : s->snapshotBlockRun(); +} + +bool ThreadFilter::isOwnedBlockSuppressionCandidate( + const ThreadEntry& entry) const { + u64 generation = 0; + return ownedBlockGeneration(entry, generation, true); +} + +bool ThreadFilter::ownedBlockGeneration(const ThreadEntry& entry, + u64& generation, + bool require_sampled) const { + Slot* slot = entry.slot; + if (!unfilteredWallTrackingActive() || slot == nullptr || + slot->nativeTid() != entry.tid || + slot->lifecycleGeneration() != entry.lifecycle_generation) { + return false; } -#endif - u32 block_generation = slot->blockGeneration(); - BlockRunOwner owner = slot->activeBlockOwner(); + // active_block_state publishes the rest of the block-run payload. Acquire + // it before reading the context epoch, owner, or generation so those reads + // observe the stores that preceded publishActiveBlockRun(). OSThreadState state = slot->activeBlockState(); - bool context_eligible = - !unfiltered_tracking || slot->activeBlockRemainedOutsideContextWindow(); - bool sampled = slot->sampledThisRun(); - OSThreadState last_sampled_state = - sampled ? slot->lastSampledState() : OSThreadState::UNKNOWN; bool suppressible_state = state == OSThreadState::SLEEPING || state == OSThreadState::CONDVAR_WAIT || state == OSThreadState::OBJECT_WAIT || state == OSThreadState::MONITOR_WAIT; - if (owner == BlockRunOwner::NONE || !context_eligible || - !suppressible_state || !sampled || state != last_sampled_state) { + if (!suppressible_state) return false; + + RecordingEpoch epoch = recordingEpoch(); + if (epoch == 0 || entry.recording_epoch != epoch || + slot->recordingEpoch() != epoch || + !slot->activeBlockRemainedOutsideContextWindow()) { return false; } + u64 block_generation = slot->blockGeneration(); + BlockRunOwner owner = slot->activeBlockOwner(); + if (owner == BlockRunOwner::NONE || + (require_sampled && + slot->sampledBlockGeneration() != block_generation)) { + return false; + } + +#ifdef UNIT_TEST + if (_suppression_snapshot_hook != nullptr) { + _suppression_snapshot_hook(_suppression_snapshot_hook_arg); + } +#endif + // The payload is spread across independent atomics. Accept it only if the // slot still represents the lifecycle and block run captured by the timer. if (slot->activeBlockOwner() != owner || slot->blockGeneration() != block_generation || - slot->nativeTid() != entry.tid || - slot->lifecycleGeneration() != entry.lifecycle_generation) { + slot->activeBlockState() != state || slot->nativeTid() != entry.tid || + slot->lifecycleGeneration() != entry.lifecycle_generation || + (require_sampled && + slot->sampledBlockGeneration() != block_generation)) { return false; } - if (unfiltered_tracking && - (recordingEpoch() != epoch || slot->recordingEpoch() != epoch || - !slot->activeBlockRemainedOutsideContextWindow())) { + if (recordingEpoch() != epoch || slot->recordingEpoch() != epoch || + !slot->activeBlockRemainedOutsideContextWindow()) { return false; } + generation = block_generation; return true; } diff --git a/ddprof-lib/src/main/cpp/threadFilter.h b/ddprof-lib/src/main/cpp/threadFilter.h index 23ec4189b..514bbd3a7 100644 --- a/ddprof-lib/src/main/cpp/threadFilter.h +++ b/ddprof-lib/src/main/cpp/threadFilter.h @@ -22,10 +22,12 @@ #include #include #include +#include #include "arch.h" #include "threadState.h" +class ProfiledThread; struct ThreadEntry; // defined after ThreadFilter; carries a pointer to a ThreadFilter::Slot enum class BlockRunOwner : int { @@ -35,6 +37,14 @@ enum class BlockRunOwner : int { NATIVE = 3, }; +struct BlockRunSnapshot { + OSThreadState active_state{OSThreadState::UNKNOWN}; + BlockRunOwner owner{BlockRunOwner::NONE}; + u64 generation{0}; + bool active{false}; + bool context_eligible{false}; +}; + class ThreadFilter { public: using SlotID = int; @@ -46,6 +56,11 @@ class ThreadFilter { static constexpr int kChunkMask = kChunkSize - 1; static constexpr int kMaxThreads = 2048; static constexpr int kMaxChunks = (kMaxThreads + kChunkSize - 1) / kChunkSize; // = 8 chunks + static constexpr int kBlockRunSlotBits = 11; + static constexpr u64 kBlockRunSlotMask = (1ULL << kBlockRunSlotBits) - 1; + static constexpr u64 kMaxBlockRunGeneration = UINT64_MAX >> kBlockRunSlotBits; + static_assert(kMaxThreads == (1 << kBlockRunSlotBits), + "block-run token slot bits must cover every ThreadFilter slot"); // High-performance free list using Treiber stack, 64 shards static constexpr int kFreeListSize = kMaxThreads; static constexpr int kShardCount = 64; // power-of-two for fast modulo @@ -70,23 +85,21 @@ class ThreadFilter { // release-published. std::atomic recording_epoch{0}; std::atomic active_block_context_epoch{0}; + std::atomic block_generation{0}; + // The most recent owned-block generation for which a MethodSample was + // recorded successfully. Generations are monotonic, so a delayed + // completion from an older run cannot mark a newer run as sampled. + std::atomic sampled_block_generation{0}; std::atomic unowned_blocked_state{OSThreadState::UNKNOWN}; // Native identity and context-window membership are independent so an // unfiltered wall recording can retain lifecycle metadata without // changing ordinary thread selection. std::atomic tid{-1}; std::atomic active_block_owner{static_cast(BlockRunOwner::NONE)}; - std::atomic block_generation{0}; - // Wall-clock once-per-run suppression state. The signal handler records the - // last sampled blocked state; the signal handler and timer thread read it to - // suppress duplicate samples, while lifecycle/block-exit paths reset it. - // Release/acquire on sampled_this_run pairs with relaxed last_sampled_state, - // following the standard flag+payload pattern. - std::atomic last_sampled_state{OSThreadState::UNKNOWN}; // 4 bytes + std::atomic unowned_blocked_fallback_enabled{1}; // Set by explicit block enter/exit hooks. It lets the timer skip sending a signal // only while instrumentation still owns a suppressible blocking interval. std::atomic active_block_state{OSThreadState::UNKNOWN}; - std::atomic sampled_this_run{false}; char padding[2 * DEFAULT_CACHE_LINE_SIZE - sizeof(std::atomic) - sizeof(std::atomic) @@ -95,13 +108,13 @@ class ThreadFilter { - sizeof(std::atomic) - sizeof(std::atomic) - sizeof(std::atomic) + - sizeof(std::atomic) - sizeof(std::atomic) - sizeof(std::atomic) - sizeof(std::atomic) - - sizeof(std::atomic) - - sizeof(std::atomic) - - sizeof(std::atomic) - - sizeof(std::atomic)]; + - sizeof(std::atomic) + - sizeof(std::atomic) + - sizeof(std::atomic)]; inline int nativeTid() const { return tid.load(std::memory_order_acquire); @@ -141,21 +154,6 @@ class ThreadFilter { return false; } - inline bool sampledThisRun() const { - return sampled_this_run.load(std::memory_order_acquire); - } - inline OSThreadState lastSampledState() const { - return last_sampled_state.load(std::memory_order_relaxed); - } - inline void markSampledThisRun(OSThreadState state) { - last_sampled_state.store(state, std::memory_order_relaxed); - sampled_this_run.store(true, std::memory_order_release); - } - inline void resetSampledRun(OSThreadState state) { - resetUnownedBlockedSampling(); - last_sampled_state.store(state, std::memory_order_relaxed); - sampled_this_run.store(false, std::memory_order_release); - } inline OSThreadState activeBlockState() const { return active_block_state.load(std::memory_order_acquire); } @@ -165,9 +163,34 @@ class ThreadFilter { inline BlockRunOwner activeBlockOwner() const { return static_cast(active_block_owner.load(std::memory_order_acquire)); } - inline u32 blockGeneration() const { + inline u64 blockGeneration() const { return block_generation.load(std::memory_order_acquire); } + inline u64 sampledBlockGeneration() const { + return sampled_block_generation.load(std::memory_order_acquire); + } + inline void markBlockGenerationSampled(u64 generation) { + u64 sampled = sampled_block_generation.load(std::memory_order_relaxed); + while (sampled < generation && + !sampled_block_generation.compare_exchange_weak( + sampled, generation, std::memory_order_release, + std::memory_order_relaxed)) { + } + } + inline void resetSampledBlockGeneration() { + sampled_block_generation.store(0, std::memory_order_relaxed); + } + inline bool unownedBlockedFallbackEnabled() const { + return unowned_blocked_fallback_enabled.load(std::memory_order_acquire) != 0; + } + inline void enableUnownedBlockedFallback() { + resetUnownedBlockedSampling(); + unowned_blocked_fallback_enabled.store(1, std::memory_order_release); + } + inline void disableUnownedBlockedFallback() { + unowned_blocked_fallback_enabled.store(0, std::memory_order_release); + resetUnownedBlockedSampling(); + } inline void resetUnownedBlockedSampling() { unowned_blocked_pending_weight.store(0, std::memory_order_relaxed); unowned_blocked_decision_count.store(0, std::memory_order_relaxed); @@ -205,9 +228,9 @@ class ThreadFilter { } return true; } - inline bool trySetActiveBlockRun(OSThreadState state, BlockRunOwner owner, - u32* generation_out, - bool outside_context_required) { + inline bool tryPrepareActiveBlockRun(BlockRunOwner owner, + u64* generation_out, + bool outside_context_required) { u64 context_state = context_window_state.load(std::memory_order_acquire); if (outside_context_required && (context_state & 1) != 0) { return false; @@ -224,18 +247,27 @@ class ThreadFilter { std::memory_order_release); return false; } - u32 generation = block_generation.fetch_add(1, std::memory_order_acq_rel) + 1; + u64 generation = block_generation.load(std::memory_order_relaxed); + if (generation == kMaxBlockRunGeneration) { + active_block_owner.store(static_cast(BlockRunOwner::NONE), + std::memory_order_release); + return false; + } + generation++; + block_generation.store(generation, std::memory_order_relaxed); active_block_context_epoch.store(context_state >> 1, std::memory_order_relaxed); - resetUnownedBlockedSampling(); - last_sampled_state.store(OSThreadState::UNKNOWN, std::memory_order_relaxed); - sampled_this_run.store(false, std::memory_order_relaxed); - active_block_state.store(state, std::memory_order_release); + resetSampledBlockGeneration(); + disableUnownedBlockedFallback(); *generation_out = generation; return true; } - inline void clearActiveBlockRun(OSThreadState state) { + inline void publishActiveBlockRun(OSThreadState state) { + active_block_state.store(state, std::memory_order_release); + } + inline void clearActiveBlockRun(OSThreadState) { active_block_state.store(OSThreadState::UNKNOWN, std::memory_order_release); - resetSampledRun(state); + resetSampledBlockGeneration(); + resetUnownedBlockedSampling(); active_block_owner.store(static_cast(BlockRunOwner::NONE), std::memory_order_release); } inline bool activeBlockRemainedOutsideContextWindow() const { @@ -244,12 +276,20 @@ class ThreadFilter { active_block_context_epoch.load(std::memory_order_acquire) == (context_state >> 1); } + inline BlockRunSnapshot snapshotBlockRun() const { + BlockRunSnapshot snapshot; + snapshot.active_state = activeBlockState(); + snapshot.owner = activeBlockOwner(); + snapshot.generation = blockGeneration(); + snapshot.active = snapshot.owner != BlockRunOwner::NONE && + snapshot.active_state != OSThreadState::UNKNOWN; + snapshot.context_eligible = activeBlockRemainedOutsideContextWindow(); + return snapshot; + } }; static_assert(sizeof(Slot) == 2 * DEFAULT_CACHE_LINE_SIZE, "Slot must be exactly two cache lines"); static_assert(std::atomic::is_always_lock_free, "Slot OSThreadState fields must be lock-free for signal-handler safety"); - static_assert(std::atomic::is_always_lock_free, - "Slot::sampled_this_run must be lock-free for signal-handler safety"); static_assert(std::atomic::is_always_lock_free, "Slot::recording_epoch must be lock-free for signal-handler safety"); @@ -268,6 +308,13 @@ class ThreadFilter { void remove(SlotID slot_id); void collect(std::vector& tids) const; void collect(std::vector& entries) const; + // Liveness hook for CallTraceStorage::processTraces: a slot may cache a + // call_trace_id for a still-blocked thread's weighted fallback tail + // (recordUnownedBlockedSample) well before flushUnownedBlockedTail() emits + // it. Without this, a chunk rotation racing that window drops the trace, + // and the eventual deferred sample references an id with no constant-pool + // entry in the chunk it lands in. + void collectUnownedBlockedTraceIds(const std::function& visit) const; // Clears per-recording membership and suppression state while keeping // process-lifetime slot ownership intact. Threads must opt in again with add(). void clearActive(); @@ -278,10 +325,13 @@ class ThreadFilter { // lifecycles must use the generation-checked overload so they cannot clear // another owner. void exitBlockedRun(SlotID slot_id); - bool exitBlockedRun(SlotID slot_id, u32 generation); - // Reads the complete timer-side suppression payload and rejects it if slot - // identity or block lifecycle changes before final validation. - bool shouldSuppressOwnedBlock(const ThreadEntry& entry) const; + bool exitBlockedRun(SlotID slot_id, u64 generation); + bool snapshotAndExitBlockedRun(SlotID slot_id, u64 generation, + BlockRunSnapshot* snapshot); + bool activeOwnedBlockGeneration(const ThreadEntry& entry, + u64& generation) const; + BlockRunSnapshot snapshotBlockedRun(SlotID slot_id) const; + bool isOwnedBlockSuppressionCandidate(const ThreadEntry& entry) const; #ifdef UNIT_TEST using SuppressionSnapshotHook = void (*)(void*); @@ -292,15 +342,27 @@ class ThreadFilter { } #endif - static inline u64 encodeBlockRunToken(SlotID slot_id, u32 generation) { - return (static_cast(generation) << 32) | static_cast(slot_id + 1); + static inline u64 encodeBlockRunToken(SlotID slot_id, u64 generation) { + return (generation << kBlockRunSlotBits) | static_cast(slot_id); } static inline SlotID tokenSlotId(u64 token) { - return static_cast(static_cast(token) - 1); + return static_cast(token & kBlockRunSlotMask); } - static inline u32 tokenGeneration(u64 token) { - return static_cast(token >> 32); + static inline u64 tokenGeneration(u64 token) { + return token >> kBlockRunSlotBits; } + static inline bool decodeBlockRunToken(u64 token, SlotID& slot_id, + u64& generation) { + if (token == 0) return false; + slot_id = tokenSlotId(token); + generation = tokenGeneration(token); + return generation != 0; + } + +#ifdef UNIT_TEST + using BlockRunPublishObserver = void (*)(ThreadFilter*, SlotID); + static void setBlockRunPublishObserverForTest(BlockRunPublishObserver observer); +#endif // Returns nullptr if slot_id is invalid or its chunk has not been allocated. inline Slot* slotForId(SlotID slot_id) const { @@ -318,9 +380,16 @@ class ThreadFilter { Slot* lookupByTid(int tid) const; Slot* lookupByTid(int tid, RecordingEpoch epoch) const; Slot* activeSlotForId(SlotID slot_id, int tid) const; + // Populates lifecycle metadata from an existing mapping without registering + // the TID. Timer-side observation must remain read-only. + bool lookupThreadEntry(ThreadEntry& entry, RecordingEpoch epoch) const; + SlotID ensureCurrentThreadSlot(ProfiledThread* current); void deactivateRecording(); + SlotID slotIdByTid(int tid) const { return lookupSlotIdByTid(tid); } private: + bool ownedBlockGeneration(const ThreadEntry& entry, u64& generation, + bool require_sampled) const; // Lock-free free list using a stack-like structure struct FreeListNode { @@ -354,6 +423,7 @@ class ThreadFilter { std::mutex _registry_lock; #ifdef UNIT_TEST + static std::atomic _block_run_publish_observer; SuppressionSnapshotHook _suppression_snapshot_hook = nullptr; void* _suppression_snapshot_hook_arg = nullptr; #endif diff --git a/ddprof-lib/src/main/cpp/threadLocalData.h b/ddprof-lib/src/main/cpp/threadLocalData.h index a571467df..a990afd80 100644 --- a/ddprof-lib/src/main/cpp/threadLocalData.h +++ b/ddprof-lib/src/main/cpp/threadLocalData.h @@ -46,7 +46,8 @@ class ProfiledThread : public ThreadLocalData { TYPE_MASK = TYPE_JAVA_THREAD | TYPE_NOT_JAVA_THREAD }; - static constexpr u32 FLAG_PARKED = 0x4u; // next free bit after TYPE_MASK (0x1|0x2) + static constexpr u32 FLAG_PARKED = 0x4u; + static constexpr u32 FLAG_MONITOR_BLOCKED = 0x8u; // We are allowing several levels of nesting because we can be // eg. in a crash handler when wallclock signal kicks in, @@ -76,7 +77,17 @@ class ProfiledThread : public ThreadLocalData { u64 _call_trace_id; u32 _recording_epoch; u32 _misc_flags; + u64 _park_start_ticks; u64 _park_block_token; + Context _park_context; + u64 _task_block_start_ticks; + u64 _task_block_token; + Context _task_block_context; + u64 _monitor_start_ticks; + Context _monitor_context; + u64 _monitor_blocker; + u64 _monitor_block_token; + OSThreadState _monitor_block_state; int _filter_slot_id; // Slot ID for thread filtering uint8_t _init_window; // Countdown for JVM thread init race window (PROF-13072) uint8_t _signal_depth; // Nested signal-handler depth (see SignalHandlerScope) @@ -100,7 +111,12 @@ class ProfiledThread : public ThreadLocalData { ProfiledThread(int tid) : ThreadLocalData(), _jmp_buf(nullptr), _pc(0), _sp(0), _span_id(0), _crash_depth(0), _tid(tid), _cpu_epoch(0), _wall_epoch(0), _call_trace_id(0), _recording_epoch(0), _misc_flags(0), - _park_block_token(0), _filter_slot_id(-1), _init_window(0), + _park_start_ticks(0), _park_block_token(0), _park_context{}, + _task_block_start_ticks(0), _task_block_token(0), _task_block_context{}, + _monitor_start_ticks(0), _monitor_context{}, _monitor_blocker(0), + _monitor_block_token(0), _monitor_block_state(OSThreadState::UNKNOWN), + _filter_slot_id(-1), + _init_window(0), _signal_depth(0), _otel_ctx_initialized(false), _otel_ctx_record{}, _otel_tag_encodings{}, _otel_local_root_span_id(0) { @@ -344,26 +360,114 @@ class ProfiledThread : public ThreadLocalData { _otel_local_root_span_id = 0; } - inline bool parkEnter() { - u32 prev = __atomic_fetch_or(&_misc_flags, FLAG_PARKED, __ATOMIC_RELEASE); - return (prev & FLAG_PARKED) == 0; + inline bool parkEnter(u64 start_ticks, const Context& context) { + u32 flags = __atomic_load_n(&_misc_flags, __ATOMIC_ACQUIRE); + while ((flags & FLAG_PARKED) == 0) { + _park_start_ticks = start_ticks; + _park_context = context; + if (__atomic_compare_exchange_n(&_misc_flags, &flags, + flags | FLAG_PARKED, true, + __ATOMIC_RELEASE, __ATOMIC_ACQUIRE)) { + return true; + } + } + return false; } +#ifdef UNIT_TEST + inline bool parkEnter() { return parkEnter(0, Context{}); } +#endif + inline void setParkBlockToken(u64 token) { _park_block_token = token; } + inline bool taskBlockEnter(u64 token, u64 start_ticks, + const Context& context) { + if (token == 0 || _task_block_token != 0) return false; + _task_block_start_ticks = start_ticks; + _task_block_context = context; + _task_block_token = token; + return true; + } + + inline bool taskBlockExit(u64 token, u64& start_ticks, Context& context) { + if (token == 0 || _task_block_token != token) return false; + start_ticks = _task_block_start_ticks; + context = _task_block_context; + _task_block_token = 0; + return true; + } + // Returns false if the thread was not parked (idempotent). - inline bool parkExit(u64 &park_block_token) { + inline bool parkExit(u64& start_ticks, Context& context, + u64& park_block_token) { u32 prev = __atomic_fetch_and(&_misc_flags, ~FLAG_PARKED, __ATOMIC_ACQ_REL); if ((prev & FLAG_PARKED) == 0) { return false; } + start_ticks = _park_start_ticks; + context = _park_context; park_block_token = _park_block_token; _park_block_token = 0; return true; } +#ifdef UNIT_TEST + inline bool parkExit(u64& park_block_token) { + u64 start_ticks = 0; + Context context{}; + return parkExit(start_ticks, context, park_block_token); + } +#endif + + // Object.wait owns its interval until MonitorWaited, including monitor + // reacquisition. A nested contention callback must not overwrite that state. + inline bool monitorEnter(u64 start_ticks, const Context& context, u64 blocker, + OSThreadState state) { + u32 flags = __atomic_load_n(&_misc_flags, __ATOMIC_ACQUIRE); + if ((flags & FLAG_MONITOR_BLOCKED) != 0) return false; + _monitor_start_ticks = start_ticks; + _monitor_context = context; + _monitor_blocker = blocker; + _monitor_block_token = 0; + _monitor_block_state = state; + __atomic_fetch_or(&_misc_flags, FLAG_MONITOR_BLOCKED, __ATOMIC_RELEASE); + return true; + } + + inline void setMonitorBlockToken(u64 token) { + _monitor_block_token = token; + } + + inline u64 monitorBlockToken() const { return _monitor_block_token; } + + inline void clearMonitorBlock() { + __atomic_fetch_and(&_misc_flags, ~FLAG_MONITOR_BLOCKED, __ATOMIC_ACQ_REL); + _monitor_block_token = 0; + _monitor_block_state = OSThreadState::UNKNOWN; + } + + inline bool monitorExit(OSThreadState expected_state, u64& start_ticks, + Context& context, u64& blocker, + u64& monitor_block_token) { + u32 flags = __atomic_load_n(&_misc_flags, __ATOMIC_ACQUIRE); + if ((flags & FLAG_MONITOR_BLOCKED) == 0 || + _monitor_block_state != expected_state) { + return false; + } + u32 prev = __atomic_fetch_and(&_misc_flags, ~FLAG_MONITOR_BLOCKED, + __ATOMIC_ACQ_REL); + if ((prev & FLAG_MONITOR_BLOCKED) == 0) return false; + start_ticks = _monitor_start_ticks; + context = _monitor_context; + blocker = _monitor_blocker; + monitor_block_token = _monitor_block_token; + _monitor_block_token = 0; + _monitor_block_state = OSThreadState::UNKNOWN; + return true; + } + Context snapshotContext(size_t numAttrs); private: diff --git a/ddprof-lib/src/main/cpp/vmEntry.cpp b/ddprof-lib/src/main/cpp/vmEntry.cpp index f6b6946ad..1febe793c 100644 --- a/ddprof-lib/src/main/cpp/vmEntry.cpp +++ b/ddprof-lib/src/main/cpp/vmEntry.cpp @@ -8,6 +8,7 @@ #include "vmEntry.h" #include "arguments.h" #include "context.h" +#include "context_api.h" #include "counters.h" #include "j9/j9Support.h" #include "jniHelper.h" @@ -15,10 +16,13 @@ #include "jvmThread.h" #include "libraries.h" #include "log.h" +#include "mutex.h" #include "os.h" #include "profiler.h" #include "safeAccess.h" #include "threadLocalData.h" +#include "taskBlockRecorder.h" +#include "tsc.h" // Pulls in vmStructs.h plus the definitions of crashProtectionActive()/cast_to() that its inline // accessors odr-use here; the light vmStructs.h alone leaves those unresolved in assertion-enabled // builds (see the note in hotspotStackFrame_aarch64.cpp). @@ -48,8 +52,16 @@ bool VM::_hotspot = false; bool VM::_zing = false; bool VM::_can_sample_objects = false; bool VM::_can_intercept_binding = false; +bool VM::_monitor_wait_events_delegated = false; +bool VM::_native_monitor_events_available = false; +bool VM::_profiler_bridge_initialized = false; bool VM::_is_adaptive_gc_boundary_flag_set = false; +// Serializes the one-time bridge installation and ownership negotiation. +// Callback readers need no synchronization because ownership is assigned +// before callbacks can be enabled and is never changed afterward. +static Mutex profiler_bridge_init_lock; + jvmtiExtensionFunction VM::_request_stack_trace = nullptr; jvmtiExtensionFunction VM::_init_request_stack_trace = nullptr; @@ -67,6 +79,118 @@ static void wakeupHandler(int signo) { // Dummy handler for interrupting syscalls } +static u64 monitorBlockerHash(jvmtiEnv *jvmti, jobject object) { + if (object == NULL) return 0; + jint hash = 0; + if (jvmti->GetObjectHashCode(object, &hash) != JVMTI_ERROR_NONE) return 0; + return static_cast(static_cast(hash)); +} + +static void monitorBlockEnter(jvmtiEnv *jvmti, JNIEnv *jni, jthread thread, + jobject object, OSThreadState state) { + Profiler *profiler = Profiler::instance(); + if (!profiler->taskBlockEnabled() || + !profiler->nativeMonitorTaskBlockEnabled() || + !JVMSupport::isPlatformThread(jni, thread)) { + return; + } + ProfiledThread *current = ProfiledThread::initCurrentThreadSignalSafe(); + if (current == nullptr) return; + Context context = ContextApi::snapshot(); + if (context.spanId != 0) { + Counters::increment(TASK_BLOCK_SKIPPED_TRACE_CONTEXT); + return; + } + + if (!current->monitorEnter(TSC::ticks(), context, + monitorBlockerHash(jvmti, object), state)) { + u64 token = current->monitorBlockToken(); + ThreadFilter *tf = profiler->threadFilter(); + bool current_owner = false; + if (token != 0) { + ThreadFilter::SlotID slot_id = ThreadFilter::tokenSlotId(token); + ThreadFilter::Slot *slot = current->filterSlotId() == slot_id + ? tf->activeSlotForId(slot_id, current->tid()) + : nullptr; + if (slot != nullptr) { + BlockRunSnapshot snapshot = slot->snapshotBlockRun(); + current_owner = snapshot.active && + snapshot.owner == BlockRunOwner::JVMTI && + snapshot.generation == ThreadFilter::tokenGeneration(token); + } + } + if (current_owner) { + return; + } + current->clearMonitorBlock(); + if (!current->monitorEnter(TSC::ticks(), context, + monitorBlockerHash(jvmti, object), state)) { + return; + } + } + + ThreadFilter *tf = profiler->threadFilter(); + ThreadFilter::SlotID slot_id = tf->ensureCurrentThreadSlot(current); + if (!tf->unfilteredWallTrackingActive() || slot_id < 0) { + current->clearMonitorBlock(); + return; + } + u64 token = + tf->enterBlockedRun(slot_id, state, BlockRunOwner::JVMTI); + if (token == 0) { + ThreadFilter::Slot *slot = tf->slotForId(slot_id); + if (slot != nullptr && slot->inContextWindow()) { + Counters::increment(TASK_BLOCK_SKIPPED_TRACE_CONTEXT); + } + current->clearMonitorBlock(); + return; + } + current->setMonitorBlockToken(token); +} + +static void monitorBlockExit(JNIEnv *jni, jthread thread, OSThreadState state) { + if (!JVMSupport::isPlatformThread(jni, thread)) return; + ProfiledThread *current = ProfiledThread::current(); + if (current == nullptr) return; + + u64 start_ticks = 0; + Context context{}; + u64 blocker = 0; + u64 token = 0; + if (!current->monitorExit(state, start_ticks, context, blocker, token) || + token == 0) { + return; + } + + Profiler *profiler = Profiler::instance(); + finishTaskBlockAtExit(current, profiler->threadFilter(), thread, 0, token, + start_ticks, context, blocker, 0); +} + +static void JNICALL MonitorContendedEnter(jvmtiEnv *jvmti, JNIEnv *jni, + jthread thread, jobject object) { + monitorBlockEnter(jvmti, jni, thread, object, OSThreadState::MONITOR_WAIT); +} + +static void JNICALL MonitorContendedEntered(jvmtiEnv *jvmti, JNIEnv *jni, + jthread thread, jobject object) { + monitorBlockExit(jni, thread, OSThreadState::MONITOR_WAIT); +} + +static void JNICALL MonitorWait(jvmtiEnv *jvmti, JNIEnv *jni, jthread thread, + jobject object, jlong timeout) { + if (!VM::monitorWaitEventsDelegated()) { + monitorBlockEnter(jvmti, jni, thread, object, OSThreadState::OBJECT_WAIT); + } +} + +static void JNICALL MonitorWaited(jvmtiEnv *jvmti, JNIEnv *jni, jthread thread, + jobject object, jboolean timed_out) { + if (!VM::monitorWaitEventsDelegated()) { + monitorBlockExit(jni, thread, OSThreadState::OBJECT_WAIT); + } +} + static bool isVmRuntimeEntry(const char* blob_name) { return strcmp(blob_name, "_ZNK12MemAllocator8allocateEv") == 0 || strncmp(blob_name, "_Z22post_allocation_notify", 26) == 0 @@ -385,6 +509,11 @@ bool VM::initShared(JavaVM* vm) { } bool VM::initLibrary(JavaVM *vm) { + MutexLocker init_locker(profiler_bridge_init_lock); + if (_profiler_bridge_initialized) { + return true; + } + TEST_LOG("VM::initLibrary"); if (!initShared(vm)) { return false; @@ -443,15 +572,31 @@ bool VM::initializeRequestStackTrace() { return false; } -bool VM::initProfilerBridge(JavaVM *vm, bool attach) { +void VM::configureMonitorEvents(bool delegateMonitorWaitEvents) { + jvmtiCapabilities actual_capabilities = {0}; + _jvmti->GetCapabilities(&actual_capabilities); + _native_monitor_events_available = + actual_capabilities.can_generate_monitor_events; + _monitor_wait_events_delegated = delegateMonitorWaitEvents; +} + +ProfilerBridgeInitResult VM::initProfilerBridge(JavaVM *vm, bool attach, + bool delegateMonitorWaitEvents) { + MutexLocker init_locker(profiler_bridge_init_lock); + if (_profiler_bridge_initialized) { + return delegateMonitorWaitEvents == _monitor_wait_events_delegated + ? ProfilerBridgeInitResult::SUCCESS + : ProfilerBridgeInitResult::MONITOR_EVENTS_DELEGATION_CONFLICT; + } + TEST_LOG("VM::initProfilerBridge"); if (!initShared(vm)) { - return false; + return ProfilerBridgeInitResult::FAILURE; } CodeCache *lib = openJvmLibrary(); if (lib == nullptr) { - return false; + return ProfilerBridgeInitResult::FAILURE; } // Under Agent_OnLoad (attach == false), this is the first native entry point and @@ -482,6 +627,8 @@ bool VM::initProfilerBridge(JavaVM *vm, bool attach) { _can_intercept_binding = potential_capabilities.can_generate_native_method_bind_events && HeapUsage::needsNativeBindingInterception(); + bool can_add_monitor_events = + potential_capabilities.can_generate_monitor_events; jvmtiCapabilities capabilities = {0}; capabilities.can_generate_all_class_hook_events = 1; @@ -498,11 +645,13 @@ bool VM::initProfilerBridge(JavaVM *vm, bool attach) { capabilities.can_get_source_file_name = 1; capabilities.can_get_line_numbers = 1; capabilities.can_generate_compiled_method_load_events = 1; - capabilities.can_generate_monitor_events = 1; + capabilities.can_generate_monitor_events = can_add_monitor_events ? 1 : 0; capabilities.can_tag_objects = 1; _jvmti->AddCapabilities(&capabilities); + configureMonitorEvents(delegateMonitorWaitEvents); + if (_hotspot) { probeJFRRequestStackTrace(); } @@ -519,6 +668,12 @@ bool VM::initProfilerBridge(JavaVM *vm, bool attach) { callbacks.SampledObjectAlloc = ObjectSampler::SampledObjectAlloc; callbacks.GarbageCollectionFinish = LivenessTracker::GarbageCollectionFinish; callbacks.NativeMethodBind = VMStructs::NativeMethodBind; + if (_native_monitor_events_available) { + callbacks.MonitorContendedEnter = MonitorContendedEnter; + callbacks.MonitorContendedEntered = MonitorContendedEntered; + callbacks.MonitorWait = MonitorWait; + callbacks.MonitorWaited = MonitorWaited; + } _jvmti->SetEventCallbacks(&callbacks, sizeof(callbacks)); _jvmti->SetEventNotificationMode(JVMTI_ENABLE, JVMTI_EVENT_VM_DEATH, NULL); @@ -571,7 +726,70 @@ bool VM::initProfilerBridge(JavaVM *vm, bool attach) { OS::installSignalHandler(WAKEUP_SIGNAL, NULL, wakeupHandler); - return true; + _profiler_bridge_initialized = true; + return ProfilerBridgeInitResult::SUCCESS; +} + +bool VM::setNativeMonitorEventsEnabled(bool enabled) { + if (!_native_monitor_events_available) return false; + + jvmtiError enter = JVMTI_ERROR_NONE; + jvmtiError entered = JVMTI_ERROR_NONE; + jvmtiError wait = JVMTI_ERROR_NONE; + jvmtiError waited = JVMTI_ERROR_NONE; + + if (enabled) { + // JVMTI enables each event independently and does not queue events that + // occur while disabled. Install every terminal notification before its + // entry notification so an admitted interval always has an exit path. + entered = _jvmti->SetEventNotificationMode( + JVMTI_ENABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTERED, NULL); + if (entered != JVMTI_ERROR_NONE) goto enable_failed; + + if (!_monitor_wait_events_delegated) { + waited = _jvmti->SetEventNotificationMode( + JVMTI_ENABLE, JVMTI_EVENT_MONITOR_WAITED, NULL); + if (waited != JVMTI_ERROR_NONE) goto enable_failed; + } + + enter = _jvmti->SetEventNotificationMode( + JVMTI_ENABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTER, NULL); + if (enter != JVMTI_ERROR_NONE) goto enable_failed; + + if (!_monitor_wait_events_delegated) { + wait = _jvmti->SetEventNotificationMode( + JVMTI_ENABLE, JVMTI_EVENT_MONITOR_WAIT, NULL); + if (wait != JVMTI_ERROR_NONE) goto enable_failed; + } + return true; + +enable_failed: + Log::warn("Unable to enable JVMTI monitor events: %d/%d/%d/%d", + enter, entered, wait, waited); + setNativeMonitorEventsEnabled(false); + return false; + } + + // Stop admitting new intervals before removing the terminal notifications. + // Disable all four events even when Object.wait is delegated so teardown + // also cleans up modes established before ownership was configured. + enter = _jvmti->SetEventNotificationMode( + JVMTI_DISABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTER, NULL); + wait = _jvmti->SetEventNotificationMode( + JVMTI_DISABLE, JVMTI_EVENT_MONITOR_WAIT, NULL); + entered = _jvmti->SetEventNotificationMode( + JVMTI_DISABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTERED, NULL); + waited = _jvmti->SetEventNotificationMode( + JVMTI_DISABLE, JVMTI_EVENT_MONITOR_WAITED, NULL); + + if (enter == JVMTI_ERROR_NONE && entered == JVMTI_ERROR_NONE && + wait == JVMTI_ERROR_NONE && waited == JVMTI_ERROR_NONE) { + return true; + } + + Log::warn("Unable to disable JVMTI monitor events: %d/%d/%d/%d", + enter, entered, wait, waited); + return false; } // Run late initialization when JVM is ready. May be called more than once (from @@ -705,7 +923,8 @@ Agent_OnLoad(JavaVM* vm, char* options, void* reserved) { return ARGUMENTS_ERROR; } - if (!VM::initProfilerBridge(vm, false)) { + if (VM::initProfilerBridge(vm, false) != + ProfilerBridgeInitResult::SUCCESS) { Log::error("JVM does not support Tool Interface"); return COMMAND_ERROR; } diff --git a/ddprof-lib/src/main/cpp/vmEntry.h b/ddprof-lib/src/main/cpp/vmEntry.h index 75725ef15..35268a62a 100644 --- a/ddprof-lib/src/main/cpp/vmEntry.h +++ b/ddprof-lib/src/main/cpp/vmEntry.h @@ -132,6 +132,15 @@ class JavaVersionAccess { static int get_hotspot_version(char* prop_value); }; +// The profiler bridge is process-wide and initialized exactly once. Later Java +// API initialization may reuse it only with the same requested Object.wait +// ownership, independently of native monitor-event availability. +enum class ProfilerBridgeInitResult { + SUCCESS, + FAILURE, + MONITOR_EVENTS_DELEGATION_CONFLICT, +}; + class VM { friend class VMTestAccessor; @@ -147,6 +156,9 @@ class VM { static bool _zing; static bool _can_sample_objects; static bool _can_intercept_binding; + static bool _monitor_wait_events_delegated; + static bool _native_monitor_events_available; + static bool _profiler_bridge_initialized; static bool _is_adaptive_gc_boundary_flag_set; static CodeCache *_libjvm; @@ -168,6 +180,7 @@ class VM { static void *getLibraryHandle(const char *name); static bool initShared(JavaVM *vm); + static void configureMonitorEvents(bool delegateMonitorWaitEvents); static void probeJFRRequestStackTrace(); static CodeCache* openJvmLibrary(); @@ -183,7 +196,8 @@ class VM { static JVM_GetManagement _getManagement; static bool initLibrary(JavaVM *vm); - static bool initProfilerBridge(JavaVM *vm, bool attach); + static ProfilerBridgeInitResult initProfilerBridge( + JavaVM *vm, bool attach, bool delegateMonitorWaitEvents = false); static jvmtiEnv *jvmti() { return _jvmti; } @@ -218,6 +232,15 @@ class VM { static bool canSampleObjects() { return _can_sample_objects; } + static bool monitorWaitEventsDelegated() { + return _monitor_wait_events_delegated; + } + + static bool nativeMonitorEventsAvailable() { + return _native_monitor_events_available; + } + static bool setNativeMonitorEventsEnabled(bool enabled); + static bool isZing() { return _zing; } static bool isUseAdaptiveGCBoundarySet() { diff --git a/ddprof-lib/src/main/cpp/wallClock.cpp b/ddprof-lib/src/main/cpp/wallClock.cpp index 77a4ac135..be4577f65 100644 --- a/ddprof-lib/src/main/cpp/wallClock.cpp +++ b/ddprof-lib/src/main/cpp/wallClock.cpp @@ -59,8 +59,8 @@ static inline bool hasKnownActiveTraceContext(ProfiledThread* thread) { struct WallPrecheckResult { bool suppress = false; - ThreadFilter::Slot* slot_to_arm = nullptr; - OSThreadState state_to_arm = OSThreadState::UNKNOWN; + ThreadFilter::Slot* owned_block_slot = nullptr; + u64 owned_block_generation = 0; OSThreadState observed_state = OSThreadState::UNKNOWN; bool observed_state_valid = false; ThreadFilter::Slot* unowned_weight_slot = nullptr; @@ -71,18 +71,17 @@ struct WallPrecheckResult { OSThreadState flush_state = OSThreadState::UNKNOWN; }; -static inline void incrementSuppressedSampledRun() { - Counters::increment(WC_SIGNAL_SUPPRESSED_SAMPLED_RUN); - WallClockCounters::incrementSuppressedSampledRun(); +static inline void incrementSuppressedOwnedBlock() { + Counters::increment(WC_SIGNAL_SUPPRESSED_OWNED_BLOCK); + WallClockCounters::incrementSuppressedOwnedBlock(); } -static inline bool suppressAlreadySampledBlock(const ThreadEntry& entry) { - ThreadFilter* thread_filter = Profiler::instance()->threadFilter(); - if (!thread_filter->shouldSuppressOwnedBlock(entry)) { - return false; +static inline bool suppressOwnedBlock(const ThreadEntry& entry) { + if (Profiler::instance()->threadFilter()->isOwnedBlockSuppressionCandidate(entry)) { + incrementSuppressedOwnedBlock(); + return true; } - incrementSuppressedSampledRun(); - return true; + return false; } static inline WallPrecheckResult prepareWallPrecheck(ProfiledThread* current, @@ -104,39 +103,29 @@ static inline WallPrecheckResult prepareWallPrecheck(ProfiledThread* current, return result; } - // In an unfiltered recording, context threads keep their normal MethodSample - // stream. Only owned blocks that remain outside the context window may replace - // repeated signals. - if (registry->unfilteredWallTrackingActive() && slot->inContextWindow()) { + // Owned blocks replace repeated signals only after their current generation + // has produced one MethodSample. Context-scoped profiling must continue + // sampling its selected threads normally. + if (!registry->unfilteredWallTrackingActive() || slot->inContextWindow()) { return result; } - OSThreadState active_block_state = slot->activeBlockState(); - BlockRunOwner active_block_owner = slot->activeBlockOwner(); - bool has_owned_block = - active_block_owner != BlockRunOwner::NONE && - isPrecheckSuppressionState(active_block_state) && - (!registry->unfilteredWallTrackingActive() || - slot->activeBlockRemainedOutsideContextWindow()); - if (has_owned_block) { - if (slot->sampledThisRun() && - active_block_state == slot->lastSampledState()) { - incrementSuppressedSampledRun(); - result.suppress = true; - return result; - } - // Arm only after the MethodSample has been successfully recorded. If the - // JFR write is skipped due to lock contention, the next signal must retry - // instead of losing the only stack for this blocked run. - result.slot_to_arm = slot; - result.state_to_arm = active_block_state; + ThreadEntry entry{current->tid(), slot, slot->lifecycleGeneration(), + slot->recordingEpoch()}; + if (registry->isOwnedBlockSuppressionCandidate(entry)) { + incrementSuppressedOwnedBlock(); + result.suppress = true; return result; } - - // Unfiltered tracking exists only to support explicit context and owned-block - // hooks. Keep unowned observations on ordinary per-signal sampling: the JVMTI - // path has no call_trace_id with which to replay a suppressed tail. - if (registry->unfilteredWallTrackingActive()) { + u64 block_generation = 0; + if (registry->activeOwnedBlockGeneration(entry, block_generation)) { + // Arm only after recordSample succeeds. A skipped JFR write must leave the + // run eligible so the next signal retries instead of losing its only stack. + result.owned_block_slot = slot; + result.owned_block_generation = block_generation; + return result; + } + if (!slot->unownedBlockedFallbackEnabled()) { return result; } @@ -160,6 +149,10 @@ static inline WallPrecheckResult prepareWallPrecheck(ProfiledThread* current, static inline void finishWallPrecheck(const WallPrecheckResult& precheck, bool recorded, u64 recorded_call_trace_id = 0) { + if (recorded && precheck.owned_block_slot != nullptr) { + precheck.owned_block_slot->markBlockGenerationSampled( + precheck.owned_block_generation); + } if (!recorded && precheck.unowned_weight_slot != nullptr) { precheck.unowned_weight_slot->restoreUnownedBlockedWeight( precheck.unowned_weight); @@ -170,9 +163,6 @@ static inline void finishWallPrecheck(const WallPrecheckResult& precheck, recorded_call_trace_id, precheck.observed_state); } } - if (recorded && precheck.slot_to_arm != nullptr) { - precheck.slot_to_arm->markSampledThisRun(precheck.state_to_arm); - } } static inline void recordDeferredWallSample(int tid, u64 call_trace_id, @@ -262,12 +252,10 @@ void WallClockASGCT::signalHandler(int signo, siginfo_t *siginfo, void *ucontext current->tickInitWindow(); return; } - // Once-per-run filter (wallprecheck=true): for untraced threads, exact - // suppression is only valid while an explicit lifecycle hook owns the blocked - // interval. Raw OS thread state is only an observation; it cannot distinguish - // one long sleep from several short sleeps separated by runnable gaps between - // signals. Unowned blocked observations therefore use weighted fallback - // sampling instead of arming sampled_this_run. + // Once-per-run filter (wallprecheck=true): an explicitly owned block keeps + // its first successful MethodSample and suppresses subsequent signals. + // Unowned blocked observations use weighted fallback sampling because raw OS + // state cannot distinguish one long sleep from several shorter runs. WallPrecheckResult precheck = prepareWallPrecheck(current, _precheck); if (precheck.suppress) { return; @@ -391,7 +379,7 @@ void WallClockASGCT::timerLoop() { } if (_precheck && !lazy_backfill) { entries.erase(std::remove_if(entries.begin(), entries.end(), - suppressAlreadySampledBlock), + suppressOwnedBlock), entries.end()); } }; @@ -401,19 +389,11 @@ void WallClockASGCT::timerLoop() { int& registry_lookups, bool lookup_registry_slot) { if (lookup_registry_slot && entry.slot == nullptr) { registry_lookups++; - ThreadFilter::Slot* slot = - thread_filter->lookupByTid(entry.tid, recording_epoch); - if (slot != nullptr) { - entry.slot = slot; - entry.lifecycle_generation = slot->lifecycleGeneration(); - entry.recording_epoch = slot->recordingEpoch(); - } + thread_filter->lookupThreadEntry(entry, recording_epoch); } - // Timer-thread fast path (wallprecheck=true): skip the kernel IPI entirely - // only when an explicit lifecycle hook still owns an already-sampled blocked - // run. Raw OS thread state is intentionally not used here because the timer - // thread cannot prove run boundaries for the target thread. - if (_precheck && suppressAlreadySampledBlock(entry)) { + // Timer-thread fast path (wallprecheck=true): skip the kernel IPI only + // after an explicitly owned run has recorded its first MethodSample. + if (_precheck && suppressOwnedBlock(entry)) { return WallClockCandidateOutcome::PRECHECK_REJECTED; } if (!OS::sendSignalWithCookie(entry.tid, SIGVTALRM, SignalCookie::wallclock())) { @@ -515,8 +495,8 @@ void WallClockJvmti::signalHandler(int signo, siginfo_t *siginfo, // Pass nullptr ucontext so the JVM uses safepoint-based stack walking. // Passing the signal-frame PC causes the extension to reject samples where // the thread is currently inside JVM-internal (non-Java) code. - // JVMTI-delegated samples carry a correlation_id, not a call_trace_id, so - // unowned tail flushing remains limited to the ASGCT wall engine. + // JVMTI-delegated samples carry no call_trace_id, so unowned tail flushing + // remains limited to the ASGCT wall engine. bool recorded = Profiler::instance()->recordSampleDelegated( nullptr, last_sample, tid, BCI_WALL, &event); finishWallPrecheck(precheck, recorded); @@ -556,7 +536,7 @@ void WallClockJvmti::timerLoop() { } if (_precheck && !lazy_backfill) { entries.erase(std::remove_if(entries.begin(), entries.end(), - suppressAlreadySampledBlock), + suppressOwnedBlock), entries.end()); } }; @@ -566,15 +546,9 @@ void WallClockJvmti::timerLoop() { int ®istry_lookups, bool lookup_registry_slot) { if (lookup_registry_slot && entry.slot == nullptr) { registry_lookups++; - ThreadFilter::Slot* slot = - thread_filter->lookupByTid(entry.tid, recording_epoch); - if (slot != nullptr) { - entry.slot = slot; - entry.lifecycle_generation = slot->lifecycleGeneration(); - entry.recording_epoch = slot->recordingEpoch(); - } + thread_filter->lookupThreadEntry(entry, recording_epoch); } - if (_precheck && suppressAlreadySampledBlock(entry)) { + if (_precheck && suppressOwnedBlock(entry)) { return WallClockCandidateOutcome::PRECHECK_REJECTED; } if (!OS::sendSignalWithCookie(entry.tid, SIGVTALRM, SignalCookie::wallclock())) { diff --git a/ddprof-lib/src/main/cpp/wallClock.h b/ddprof-lib/src/main/cpp/wallClock.h index a9bee7c99..2ad58e412 100644 --- a/ddprof-lib/src/main/cpp/wallClock.h +++ b/ddprof-lib/src/main/cpp/wallClock.h @@ -140,7 +140,7 @@ class BaseWallClock : public Engine { epoch.updateNumSamplableThreads(threads.size()); epoch.updateNumFailedSamples(num_failures); epoch.updateNumSuccessfulSamples(num_successful_samples); - epoch.addNumSuppressedSampledRun(WallClockCounters::drainSuppressedSampledRun()); + epoch.addNumSuppressedOwnedBlock(WallClockCounters::drainSuppressedOwnedBlock()); epoch.updateNumExitedThreads(threads_already_exited); epoch.updateNumPermissionDenied(permission_denied); u64 endTime = TSC::ticks(); diff --git a/ddprof-lib/src/main/cpp/wallClockCounters.h b/ddprof-lib/src/main/cpp/wallClockCounters.h index f295ce87a..72435b104 100644 --- a/ddprof-lib/src/main/cpp/wallClockCounters.h +++ b/ddprof-lib/src/main/cpp/wallClockCounters.h @@ -17,19 +17,19 @@ static_assert(std::atomic::is_always_lock_free, // increment is counted in either the current drain or a later one. class WallClockCounters { private: - inline static std::atomic _suppressed_sampled_run{0}; + inline static std::atomic _suppressed_owned_block{0}; public: - static void incrementSuppressedSampledRun() { - _suppressed_sampled_run.fetch_add(1, std::memory_order_relaxed); + static void incrementSuppressedOwnedBlock() { + _suppressed_owned_block.fetch_add(1, std::memory_order_relaxed); } - static u64 drainSuppressedSampledRun() { - return (u64)_suppressed_sampled_run.exchange(0, std::memory_order_acq_rel); + static u64 drainSuppressedOwnedBlock() { + return (u64)_suppressed_owned_block.exchange(0, std::memory_order_acq_rel); } static void reset() { - _suppressed_sampled_run.store(0, std::memory_order_relaxed); + _suppressed_owned_block.store(0, std::memory_order_relaxed); } }; diff --git a/ddprof-lib/src/main/java/com/datadoghq/profiler/JavaProfiler.java b/ddprof-lib/src/main/java/com/datadoghq/profiler/JavaProfiler.java index 74ebd9ac7..10e790621 100644 --- a/ddprof-lib/src/main/java/com/datadoghq/profiler/JavaProfiler.java +++ b/ddprof-lib/src/main/java/com/datadoghq/profiler/JavaProfiler.java @@ -104,7 +104,35 @@ public static JavaProfiler getInstance(String scratchDir) throws IOException { * @param scratchDir directory where the bundled library will be exploded before linking; ignored when 'libLocation' is {@literal null} */ public static synchronized JavaProfiler getInstance(String libLocation, String scratchDir) throws IOException { + return getInstance(libLocation, scratchDir, false); + } + + /** + * Get a {@linkplain JavaProfiler} instance with explicit monitor-event ownership. + * + *

The first successful native bridge initialization fixes this process-wide setting because + * the native profiler is a singleton. This may occur during {@code -agentpath} startup before + * this method is called. When delegation is enabled, Java instrumentation owns + * {@code Object.wait} TaskBlock intervals and native JVMTI wait callbacks are suppressed; + * native JVMTI callbacks continue to own synchronized monitor contention. Ownership is + * preserved independently of whether the JVM provides native monitor-event capability. + * + * @param libLocation the path to the native library to use, or {@literal null} for the bundled library + * @param scratchDir directory where the bundled library will be exploded before linking + * @param delegateMonitorWaitEvents whether Java instrumentation owns {@code Object.wait} intervals + * @return the process-wide profiler instance + * @throws IOException if the native library cannot be loaded + * @throws IllegalStateException if monitor ownership conflicts with an earlier native bridge + * initialization + */ + public static synchronized JavaProfiler getInstance(String libLocation, String scratchDir, + boolean delegateMonitorWaitEvents) throws IOException { if (instance != null) { + if (monitorWaitEventsDelegated0() != delegateMonitorWaitEvents) { + throw new IllegalStateException( + "Monitor-event ownership conflicts with the profiler's " + + "process-wide initialization"); + } return instance; } @@ -113,12 +141,11 @@ public static synchronized JavaProfiler getInstance(String libLocation, String s if (!result.succeeded) { throw new IOException("Failed to load Datadog Java profiler library", result.error); } - if (isVirtualThread(Thread.currentThread())) { throw new IOException("Cannot initialize profiler on a virtual thread"); } - init0(); + init0(delegateMonitorWaitEvents); instance = profiler; @@ -134,6 +161,18 @@ public static synchronized JavaProfiler getInstance(String libLocation, String s return profiler; } + /** + * Reports whether Java instrumentation owns {@code Object.wait} TaskBlock intervals instead + * of native JVMTI {@code MonitorWait} and {@code MonitorWaited} callbacks. Synchronized-monitor + * contention remains owned by native JVMTI callbacks. This reports the process-wide ownership + * selected during bridge initialization, independently of native monitor-event capability. + * + * @return {@code true} when {@code Object.wait} handling is delegated to Java instrumentation + */ + public boolean isMonitorWaitEventsDelegated() { + return monitorWaitEventsDelegated0(); + } + /** * Stop profiling (without dumping results) * @@ -394,38 +433,68 @@ public void recordQueueTime(long startTicks, } /** - * Internal hook called before {@code LockSupport.park}. This remains package-scoped - * until PR2 wires production TaskBlock instrumentation. + * Internal hook called before {@code LockSupport.park}. Park-specific TaskBlock + * production is intentionally separate from the public paired API. + * + * @return {@code true} when this call owns a park interval that must be closed */ - void parkEnter() { - parkEnter0(); + boolean parkEnter() { + return parkEnter0(Thread.currentThread()); } /** * Internal hook called after {@code LockSupport.park}. Clears the parked flag. - * {@code blocker} and {@code unblockingSpanId} are reserved for PR2 TaskBlock use. + * {@code blocker} and {@code unblockingSpanId} are reserved for park instrumentation. */ void parkExit(long blocker, long unblockingSpanId) { - parkExit0(blocker, unblockingSpanId); + parkExit0(Thread.currentThread(), blocker, unblockingSpanId); } /** * Internal hook marking the current platform thread as entering an explicitly instrumented - * blocked interval. This is not public API in this PR; production TaskBlock wiring lands in PR2. + * blocked interval. The public paired API is {@link #beginTaskBlock()}. * * @param state native {@code OSThreadState} value for the blocked interval; * currently only {@code SLEEPING} is armed * @return an opaque token to pass to {@link #blockExit(long)}, or 0 if no state was armed */ long blockEnter(int state) { - return blockEnter0(state); + return blockEnter0(Thread.currentThread(), state); } /** * Clears a blocked interval previously armed by {@link #blockEnter(int)}. */ void blockExit(long token) { - blockExit0(token); + blockExit0(Thread.currentThread(), token); + } + + /** + * Begins an explicitly instrumented {@link Thread#sleep(long) sleeping} interval on the current + * platform thread. The resulting {@code TaskBlock} event is classified as {@code SLEEPING}. + * The returned token is bound to the current thread and must be passed to {@link + * #endTaskBlock(long, long, long)}. + * + * @return an opaque token, or {@code 0} when the interval could not be armed or the current + * thread is virtual; any non-zero value, including a negative value, is valid + */ + public long beginTaskBlock() { + return beginTaskBlock0(Thread.currentThread()); + } + + /** + * Ends a blocking interval created by {@link #beginTaskBlock()} and records its + * {@code TaskBlock} event when it satisfies the profiler's eligibility rules. + * Lifecycle state is cleared even when no event is recorded. + * + * @param token opaque token returned by {@link #beginTaskBlock()}; {@code 0} is the only + * invalid sentinel + * @param blocker stable identifier describing the blocking resource + * @param unblockingSpanId span responsible for unblocking the interval, or {@code 0} + * @return {@code true} when an event was recorded; virtual threads always return {@code false} + */ + public boolean endTaskBlock(long token, long blocker, long unblockingSpanId) { + return endTaskBlock0(Thread.currentThread(), token, blocker, unblockingSpanId); } /** @@ -453,7 +522,7 @@ public Map getDebugCounters() { return counters; } - private static native boolean init0(); + private static native boolean init0(boolean delegateMonitorWaitEvents); private native void stop0() throws IllegalStateException; private native String execute0(String command) throws IllegalArgumentException, IllegalStateException, IOException; @@ -461,6 +530,7 @@ public Map getDebugCounters() { private static native void filterThreadRemove0(); private static native int getTid0(); + private static native boolean monitorWaitEventsDelegated0(); private static native boolean recordTrace0(long rootSpanId, String endpoint, String operation, int sizeLimit); @@ -474,13 +544,18 @@ public Map getDebugCounters() { private static native void recordQueueEnd0(long startTicks, long endTicks, String task, String scheduler, Thread origin, String queueType, int queueLength); - private static native void parkEnter0(); + private static native boolean parkEnter0(Thread thread); + + private static native void parkExit0(Thread thread, long blocker, long unblockingSpanId); + + private static native long blockEnter0(Thread thread, int state); - private static native void parkExit0(long blocker, long unblockingSpanId); + private static native void blockExit0(Thread thread, long token); - private static native long blockEnter0(int state); + private static native long beginTaskBlock0(Thread thread); - private static native void blockExit0(long token); + private static native boolean endTaskBlock0(Thread thread, long token, long blocker, + long unblockingSpanId); private static native long currentTicks0(); diff --git a/ddprof-lib/src/test/cpp/jvmSupport_ut.cpp b/ddprof-lib/src/test/cpp/jvmSupport_ut.cpp index c203d296e..a4a94809d 100644 --- a/ddprof-lib/src/test/cpp/jvmSupport_ut.cpp +++ b/ddprof-lib/src/test/cpp/jvmSupport_ut.cpp @@ -38,6 +38,127 @@ class JvmSupportGlobalSetup { }; static JvmSupportGlobalSetup jvm_support_global_setup; +class JvmSupportThreadClassificationTest : public ::testing::Test { +protected: + using JniFunction = void (JNICALL*)(); + + static constexpr int GET_VERSION_INDEX = 4; + static constexpr int IS_VIRTUAL_THREAD_INDEX = 234; + static constexpr int FUNCTION_TABLE_SIZE = IS_VIRTUAL_THREAD_INDEX + 1; + + inline static jint jni_version; + inline static jboolean virtual_thread; + inline static int is_virtual_thread_calls; + inline static jobject last_thread; + + JniFunction function_table[FUNCTION_TABLE_SIZE]{}; + JNIEnv jni{}; + _jobject thread_object; + jthread thread = &thread_object; + + static jint JNICALL getVersion(JNIEnv*) { return jni_version; } + + static jboolean JNICALL isVirtualThread(JNIEnv*, jobject candidate) { + is_virtual_thread_calls++; + last_thread = candidate; + return virtual_thread; + } + + void SetUp() override { + jni_version = 0x00150000; + virtual_thread = JNI_FALSE; + is_virtual_thread_calls = 0; + last_thread = nullptr; + function_table[GET_VERSION_INDEX] = + reinterpret_cast(&getVersion); + function_table[IS_VIRTUAL_THREAD_INDEX] = + reinterpret_cast(&isVirtualThread); + jni.functions = + reinterpret_cast(function_table); + } +}; + +TEST_F(JvmSupportThreadClassificationTest, NullInputsFailClosed) { + EXPECT_FALSE(JVMSupport::isPlatformThread(nullptr, thread)); + EXPECT_FALSE(JVMSupport::isPlatformThread(&jni, nullptr)); +} + +TEST_F(JvmSupportThreadClassificationTest, InvalidJniVersionFailsClosed) { + jni_version = 0; + EXPECT_FALSE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(0, is_virtual_thread_calls); +} + +TEST_F(JvmSupportThreadClassificationTest, PreJni19ThreadIsPlatform) { + jni_version = 0x000a0000; + function_table[IS_VIRTUAL_THREAD_INDEX] = nullptr; + EXPECT_TRUE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(0, is_virtual_thread_calls); +} + +TEST_F(JvmSupportThreadClassificationTest, Jni19PlatformThreadIsAccepted) { + jni_version = 0x00130000; + EXPECT_TRUE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(1, is_virtual_thread_calls); + EXPECT_EQ(thread, last_thread); +} + +TEST_F(JvmSupportThreadClassificationTest, Jni19VirtualThreadIsRejected) { + jni_version = 0x00130000; + virtual_thread = JNI_TRUE; + EXPECT_FALSE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(1, is_virtual_thread_calls); + EXPECT_EQ(thread, last_thread); +} + +TEST_F(JvmSupportThreadClassificationTest, MissingJni19FunctionFailsClosed) { + jni_version = 0x00130000; + function_table[IS_VIRTUAL_THREAD_INDEX] = nullptr; + EXPECT_FALSE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(0, is_virtual_thread_calls); +} + +TEST_F(JvmSupportThreadClassificationTest, Jni20PlatformThreadIsAccepted) { + jni_version = 0x00140000; + EXPECT_TRUE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(1, is_virtual_thread_calls); + EXPECT_EQ(thread, last_thread); +} + +TEST_F(JvmSupportThreadClassificationTest, Jni20VirtualThreadIsRejected) { + jni_version = 0x00140000; + virtual_thread = JNI_TRUE; + EXPECT_FALSE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(1, is_virtual_thread_calls); + EXPECT_EQ(thread, last_thread); +} + +TEST_F(JvmSupportThreadClassificationTest, MissingJni20FunctionFailsClosed) { + jni_version = 0x00140000; + function_table[IS_VIRTUAL_THREAD_INDEX] = nullptr; + EXPECT_FALSE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(0, is_virtual_thread_calls); +} + +TEST_F(JvmSupportThreadClassificationTest, Jni21PlatformThreadIsAccepted) { + EXPECT_TRUE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(1, is_virtual_thread_calls); + EXPECT_EQ(thread, last_thread); +} + +TEST_F(JvmSupportThreadClassificationTest, Jni21VirtualThreadIsRejected) { + virtual_thread = JNI_TRUE; + EXPECT_FALSE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(1, is_virtual_thread_calls); + EXPECT_EQ(thread, last_thread); +} + +TEST_F(JvmSupportThreadClassificationTest, MissingJni21FunctionFailsClosed) { + function_table[IS_VIRTUAL_THREAD_INDEX] = nullptr; + EXPECT_FALSE(JVMSupport::isPlatformThread(&jni, thread)); + EXPECT_EQ(0, is_virtual_thread_calls); +} + // --------------------------------------------------------------------------- // VMTestAccessor — friend of VM, lets tests swap VM::_jvmti for a mock so // JVMThread::currentThreadSlow() can be exercised without a live JVM. diff --git a/ddprof-lib/src/test/cpp/park_state_ut.cpp b/ddprof-lib/src/test/cpp/park_state_ut.cpp index 69f379242..a7f558fc4 100644 --- a/ddprof-lib/src/test/cpp/park_state_ut.cpp +++ b/ddprof-lib/src/test/cpp/park_state_ut.cpp @@ -39,7 +39,7 @@ TestProfiledThread testThread(int tid) { } // namespace -// Tests cover FLAG_PARKED lifecycle and the once-per-run slot filter state transitions. +// Tests cover FLAG_PARKED lifecycle and owned-block slot state transitions. // The slot state lives in ThreadFilter process-lifetime storage so the wall-clock // timer can read it without dereferencing per-thread objects from another thread. @@ -137,48 +137,91 @@ TEST(ProfiledThreadParkStateTest, ParkExitReturnsZeroTokenWhenBlockRunWasNotArme EXPECT_EQ(0ULL, park_block_token); } -TEST(WallClockOncePerRunFilterTest, SlotStateTransitions) { +TEST(ProfiledThreadParkStateTest, ParkExitReturnsEntrySnapshot) { + TestProfiledThread thread = testThread(12351); + Context entered{}; + entered.spanId = 17; + entered.rootSpanId = 18; + ASSERT_TRUE(thread->parkEnter(123, entered)); + thread->setParkBlockToken(456); + + u64 start_ticks = 0; + u64 token = 0; + Context exited{}; + ASSERT_TRUE(thread->parkExit(start_ticks, exited, token)); + EXPECT_EQ(123ULL, start_ticks); + EXPECT_EQ(456ULL, token); + EXPECT_EQ(17ULL, exited.spanId); + EXPECT_EQ(18ULL, exited.rootSpanId); +} + +TEST(ProfiledThreadMonitorStateTest, MatchingExitReturnsEntrySnapshot) { + TestProfiledThread thread = testThread(12352); + Context entered{}; + entered.spanId = 21; + ASSERT_TRUE(thread->monitorEnter( + 100, entered, 200, OSThreadState::MONITOR_WAIT)); + thread->setMonitorBlockToken(300); + + u64 start_ticks = 0; + u64 blocker = 0; + u64 token = 0; + Context exited{}; + ASSERT_TRUE(thread->monitorExit(OSThreadState::MONITOR_WAIT, start_ticks, + exited, blocker, token)); + EXPECT_EQ(100ULL, start_ticks); + EXPECT_EQ(200ULL, blocker); + EXPECT_EQ(300ULL, token); + EXPECT_EQ(21ULL, exited.spanId); +} + +TEST(ProfiledThreadMonitorStateTest, NestedContentionDoesNotReplaceObjectWait) { + TestProfiledThread thread = testThread(12353); + Context context{}; + ASSERT_TRUE(thread->monitorEnter( + 100, context, 200, OSThreadState::OBJECT_WAIT)); + thread->setMonitorBlockToken(300); + EXPECT_FALSE(thread->monitorEnter( + 400, context, 500, OSThreadState::MONITOR_WAIT)); + + u64 start_ticks = 0; + u64 blocker = 0; + u64 token = 0; + Context exited{}; + EXPECT_FALSE(thread->monitorExit(OSThreadState::MONITOR_WAIT, start_ticks, + exited, blocker, token)); + ASSERT_TRUE(thread->monitorExit(OSThreadState::OBJECT_WAIT, start_ticks, + exited, blocker, token)); + EXPECT_EQ(100ULL, start_ticks); + EXPECT_EQ(200ULL, blocker); + EXPECT_EQ(300ULL, token); +} + +TEST(ProfiledThreadMonitorStateTest, ClearAllowsRecoveryFromStaleState) { + TestProfiledThread thread = testThread(12354); + Context context{}; + ASSERT_TRUE(thread->monitorEnter( + 100, context, 200, OSThreadState::OBJECT_WAIT)); + thread->setMonitorBlockToken(300); + thread->clearMonitorBlock(); + + ASSERT_TRUE(thread->monitorEnter( + 400, context, 500, OSThreadState::MONITOR_WAIT)); + EXPECT_EQ(0ULL, thread->monitorBlockToken()); +} + +TEST(WallClockOwnedBlockFilterTest, SlotStateTransitions) { ThreadFilter::Slot slot; - EXPECT_FALSE(slot.sampledThisRun()); - EXPECT_EQ(OSThreadState::UNKNOWN, slot.lastSampledState()); EXPECT_EQ(OSThreadState::UNKNOWN, slot.activeBlockState()); - // First signal: arm. slot.setActiveBlockState(OSThreadState::SLEEPING); - slot.markSampledThisRun(OSThreadState::SLEEPING); - EXPECT_TRUE(slot.sampledThisRun()); - EXPECT_EQ(OSThreadState::SLEEPING, slot.lastSampledState()); EXPECT_EQ(OSThreadState::SLEEPING, slot.activeBlockState()); - // Same state again: suppress (flag + state both match). - EXPECT_TRUE(slot.sampledThisRun() && - OSThreadState::SLEEPING == slot.lastSampledState()); - EXPECT_TRUE(slot.sampledThisRun() && - slot.activeBlockState() == slot.lastSampledState()); - - // Transition within skip set (SLEEPING -> CONDVAR_WAIT): state mismatch -> re-arm. slot.setActiveBlockState(OSThreadState::CONDVAR_WAIT); - EXPECT_FALSE(slot.sampledThisRun() && - OSThreadState::CONDVAR_WAIT == slot.lastSampledState()); - slot.markSampledThisRun(OSThreadState::CONDVAR_WAIT); - EXPECT_TRUE(slot.sampledThisRun()); - EXPECT_EQ(OSThreadState::CONDVAR_WAIT, slot.lastSampledState()); - EXPECT_TRUE(slot.sampledThisRun() && - slot.activeBlockState() == slot.lastSampledState()); - - // Leave skip set: reset -> next blocked entry re-arms. + EXPECT_EQ(OSThreadState::CONDVAR_WAIT, slot.activeBlockState()); slot.setActiveBlockState(OSThreadState::UNKNOWN); - slot.resetSampledRun(OSThreadState::RUNNABLE); - EXPECT_FALSE(slot.sampledThisRun()); - EXPECT_EQ(OSThreadState::RUNNABLE, slot.lastSampledState()); EXPECT_EQ(OSThreadState::UNKNOWN, slot.activeBlockState()); - - slot.setActiveBlockState(OSThreadState::SLEEPING); - slot.markSampledThisRun(OSThreadState::SLEEPING); - EXPECT_TRUE(slot.sampledThisRun()); - EXPECT_EQ(OSThreadState::SLEEPING, slot.lastSampledState()); - EXPECT_EQ(OSThreadState::SLEEPING, slot.activeBlockState()); } TEST(WallClockOncePerRunFilterTest, UnownedBlockedFallbackCarriesWeight) { @@ -332,33 +375,24 @@ TEST(WallClockOncePerRunFilterTest, FilterHelpersManageActiveBlockState) { ASSERT_NE(nullptr, slot); EXPECT_EQ(OSThreadState::CONDVAR_WAIT, slot->activeBlockState()); - slot->markSampledThisRun(OSThreadState::CONDVAR_WAIT); - EXPECT_TRUE(slot->sampledThisRun()); - EXPECT_TRUE(slot->sampledThisRun() && - slot->activeBlockState() == slot->lastSampledState()); - filter.exitBlockedRun(slot_id); EXPECT_EQ(OSThreadState::UNKNOWN, slot->activeBlockState()); - EXPECT_FALSE(slot->sampledThisRun()); - EXPECT_EQ(OSThreadState::RUNNABLE, slot->lastSampledState()); + EXPECT_EQ(0ULL, slot->sampledBlockGeneration()); } -// Slot reuse: stale armed state from the previous owner must be cleared before -// the new thread takes the slot (ThreadFilter::resetSlotRunState does this). -TEST(WallClockOncePerRunFilterTest, ResetClearsArmedFlagOnSlotReuse) { +TEST(WallClockOncePerRunFilterTest, ResetClearsOwnedBlockOnSlotReuse) { ThreadFilter filter; filter.init("1"); ThreadFilter::SlotID slot_id = filter.registerThread(); filter.enterBlockedRun(slot_id, OSThreadState::CONDVAR_WAIT); ThreadFilter::Slot *slot = filter.slotForId(slot_id); ASSERT_NE(nullptr, slot); - slot->markSampledThisRun(OSThreadState::CONDVAR_WAIT); - EXPECT_TRUE(slot->sampledThisRun()); EXPECT_EQ(OSThreadState::CONDVAR_WAIT, slot->activeBlockState()); + slot->markBlockGenerationSampled(slot->blockGeneration()); + ASSERT_EQ(slot->blockGeneration(), slot->sampledBlockGeneration()); filter.resetSlotRunState(slot_id); - EXPECT_FALSE(slot->sampledThisRun()); - EXPECT_EQ(OSThreadState::UNKNOWN, slot->lastSampledState()); EXPECT_EQ(OSThreadState::UNKNOWN, slot->activeBlockState()); + EXPECT_EQ(0ULL, slot->sampledBlockGeneration()); } diff --git a/ddprof-lib/src/test/cpp/taskBlockRecorder_ut.cpp b/ddprof-lib/src/test/cpp/taskBlockRecorder_ut.cpp new file mode 100644 index 000000000..3c90c672f --- /dev/null +++ b/ddprof-lib/src/test/cpp/taskBlockRecorder_ut.cpp @@ -0,0 +1,334 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +#include + +#include "counters.h" +#include "profiler.h" +#include "taskBlockRecorder.h" +#include "tsc.h" + +#include +#include +#include +#include +#include + +namespace { + +std::atomic g_record_result{ + Profiler::TaskBlockRecordResult::RECORDED}; +std::atomic g_record_calls{0}; + +Profiler::TaskBlockRecordResult recordTaskBlockForTest( + int tid, jthread thread, int start_depth, TaskBlockEvent* event) { + g_record_calls.fetch_add(1, std::memory_order_relaxed); + return g_record_result.load(std::memory_order_acquire); +} + +u64 minEligibleEndTicks(u64 start_ticks) { + u64 low = start_ticks + 1; + u64 high = low; + while (!exceedsMinTaskBlockDuration(start_ticks, high)) { + high = start_ticks + ((high - start_ticks) * 2); + } + while (low < high) { + u64 mid = low + ((high - low) / 2); + if (exceedsMinTaskBlockDuration(start_ticks, mid)) { + high = mid; + } else { + low = mid + 1; + } + } + return low; +} + +class TaskBlockRecorderTest : public ::testing::Test { +protected: + void SetUp() override { + Counters::reset(); + initializeTaskBlockDurationThreshold(); + g_record_result.store(Profiler::TaskBlockRecordResult::RECORDED, + std::memory_order_release); + g_record_calls.store(0, std::memory_order_relaxed); + Profiler::setTaskBlockRecordOverrideForTest(recordTaskBlockForTest); + } + + void TearDown() override { + Profiler::setTaskBlockRecordOverrideForTest(nullptr); + Counters::reset(); + } +}; + +} // namespace + +TEST_F(TaskBlockRecorderTest, TraceContextIsRejectedBeforeDuration) { + Context context{}; + context.spanId = 123; + + EXPECT_FALSE(taskBlockPassesBasicEligibility(100, 100, context)); + EXPECT_EQ(1, Counters::getCounter(TASK_BLOCK_SKIPPED_TRACE_CONTEXT)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_SKIPPED_TOO_SHORT)); +} + +TEST_F(TaskBlockRecorderTest, DurationThresholdIncludesExactBoundary) { + Context context{}; + u64 start_ticks = TSC::ticks(); + u64 passing_end = minEligibleEndTicks(start_ticks); + + EXPECT_TRUE(taskBlockPassesBasicEligibility( + start_ticks, passing_end, context)); + EXPECT_FALSE(taskBlockPassesBasicEligibility( + start_ticks, passing_end - 1, context)); + EXPECT_EQ(1, Counters::getCounter(TASK_BLOCK_SKIPPED_TOO_SHORT)); +} + +TEST_F(TaskBlockRecorderTest, RotationRejectsNewActivity) { + Profiler* profiler = Profiler::instance(); + profiler->beginTaskBlockRotationForTest(); + + EXPECT_FALSE(profiler->tryEnterTaskBlockActivity()); + TaskBlockActivity activity; + EXPECT_FALSE(activity.active()); + EXPECT_EQ(1, Counters::getCounter(TASK_BLOCK_DROPPED_ROTATION)); + + profiler->endTaskBlockRotationForTest(); + ASSERT_TRUE(profiler->tryEnterTaskBlockActivity()); + profiler->leaveTaskBlockActivity(); +} + +TEST_F(TaskBlockRecorderTest, RotationWaitsForInflightActivity) { + Profiler* profiler = Profiler::instance(); + ASSERT_TRUE(profiler->tryEnterTaskBlockActivity()); + ASSERT_EQ(1, profiler->taskBlockInflightForTest()); + + std::atomic rotation_returned{false}; + std::thread rotation([&]() { + profiler->beginTaskBlockRotationForTest(); + rotation_returned.store(true, std::memory_order_release); + profiler->endTaskBlockRotationForTest(); + }); + + auto deadline = std::chrono::steady_clock::now() + std::chrono::seconds(5); + while (!profiler->taskBlockRotationActiveForTest() && + std::chrono::steady_clock::now() < deadline) { + std::this_thread::yield(); + } + + bool rotation_active = profiler->taskBlockRotationActiveForTest(); + EXPECT_TRUE(rotation_active); + EXPECT_EQ(1, profiler->taskBlockInflightForTest()); + EXPECT_FALSE(rotation_returned.load(std::memory_order_acquire)); + if (rotation_active) { + bool entered = profiler->tryEnterTaskBlockActivity(); + EXPECT_FALSE(entered); + if (entered) profiler->leaveTaskBlockActivity(); + } + + profiler->leaveTaskBlockActivity(); + rotation.join(); + + EXPECT_TRUE(rotation_returned.load(std::memory_order_acquire)); + EXPECT_FALSE(profiler->taskBlockRotationActiveForTest()); + EXPECT_EQ(0, profiler->taskBlockInflightForTest()); + ASSERT_TRUE(profiler->tryEnterTaskBlockActivity()); + profiler->leaveTaskBlockActivity(); +} + +TEST_F(TaskBlockRecorderTest, RotationRejectsEndWithoutStrandingLifecycle) { + constexpr int tid = 12345; + ThreadFilter filter; + filter.init("", true); + ThreadFilter::SlotID slot_id = filter.registerThread(tid); + ASSERT_GE(slot_id, 0); + + std::unique_ptr current( + ProfiledThread::forTid(tid), ProfiledThread::deleteForTest); + current->setFilterSlotId(slot_id); + u64 token = filter.enterBlockedRun( + slot_id, OSThreadState::SLEEPING, BlockRunOwner::JAVA); + ASSERT_NE(0ULL, token); + Context context{}; + ASSERT_TRUE(current->taskBlockEnter(token, TSC::ticks(), context)); + + Profiler* profiler = Profiler::instance(); + profiler->beginTaskBlockRotationForTest(); + std::future result = std::async(std::launch::async, [&]() { + return recordTaskBlockAtExit( + current.get(), &filter, nullptr, 1, token, + ThreadFilter::tokenSlotId(token), + ThreadFilter::tokenGeneration(token), 0, 0); + }); + + std::future_status status = result.wait_for(std::chrono::seconds(1)); + bool returned_during_rotation = status == std::future_status::ready; + EXPECT_TRUE(returned_during_rotation); + if (returned_during_rotation) { + ThreadFilter::Slot* slot = filter.slotForId(slot_id); + EXPECT_NE(nullptr, slot); + if (slot != nullptr) { + EXPECT_EQ(BlockRunOwner::NONE, slot->activeBlockOwner()); + EXPECT_EQ(OSThreadState::UNKNOWN, slot->activeBlockState()); + } + + u64 next_token = filter.enterBlockedRun( + slot_id, OSThreadState::SLEEPING, BlockRunOwner::JAVA); + EXPECT_NE(0ULL, next_token); + EXPECT_TRUE(current->taskBlockEnter(next_token, TSC::ticks(), context)); + u64 ignored_ticks = 0; + Context ignored_context{}; + EXPECT_TRUE(current->taskBlockExit( + next_token, ignored_ticks, ignored_context)); + EXPECT_TRUE(filter.exitBlockedRun( + slot_id, ThreadFilter::tokenGeneration(next_token))); + } + + profiler->endTaskBlockRotationForTest(); + EXPECT_FALSE(result.get()); + EXPECT_EQ(1, Counters::getCounter(TASK_BLOCK_DROPPED_ROTATION)); +} + +TEST_F(TaskBlockRecorderTest, RotationRejectsParkExitWithoutBlockingOrStranding) { + constexpr int tid = 12346; + ThreadFilter filter; + filter.init("", true); + ThreadFilter::SlotID slot_id = filter.registerThread(tid); + ASSERT_GE(slot_id, 0); + + std::unique_ptr current( + ProfiledThread::forTid(tid), ProfiledThread::deleteForTest); + current->setFilterSlotId(slot_id); + Context context{}; + ASSERT_TRUE(current->parkEnter(TSC::ticks(), context)); + u64 token = filter.enterBlockedRun( + slot_id, OSThreadState::CONDVAR_WAIT, BlockRunOwner::JAVA); + ASSERT_NE(0ULL, token); + current->setParkBlockToken(token); + + Profiler* profiler = Profiler::instance(); + profiler->beginTaskBlockRotationForTest(); + std::future result = std::async(std::launch::async, [&]() { + u64 start_ticks = 0; + u64 exit_token = 0; + Context exit_context{}; + if (!current->parkExit(start_ticks, exit_context, exit_token)) return true; + return finishTaskBlockAtExit( + current.get(), &filter, nullptr, 1, exit_token, start_ticks, + exit_context, 0, 0); + }); + + EXPECT_EQ(std::future_status::ready, + result.wait_for(std::chrono::seconds(1))); + ThreadFilter::Slot* slot = filter.slotForId(slot_id); + ASSERT_NE(nullptr, slot); + EXPECT_EQ(BlockRunOwner::NONE, slot->activeBlockOwner()); + EXPECT_EQ(OSThreadState::UNKNOWN, slot->activeBlockState()); + EXPECT_TRUE(current->parkEnter(TSC::ticks(), context)); + u64 ignored_ticks = 0; + u64 ignored_token = 0; + Context ignored_context{}; + EXPECT_TRUE(current->parkExit( + ignored_ticks, ignored_context, ignored_token)); + + profiler->endTaskBlockRotationForTest(); + EXPECT_FALSE(result.get()); + EXPECT_EQ(1, Counters::getCounter(TASK_BLOCK_DROPPED_ROTATION)); +} + +TEST_F(TaskBlockRecorderTest, + RotationRejectsMonitorExitWithoutBlockingOrStranding) { + constexpr int tid = 12347; + ThreadFilter filter; + filter.init("", true); + ThreadFilter::SlotID slot_id = filter.registerThread(tid); + ASSERT_GE(slot_id, 0); + + std::unique_ptr current( + ProfiledThread::forTid(tid), ProfiledThread::deleteForTest); + current->setFilterSlotId(slot_id); + Context context{}; + ASSERT_TRUE(current->monitorEnter( + TSC::ticks(), context, 7, OSThreadState::OBJECT_WAIT)); + u64 token = filter.enterBlockedRun( + slot_id, OSThreadState::OBJECT_WAIT, BlockRunOwner::JVMTI); + ASSERT_NE(0ULL, token); + current->setMonitorBlockToken(token); + + Profiler* profiler = Profiler::instance(); + profiler->beginTaskBlockRotationForTest(); + std::future result = std::async(std::launch::async, [&]() { + u64 start_ticks = 0; + u64 blocker = 0; + u64 exit_token = 0; + Context exit_context{}; + if (!current->monitorExit(OSThreadState::OBJECT_WAIT, start_ticks, + exit_context, blocker, exit_token)) { + return true; + } + return finishTaskBlockAtExit( + current.get(), &filter, nullptr, 0, exit_token, start_ticks, + exit_context, blocker, 0); + }); + + EXPECT_EQ(std::future_status::ready, + result.wait_for(std::chrono::seconds(1))); + ThreadFilter::Slot* slot = filter.slotForId(slot_id); + ASSERT_NE(nullptr, slot); + EXPECT_EQ(BlockRunOwner::NONE, slot->activeBlockOwner()); + EXPECT_EQ(OSThreadState::UNKNOWN, slot->activeBlockState()); + EXPECT_TRUE(current->monitorEnter( + TSC::ticks(), context, 8, OSThreadState::MONITOR_WAIT)); + current->clearMonitorBlock(); + + profiler->endTaskBlockRotationForTest(); + EXPECT_FALSE(result.get()); + EXPECT_EQ(1, Counters::getCounter(TASK_BLOCK_DROPPED_ROTATION)); +} + +TEST_F(TaskBlockRecorderTest, StackCaptureFailureIsCountedAndActivityReleased) { + g_record_result.store(Profiler::TaskBlockRecordResult::STACK_CAPTURE_FAILED, + std::memory_order_release); + Context context{}; + u64 start_ticks = TSC::ticks(); + u64 end_ticks = minEligibleEndTicks(start_ticks); + + EXPECT_FALSE(recordTaskBlockIfEligible( + 123, nullptr, 0, start_ticks, end_ticks, context, 0, 0, + OSThreadState::SLEEPING)); + + EXPECT_EQ(1, g_record_calls.load(std::memory_order_relaxed)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_EMITTED)); + EXPECT_EQ(1, Counters::getCounter(TASK_BLOCK_STACK_CAPTURE_FAILED)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_RECORD_FAILED)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_SKIPPED_TRACE_CONTEXT)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_SKIPPED_TOO_SHORT)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_DROPPED_ROTATION)); + EXPECT_EQ(0, Profiler::instance()->taskBlockInflightForTest()); + ASSERT_TRUE(Profiler::instance()->tryEnterTaskBlockActivity()); + Profiler::instance()->leaveTaskBlockActivity(); +} + +TEST_F(TaskBlockRecorderTest, RecordFailureIsCountedAndActivityReleased) { + g_record_result.store(Profiler::TaskBlockRecordResult::RECORD_FAILED, + std::memory_order_release); + Context context{}; + u64 start_ticks = TSC::ticks(); + u64 end_ticks = minEligibleEndTicks(start_ticks); + + EXPECT_FALSE(recordTaskBlockIfEligible( + 123, nullptr, 0, start_ticks, end_ticks, context, 0, 0, + OSThreadState::SLEEPING)); + + EXPECT_EQ(1, g_record_calls.load(std::memory_order_relaxed)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_EMITTED)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_STACK_CAPTURE_FAILED)); + EXPECT_EQ(1, Counters::getCounter(TASK_BLOCK_RECORD_FAILED)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_SKIPPED_TRACE_CONTEXT)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_SKIPPED_TOO_SHORT)); + EXPECT_EQ(0, Counters::getCounter(TASK_BLOCK_DROPPED_ROTATION)); + EXPECT_EQ(0, Profiler::instance()->taskBlockInflightForTest()); + ASSERT_TRUE(Profiler::instance()->tryEnterTaskBlockActivity()); + Profiler::instance()->leaveTaskBlockActivity(); +} diff --git a/ddprof-lib/src/test/cpp/threadFilter_ut.cpp b/ddprof-lib/src/test/cpp/threadFilter_ut.cpp index 004187b48..03744ef46 100644 --- a/ddprof-lib/src/test/cpp/threadFilter_ut.cpp +++ b/ddprof-lib/src/test/cpp/threadFilter_ut.cpp @@ -484,6 +484,24 @@ TEST_F(ThreadFilterTest, CollectMixedStates) { } } +TEST_F(ThreadFilterTest, CollectUnownedBlockedTraceIdsFindsOnlyCachedSlots) { + int with_trace_id = filter->registerThread(); + int without_trace_id = filter->registerThread(); + ASSERT_GE(with_trace_id, 0); + ASSERT_GE(without_trace_id, 0); + + ThreadFilter::Slot* slot = filter->slotForId(with_trace_id); + ASSERT_NE(slot, nullptr); + slot->recordUnownedBlockedSample(0xABCDULL, OSThreadState::SLEEPING); + + std::set collected; + filter->collectUnownedBlockedTraceIds( + [&](u64 call_trace_id) { collected.insert(call_trace_id); }); + + EXPECT_EQ(collected.size(), 1u); + EXPECT_TRUE(collected.count(0xABCDULL)); +} + TEST_F(ThreadFilterTest, ClearActiveDropsPreviousRecordingMembership) { int stale_slot = filter->registerThread(); int current_slot = filter->registerThread(); @@ -495,7 +513,6 @@ TEST_F(ThreadFilterTest, ClearActiveDropsPreviousRecordingMembership) { filter->enterBlockedRun(stale_slot, OSThreadState::SLEEPING); ThreadFilter::Slot *stale = filter->slotForId(stale_slot); ASSERT_NE(nullptr, stale); - stale->markSampledThisRun(OSThreadState::SLEEPING); filter->clearActive(); @@ -504,8 +521,6 @@ TEST_F(ThreadFilterTest, ClearActiveDropsPreviousRecordingMembership) { EXPECT_TRUE(collected_tids.empty()); EXPECT_FALSE(filter->accept(stale_slot)); EXPECT_FALSE(filter->accept(current_slot)); - EXPECT_FALSE(stale->sampledThisRun()); - EXPECT_EQ(OSThreadState::UNKNOWN, stale->lastSampledState()); EXPECT_EQ(OSThreadState::UNKNOWN, stale->activeBlockState()); filter->add(2222, current_slot); @@ -553,15 +568,181 @@ TEST_F(ThreadFilterTest, NewGenerationRejectsStaleToken) { EXPECT_TRUE(filter->exitBlockedRun(slot_id, ThreadFilter::tokenGeneration(current_token))); } -TEST_F(ThreadFilterTest, TokenRoundTripPreservesHighGenerationBit) { +TEST_F(ThreadFilterTest, TokenRoundTripPreservesNegativeJavaLongBitPattern) { ThreadFilter::SlotID slot_id = 7; - u32 generation = 0x80000001u; + u64 generation = 1ULL << 52; u64 token = ThreadFilter::encodeBlockRunToken(slot_id, generation); int64_t java_token = static_cast(token); EXPECT_LT(java_token, 0); - EXPECT_EQ(slot_id, ThreadFilter::tokenSlotId(static_cast(java_token))); - EXPECT_EQ(generation, ThreadFilter::tokenGeneration(static_cast(java_token))); + ThreadFilter::SlotID decoded_slot = -1; + u64 decoded_generation = 0; + EXPECT_TRUE(ThreadFilter::decodeBlockRunToken( + static_cast(java_token), decoded_slot, decoded_generation)); + EXPECT_EQ(slot_id, decoded_slot); + EXPECT_EQ(generation, decoded_generation); +} + +TEST_F(ThreadFilterTest, TokenRoundTripCoversSlotAndGenerationBoundaries) { + ThreadFilter::SlotID decoded_slot = -1; + u64 decoded_generation = 0; + + u64 first = ThreadFilter::encodeBlockRunToken(0, 1); + ASSERT_TRUE(ThreadFilter::decodeBlockRunToken( + first, decoded_slot, decoded_generation)); + EXPECT_EQ(0, decoded_slot); + EXPECT_EQ(1ULL, decoded_generation); + + u64 last = ThreadFilter::encodeBlockRunToken( + ThreadFilter::kMaxThreads - 1, ThreadFilter::kMaxBlockRunGeneration); + EXPECT_EQ(UINT64_MAX, last); + ASSERT_TRUE(ThreadFilter::decodeBlockRunToken( + last, decoded_slot, decoded_generation)); + EXPECT_EQ(ThreadFilter::kMaxThreads - 1, decoded_slot); + EXPECT_EQ(ThreadFilter::kMaxBlockRunGeneration, decoded_generation); + + EXPECT_FALSE(ThreadFilter::decodeBlockRunToken( + 0, decoded_slot, decoded_generation)); + EXPECT_FALSE(ThreadFilter::decodeBlockRunToken( + static_cast(ThreadFilter::kMaxThreads - 1), + decoded_slot, decoded_generation)); +} + +TEST_F(ThreadFilterTest, SaturatedGenerationRefusesEntryWithoutClaimingSlot) { + int slot_id = filter->registerThread(); + ASSERT_GE(slot_id, 0); + ThreadFilter::Slot* slot = filter->slotForId(slot_id); + ASSERT_NE(nullptr, slot); + slot->block_generation.store(ThreadFilter::kMaxBlockRunGeneration - 1, + std::memory_order_release); + + u64 token = filter->enterBlockedRun(slot_id, OSThreadState::SLEEPING); + ASSERT_NE(0ULL, token); + EXPECT_EQ(ThreadFilter::kMaxBlockRunGeneration, + ThreadFilter::tokenGeneration(token)); + ASSERT_TRUE(filter->exitBlockedRun( + slot_id, ThreadFilter::tokenGeneration(token))); + + EXPECT_EQ(0ULL, filter->enterBlockedRun(slot_id, OSThreadState::SLEEPING)); + EXPECT_EQ(0ULL, filter->enterBlockedRun(slot_id, OSThreadState::SLEEPING)); + EXPECT_EQ(BlockRunOwner::NONE, slot->activeBlockOwner()); + EXPECT_EQ(OSThreadState::UNKNOWN, slot->activeBlockState()); + EXPECT_EQ(ThreadFilter::kMaxBlockRunGeneration, slot->blockGeneration()); +} + +TEST_F(ThreadFilterTest, SnapshotCapturesOwnedLifecycle) { + int slot_id = filter->registerThread(); + ASSERT_GE(slot_id, 0); + ThreadFilter::Slot* slot = filter->slotForId(slot_id); + ASSERT_NE(nullptr, slot); + u64 token = filter->enterBlockedRun(slot_id, OSThreadState::SLEEPING); + ASSERT_NE(0ULL, token); + + BlockRunSnapshot snapshot = slot->snapshotBlockRun(); + EXPECT_TRUE(snapshot.active); + EXPECT_EQ(OSThreadState::SLEEPING, snapshot.active_state); + EXPECT_EQ(BlockRunOwner::JAVA, snapshot.owner); + EXPECT_EQ(ThreadFilter::tokenGeneration(token), snapshot.generation); + + ASSERT_TRUE(filter->snapshotAndExitBlockedRun( + slot_id, ThreadFilter::tokenGeneration(token), &snapshot)); + EXPECT_FALSE(slot->snapshotBlockRun().active); +} + +TEST_F(ThreadFilterTest, OwnedBlockSuppressesOnlyAfterSuccessfulWallSample) { + filter->init(nullptr, true); + int slot_id = filter->registerThread(1234); + ASSERT_GE(slot_id, 0); + ThreadFilter::Slot* slot = filter->slotForId(slot_id); + ASSERT_NE(nullptr, slot); + u64 token = filter->enterBlockedRun(slot_id, OSThreadState::SLEEPING); + ASSERT_NE(0ULL, token); + + ThreadEntry entry{1234, slot, slot->lifecycleGeneration(), + slot->recordingEpoch()}; + u64 generation = 0; + EXPECT_TRUE(filter->activeOwnedBlockGeneration(entry, generation)); + EXPECT_EQ(ThreadFilter::tokenGeneration(token), generation); + EXPECT_FALSE(filter->isOwnedBlockSuppressionCandidate(entry)); + + slot->markBlockGenerationSampled(generation); + EXPECT_TRUE(filter->isOwnedBlockSuppressionCandidate(entry)); + EXPECT_FALSE(filter->isOwnedBlockSuppressionCandidate( + {1235, slot, slot->lifecycleGeneration(), slot->recordingEpoch()})); + EXPECT_FALSE(filter->isOwnedBlockSuppressionCandidate( + {1234, slot, slot->lifecycleGeneration() + 1, + slot->recordingEpoch()})); + + ASSERT_TRUE(filter->exitBlockedRun( + slot_id, ThreadFilter::tokenGeneration(token))); + EXPECT_FALSE(filter->isOwnedBlockSuppressionCandidate(entry)); +} + +TEST_F(ThreadFilterTest, StaleSampleCompletionCannotSuppressNewBlockGeneration) { + filter->init(nullptr, true); + int slot_id = filter->registerThread(1234); + ASSERT_GE(slot_id, 0); + ThreadFilter::Slot* slot = filter->slotForId(slot_id); + ASSERT_NE(nullptr, slot); + + u64 first_token = filter->enterBlockedRun(slot_id, OSThreadState::SLEEPING); + ASSERT_NE(0ULL, first_token); + u64 first_generation = ThreadFilter::tokenGeneration(first_token); + ASSERT_TRUE(filter->exitBlockedRun(slot_id, first_generation)); + + u64 second_token = + filter->enterBlockedRun(slot_id, OSThreadState::CONDVAR_WAIT); + ASSERT_NE(0ULL, second_token); + u64 second_generation = ThreadFilter::tokenGeneration(second_token); + ASSERT_GT(second_generation, first_generation); + + ThreadEntry entry{1234, slot, slot->lifecycleGeneration(), + slot->recordingEpoch()}; + slot->markBlockGenerationSampled(first_generation); + EXPECT_FALSE(filter->isOwnedBlockSuppressionCandidate(entry)); + + slot->markBlockGenerationSampled(second_generation); + EXPECT_TRUE(filter->isOwnedBlockSuppressionCandidate(entry)); + + // A delayed completion from the first run must not overwrite the newer mark. + slot->markBlockGenerationSampled(first_generation); + EXPECT_EQ(second_generation, slot->sampledBlockGeneration()); + EXPECT_TRUE(filter->isOwnedBlockSuppressionCandidate(entry)); +} + +TEST_F(ThreadFilterTest, ContextScopeNeverSuppressesOwnedBlock) { + filter->init("0", false); + int slot_id = filter->registerThread(1234); + ASSERT_GE(slot_id, 0); + filter->add(1234, slot_id); + ThreadFilter::Slot* slot = filter->slotForId(slot_id); + ASSERT_NE(nullptr, slot); + ASSERT_NE(0ULL, filter->enterBlockedRun( + slot_id, OSThreadState::CONDVAR_WAIT)); + + ThreadEntry entry{1234, slot, slot->lifecycleGeneration(), + slot->recordingEpoch()}; + slot->markBlockGenerationSampled(slot->blockGeneration()); + EXPECT_FALSE(filter->isOwnedBlockSuppressionCandidate(entry)); +} + +TEST_F(ThreadFilterTest, ContextEpochDisablesOwnedBlockSuppression) { + filter->init(nullptr, true); + int slot_id = filter->registerThread(1234); + ASSERT_GE(slot_id, 0); + ThreadFilter::Slot* slot = filter->slotForId(slot_id); + ASSERT_NE(nullptr, slot); + ASSERT_NE(0ULL, filter->enterBlockedRun( + slot_id, OSThreadState::CONDVAR_WAIT)); + ThreadEntry entry{1234, slot, slot->lifecycleGeneration(), + slot->recordingEpoch()}; + slot->markBlockGenerationSampled(slot->blockGeneration()); + ASSERT_TRUE(filter->isOwnedBlockSuppressionCandidate(entry)); + + filter->add(1234, slot_id); + EXPECT_FALSE(filter->isOwnedBlockSuppressionCandidate(entry)); + filter->remove(slot_id); + EXPECT_FALSE(filter->isOwnedBlockSuppressionCandidate(entry)); } class ThreadRegistryTest : public ::testing::Test { @@ -603,6 +784,25 @@ TEST_F(ThreadRegistryTest, UnfilteredTrackingSeparatesRegistrationFromContextWin EXPECT_TRUE(context.empty()); } +TEST_F(ThreadRegistryTest, LookupThreadEntryDoesNotRegisterUnknownTid) { + constexpr int tid = 3210; + ThreadEntry entry{tid, nullptr, 0, 0}; + + EXPECT_FALSE(registry.lookupThreadEntry(entry, registry.recordingEpoch())); + EXPECT_EQ(nullptr, entry.slot); + EXPECT_EQ(nullptr, registry.lookupByTid(tid)); + + int slot_id = registry.registerThread(tid); + ASSERT_GE(slot_id, 0); + ThreadFilter::Slot* slot = registry.slotForId(slot_id); + ASSERT_NE(nullptr, slot); + + EXPECT_TRUE(registry.lookupThreadEntry(entry, registry.recordingEpoch())); + EXPECT_EQ(slot, entry.slot); + EXPECT_EQ(slot->lifecycleGeneration(), entry.lifecycle_generation); + EXPECT_EQ(slot->recordingEpoch(), entry.recording_epoch); +} + TEST_F(ThreadRegistryTest, RegisteringKnownTidReturnsExistingSlotWithoutMutation) { constexpr int tid = 4321; int slot_id = registry.registerThread(tid); @@ -612,14 +812,13 @@ TEST_F(ThreadRegistryTest, RegisteringKnownTidReturnsExistingSlotWithoutMutation u64 token = registry.enterBlockedRun(slot_id, OSThreadState::SLEEPING); ASSERT_NE(0ULL, token); - slot->markSampledThisRun(OSThreadState::SLEEPING); u64 lifecycle_generation = slot->lifecycleGeneration(); EXPECT_EQ(slot_id, registry.registerThread(tid)); EXPECT_EQ(slot, registry.lookupByTid(tid)); EXPECT_EQ(lifecycle_generation, slot->lifecycleGeneration()); EXPECT_EQ(OSThreadState::SLEEPING, slot->activeBlockState()); - EXPECT_TRUE(slot->sampledThisRun()); + EXPECT_EQ(BlockRunOwner::JAVA, slot->activeBlockOwner()); EXPECT_TRUE(registry.exitBlockedRun( slot_id, ThreadFilter::tokenGeneration(token))); } @@ -708,7 +907,6 @@ TEST_F(ThreadRegistryTest, ContextTransitionInvalidatesOwnedRunSuppression) { u64 token = registry.enterBlockedRun(slot_id, OSThreadState::SLEEPING); ASSERT_NE(0u, token); - slot->markSampledThisRun(OSThreadState::SLEEPING); EXPECT_TRUE(slot->activeBlockRemainedOutsideContextWindow()); registry.add(3333, slot_id); @@ -717,7 +915,7 @@ TEST_F(ThreadRegistryTest, ContextTransitionInvalidatesOwnedRunSuppression) { ThreadEntry entry{3333, slot, slot->lifecycleGeneration(), slot->recordingEpoch()}; - EXPECT_FALSE(registry.shouldSuppressOwnedBlock(entry)); + EXPECT_FALSE(registry.isOwnedBlockSuppressionCandidate(entry)); } TEST_F(ThreadRegistryTest, UnfilteredSuppressionValidatesIdentityAndLifecycle) { @@ -728,24 +926,24 @@ TEST_F(ThreadRegistryTest, UnfilteredSuppressionValidatesIdentityAndLifecycle) { u64 token = registry.enterBlockedRun(slot_id, OSThreadState::SLEEPING); ASSERT_NE(0u, token); - slot->markSampledThisRun(OSThreadState::SLEEPING); + slot->markBlockGenerationSampled(ThreadFilter::tokenGeneration(token)); ThreadEntry entry{4444, slot, slot->lifecycleGeneration(), slot->recordingEpoch()}; - EXPECT_TRUE(registry.shouldSuppressOwnedBlock(entry)); + EXPECT_TRUE(registry.isOwnedBlockSuppressionCandidate(entry)); ThreadEntry wrong_tid{4445, slot, entry.lifecycle_generation, entry.recording_epoch}; - EXPECT_FALSE(registry.shouldSuppressOwnedBlock(wrong_tid)); + EXPECT_FALSE(registry.isOwnedBlockSuppressionCandidate(wrong_tid)); ThreadEntry stale_generation{4444, slot, entry.lifecycle_generation + 1, entry.recording_epoch}; - EXPECT_FALSE(registry.shouldSuppressOwnedBlock(stale_generation)); + EXPECT_FALSE(registry.isOwnedBlockSuppressionCandidate(stale_generation)); EXPECT_TRUE(registry.exitBlockedRun( slot_id, ThreadFilter::tokenGeneration(token))); - EXPECT_FALSE(registry.shouldSuppressOwnedBlock(entry)); + EXPECT_FALSE(registry.isOwnedBlockSuppressionCandidate(entry)); } -TEST_F(ThreadRegistryTest, ContextFilteredSuppressionPreservesHistoricalEligibility) { +TEST_F(ThreadRegistryTest, ContextFilteredSuppressionRemainsDisabled) { registry.init("0"); int slot_id = registry.registerThread(5555); ASSERT_GE(slot_id, 0); @@ -755,10 +953,9 @@ TEST_F(ThreadRegistryTest, ContextFilteredSuppressionPreservesHistoricalEligibil u64 token = registry.enterBlockedRun(slot_id, OSThreadState::SLEEPING); ASSERT_NE(0u, token); - slot->markSampledThisRun(OSThreadState::SLEEPING); ThreadEntry entry{5555, slot, slot->lifecycleGeneration(), slot->recordingEpoch()}; - EXPECT_TRUE(registry.shouldSuppressOwnedBlock(entry)); + EXPECT_FALSE(registry.isOwnedBlockSuppressionCandidate(entry)); } TEST_F(ThreadRegistryTest, ConcurrentTidReuseInvalidatesSuppressionSnapshot) { @@ -767,8 +964,9 @@ TEST_F(ThreadRegistryTest, ConcurrentTidReuseInvalidatesSuppressionSnapshot) { ASSERT_GE(slot_id, 0); ThreadFilter::Slot* slot = registry.slotForId(slot_id); ASSERT_NE(nullptr, slot); - ASSERT_NE(0u, registry.enterBlockedRun(slot_id, OSThreadState::SLEEPING)); - slot->markSampledThisRun(OSThreadState::SLEEPING); + u64 token = registry.enterBlockedRun(slot_id, OSThreadState::SLEEPING); + ASSERT_NE(0u, token); + slot->markBlockGenerationSampled(ThreadFilter::tokenGeneration(token)); ThreadEntry stale{tid, slot, slot->lifecycleGeneration(), slot->recordingEpoch()}; @@ -788,7 +986,7 @@ TEST_F(ThreadRegistryTest, ConcurrentTidReuseInvalidatesSuppressionSnapshot) { std::atomic suppressed{true}; std::thread reader([&] { - suppressed.store(registry.shouldSuppressOwnedBlock(stale), + suppressed.store(registry.isOwnedBlockSuppressionCandidate(stale), std::memory_order_release); }); auto deadline = std::chrono::steady_clock::now() + std::chrono::seconds(5); @@ -807,9 +1005,6 @@ TEST_F(ThreadRegistryTest, ConcurrentTidReuseInvalidatesSuppressionSnapshot) { int reused_id = registry.registerThread(tid); ThreadFilter::Slot* reused = registry.slotForId(reused_id); u64 new_token = registry.enterBlockedRun(reused_id, OSThreadState::SLEEPING); - if (reused != nullptr && new_token != 0) { - reused->markSampledThisRun(OSThreadState::SLEEPING); - } pause.resume.store(true, std::memory_order_release); reader.join(); @@ -862,10 +1057,10 @@ TEST_F(ThreadRegistryTest, NewUnfilteredRecordingReclaimsRetainedSlot) { u64 token = registry.enterBlockedRun(slot_id, OSThreadState::SLEEPING); ASSERT_NE(0u, token); - slot->markSampledThisRun(OSThreadState::SLEEPING); + slot->markBlockGenerationSampled(ThreadFilter::tokenGeneration(token)); ThreadEntry stale{tid, slot, slot->lifecycleGeneration(), slot->recordingEpoch()}; - ASSERT_TRUE(registry.shouldSuppressOwnedBlock(stale)); + ASSERT_TRUE(registry.isOwnedBlockSuppressionCandidate(stale)); registry.init("", true); ThreadFilter::RecordingEpoch second_epoch = registry.recordingEpoch(); @@ -875,11 +1070,10 @@ TEST_F(ThreadRegistryTest, NewUnfilteredRecordingReclaimsRetainedSlot) { EXPECT_EQ(nullptr, registry.lookupByTid(tid)); EXPECT_EQ(-1, slot->nativeTid()); EXPECT_GT(slot->lifecycleGeneration(), first_lifecycle_generation); - EXPECT_FALSE(registry.shouldSuppressOwnedBlock(stale)); + EXPECT_FALSE(registry.isOwnedBlockSuppressionCandidate(stale)); EXPECT_EQ(slot_id, registry.registerThread(tid)); EXPECT_EQ(slot, registry.lookupByTid(tid, second_epoch)); - EXPECT_FALSE(slot->sampledThisRun()); EXPECT_EQ(OSThreadState::UNKNOWN, slot->activeBlockState()); EXPECT_EQ(BlockRunOwner::NONE, slot->activeBlockOwner()); } diff --git a/ddprof-lib/src/test/cpp/vmEntry_ut.cpp b/ddprof-lib/src/test/cpp/vmEntry_ut.cpp new file mode 100644 index 000000000..fa740cd17 --- /dev/null +++ b/ddprof-lib/src/test/cpp/vmEntry_ut.cpp @@ -0,0 +1,500 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +#include +#include +#include + +#include + +#include "profiler.h" +#include "vmEntry.h" + +class VMTestAccessor { + public: + static jvmtiEnv* jvmti() { return VM::_jvmti; } + static void setJvmti(jvmtiEnv* jvmti) { VM::_jvmti = jvmti; } + + static bool nativeMonitorEventsAvailable() { + return VM::_native_monitor_events_available; + } + static void setNativeMonitorEventsAvailable(bool available) { + VM::_native_monitor_events_available = available; + } + + static bool monitorWaitEventsDelegated() { + return VM::_monitor_wait_events_delegated; + } + static void setMonitorWaitEventsDelegated(bool delegated) { + VM::_monitor_wait_events_delegated = delegated; + } + + static bool profilerBridgeInitialized() { + return VM::_profiler_bridge_initialized; + } + static void setProfilerBridgeInitialized(bool initialized) { + VM::_profiler_bridge_initialized = initialized; + } + + static void configureMonitorEvents(bool delegate_monitor_wait_events) { + VM::configureMonitorEvents(delegate_monitor_wait_events); + } +}; + +class ProfilerTestAccessor { + public: + static void setTaskBlockEnabled(Profiler* profiler, bool enabled) { + profiler->setTaskBlockEnabled(enabled); + } + + static void setTaskBlockState(Profiler* profiler, bool enabled, + bool monitor_events_enabled) { + profiler->_task_block_enabled.store(enabled, std::memory_order_release); + profiler->_task_block_monitor_events_enabled.store( + monitor_events_enabled, std::memory_order_release); + } + + static bool monitorEventsEnabled(Profiler* profiler) { + return profiler->_task_block_monitor_events_enabled.load( + std::memory_order_acquire); + } +}; + +class MonitorEventConfigurationTest : public ::testing::Test { + protected: + inline static MonitorEventConfigurationTest* active_test = nullptr; + + jvmtiInterface_1_ functions{}; + _jvmtiEnv mock_env{}; + jvmtiEnv* original_jvmti = nullptr; + bool original_initialized = false; + bool original_available = false; + bool original_delegated = false; + bool capability_available = false; + int get_capabilities_calls = 0; + + static jvmtiError JNICALL getCapabilities( + jvmtiEnv*, jvmtiCapabilities* capabilities) { + MonitorEventConfigurationTest* test = active_test; + *capabilities = jvmtiCapabilities{}; + capabilities->can_generate_monitor_events = test->capability_available; + test->get_capabilities_calls++; + return JVMTI_ERROR_NONE; + } + + void SetUp() override { + original_jvmti = VMTestAccessor::jvmti(); + original_initialized = VMTestAccessor::profilerBridgeInitialized(); + original_available = VMTestAccessor::nativeMonitorEventsAvailable(); + original_delegated = VMTestAccessor::monitorWaitEventsDelegated(); + + functions.GetCapabilities = &getCapabilities; + mock_env.functions = &functions; + VMTestAccessor::setJvmti(&mock_env); + VMTestAccessor::setProfilerBridgeInitialized(false); + active_test = this; + } + + void TearDown() override { + active_test = nullptr; + VMTestAccessor::setMonitorWaitEventsDelegated(original_delegated); + VMTestAccessor::setNativeMonitorEventsAvailable(original_available); + VMTestAccessor::setProfilerBridgeInitialized(original_initialized); + VMTestAccessor::setJvmti(original_jvmti); + } +}; + +TEST_F(MonitorEventConfigurationTest, + StoresRequestedOwnershipIndependentlyOfCapability) { + for (bool available : {false, true}) { + for (bool delegated : {false, true}) { + SCOPED_TRACE(::testing::Message() + << "available=" << available + << ", delegated=" << delegated); + capability_available = available; + get_capabilities_calls = 0; + + VMTestAccessor::configureMonitorEvents(delegated); + + EXPECT_EQ(1, get_capabilities_calls); + EXPECT_EQ(available, VMTestAccessor::nativeMonitorEventsAvailable()); + EXPECT_EQ(delegated, VMTestAccessor::monitorWaitEventsDelegated()); + EXPECT_FALSE(VMTestAccessor::profilerBridgeInitialized()); + } + } +} + +class ProfilerBridgeDelegationTest : public ::testing::Test { + protected: + bool original_initialized = false; + bool original_available = false; + bool original_delegated = false; + + void SetUp() override { + original_initialized = VMTestAccessor::profilerBridgeInitialized(); + original_available = VMTestAccessor::nativeMonitorEventsAvailable(); + original_delegated = VMTestAccessor::monitorWaitEventsDelegated(); + VMTestAccessor::setProfilerBridgeInitialized(true); + } + + void TearDown() override { + VMTestAccessor::setMonitorWaitEventsDelegated(original_delegated); + VMTestAccessor::setNativeMonitorEventsAvailable(original_available); + VMTestAccessor::setProfilerBridgeInitialized(original_initialized); + } + + static void expectNegotiation(bool available, bool delegated, + bool requested, + ProfilerBridgeInitResult expected) { + VMTestAccessor::setNativeMonitorEventsAvailable(available); + VMTestAccessor::setMonitorWaitEventsDelegated(delegated); + + EXPECT_EQ(expected, VM::initProfilerBridge(nullptr, true, requested)); + EXPECT_TRUE(VMTestAccessor::profilerBridgeInitialized()); + EXPECT_EQ(available, VMTestAccessor::nativeMonitorEventsAvailable()); + EXPECT_EQ(delegated, VMTestAccessor::monitorWaitEventsDelegated()); + } +}; + +TEST_F(ProfilerBridgeDelegationTest, + ReusesMatchingOwnershipWhenCapabilityIsUnavailable) { + expectNegotiation(false, false, false, ProfilerBridgeInitResult::SUCCESS); + expectNegotiation(false, true, true, ProfilerBridgeInitResult::SUCCESS); +} + +TEST_F(ProfilerBridgeDelegationTest, + RejectsConflictingOwnershipWhenCapabilityIsUnavailable) { + expectNegotiation( + false, false, true, + ProfilerBridgeInitResult::MONITOR_EVENTS_DELEGATION_CONFLICT); + expectNegotiation( + false, true, false, + ProfilerBridgeInitResult::MONITOR_EVENTS_DELEGATION_CONFLICT); +} + +TEST_F(ProfilerBridgeDelegationTest, + ReusesMatchingOwnershipWhenCapabilityIsAvailable) { + expectNegotiation(true, false, false, ProfilerBridgeInitResult::SUCCESS); + expectNegotiation(true, true, true, ProfilerBridgeInitResult::SUCCESS); +} + +TEST_F(ProfilerBridgeDelegationTest, + RejectsConflictingOwnershipWhenCapabilityIsAvailable) { + expectNegotiation( + true, false, true, + ProfilerBridgeInitResult::MONITOR_EVENTS_DELEGATION_CONFLICT); + expectNegotiation( + true, true, false, + ProfilerBridgeInitResult::MONITOR_EVENTS_DELEGATION_CONFLICT); +} + +class NativeMonitorEventsTest : public ::testing::Test { + protected: + struct EventCall { + jvmtiEventMode mode; + jvmtiEvent event; + bool task_block_enabled; + }; + + static constexpr std::array MONITOR_EVENTS = { + JVMTI_EVENT_MONITOR_CONTENDED_ENTER, + JVMTI_EVENT_MONITOR_CONTENDED_ENTERED, + JVMTI_EVENT_MONITOR_WAIT, + JVMTI_EVENT_MONITOR_WAITED, + }; + + inline static NativeMonitorEventsTest* active_test = nullptr; + + jvmtiInterface_1_ functions{}; + _jvmtiEnv mock_env{}; + std::vector calls; + std::array event_enabled{}; + bool inject_failure = false; + bool fail_all_disables = false; + jvmtiEventMode failure_mode = JVMTI_ENABLE; + jvmtiEvent failure_event = JVMTI_EVENT_MONITOR_CONTENDED_ENTER; + + Profiler* profiler = Profiler::instance(); + jvmtiEnv* original_jvmti = nullptr; + bool original_available = false; + bool original_delegated = false; + bool original_task_block_enabled = false; + bool original_monitor_events_enabled = false; + + static jvmtiError JNICALL setEventNotificationMode( + jvmtiEnv*, jvmtiEventMode mode, jvmtiEvent event, jthread, ...) { + NativeMonitorEventsTest* test = active_test; + test->calls.push_back( + {mode, event, test->profiler->taskBlockEnabled()}); + if (test->inject_failure && mode == test->failure_mode && + event == test->failure_event) { + return JVMTI_ERROR_INTERNAL; + } + if (test->fail_all_disables && mode == JVMTI_DISABLE) { + return JVMTI_ERROR_INTERNAL; + } + + test->event_enabled[test->eventIndex(event)] = mode == JVMTI_ENABLE; + return JVMTI_ERROR_NONE; + } + + void SetUp() override { + original_jvmti = VMTestAccessor::jvmti(); + original_available = VMTestAccessor::nativeMonitorEventsAvailable(); + original_delegated = VMTestAccessor::monitorWaitEventsDelegated(); + original_task_block_enabled = profiler->taskBlockEnabled(); + original_monitor_events_enabled = + ProfilerTestAccessor::monitorEventsEnabled(profiler); + + functions.SetEventNotificationMode = &setEventNotificationMode; + mock_env.functions = &functions; + VMTestAccessor::setJvmti(&mock_env); + VMTestAccessor::setNativeMonitorEventsAvailable(true); + VMTestAccessor::setMonitorWaitEventsDelegated(false); + ProfilerTestAccessor::setTaskBlockState(profiler, false, false); + active_test = this; + } + + void TearDown() override { + active_test = nullptr; + ProfilerTestAccessor::setTaskBlockState( + profiler, original_task_block_enabled, original_monitor_events_enabled); + VMTestAccessor::setMonitorWaitEventsDelegated(original_delegated); + VMTestAccessor::setNativeMonitorEventsAvailable(original_available); + VMTestAccessor::setJvmti(original_jvmti); + } + + static size_t eventIndex(jvmtiEvent event) { + for (size_t i = 0; i < MONITOR_EVENTS.size(); i++) { + if (MONITOR_EVENTS[i] == event) return i; + } + ADD_FAILURE() << "Unexpected JVMTI event " << event; + return 0; + } + + bool eventIsEnabled(jvmtiEvent event) const { + return event_enabled[eventIndex(event)]; + } + + void setAllEventsEnabled(bool enabled) { + event_enabled.fill(enabled); + } + + void resetObservations() { + calls.clear(); + event_enabled.fill(false); + inject_failure = false; + fail_all_disables = false; + } + + void fail(jvmtiEventMode mode, jvmtiEvent event) { + inject_failure = true; + failure_mode = mode; + failure_event = event; + } + + void expectCalls( + const std::vector>& expected) { + ASSERT_EQ(expected.size(), calls.size()); + for (size_t i = 0; i < expected.size(); i++) { + EXPECT_EQ(expected[i].first, calls[i].mode) << "call " << i; + EXPECT_EQ(expected[i].second, calls[i].event) << "call " << i; + } + } + + static std::vector> disableCalls() { + return { + {JVMTI_DISABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTER}, + {JVMTI_DISABLE, JVMTI_EVENT_MONITOR_WAIT}, + {JVMTI_DISABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTERED}, + {JVMTI_DISABLE, JVMTI_EVENT_MONITOR_WAITED}, + }; + } +}; + +TEST_F(NativeMonitorEventsTest, EnablesTerminalEventsBeforeEntryEvents) { + EXPECT_TRUE(VM::setNativeMonitorEventsEnabled(true)); + + expectCalls({ + {JVMTI_ENABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTERED}, + {JVMTI_ENABLE, JVMTI_EVENT_MONITOR_WAITED}, + {JVMTI_ENABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTER}, + {JVMTI_ENABLE, JVMTI_EVENT_MONITOR_WAIT}, + }); + for (jvmtiEvent event : MONITOR_EVENTS) { + EXPECT_TRUE(eventIsEnabled(event)); + } +} + +TEST_F(NativeMonitorEventsTest, DelegatedEnableOnlyInstallsContendedPair) { + VMTestAccessor::setMonitorWaitEventsDelegated(true); + + EXPECT_TRUE(VM::setNativeMonitorEventsEnabled(true)); + + expectCalls({ + {JVMTI_ENABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTERED}, + {JVMTI_ENABLE, JVMTI_EVENT_MONITOR_CONTENDED_ENTER}, + }); + EXPECT_TRUE(eventIsEnabled(JVMTI_EVENT_MONITOR_CONTENDED_ENTER)); + EXPECT_TRUE(eventIsEnabled(JVMTI_EVENT_MONITOR_CONTENDED_ENTERED)); + EXPECT_FALSE(eventIsEnabled(JVMTI_EVENT_MONITOR_WAIT)); + EXPECT_FALSE(eventIsEnabled(JVMTI_EVENT_MONITOR_WAITED)); +} + +TEST_F(NativeMonitorEventsTest, DisableRemovesEntriesBeforeTerminalEvents) { + for (bool delegated : {false, true}) { + SCOPED_TRACE(delegated); + resetObservations(); + setAllEventsEnabled(true); + VMTestAccessor::setMonitorWaitEventsDelegated(delegated); + + EXPECT_TRUE(VM::setNativeMonitorEventsEnabled(false)); + + expectCalls(disableCalls()); + for (jvmtiEvent event : MONITOR_EVENTS) { + EXPECT_FALSE(eventIsEnabled(event)); + } + } +} + +TEST_F(NativeMonitorEventsTest, EnableFailureStopsAndRollsBackAllEvents) { + const std::array enable_order = { + JVMTI_EVENT_MONITOR_CONTENDED_ENTERED, + JVMTI_EVENT_MONITOR_WAITED, + JVMTI_EVENT_MONITOR_CONTENDED_ENTER, + JVMTI_EVENT_MONITOR_WAIT, + }; + + for (size_t failure_index = 0; failure_index < enable_order.size(); + failure_index++) { + SCOPED_TRACE(failure_index); + resetObservations(); + fail(JVMTI_ENABLE, enable_order[failure_index]); + + EXPECT_FALSE(VM::setNativeMonitorEventsEnabled(true)); + + std::vector> expected; + for (size_t i = 0; i <= failure_index; i++) { + expected.push_back({JVMTI_ENABLE, enable_order[i]}); + } + std::vector> rollback = + disableCalls(); + expected.insert(expected.end(), rollback.begin(), rollback.end()); + expectCalls(expected); + for (jvmtiEvent event : MONITOR_EVENTS) { + EXPECT_FALSE(eventIsEnabled(event)); + } + } +} + +TEST_F(NativeMonitorEventsTest, DelegatedEnableFailureRollsBackAllEvents) { + VMTestAccessor::setMonitorWaitEventsDelegated(true); + const std::array enable_order = { + JVMTI_EVENT_MONITOR_CONTENDED_ENTERED, + JVMTI_EVENT_MONITOR_CONTENDED_ENTER, + }; + + for (size_t failure_index = 0; failure_index < enable_order.size(); + failure_index++) { + SCOPED_TRACE(failure_index); + resetObservations(); + fail(JVMTI_ENABLE, enable_order[failure_index]); + + EXPECT_FALSE(VM::setNativeMonitorEventsEnabled(true)); + + std::vector> expected; + for (size_t i = 0; i <= failure_index; i++) { + expected.push_back({JVMTI_ENABLE, enable_order[i]}); + } + std::vector> rollback = + disableCalls(); + expected.insert(expected.end(), rollback.begin(), rollback.end()); + expectCalls(expected); + for (jvmtiEvent event : MONITOR_EVENTS) { + EXPECT_FALSE(eventIsEnabled(event)); + } + } +} + +TEST_F(NativeMonitorEventsTest, DisableFailureStillAttemptsEveryEvent) { + for (jvmtiEvent failed_event : MONITOR_EVENTS) { + SCOPED_TRACE(failed_event); + resetObservations(); + setAllEventsEnabled(true); + fail(JVMTI_DISABLE, failed_event); + + EXPECT_FALSE(VM::setNativeMonitorEventsEnabled(false)); + + expectCalls(disableCalls()); + for (jvmtiEvent event : MONITOR_EVENTS) { + EXPECT_EQ(event == failed_event, eventIsEnabled(event)); + } + } +} + +TEST_F(NativeMonitorEventsTest, UnavailableCapabilityDoesNotCallJvmti) { + VMTestAccessor::setNativeMonitorEventsAvailable(false); + + EXPECT_FALSE(VM::setNativeMonitorEventsEnabled(true)); + EXPECT_TRUE(calls.empty()); +} + +TEST_F(NativeMonitorEventsTest, AdmissionRemainsClosedDuringSuccessfulSetup) { + ProfilerTestAccessor::setTaskBlockEnabled(profiler, true); + + ASSERT_FALSE(calls.empty()); + for (const EventCall& call : calls) { + EXPECT_FALSE(call.task_block_enabled); + } + EXPECT_TRUE(profiler->taskBlockEnabled()); + EXPECT_TRUE(ProfilerTestAccessor::monitorEventsEnabled(profiler)); +} + +TEST_F(NativeMonitorEventsTest, + AdmissionRemainsClosedDuringFailedSetupAndRollback) { + fail(JVMTI_ENABLE, JVMTI_EVENT_MONITOR_WAIT); + + ProfilerTestAccessor::setTaskBlockEnabled(profiler, true); + + ASSERT_FALSE(calls.empty()); + for (const EventCall& call : calls) { + EXPECT_FALSE(call.task_block_enabled); + } + EXPECT_TRUE(profiler->taskBlockEnabled()); + EXPECT_FALSE(ProfilerTestAccessor::monitorEventsEnabled(profiler)); + for (jvmtiEvent event : MONITOR_EVENTS) { + EXPECT_FALSE(eventIsEnabled(event)); + } +} + +TEST_F(NativeMonitorEventsTest, + NativeAdmissionRemainsClosedWhenSetupAndRollbackFail) { + fail(JVMTI_ENABLE, JVMTI_EVENT_MONITOR_WAIT); + fail_all_disables = true; + + ProfilerTestAccessor::setTaskBlockEnabled(profiler, true); + + EXPECT_TRUE(profiler->taskBlockEnabled()); + EXPECT_FALSE(profiler->nativeMonitorTaskBlockEnabled()); + EXPECT_FALSE(ProfilerTestAccessor::monitorEventsEnabled(profiler)); + EXPECT_TRUE(eventIsEnabled(JVMTI_EVENT_MONITOR_CONTENDED_ENTER)); + EXPECT_TRUE(eventIsEnabled(JVMTI_EVENT_MONITOR_CONTENDED_ENTERED)); + EXPECT_FALSE(eventIsEnabled(JVMTI_EVENT_MONITOR_WAIT)); + EXPECT_TRUE(eventIsEnabled(JVMTI_EVENT_MONITOR_WAITED)); +} + +TEST_F(NativeMonitorEventsTest, AdmissionClosesBeforeNativeTeardown) { + setAllEventsEnabled(true); + ProfilerTestAccessor::setTaskBlockState(profiler, true, true); + + ProfilerTestAccessor::setTaskBlockEnabled(profiler, false); + + expectCalls(disableCalls()); + for (const EventCall& call : calls) { + EXPECT_FALSE(call.task_block_enabled); + } + EXPECT_FALSE(profiler->taskBlockEnabled()); + EXPECT_FALSE(ProfilerTestAccessor::monitorEventsEnabled(profiler)); +} diff --git a/ddprof-lib/src/test/cpp/wallClockCounters_ut.cpp b/ddprof-lib/src/test/cpp/wallClockCounters_ut.cpp index c908b84fc..7a6482d45 100644 --- a/ddprof-lib/src/test/cpp/wallClockCounters_ut.cpp +++ b/ddprof-lib/src/test/cpp/wallClockCounters_ut.cpp @@ -18,25 +18,25 @@ class WallClockCountersTest : public ::testing::Test { } }; -TEST_F(WallClockCountersTest, DrainReturnsAndClearsSuppressedSampledRun) { - WallClockCounters::incrementSuppressedSampledRun(); - WallClockCounters::incrementSuppressedSampledRun(); +TEST_F(WallClockCountersTest, DrainReturnsAndClearsSuppressedOwnedBlock) { + WallClockCounters::incrementSuppressedOwnedBlock(); + WallClockCounters::incrementSuppressedOwnedBlock(); - EXPECT_EQ(2ULL, WallClockCounters::drainSuppressedSampledRun()); - EXPECT_EQ(0ULL, WallClockCounters::drainSuppressedSampledRun()); + EXPECT_EQ(2ULL, WallClockCounters::drainSuppressedOwnedBlock()); + EXPECT_EQ(0ULL, WallClockCounters::drainSuppressedOwnedBlock()); } -TEST_F(WallClockCountersTest, ResetClearsPendingSuppressedSampledRun) { - WallClockCounters::incrementSuppressedSampledRun(); +TEST_F(WallClockCountersTest, ResetClearsPendingSuppressedOwnedBlock) { + WallClockCounters::incrementSuppressedOwnedBlock(); WallClockCounters::reset(); - EXPECT_EQ(0ULL, WallClockCounters::drainSuppressedSampledRun()); + EXPECT_EQ(0ULL, WallClockCounters::drainSuppressedOwnedBlock()); } TEST_F(WallClockCountersTest, ResetIsIdempotent) { WallClockCounters::reset(); WallClockCounters::reset(); - EXPECT_EQ(0ULL, WallClockCounters::drainSuppressedSampledRun()); + EXPECT_EQ(0ULL, WallClockCounters::drainSuppressedOwnedBlock()); } diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/ExternalLauncher.java b/ddprof-test/src/test/java/com/datadoghq/profiler/ExternalLauncher.java index cb83816df..995d17fce 100644 --- a/ddprof-test/src/test/java/com/datadoghq/profiler/ExternalLauncher.java +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/ExternalLauncher.java @@ -9,7 +9,14 @@ import java.lang.management.ManagementFactory; import java.lang.management.ThreadMXBean; import java.lang.reflect.Method; +import java.nio.file.Files; +import java.nio.file.Path; import java.util.Random; +import java.util.concurrent.CountDownLatch; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.Future; +import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.LongAdder; /** @@ -26,6 +33,14 @@ *

  • profiler-sequence [';'-delimited steps] - runs a sequence of start/stop calls in this * process; each step is either the literal {@code STOP} (calls {@link JavaProfiler#stop()}) * or a comma delimited profiler command list (calls {@link JavaProfiler#execute(String)})
    • + *
  • profiler-agent-compatible - reuses native monitor ownership after agent initialization
    • + *
  • profiler-delegation-conflict - requests delegated monitor ownership after agent initialization
    • + *
  • profiler-java-default-delegation-reuse - verifies explicit native ownership after default initialization
    • + *
  • profiler-java-default-delegation-conflict - verifies delegated ownership conflicts after default initialization
    • + *
  • profiler-java-delegation-reuse:<delegated> - verifies compatible Java singleton ownership reuse
    • + *
  • profiler-java-delegation-conflict:<initial>:<requested> - verifies conflicting Java singleton ownership requests
    • + *
  • profiler-preexisting-monitor-wait - exercises Object.wait on a thread created before profiler initialization
    • + *
  • profiler-preexisting-monitor-contention - exercises monitor contention on a thread created before profiler initialization
    • * */ public class ExternalLauncher { @@ -41,6 +56,63 @@ private static Thread startVirtualThread(Runnable task) throws Exception { return (Thread) start.invoke(builder, task); } + /** Runs one native monitor callback lifecycle on a platform thread created before JNI load. */ + private static void runPreExistingMonitorCallback(boolean contention) throws Exception { + ExecutorService executor = Executors.newSingleThreadExecutor(task -> { + Thread thread = new Thread(task, "preexisting-monitor-callback"); + thread.setDaemon(true); + return thread; + }); + executor.submit(Thread::currentThread).get(5, TimeUnit.SECONDS); + + Path recording = Files.createTempFile("preexisting-monitor-callback", ".jfr"); + JavaProfiler profiler = null; + boolean started = false; + try { + profiler = JavaProfiler.getInstance(); + profiler.execute("start,wall=1ms,filter=,wallprecheck=true,jfr,file=" + + recording.toAbsolutePath()); + started = true; + long before = profiler.getDebugCounters().getOrDefault("task_block_emitted", 0L); + Object monitor = new Object(); + + if (contention) { + CountDownLatch attempting = new CountDownLatch(1); + Future blocked; + synchronized (monitor) { + blocked = executor.submit(() -> { + attempting.countDown(); + synchronized (monitor) { + // Acquiring the monitor completes the contended interval. + } + }); + if (!attempting.await(5, TimeUnit.SECONDS)) { + throw new IllegalStateException("Worker did not attempt monitor entry"); + } + Thread.sleep(100L); + } + blocked.get(5, TimeUnit.SECONDS); + } else { + executor.submit(() -> { + synchronized (monitor) { + monitor.wait(100L); + } + return null; + }).get(5, TimeUnit.SECONDS); + } + + long emitted = profiler.getDebugCounters().getOrDefault("task_block_emitted", 0L) - before; + System.out.println("[preexisting-monitor-events] " + emitted); + } finally { + if (started) { + profiler.stop(); + } + executor.shutdownNow(); + executor.awaitTermination(5, TimeUnit.SECONDS); + Files.deleteIfExists(recording); + } + } + public static void main(String[] args) throws Exception { Thread worker = null; try { @@ -61,6 +133,70 @@ public static void main(String[] args) throws Exception { } }); vt.join(); + JavaProfiler initial = JavaProfiler.getInstance(); + JavaProfiler reused = JavaProfiler.getInstance(); + System.out.println("[virtual-thread-recovery] " + + (initial == reused) + " " + reused.isMonitorWaitEventsDelegated()); + } else if (args[0].equals("profiler-delegation-conflict")) { + String libraryPath = System.getProperty("ddprof.test.agent.path"); + try { + JavaProfiler.getInstance(libraryPath, null, true); + System.out.println("[delegation-conflict-missed]"); + } catch (IllegalStateException expected) { + JavaProfiler recovered = + JavaProfiler.getInstance(libraryPath, null, false); + System.out.println("[delegation-conflict] " + + recovered.isMonitorWaitEventsDelegated()); + } + } else if (args[0].equals("profiler-java-default-delegation-reuse")) { + JavaProfiler initial = JavaProfiler.getInstance(); + JavaProfiler reused = JavaProfiler.getInstance(null, null, false); + System.out.println("[java-default-delegation-reuse] " + + (initial == reused) + " " + reused.isMonitorWaitEventsDelegated()); + } else if (args[0].equals("profiler-java-default-delegation-conflict")) { + JavaProfiler initial = JavaProfiler.getInstance(); + try { + JavaProfiler.getInstance(null, null, true); + System.out.println("[java-default-delegation-conflict-missed]"); + } catch (IllegalStateException expected) { + JavaProfiler recovered = + JavaProfiler.getInstance(null, null, false); + System.out.println("[java-default-delegation-conflict] " + + (initial == recovered) + " " + + recovered.isMonitorWaitEventsDelegated()); + } + } else if (args[0].startsWith("profiler-java-delegation-reuse:")) { + boolean delegated = Boolean.parseBoolean( + args[0].substring("profiler-java-delegation-reuse:".length())); + JavaProfiler initial = JavaProfiler.getInstance(null, null, delegated); + JavaProfiler reused = JavaProfiler.getInstance(null, null, delegated); + System.out.println("[java-delegation-reuse] " + + (initial == reused) + " " + reused.isMonitorWaitEventsDelegated()); + } else if (args[0].startsWith("profiler-java-delegation-conflict:")) { + String[] delegationModes = args[0].split(":"); + boolean initialDelegation = Boolean.parseBoolean(delegationModes[1]); + boolean requestedDelegation = Boolean.parseBoolean(delegationModes[2]); + JavaProfiler initial = + JavaProfiler.getInstance(null, null, initialDelegation); + try { + JavaProfiler.getInstance(null, null, requestedDelegation); + System.out.println("[java-delegation-conflict-missed]"); + } catch (IllegalStateException expected) { + JavaProfiler recovered = + JavaProfiler.getInstance(null, null, initialDelegation); + System.out.println("[java-delegation-conflict] " + + (initial == recovered) + " " + + recovered.isMonitorWaitEventsDelegated()); + } + } else if (args[0].equals("profiler-agent-compatible")) { + String libraryPath = System.getProperty("ddprof.test.agent.path"); + JavaProfiler profiler = JavaProfiler.getInstance(libraryPath, null, false); + System.out.println("[agent-compatible] " + + profiler.isMonitorWaitEventsDelegated()); + } else if (args[0].equals("profiler-preexisting-monitor-wait")) { + runPreExistingMonitorCallback(false); + } else if (args[0].equals("profiler-preexisting-monitor-contention")) { + runPreExistingMonitorCallback(true); } else if (args[0].equals("profiler")) { JavaProfiler instance = JavaProfiler.getInstance(); if (args.length == 2) { diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerApiSurfaceTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerApiSurfaceTest.java index b3052f3a2..c74e26fa2 100644 --- a/ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerApiSurfaceTest.java +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerApiSurfaceTest.java @@ -10,20 +10,39 @@ import java.lang.reflect.Method; import java.lang.reflect.Modifier; +import static org.junit.jupiter.api.Assertions.assertEquals; import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertTrue; +/** Locks the supported public boundary and package-scoped producer hooks. */ public class JavaProfilerApiSurfaceTest { @Test - public void ownedBlockHooksAreNotPublicApiBeforeTaskBlockInstrumentation() throws Exception { - assertNotPublic(JavaProfiler.class.getDeclaredMethod("parkEnter")); + public void taskBlockApiIsPublicButInternalHooksRemainPackageScoped() throws Exception { + Method parkEnter = JavaProfiler.class.getDeclaredMethod("parkEnter"); + assertNotPublic(parkEnter); + assertEquals(boolean.class, parkEnter.getReturnType()); assertNotPublic(JavaProfiler.class.getDeclaredMethod( "parkExit", long.class, long.class)); assertNotPublic(JavaProfiler.class.getDeclaredMethod("blockEnter", int.class)); assertNotPublic(JavaProfiler.class.getDeclaredMethod("blockExit", long.class)); + assertTrue(Modifier.isPublic(JavaProfiler.class + .getDeclaredMethod("beginTaskBlock").getModifiers())); + assertTrue(Modifier.isPublic(JavaProfiler.class + .getDeclaredMethod("endTaskBlock", long.class, long.class, long.class) + .getModifiers())); + } + + @Test + public void monitorWaitOwnershipIsExplicitPublicApi() throws Exception { + assertTrue(Modifier.isPublic(JavaProfiler.class + .getDeclaredMethod("getInstance", String.class, String.class, boolean.class) + .getModifiers())); + assertTrue(Modifier.isPublic(JavaProfiler.class + .getDeclaredMethod("isMonitorWaitEventsDelegated").getModifiers())); } private static void assertNotPublic(Method method) { assertFalse(Modifier.isPublic(method.getModifiers()), - method.getName() + " must remain non-public until PR2 wires TaskBlock instrumentation"); + method.getName() + " is an internal instrumentation hook"); } } diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerTest.java index 2023c4757..02a378d3e 100644 --- a/ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerTest.java +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerTest.java @@ -7,8 +7,10 @@ import org.junit.jupiter.api.Test; +import java.io.InputStream; import java.nio.file.Files; import java.nio.file.Path; +import java.nio.file.StandardCopyOption; import java.util.ArrayList; import java.util.Collections; import java.util.List; @@ -18,12 +20,46 @@ import java.util.concurrent.atomic.AtomicReference; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.LockSupport; +import java.util.function.Function; import static org.junit.jupiter.api.Assertions.*; import static org.junit.jupiter.api.Assumptions.assumeFalse; import static org.junit.jupiter.api.Assumptions.assumeTrue; public class JavaProfilerTest extends AbstractProcessProfilerTest { + /** Extracts the packaged native library so a child JVM can load it through {@code -agentpath}. */ + private static Path extractProfilerLibrary() throws Exception { + OperatingSystem os = OperatingSystem.current(); + String extension = os == OperatingSystem.macos ? "dylib" : "so"; + String qualifier = os == OperatingSystem.linux && os.isMusl() ? "-musl" : ""; + String resource = "/META-INF/native-libs/" + os.name().toLowerCase() + "-" + + Arch.current().name().toLowerCase() + qualifier + "/libjavaProfiler." + extension; + Path library = Files.createTempFile("libjavaProfiler-agent-", "." + extension); + try (InputStream input = JavaProfiler.class.getResourceAsStream(resource)) { + assertNotNull(input, "Profiler library resource not found: " + resource); + Files.copy(input, library, StandardCopyOption.REPLACE_EXISTING); + } + return library; + } + + /** Launches a child JVM whose profiler bridge is initialized before Java application startup. */ + private LaunchResult launchWithProfilerAgent( + String target, Function onStdoutLine) throws Exception { + Path library = extractProfilerLibrary(); + Path recording = Files.createTempFile("agent-initialization-", ".jfr"); + try { + List jvmArgs = new ArrayList<>(); + jvmArgs.add("-agentpath:" + library.toAbsolutePath() + + "=start,wall=10ms,filter=,wallprecheck=true,jfr,file=" + + recording.toAbsolutePath()); + jvmArgs.add("-Dddprof.test.agent.path=" + library.toAbsolutePath()); + return launch(target, jvmArgs, "", onStdoutLine, null); + } finally { + Files.deleteIfExists(recording); + Files.deleteIfExists(library); + } + } + @Test void sanityInitailizationTest() throws Exception { String config = System.getProperty("ddprof_test.config"); @@ -118,20 +154,173 @@ void testJ9ForceJvmtiSanity() throws Exception { void getInstanceFromVirtualThreadThrowsIOException() throws Exception { assumeTrue(Platform.isJavaVersionAtLeast(21)); - AtomicReference resultLine = new AtomicReference<>(); + AtomicReference attemptLine = new AtomicReference<>(); + AtomicReference recoveryLine = new AtomicReference<>(); boolean val = launch("profiler-virtual-thread", Collections.emptyList(), "", l -> { if (l.startsWith("[virtual-thread-")) { - resultLine.set(l); - return LineConsumerResult.STOP; + if (l.startsWith("[virtual-thread-recovery]")) { + recoveryLine.set(l); + return LineConsumerResult.STOP; + } + attemptLine.set(l); + return LineConsumerResult.CONTINUE; } return LineConsumerResult.CONTINUE; }, null).inTime; assertTrue(val); - String result = resultLine.get(); + String result = attemptLine.get(); assertNotNull(result, "getInstance() did not report a result from the virtual thread"); assertTrue(result.startsWith("[virtual-thread-ioexception]"), "Expected IOException from getInstance() on a virtual thread, got: " + result); + assertEquals("[virtual-thread-recovery] true false", recoveryLine.get()); + } + + @Test + void compatibleLateJavaInitializationReusesAgentBridge() throws Exception { + AtomicReference resultLine = new AtomicReference<>(); + LaunchResult result = launchWithProfilerAgent("profiler-agent-compatible", line -> { + if (line.startsWith("[agent-compatible]")) { + resultLine.set(line); + return LineConsumerResult.STOP; + } + return LineConsumerResult.CONTINUE; + }); + + assertTrue(result.inTime); + assertEquals(0, result.exitCode); + assertEquals("[agent-compatible] false", resultLine.get()); + } + + @Test + void conflictingLateMonitorDelegationIsRejected() throws Exception { + AtomicReference resultLine = new AtomicReference<>(); + LaunchResult result = launchWithProfilerAgent("profiler-delegation-conflict", line -> { + if (line.startsWith("[delegation-conflict")) { + resultLine.set(line); + return LineConsumerResult.STOP; + } + return LineConsumerResult.CONTINUE; + }); + + assertTrue(result.inTime); + assertEquals(0, result.exitCode); + assertEquals("[delegation-conflict] false", resultLine.get()); + } + + @Test + void defaultJavaSingletonMonitorDelegationIsReused() throws Exception { + assertJavaDelegationScenario( + "profiler-java-default-delegation-reuse", + "[java-default-delegation-reuse]", + "[java-default-delegation-reuse] true false"); + } + + @Test + void conflictingDefaultJavaSingletonMonitorDelegationDoesNotPoisonInstance() + throws Exception { + assertJavaDelegationScenario( + "profiler-java-default-delegation-conflict", + "[java-default-delegation-conflict", + "[java-default-delegation-conflict] true false"); + } + + @Test + void conflictingJavaSingletonMonitorDelegationIsRejected() throws Exception { + assertJavaSingletonDelegationConflict(false, true); + assertJavaSingletonDelegationConflict(true, false); + } + + @Test + void compatibleJavaSingletonMonitorDelegationIsReused() throws Exception { + assertJavaSingletonDelegationReuse(false); + assertJavaSingletonDelegationReuse(true); + } + + /** Launches a fresh JVM and verifies that repeated ownership returns the same singleton. */ + private void assertJavaSingletonDelegationReuse(boolean delegated) throws Exception { + AtomicReference resultLine = new AtomicReference<>(); + LaunchResult result = launch( + "profiler-java-delegation-reuse:" + delegated, + Collections.emptyList(), "", line -> { + if (line.startsWith("[java-delegation-reuse]")) { + resultLine.set(line); + return LineConsumerResult.STOP; + } + return LineConsumerResult.CONTINUE; + }, null); + + assertTrue(result.inTime); + assertEquals(0, result.exitCode); + assertEquals("[java-delegation-reuse] true " + delegated, resultLine.get()); + } + + /** Launches a fresh JVM and verifies that a second ownership mode is rejected. */ + private void assertJavaSingletonDelegationConflict(boolean initialDelegation, + boolean requestedDelegation) throws Exception { + AtomicReference resultLine = new AtomicReference<>(); + LaunchResult result = launch( + "profiler-java-delegation-conflict:" + initialDelegation + ":" + requestedDelegation, + Collections.emptyList(), "", line -> { + if (line.startsWith("[java-delegation-conflict")) { + resultLine.set(line); + return LineConsumerResult.STOP; + } + return LineConsumerResult.CONTINUE; + }, null); + + assertTrue(result.inTime); + assertEquals(0, result.exitCode); + assertEquals( + "[java-delegation-conflict] true " + initialDelegation, + resultLine.get()); + } + + /** Launches a fresh JVM and verifies the exact output of a delegation scenario. */ + private void assertJavaDelegationScenario( + String target, String marker, String expected) throws Exception { + AtomicReference resultLine = new AtomicReference<>(); + LaunchResult result = launch( + target, Collections.emptyList(), "", line -> { + if (line.startsWith(marker)) { + resultLine.set(line); + return LineConsumerResult.STOP; + } + return LineConsumerResult.CONTINUE; + }, null); + + assertTrue(result.inTime); + assertEquals(0, result.exitCode); + assertEquals(expected, resultLine.get()); + } + + @Test + void preExistingThreadObjectWaitUsesNativeMonitorCallbacks() throws Exception { + assertPreExistingMonitorCallback("profiler-preexisting-monitor-wait"); + } + + @Test + void preExistingThreadContentionUsesNativeMonitorCallbacks() throws Exception { + assertPreExistingMonitorCallback("profiler-preexisting-monitor-contention"); + } + + /** Verifies that a pre-JNI-load worker emits a TaskBlock through its first monitor callback. */ + private void assertPreExistingMonitorCallback(String target) throws Exception { + AtomicReference resultLine = new AtomicReference<>(); + LaunchResult result = launch(target, Collections.emptyList(), "", line -> { + if (line.startsWith("[preexisting-monitor-events]")) { + resultLine.set(line); + return LineConsumerResult.STOP; + } + return LineConsumerResult.CONTINUE; + }, null); + + assertTrue(result.inTime); + assertEquals(0, result.exitCode); + assertNotNull(resultLine.get(), "Pre-existing monitor callback did not report a result"); + long emitted = Long.parseLong(resultLine.get().substring( + "[preexisting-monitor-events] ".length())); + assertTrue(emitted > 0, "Pre-existing thread emitted no native monitor TaskBlock event"); } @Test diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/ProfilerOwnedBlockHooks.java b/ddprof-test/src/test/java/com/datadoghq/profiler/ProfilerOwnedBlockHooks.java index f58837f5d..54b910619 100644 --- a/ddprof-test/src/test/java/com/datadoghq/profiler/ProfilerOwnedBlockHooks.java +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/ProfilerOwnedBlockHooks.java @@ -9,8 +9,8 @@ public final class ProfilerOwnedBlockHooks { private ProfilerOwnedBlockHooks() {} - public static void parkEnter(JavaProfiler profiler) { - profiler.parkEnter(); + public static boolean parkEnter(JavaProfiler profiler) { + return profiler.parkEnter(); } public static void parkExit(JavaProfiler profiler, long blocker, long unblockingSpanId) { diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockApiTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockApiTest.java new file mode 100644 index 000000000..e3ef5b51a --- /dev/null +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockApiTest.java @@ -0,0 +1,246 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +package com.datadoghq.profiler.wallclock; + +import com.datadoghq.profiler.AbstractProfilerTest; +import java.nio.file.Files; +import java.nio.file.Path; +import java.lang.reflect.Method; +import java.util.concurrent.CountDownLatch; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicBoolean; +import java.util.concurrent.atomic.AtomicLong; +import java.util.concurrent.atomic.AtomicReference; +import org.junit.jupiter.api.Assumptions; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.params.ParameterizedTest; +import org.junit.jupiter.params.provider.ValueSource; +import com.datadoghq.profiler.JfrEvents; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertThrows; +import static org.junit.jupiter.api.Assertions.assertTrue; + +/** End-to-end coverage for the paired synchronous TaskBlock API. */ +public class JavaProfilerTaskBlockApiTest extends AbstractProfilerTest { + private static final long BLOCKER = 0x7301L; + private static final long UNBLOCKING_SPAN_ID = 0x7302L; + + @Test + public void pairedApiEmitsTaskBlockWithStack() throws Exception { + assertTrue(runEligibleBlock(BLOCKER)); + stopProfiler(); + + JfrEvents events = verifyEvents("datadog.TaskBlock"); + TaskBlockAssertions.assertNoAnchorFields(events); + TaskBlockAssertions.assertContainsStackTrace(events); + TaskBlockAssertions.assertContainsJavaType(events, "JavaProfilerTaskBlockApiTest"); + TaskBlockAssertions.assertNoCorrelationId(events); + TaskBlockAssertions.assertContains(events, 0L, 0L, BLOCKER, UNBLOCKING_SPAN_ID); + TaskBlockAssertions.assertContainsObservedState(events, "SLEEPING"); + } + + @ParameterizedTest + @ValueSource(strings = {"start", "resume"}) + public void rejectedDuplicateStartOrResumePreservesActiveTaskBlockRecording(String action) + throws Exception { + IllegalStateException rejected = assertThrows( + IllegalStateException.class, + () -> profiler.execute(action + "," + getProfilerCommand())); + assertEquals("Profiler already started", rejected.getMessage()); + + assertTrue(runEligibleBlock(BLOCKER)); + stopProfiler(); + + TaskBlockAssertions.assertContains( + verifyEvents("datadog.TaskBlock"), 0L, 0L, BLOCKER, UNBLOCKING_SPAN_ID); + } + + @Test + public void invalidAndNestedTokensDoNotLoseCurrentOwner() throws Exception { + AtomicBoolean recorded = new AtomicBoolean(); + runWorker(() -> { + long token = profiler.beginTaskBlock(); + assertTrue(token != 0); + assertEquals(0L, profiler.beginTaskBlock()); + assertFalse(profiler.endTaskBlock(token + 1, BLOCKER, UNBLOCKING_SPAN_ID)); + Thread.sleep(200L); + recorded.set(profiler.endTaskBlock(token, BLOCKER, UNBLOCKING_SPAN_ID)); + }); + assertTrue(recorded.get()); + } + + @Test + public void tooShortIntervalStillClearsLifecycle() throws Exception { + AtomicBoolean recorded = new AtomicBoolean(true); + AtomicLong secondToken = new AtomicLong(); + runWorker(() -> { + long token = profiler.beginTaskBlock(); + recorded.set(profiler.endTaskBlock(token, BLOCKER, UNBLOCKING_SPAN_ID)); + secondToken.set(profiler.beginTaskBlock()); + profiler.endTaskBlock(secondToken.get(), BLOCKER, UNBLOCKING_SPAN_ID); + }); + + assertFalse(recorded.get()); + assertTrue(secondToken.get() != 0); + stopProfiler(); + assertTrue(getRecordedCounterValue("task_block_skipped_too_short") > 0); + } + + @Test + public void contextWindowAdmissionAndCrossingAreEnforced() throws Exception { + AtomicLong tokenAfterWindow = new AtomicLong(); + runWorker(() -> { + profiler.addThread(); + try { + assertEquals(0L, profiler.beginTaskBlock()); + } finally { + profiler.removeThread(); + } + + long crossedToken = profiler.beginTaskBlock(); + assertTrue(crossedToken != 0); + profiler.addThread(); + profiler.removeThread(); + Thread.sleep(20L); + assertFalse(profiler.endTaskBlock( + crossedToken, BLOCKER, UNBLOCKING_SPAN_ID)); + + tokenAfterWindow.set(profiler.beginTaskBlock()); + profiler.endTaskBlock(tokenAfterWindow.get(), BLOCKER, UNBLOCKING_SPAN_ID); + }); + assertTrue(tokenAfterWindow.get() != 0, + "context rejection must still clear the prior lifecycle"); + } + + @Test + public void traceContextRejectsAtEntry() throws Exception { + AtomicLong token = new AtomicLong(-1L); + runWorker(() -> { + profiler.setTraceContext(0x5100L, 0x5101L, 0L, 0x5101L, -1, null, -1, null); + try { + token.set(profiler.beginTaskBlock()); + } finally { + profiler.clearTraceContext(); + } + }); + assertEquals(0L, token.get(), + "a traced interval must not arm timer-side suppression"); + } + + @Test + public void virtualThreadCannotMutateCarrierTaskBlockState() throws Exception { + Method startVirtualThread; + try { + startVirtualThread = + Thread.class.getMethod("startVirtualThread", Runnable.class); + } catch (NoSuchMethodException unavailableBeforeJdk21) { + Assumptions.assumeTrue(false, "virtual threads require JDK 21"); + return; + } + + AtomicLong token = new AtomicLong(-1L); + Thread virtual = (Thread) startVirtualThread.invoke(null, (Runnable) () -> + token.set(profiler.beginTaskBlock())); + virtual.join(5_000L); + assertFalse(virtual.isAlive()); + assertEquals(0L, token.get()); + + AtomicLong platformToken = new AtomicLong(); + runWorker(() -> { + platformToken.set(profiler.beginTaskBlock()); + profiler.endTaskBlock(platformToken.get(), BLOCKER, UNBLOCKING_SPAN_ID); + }); + assertTrue(platformToken.get() != 0, + "virtual-thread rejection must not strand carrier ownership"); + } + + @Test + public void liveDumpPreservesTaskBlockAfterEntrySample() throws Exception { + CountDownLatch armed = new CountDownLatch(1); + CountDownLatch release = new CountDownLatch(1); + AtomicBoolean recorded = new AtomicBoolean(); + AtomicReference error = new AtomicReference<>(); + long before = profiler.getDebugCounters() + .getOrDefault("wc_signals_suppressed_owned_block", 0L); + Thread worker = new Thread(() -> { + try { + long token = profiler.beginTaskBlock(); + assertTrue(token != 0); + armed.countDown(); + assertTrue(release.await(5, TimeUnit.SECONDS)); + recorded.set(profiler.endTaskBlock(token, BLOCKER, UNBLOCKING_SPAN_ID)); + } catch (Throwable t) { + error.set(t); + } + }, "taskblock-live-dump"); + + worker.start(); + assertTrue(armed.await(5, TimeUnit.SECONDS)); + waitForCounterAbove("wc_signals_suppressed_owned_block", before, 5_000L); + Path snapshot = Files.createTempFile("taskblock-live-dump-", ".jfr"); + try { + dump(snapshot); + } finally { + Files.deleteIfExists(snapshot); + } + release.countDown(); + worker.join(5_000L); + assertFalse(worker.isAlive()); + if (error.get() != null) throw new AssertionError(error.get()); + assertTrue(recorded.get()); + + stopProfiler(); + TaskBlockAssertions.assertContainsStackTrace(verifyEvents("datadog.TaskBlock")); + } + + @Override + protected String getProfilerCommand() { + return "wall=1ms,filter=,wallprecheck=true"; + } + + private boolean runEligibleBlock(long blocker) throws Exception { + AtomicBoolean result = new AtomicBoolean(); + runWorker(() -> { + long token = profiler.beginTaskBlock(); + if (token == 0) throw new AssertionError("interval was not armed"); + Thread.sleep(200L); + result.set(profiler.endTaskBlock(token, blocker, UNBLOCKING_SPAN_ID)); + }); + return result.get(); + } + + private void runWorker(ThrowingRunnable action) throws Exception { + AtomicReference error = new AtomicReference<>(); + Thread worker = new Thread(() -> { + try { + action.run(); + } catch (Throwable t) { + error.set(t); + } + }, "taskblock-paired-api"); + worker.start(); + worker.join(5_000L); + assertFalse(worker.isAlive()); + if (error.get() != null) throw new AssertionError(error.get()); + } + + private void waitForCounterAbove(String name, long baseline, long timeoutMillis) + throws Exception { + long deadline = System.nanoTime() + TimeUnit.MILLISECONDS.toNanos(timeoutMillis); + while (System.nanoTime() < deadline) { + if (profiler.getDebugCounters().getOrDefault(name, 0L) > baseline) return; + Thread.sleep(10L); + } + throw new AssertionError("Counter did not increase: " + name); + } + + @FunctionalInterface + private interface ThrowingRunnable { + void run() throws Exception; + } +} diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockDisabledTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockDisabledTest.java new file mode 100644 index 000000000..2a04c8fdf --- /dev/null +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockDisabledTest.java @@ -0,0 +1,24 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +package com.datadoghq.profiler.wallclock; + +import com.datadoghq.profiler.AbstractProfilerTest; +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +/** Verifies that TaskBlock does not change legacy/context wall-clock scope. */ +public class JavaProfilerTaskBlockDisabledTest extends AbstractProfilerTest { + @Test + public void pairedApiIsInactiveOutsideAllThreadScope() { + assertEquals(0L, profiler.beginTaskBlock()); + } + + @Override + protected String getProfilerCommand() { + return "wall=1ms,filter=0,wallprecheck=true"; + } +} diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockLightweightTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockLightweightTest.java new file mode 100644 index 000000000..3654a90a3 --- /dev/null +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockLightweightTest.java @@ -0,0 +1,85 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +package com.datadoghq.profiler.wallclock; + +import com.datadoghq.profiler.AbstractProfilerTest; +import java.util.concurrent.CountDownLatch; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicBoolean; +import java.util.concurrent.atomic.AtomicReference; +import org.junit.jupiter.api.Test; +import com.datadoghq.profiler.JfrEvents; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertTrue; + +/** End-to-end coverage for stackless TaskBlock events in lightweight mode. */ +public class JavaProfilerTaskBlockLightweightTest extends AbstractProfilerTest { + private static final long BLOCKER = 0x7401L; + private static final long UNBLOCKING_SPAN_ID = 0x7402L; + + @Test + public void suppressedWallSamplesAreReplacedByAStacklessTaskBlock() throws Exception { + CountDownLatch armed = new CountDownLatch(1); + CountDownLatch release = new CountDownLatch(1); + AtomicBoolean recorded = new AtomicBoolean(); + AtomicReference error = new AtomicReference<>(); + long suppressedBefore = profiler.getDebugCounters() + .getOrDefault("wc_signals_suppressed_owned_block", 0L); + Thread worker = new Thread(() -> { + try { + long token = profiler.beginTaskBlock(); + assertTrue(token != 0, "Expected TaskBlock interval to be armed"); + armed.countDown(); + assertTrue(release.await(5, TimeUnit.SECONDS)); + recorded.set(profiler.endTaskBlock(token, BLOCKER, UNBLOCKING_SPAN_ID)); + } catch (Throwable t) { + error.set(t); + } + }, "taskblock-lightweight"); + + worker.start(); + assertTrue(armed.await(5, TimeUnit.SECONDS)); + waitForCounterAbove( + "wc_signals_suppressed_owned_block", suppressedBefore, 5_000L); + // The periodic signal may arrive less than 1 ms after beginTaskBlock(). + Thread.sleep(10L); + release.countDown(); + worker.join(5_000L); + assertFalse(worker.isAlive()); + if (error.get() != null) throw new AssertionError(error.get()); + assertTrue(recorded.get(), "Expected stackless TaskBlock event to be recorded"); + + stopProfiler(); + JfrEvents events = verifyEvents("datadog.TaskBlock"); + assertEquals(1L, events.count()); + TaskBlockAssertions.assertContainsNoStackTrace(events); + TaskBlockAssertions.assertNoAnchorFields(events); + TaskBlockAssertions.assertNoCorrelationId(events); + TaskBlockAssertions.assertContains(events, 0L, 0L, BLOCKER, UNBLOCKING_SPAN_ID); + TaskBlockAssertions.assertContainsObservedState(events, "SLEEPING"); + assertTrue(getRecordedCounterValue("wc_signals_suppressed_owned_block") + > suppressedBefore); + assertEquals(1L, getRecordedCounterValue("task_block_emitted")); + assertEquals(0L, getRecordedCounterValue("task_block_stack_capture_failed")); + } + + private void waitForCounterAbove(String name, long baseline, long timeoutMillis) + throws Exception { + long deadline = System.nanoTime() + TimeUnit.MILLISECONDS.toNanos(timeoutMillis); + while (System.nanoTime() < deadline) { + if (profiler.getDebugCounters().getOrDefault(name, 0L) > baseline) return; + Thread.sleep(10L); + } + throw new AssertionError("Counter did not increase: " + name); + } + + @Override + protected String getProfilerCommand() { + return "wall=1ms,filter=,wallprecheck=true,lightweight=yes"; + } +} diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockPreExistingThreadTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockPreExistingThreadTest.java new file mode 100644 index 000000000..bb21a3bee --- /dev/null +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockPreExistingThreadTest.java @@ -0,0 +1,76 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +package com.datadoghq.profiler.wallclock; + +import com.datadoghq.profiler.AbstractProfilerTest; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.Future; +import java.util.concurrent.TimeUnit; +import org.junit.jupiter.api.AfterEach; +import org.junit.jupiter.api.Test; +import com.datadoghq.profiler.JfrEvents; + +import static org.junit.jupiter.api.Assertions.assertSame; +import static org.junit.jupiter.api.Assertions.assertTrue; + +/** Verifies TaskBlock TLS initialization for threads created before profiler startup. */ +public class JavaProfilerTaskBlockPreExistingThreadTest extends AbstractProfilerTest { + private static final long BLOCKER = 0x7401L; + private static final long UNBLOCKING_SPAN_ID = 0x7402L; + + private ExecutorService preExistingWorker; + private Thread preExistingThread; + + @Override + protected void beforeProfilerStart() throws Exception { + preExistingWorker = + Executors.newSingleThreadExecutor( + task -> { + Thread worker = new Thread(task, "taskblock-pre-existing"); + worker.setDaemon(true); + return worker; + }); + preExistingThread = preExistingWorker.submit(Thread::currentThread).get(); + } + + /** Stops the worker that was deliberately created before profiler startup. */ + @AfterEach + public void stopPreExistingWorker() throws InterruptedException { + if (preExistingWorker == null) return; + preExistingWorker.shutdownNow(); + assertTrue( + preExistingWorker.awaitTermination(5, TimeUnit.SECONDS), + "Pre-existing TaskBlock worker did not terminate"); + } + + /** Verifies that the first post-start TaskBlock call initializes carrier-local TLS. */ + @Test + public void preExistingThreadCanRecordTaskBlockAfterProfilerStart() throws Exception { + Future recorded = + preExistingWorker.submit( + () -> { + assertSame(preExistingThread, Thread.currentThread()); + long token = profiler.beginTaskBlock(); + assertTrue(token != 0, "Pre-existing thread must initialize TaskBlock TLS"); + Thread.sleep(200L); + return profiler.endTaskBlock(token, BLOCKER, UNBLOCKING_SPAN_ID); + }); + + assertTrue(recorded.get(5, TimeUnit.SECONDS)); + stopProfiler(); + + JfrEvents events = verifyEvents("datadog.TaskBlock"); + TaskBlockAssertions.assertContainsStackTrace(events); + TaskBlockAssertions.assertContains( + events, 0L, 0L, BLOCKER, UNBLOCKING_SPAN_ID); + } + + @Override + protected String getProfilerCommand() { + return "wall=1ms,filter=,wallprecheck=true"; + } +} diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedMonitorTaskBlockTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedMonitorTaskBlockTest.java new file mode 100644 index 000000000..ff6df5c97 --- /dev/null +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedMonitorTaskBlockTest.java @@ -0,0 +1,30 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +package com.datadoghq.profiler.wallclock; + +import com.datadoghq.profiler.Platform; +import java.util.Map; +import org.junit.jupiter.api.Assumptions; + +/** Verifies synchronous monitor production when delegated wall-clock stacks are enabled. */ +public class JvmtiBasedMonitorTaskBlockTest extends MonitorTaskBlockTest { + @Override + protected void before() { + Map counters = profiler.getDebugCounters(); + Assumptions.assumeTrue(counters.getOrDefault("jvmti_stacks_init_ok", 0L) > 0, + "HotSpot RequestStackTrace JVMTI extension is not available"); + } + + @Override + protected void withTestAssumptions() { + Assumptions.assumeTrue(Platform.isJavaVersionAtLeast(11)); + } + + @Override + protected String getProfilerCommand() { + return "wall=1ms,filter=,wallprecheck=true,jvmtistacks=true"; + } +} diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedParkTaskBlockTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedParkTaskBlockTest.java new file mode 100644 index 000000000..63e56c380 --- /dev/null +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedParkTaskBlockTest.java @@ -0,0 +1,30 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +package com.datadoghq.profiler.wallclock; + +import com.datadoghq.profiler.Platform; +import java.util.Map; +import org.junit.jupiter.api.Assumptions; + +/** Verifies synchronous park production when delegated wall-clock stacks are enabled. */ +public class JvmtiBasedParkTaskBlockTest extends ParkTaskBlockTest { + @Override + protected void before() { + Map counters = profiler.getDebugCounters(); + Assumptions.assumeTrue(counters.getOrDefault("jvmti_stacks_init_ok", 0L) > 0, + "HotSpot RequestStackTrace JVMTI extension is not available"); + } + + @Override + protected void withTestAssumptions() { + Assumptions.assumeTrue(Platform.isJavaVersionAtLeast(11)); + } + + @Override + protected String getProfilerCommand() { + return "wall=1ms,filter=,wallprecheck=true,jvmtistacks=true"; + } +} diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedPrecheckTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedPrecheckTest.java index 22a2926d1..07ae6de49 100644 --- a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedPrecheckTest.java +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedPrecheckTest.java @@ -54,11 +54,11 @@ protected void withTestAssumptions() { @Override protected String getProfilerCommand() { - return "wall=1ms,wallscope=all,wallprecheck=true,jvmtistacks=true"; + return "wall=1ms,filter=,wallprecheck=true,jvmtistacks=true"; } @Override protected String getPrecheckDisabledProfilerCommand() { - return "wall=1ms,wallscope=all,wallprecheck=false,jvmtistacks=true"; + return "wall=1ms,filter=,wallprecheck=false,jvmtistacks=true"; } } diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/MonitorTaskBlockTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/MonitorTaskBlockTest.java new file mode 100644 index 000000000..25d81b8e4 --- /dev/null +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/MonitorTaskBlockTest.java @@ -0,0 +1,240 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +package com.datadoghq.profiler.wallclock; + +import com.datadoghq.profiler.AbstractProfilerTest; +import java.lang.reflect.Method; +import java.nio.file.Files; +import java.nio.file.Path; +import java.util.concurrent.CountDownLatch; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicReference; +import com.datadoghq.profiler.JfrEvents; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.api.Assumptions; + +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertTrue; + +/** Verifies TaskBlock production from native JVMTI monitor callbacks. */ +public class MonitorTaskBlockTest extends AbstractProfilerTest { + @Test + public void objectWaitEmitsTaskBlockOutsideContextWindow() throws Exception { + Object monitor = new Object(); + CountDownLatch entered = new CountDownLatch(1); + AtomicReference failure = new AtomicReference<>(); + Thread worker = new Thread(() -> { + try { + synchronized (monitor) { + entered.countDown(); + monitor.wait(100); + } + } catch (Throwable t) { + failure.set(t); + } + }, "taskblock-object-wait"); + + worker.start(); + assertTrue(entered.await(5, TimeUnit.SECONDS)); + assertCompleted(worker, failure); + stopProfiler(); + + JfrEvents events = verifyEvents("datadog.TaskBlock"); + assertTaskBlockStackReference(events); + TaskBlockAssertions.assertContains(events, 0, 0, identityHash(monitor), 0); + TaskBlockAssertions.assertContainsObservedState(events, "WAITING"); + } + + @Test + public void monitorContentionEmitsTaskBlockOutsideContextWindow() throws Exception { + Object monitor = new Object(); + CountDownLatch attempting = new CountDownLatch(1); + AtomicReference failure = new AtomicReference<>(); + Thread worker; + synchronized (monitor) { + worker = new Thread(() -> { + try { + attempting.countDown(); + synchronized (monitor) { + } + } catch (Throwable t) { + failure.set(t); + } + }, "taskblock-monitor-contention"); + worker.start(); + assertTrue(attempting.await(5, TimeUnit.SECONDS)); + Thread.sleep(100); + } + + assertCompleted(worker, failure); + stopProfiler(); + + JfrEvents events = verifyEvents("datadog.TaskBlock"); + assertTaskBlockStackReference(events); + TaskBlockAssertions.assertContains(events, 0, 0, identityHash(monitor), 0); + TaskBlockAssertions.assertContainsObservedState(events, "CONTENDED"); + } + + @Test + public void contextWindowObjectWaitDoesNotEmitTaskBlock() throws Exception { + Object monitor = new Object(); + AtomicReference failure = new AtomicReference<>(); + Thread worker = new Thread(() -> { + try { + registerCurrentThreadForWallClockProfiling(); + profiler.setTraceContext(0x4400L, 0x4401L, 0L, 0x4401L, -1, null, -1, null); + synchronized (monitor) { + monitor.wait(100); + } + } catch (Throwable t) { + failure.set(t); + } finally { + profiler.clearTraceContext(); + profiler.removeThread(); + } + }, "taskblock-traced-object-wait"); + + worker.start(); + assertCompleted(worker, failure); + stopProfiler(); + + assertFalse(TaskBlockAssertions.containsBlocker( + verifyEvents("datadog.TaskBlock", false), identityHash(monitor))); + } + + @Test + public void staleWaitStateIsRecoveredAfterProfilerRestart() throws Exception { + Object waitMonitor = new Object(); + Object contentionMonitor = new Object(); + CountDownLatch waiting = new CountDownLatch(1); + CountDownLatch waitCompleted = new CountDownLatch(1); + CountDownLatch restartReady = new CountDownLatch(1); + CountDownLatch attemptingContention = new CountDownLatch(1); + AtomicReference failure = new AtomicReference<>(); + Thread worker = new Thread(() -> { + try { + synchronized (waitMonitor) { + waiting.countDown(); + waitMonitor.wait(); + } + waitCompleted.countDown(); + assertTrue(restartReady.await(5, TimeUnit.SECONDS)); + attemptingContention.countDown(); + synchronized (contentionMonitor) { + } + } catch (Throwable t) { + failure.set(t); + } + }, "taskblock-monitor-restart"); + + worker.start(); + assertTrue(waiting.await(5, TimeUnit.SECONDS)); + Thread.sleep(50); + stopProfiler(); + synchronized (waitMonitor) { + waitMonitor.notifyAll(); + } + assertTrue(waitCompleted.await(5, TimeUnit.SECONDS)); + + Path recording = Files.createTempFile("MonitorTaskBlockTest-restart-", ".jfr"); + boolean restarted = false; + try { + profiler.execute("start,wall=1ms,filter=,wallprecheck=true,jfr,file=" + + recording.toAbsolutePath()); + restarted = true; + synchronized (contentionMonitor) { + restartReady.countDown(); + assertTrue(attemptingContention.await(5, TimeUnit.SECONDS)); + Thread.sleep(100); + } + assertCompleted(worker, failure); + profiler.stop(); + restarted = false; + + JfrEvents events = verifyEvents(recording, "datadog.TaskBlock", false); + assertTaskBlockStackReference(events); + assertTrue(TaskBlockAssertions.containsBlocker( + events, identityHash(contentionMonitor))); + } finally { + restartReady.countDown(); + synchronized (waitMonitor) { + waitMonitor.notifyAll(); + } + if (restarted) profiler.stop(); + worker.join(5_000); + Files.deleteIfExists(recording); + } + } + + @Test + public void virtualMonitorCallbacksDoNotEmitCarrierTaskBlocks() throws Exception { + Method startVirtualThread; + try { + startVirtualThread = Thread.class.getMethod("startVirtualThread", Runnable.class); + } catch (NoSuchMethodException unavailableBeforeJdk21) { + Assumptions.assumeTrue(false, "virtual threads require JDK 21"); + return; + } + + Object waitMonitor = new Object(); + AtomicReference failure = new AtomicReference<>(); + Thread waiter = (Thread) startVirtualThread.invoke(null, (Runnable) () -> { + try { + synchronized (waitMonitor) { + waitMonitor.wait(100); + } + } catch (Throwable t) { + failure.set(t); + } + }); + assertCompleted(waiter, failure); + + Object contentionMonitor = new Object(); + CountDownLatch attempting = new CountDownLatch(1); + Thread contender; + synchronized (contentionMonitor) { + contender = (Thread) startVirtualThread.invoke(null, (Runnable) () -> { + try { + attempting.countDown(); + synchronized (contentionMonitor) { + } + } catch (Throwable t) { + failure.set(t); + } + }); + assertTrue(attempting.await(5, TimeUnit.SECONDS)); + Thread.sleep(100); + } + assertCompleted(contender, failure); + stopProfiler(); + + JfrEvents events = verifyEvents("datadog.TaskBlock", false); + assertFalse(TaskBlockAssertions.containsBlocker(events, identityHash(waitMonitor))); + assertFalse(TaskBlockAssertions.containsBlocker(events, identityHash(contentionMonitor))); + } + + @Override + protected String getProfilerCommand() { + return "wall=1ms,filter=,wallprecheck=true"; + } + + protected void assertTaskBlockStackReference(JfrEvents events) { + TaskBlockAssertions.assertContainsStackTrace(events); + TaskBlockAssertions.assertContainsJavaType(events, "MonitorTaskBlockTest"); + TaskBlockAssertions.assertNoCorrelationId(events); + } + + private static void assertCompleted(Thread thread, AtomicReference failure) + throws InterruptedException { + thread.join(5_000); + assertFalse(thread.isAlive(), "worker did not complete"); + if (failure.get() != null) throw new AssertionError(failure.get()); + } + + private static long identityHash(Object object) { + return Integer.toUnsignedLong(System.identityHashCode(object)); + } +} diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/ParkTaskBlockTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/ParkTaskBlockTest.java new file mode 100644 index 000000000..a1c288be5 --- /dev/null +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/ParkTaskBlockTest.java @@ -0,0 +1,169 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +package com.datadoghq.profiler.wallclock; + +import com.datadoghq.profiler.AbstractProfilerTest; +import com.datadoghq.profiler.JfrEvents; +import com.datadoghq.profiler.ProfilerOwnedBlockHooks; +import java.lang.reflect.Method; +import java.util.concurrent.CountDownLatch; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicBoolean; +import java.util.concurrent.atomic.AtomicReference; +import java.util.concurrent.locks.LockSupport; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.api.Assumptions; + +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertTrue; + +/** Verifies TaskBlock production from Java-owned platform-thread park hooks. */ +public class ParkTaskBlockTest extends AbstractProfilerTest { + private static final long BLOCKER = 0x3102L; + private static final long UNBLOCKING_SPAN_ID = 0x3103L; + + @Test + public void platformParkEmitsTaskBlockOutsideContextWindow() { + ProfilerOwnedBlockHooks.parkEnter(profiler); + try { + parkForMillis(200); + } finally { + ProfilerOwnedBlockHooks.parkExit(profiler, BLOCKER, UNBLOCKING_SPAN_ID); + } + stopProfiler(); + + JfrEvents events = verifyEvents("datadog.TaskBlock"); + TaskBlockAssertions.assertNoAnchorFields(events); + assertTaskBlockStackReference(events); + TaskBlockAssertions.assertContains(events, 0, 0, BLOCKER, UNBLOCKING_SPAN_ID); + TaskBlockAssertions.assertContainsObservedState(events, "PARKED"); + } + + @Test + public void contextWindowParkDoesNotEmitTaskBlock() { + registerCurrentThreadForWallClockProfiling(); + profiler.setTraceContext(0x3100L, 0x3101L, 0L, 0x3101L, -1, null, -1, null); + try { + ProfilerOwnedBlockHooks.parkEnter(profiler); + try { + parkForMillis(200); + } finally { + ProfilerOwnedBlockHooks.parkExit(profiler, BLOCKER, UNBLOCKING_SPAN_ID); + } + } finally { + profiler.clearTraceContext(); + profiler.removeThread(); + } + stopProfiler(); + + assertFalse(verifyEvents("datadog.TaskBlock", false).hasItems(), + "A park inside the context window must remain ordinary wall-clock data"); + } + + @Test + public void virtualParkDoesNotMutateCarrierProducerState() throws Exception { + Method startVirtualThread; + try { + startVirtualThread = Thread.class.getMethod("startVirtualThread", Runnable.class); + } catch (NoSuchMethodException unavailableBeforeJdk21) { + Assumptions.assumeTrue(false, "virtual threads require JDK 21"); + return; + } + + long virtualBlocker = 0x3201L; + Thread virtual = (Thread) startVirtualThread.invoke(null, (Runnable) () -> { + ProfilerOwnedBlockHooks.parkEnter(profiler); + try { + parkForMillis(20); + } finally { + ProfilerOwnedBlockHooks.parkExit(profiler, virtualBlocker, 0); + } + }); + virtual.join(5_000); + assertFalse(virtual.isAlive()); + + ProfilerOwnedBlockHooks.parkEnter(profiler); + try { + parkForMillis(200); + } finally { + ProfilerOwnedBlockHooks.parkExit(profiler, BLOCKER, UNBLOCKING_SPAN_ID); + } + stopProfiler(); + + JfrEvents events = verifyEvents("datadog.TaskBlock"); + assertFalse(TaskBlockAssertions.containsBlocker(events, virtualBlocker)); + TaskBlockAssertions.assertContains(events, 0, 0, BLOCKER, UNBLOCKING_SPAN_ID); + } + + @Test + public void platformParkSuppressesSignalsAndClearsOwnership() throws Exception { + long baseline = profiler.getDebugCounters() + .getOrDefault("wc_signals_suppressed_owned_block", 0L); + long afterFirstPark = runSuppressedPark(baseline); + runSuppressedPark(afterFirstPark); + } + + @Override + protected String getProfilerCommand() { + return "wall=1ms,filter=,wallprecheck=true"; + } + + protected void assertTaskBlockStackReference(JfrEvents events) { + TaskBlockAssertions.assertContainsStackTrace(events); + TaskBlockAssertions.assertContainsJavaType(events, "ParkTaskBlockTest"); + TaskBlockAssertions.assertNoCorrelationId(events); + } + + private static void parkForMillis(long millis) { + long deadline = System.nanoTime() + TimeUnit.MILLISECONDS.toNanos(millis); + long remaining; + while ((remaining = deadline - System.nanoTime()) > 0) { + LockSupport.parkNanos(remaining); + } + } + + private long runSuppressedPark(long baseline) throws Exception { + CountDownLatch armed = new CountDownLatch(1); + AtomicBoolean release = new AtomicBoolean(); + AtomicReference error = new AtomicReference<>(); + Thread worker = new Thread(() -> { + try { + ProfilerOwnedBlockHooks.parkEnter(profiler); + armed.countDown(); + while (!release.get()) { + Thread.yield(); + } + } catch (Throwable t) { + error.set(t); + } finally { + ProfilerOwnedBlockHooks.parkExit(profiler, BLOCKER, UNBLOCKING_SPAN_ID); + } + }, "taskblock-park-suppression"); + + worker.start(); + assertTrue(armed.await(5, TimeUnit.SECONDS)); + try { + waitForCounterAbove("wc_signals_suppressed_owned_block", baseline, 5_000L); + } finally { + release.set(true); + } + worker.join(5_000L); + assertFalse(worker.isAlive()); + if (error.get() != null) throw new AssertionError(error.get()); + return profiler.getDebugCounters() + .getOrDefault("wc_signals_suppressed_owned_block", 0L); + } + + private void waitForCounterAbove(String name, long baseline, long timeoutMillis) + throws Exception { + long deadline = System.nanoTime() + TimeUnit.MILLISECONDS.toNanos(timeoutMillis); + while (System.nanoTime() < deadline) { + if (profiler.getDebugCounters().getOrDefault(name, 0L) > baseline) return; + Thread.sleep(10L); + } + throw new AssertionError("Counter did not increase: " + name); + } +} diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckEfficiencyTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckEfficiencyTest.java index 177bafab4..f4b680689 100644 --- a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckEfficiencyTest.java +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckEfficiencyTest.java @@ -24,9 +24,9 @@ /** * Measures the theoretical upper bound on {@code SIGVTALRM} suppression by running with - * {@code wallprecheck=false} and classifying sample states. The once-per-run filter + * {@code wallprecheck=false} and classifying sample states. Lifecycle ownership * ({@code wallprecheck=true}) suppresses {@code SLEEPING}, {@code CONDVAR_WAIT}, and - * {@code OBJECT_WAIT} after the entry sample; {@code RUNNABLE} is not skipped. Monitor + * suppresses {@code OBJECT_WAIT}; {@code RUNNABLE} is not skipped. Monitor * contention ({@code MONITOR_WAIT}) is also suppressible when monitor hooks identify the blocked * interval. */ @@ -45,23 +45,20 @@ public void compareSuppressionRates() throws Exception { AtomicBoolean stop = new AtomicBoolean(false); Object monitor = new Object(); - // SLEEPING / CONDVAR_WAIT — suppressed by once-per-run filter + // SLEEPING / CONDVAR_WAIT — suppressible with lifecycle ownership Thread sleeping = new Thread(() -> { - registerCurrentThreadForWallClockProfiling(); ready.countDown(); try { Thread.sleep(10_000); } catch (InterruptedException ignored) {} }, EFFICIENCY_SLEEPING); - // CONDVAR_WAIT — suppressed by once-per-run filter + // CONDVAR_WAIT — suppressible with lifecycle ownership Thread parked = new Thread(() -> { - registerCurrentThreadForWallClockProfiling(); ready.countDown(); LockSupport.parkNanos(10_000_000_000L); }, EFFICIENCY_PARKED); - // OBJECT_WAIT — suppressed by the once-per-run filter. + // OBJECT_WAIT — suppressible with lifecycle ownership. Thread waiting = new Thread(() -> { - registerCurrentThreadForWallClockProfiling(); ready.countDown(); synchronized (monitor) { try { monitor.wait(10_000); } catch (InterruptedException ignored) {} @@ -70,7 +67,6 @@ public void compareSuppressionRates() throws Exception { // RUNNABLE — not skipped Thread working = new Thread(() -> { - registerCurrentThreadForWallClockProfiling(); ready.countDown(); long x = 0; while (!stop.get()) { x++; } @@ -196,10 +192,7 @@ public void realisticServiceWorkload() throws Exception { AtomicInteger threadIndex = new AtomicInteger(0); ExecutorService pool = Executors.newFixedThreadPool(POOL_SIZE, r -> { - Thread t = new Thread(() -> { - registerCurrentThreadForWallClockProfiling(); - r.run(); - }); + Thread t = new Thread(r); t.setName("realistic-pool-" + threadIndex.incrementAndGet()); t.setDaemon(true); return t; @@ -213,7 +206,6 @@ public void realisticServiceWorkload() throws Exception { Thread.sleep(50); Thread scheduler = new Thread(() -> { - registerCurrentThreadForWallClockProfiling(); while (!stop.get()) { try { Thread.sleep(SCHEDULE_INTERVAL_MS); @@ -232,7 +224,6 @@ public void realisticServiceWorkload() throws Exception { scheduler.start(); Thread hotThread = new Thread(() -> { - registerCurrentThreadForWallClockProfiling(); long x = 0; while (!stop.get()) { x++; } }, "realistic-hot"); @@ -254,6 +245,12 @@ public void realisticServiceWorkload() throws Exception { long sleepSamples = 0, parkSamples = 0, otherSamples = 0; for (JfrEvent item : events) { + String threadName = item.getThreadName("eventThread"); + if (threadName == null || (!threadName.startsWith("realistic-pool-") + && !"realistic-scheduler".equals(threadName) + && !"realistic-hot".equals(threadName))) { + continue; + } String stack = item.getStackTraceString(); if (stack == null) { otherSamples++; @@ -296,8 +293,8 @@ public void realisticServiceWorkload() throws Exception { @Override protected String getProfilerCommand() { - // The workload deliberately has no tracing context, so its samples - // require the explicit all-thread wall-clock scope. - return "wall=1ms,wallscope=all"; + // The workload deliberately has no tracing context, so keep unfiltered + // wall-clock sampling enabled explicitly. + return "wall=1ms,filter="; } } diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckTest.java index 6aeacd204..379bdd87c 100644 --- a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckTest.java +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckTest.java @@ -22,8 +22,8 @@ import static org.junit.jupiter.api.Assertions.assertTrue; /** - * Verifies once-per-run signal suppression ({@code wallprecheck=true}): a sleeping thread - * should produce a handful of {@code MethodSample} events (entry + boundary jitter), not ~300. + * Verifies lifecycle-owned signal suppression ({@code wallprecheck=true}): a sleeping thread + * should produce at most boundary-race {@code MethodSample} events, not ~300. * Requires JDK 11+ — JDK 8 HotSpot reports inconsistent OSThread states for sleep. */ public class PrecheckTest extends AbstractProfilerTest { @@ -39,7 +39,6 @@ public void testSleepingThreadIsNotSampled() throws InterruptedException { Assumptions.assumeTrue(!Platform.isJ9()); Assumptions.assumeTrue(Platform.isJavaVersionAtLeast(11)); leaveClearedInitializedContext(); - registerCurrentThreadForWallClockProfiling(); long token = ProfilerOwnedBlockHooks.blockEnter(profiler, OSTHREAD_STATE_SLEEPING); assertTrue(token != 0, "Expected native blockEnter to arm SLEEPING state"); @@ -51,17 +50,16 @@ public void testSleepingThreadIsNotSampled() throws InterruptedException { stopProfiler(); - long sampleCount = verifyEvents("datadog.MethodSample", false) - .count(); - // Explicitly owned once-per-run filter: entry signal emits, subsequent signals are - // suppressed until blockExit clears the owned run. + long sampleCount = samplesForThread(Thread.currentThread().getName()); + // Lifecycle ownership suppresses deliberate signals from blockEnter until blockExit. + // A few boundary-race samples remain possible. assertTrue(sampleCount < 10, "Expected nearly no MethodSample events for a sleeping thread with wallprecheck=true, got: " + sampleCount); Map counters = profiler.getDebugCounters(); - if (counters.containsKey("wc_signals_suppressed_sampled_run")) { - assertTrue(counters.get("wc_signals_suppressed_sampled_run") > 0, - "wc_signals_suppressed_sampled_run should be > 0 for a 300 ms Thread.sleep()"); + if (counters.containsKey("wc_signals_suppressed_owned_block")) { + assertTrue(counters.get("wc_signals_suppressed_owned_block") > 0, + "wc_signals_suppressed_owned_block should be > 0 for a 300 ms Thread.sleep()"); } } @@ -70,16 +68,19 @@ public void unownedSleepingThreadIsNotExactOncePerRunSuppressed() throws Excepti Assumptions.assumeTrue(!Platform.isJ9()); Assumptions.assumeTrue(Platform.isJavaVersionAtLeast(11)); leaveClearedInitializedContext(); - registerCurrentThreadForWallClockProfiling(); Thread.sleep(300); stopProfiler(); - long sampleCount = verifyEvents("datadog.MethodSample", false) - .count(); - assertTrue(sampleCount >= 10, - "Unowned Thread.sleep must not be exact once-per-run suppressed; got: " + sampleCount); + long sampleCount = samplesForThread(Thread.currentThread().getName()); + assertTrue(sampleCount > 0, + "Unowned Thread.sleep must remain sampled; got: " + sampleCount); + Map counters = profiler.getDebugCounters(); + assertTrue(counters.getOrDefault("wc_unowned_blocked_recorded", 0L) > 0, + "Expected the weighted unowned-block fallback to record samples"); + assertTrue(counters.getOrDefault("wc_unowned_blocked_suppressed", 0L) > 0, + "Expected the weighted unowned-block fallback to suppress intermediate samples"); } @Test @@ -88,7 +89,6 @@ public void unownedSleepingTailWeightIsPreserved() throws Exception { Assumptions.assumeTrue(Platform.isJavaVersionAtLeast(11)); Thread sleeper = new Thread(() -> { - registerCurrentThreadForWallClockProfiling(); try { for (int i = 0; i < TAIL_WEIGHT_ITERATIONS; i++) { Thread.sleep(TAIL_WEIGHT_SLEEP_MILLIS); @@ -110,19 +110,19 @@ public void unownedSleepingTailWeightIsPreserved() throws Exception { WeightedSamples weightedSamples = weightedSamplesForThread(TAIL_WEIGHT_THREAD); assertTrue(weightedSamples.count > 0, "Expected MethodSample events for " + TAIL_WEIGHT_THREAD); - long expectedTailContribution = TAIL_WEIGHT_ITERATIONS; - assertTrue(weightedSamples.weight >= weightedSamples.count + expectedTailContribution, + assertTrue(weightedSamples.weight > weightedSamples.count, "Expected preserved suppressed tail weight for " + TAIL_WEIGHT_THREAD + ", count=" + weightedSamples.count - + ", weight=" + weightedSamples.weight - + ", expectedTailContribution=" + expectedTailContribution); + + ", weight=" + weightedSamples.weight); + assertTrue(profiler.getDebugCounters() + .getOrDefault("wc_unowned_blocked_suppressed", 0L) > 0, + "Expected unowned blocked samples to be suppressed and represented by weight"); } @Test public void tracedSleepingThreadIsSampled() throws InterruptedException { Assumptions.assumeTrue(!Platform.isJ9()); Assumptions.assumeTrue(Platform.isJavaVersionAtLeast(11)); - registerCurrentThreadForWallClockProfiling(); Map countersBefore = profiler.getDebugCounters(); profiler.setTraceContext(0x5100L, 0x5101L, 0L, 0x5101L, -1, null, -1, null); @@ -134,17 +134,16 @@ public void tracedSleepingThreadIsSampled() throws InterruptedException { stopProfiler(); - long sampleCount = verifyEvents("datadog.MethodSample", false) - .count(); + long sampleCount = samplesForThread(Thread.currentThread().getName()); assertTrue(sampleCount >= 10, "Expected normal MethodSample volume for traced sleep, got: " + sampleCount); - if (countersBefore.containsKey("wc_signals_suppressed_sampled_run")) { - long suppressedBefore = countersBefore.get("wc_signals_suppressed_sampled_run"); + if (countersBefore.containsKey("wc_signals_suppressed_owned_block")) { + long suppressedBefore = countersBefore.get("wc_signals_suppressed_owned_block"); long suppressedAfter = profiler.getDebugCounters() - .getOrDefault("wc_signals_suppressed_sampled_run", 0L); + .getOrDefault("wc_signals_suppressed_owned_block", 0L); assertEquals(suppressedBefore, suppressedAfter, - "wc_signals_suppressed_sampled_run must not increment for traced sleep"); + "wc_signals_suppressed_owned_block must not increment for traced sleep"); } } @@ -152,16 +151,15 @@ public void tracedSleepingThreadIsSampled() throws InterruptedException { public void suppressionCounterIsZeroWhenPrecheckDisabled() throws Exception { Assumptions.assumeTrue(!Platform.isJ9()); Assumptions.assumeTrue(Platform.isJavaVersionAtLeast(11)); - registerCurrentThreadForWallClockProfiling(); // Stop the wallprecheck=true recording started by @BeforeEach before starting a new one. stopProfiler(); Map before = profiler.getDebugCounters(); - if (!before.containsKey("wc_signals_suppressed_sampled_run")) { + if (!before.containsKey("wc_signals_suppressed_owned_block")) { return; // counter not available in this build } - long suppressedBefore = before.get("wc_signals_suppressed_sampled_run"); + long suppressedBefore = before.get("wc_signals_suppressed_owned_block"); Path recordingB = Files.createTempFile(Paths.get("/tmp/recordings"), "PrecheckTest_disabled_", ".jfr"); @@ -171,11 +169,11 @@ public void suppressionCounterIsZeroWhenPrecheckDisabled() throws Exception { profiler.stop(); long suppressedAfter = profiler.getDebugCounters() - .getOrDefault("wc_signals_suppressed_sampled_run", 0L); + .getOrDefault("wc_signals_suppressed_owned_block", 0L); Files.deleteIfExists(recordingB); assertEquals(suppressedBefore, suppressedAfter, - "wc_signals_suppressed_sampled_run must not increment when wallprecheck=false"); + "wc_signals_suppressed_owned_block must not increment when wallprecheck=false"); } /** @@ -191,13 +189,23 @@ private void leaveClearedInitializedContext() { @Override protected String getProfilerCommand() { // This suite verifies sampling and suppression for threads outside a - // tracing-context window. Keep that population in scope explicitly; - // the production default remains wallscope=context. - return "wall=1ms,wallscope=all,wallprecheck=true"; + // tracing-context window. Keep that population in scope explicitly. + return "wall=1ms,filter=,wallprecheck=true"; } protected String getPrecheckDisabledProfilerCommand() { - return "wall=1ms,wallscope=all,wallprecheck=false"; + return "wall=1ms,filter=,wallprecheck=false"; + } + + private long samplesForThread(String threadName) { + long count = 0; + JfrEvents events = verifyEvents("datadog.MethodSample", false); + for (JfrEvent item : events) { + if (threadName.equals(item.getThreadName("eventThread"))) { + count++; + } + } + return count; } private WeightedSamples weightedSamplesForThread(String threadName) { diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/TaskBlockAssertions.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/TaskBlockAssertions.java new file mode 100644 index 000000000..5b54c2981 --- /dev/null +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/TaskBlockAssertions.java @@ -0,0 +1,103 @@ +/* + * Copyright 2026, Datadog, Inc. + * SPDX-License-Identifier: Apache-2.0 + */ + +package com.datadoghq.profiler.wallclock; + +import com.datadoghq.profiler.AbstractProfilerTest; +import com.datadoghq.profiler.JfrEvent; +import com.datadoghq.profiler.JfrEvents; +import com.datadoghq.profiler.JfrFrame; +import java.util.HashSet; +import java.util.Set; + +import static org.junit.jupiter.api.Assertions.assertNull; +import static org.junit.jupiter.api.Assertions.assertTrue; + +/** Assertions for the synchronous {@code datadog.TaskBlock} event contract. */ +final class TaskBlockAssertions { + private static final String BLOCKER = "blocker"; + private static final String UNBLOCKING_SPAN_ID = "unblockingSpanId"; + private static final String ANCHOR_SAMPLE_ID = "anchorSampleId"; + private static final String SUPPRESSED_SAMPLE_COUNT = "suppressedSampleCount"; + private static final String OBSERVED_BLOCKING_STATE = "observedBlockingState"; + private static final String CORRELATION_ID = "correlationId"; + + private TaskBlockAssertions() {} + + static boolean containsBlocker(JfrEvents events, long blocker) { + for (JfrEvent item : events) { + if (item.getLong(BLOCKER, Long.MIN_VALUE) == blocker) { + return true; + } + } + return false; + } + + static void assertContains(JfrEvents events, long rootSpanId, long spanId, + long blocker, long unblockingSpanId) { + for (JfrEvent item : events) { + if (item.getLong(AbstractProfilerTest.LOCAL_ROOT_SPAN_ID, Long.MIN_VALUE) == rootSpanId + && item.getLong(AbstractProfilerTest.SPAN_ID, Long.MIN_VALUE) == spanId + && item.getLong(BLOCKER, Long.MIN_VALUE) == blocker + && item.getLong(UNBLOCKING_SPAN_ID, Long.MIN_VALUE) == unblockingSpanId) { + return; + } + } + throw new AssertionError("Expected TaskBlock blocker=" + blocker + + ", unblockingSpanId=" + unblockingSpanId); + } + + static void assertContainsObservedState(JfrEvents events, String expected) { + Set states = new HashSet<>(); + for (JfrEvent item : events) { + states.add(item.getString(OBSERVED_BLOCKING_STATE)); + } + assertTrue(states.contains(expected), () -> "Observed states: " + states); + } + + static void assertContainsStackTrace(JfrEvents events) { + int count = 0; + for (JfrEvent item : events) { + assertTrue(!item.getStackTrace().isEmpty()); + count++; + } + assertTrue(count > 0, "Expected a TaskBlock with a non-empty stack"); + } + + static void assertContainsNoStackTrace(JfrEvents events) { + int count = 0; + for (JfrEvent item : events) { + assertTrue(item.getStackTrace().isEmpty()); + count++; + } + assertTrue(count > 0, "Expected a TaskBlock without a stack"); + } + + static void assertContainsJavaType(JfrEvents events, String expected) { + for (JfrEvent item : events) { + if (!item.has(AbstractProfilerTest.STACK_TRACE)) continue; + for (JfrFrame frame : item.getStackTrace().frames()) { + String className = frame.className(); + if (className != null && className.contains(expected)) { + return; + } + } + } + throw new AssertionError("Expected TaskBlock stack type containing " + expected); + } + + static void assertNoCorrelationId(JfrEvents events) { + for (JfrEvent item : events) { + assertNull(item.get(CORRELATION_ID)); + } + } + + static void assertNoAnchorFields(JfrEvents events) { + for (JfrEvent item : events) { + assertNull(item.get(ANCHOR_SAMPLE_ID)); + assertNull(item.get(SUPPRESSED_SAMPLE_COUNT)); + } + } +} diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/UnfilteredWallPrecheckTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/UnfilteredWallPrecheckTest.java index 2b7c98fb3..9a42c38e3 100644 --- a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/UnfilteredWallPrecheckTest.java +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/UnfilteredWallPrecheckTest.java @@ -5,7 +5,6 @@ package com.datadoghq.profiler.wallclock; -import static org.junit.jupiter.api.Assertions.assertEquals; import static org.junit.jupiter.api.Assertions.assertSame; import static org.junit.jupiter.api.Assertions.assertTrue; @@ -28,14 +27,14 @@ public class UnfilteredWallPrecheckTest extends AbstractProfilerTest { private static final int OSTHREAD_STATE_SLEEPING = 7; private static final long SLEEP_MILLIS = 300; private static final String PRE_EXISTING_THREAD_NAME = "unfiltered-precheck-existing"; - private static final String SUPPRESSED_RUN_COUNTER = "wc_signals_suppressed_sampled_run"; - private static final String UNOWNED_SUPPRESSED_COUNTER = "wc_unowned_blocked_suppressed"; + private static final String SUPPRESSED_OWNED_BLOCK_COUNTER = + "wc_signals_suppressed_owned_block"; private ExecutorService preExistingWorker; private Thread preExistingThread; /** - * Verifies that an untraced thread's owned sleeping run is sampled once and then suppressed. + * Verifies that an untraced thread's owned sleeping run is suppressed. * * @throws Exception if the worker cannot complete */ @@ -95,11 +94,9 @@ public void parkedPreExistingThreadOutsideContextWindowIsOwnedBlockSuppressed() */ @RetryingTest(3) public void unownedSleepAfterOwnedBlockUsesNormalSampling() throws Exception { - long unownedSuppressedBefore = unownedSuppressedSignals(); assertTrue( runPreExistingUnownedSleepingWorker() != 0, "Expected the setup block to register the worker"); - long unownedSuppressedAfter = unownedSuppressedSignals(); stopProfiler(); @@ -107,28 +104,25 @@ public void unownedSleepAfterOwnedBlockUsesNormalSampling() throws Exception { assertTrue( sampleCount >= 10, "Expected normal MethodSample volume for an unowned sleep, got: " + sampleCount); - if (unownedSuppressedBefore >= 0) { - assertEquals( - unownedSuppressedBefore, - unownedSuppressedAfter, - "Unfiltered mode must not use observation-only unowned suppression"); - } } /** - * Retains coverage for post-start threads, whose owned-block hook must register a slot lazily. + * Retains coverage for threads whose registry slot is installed by a post-start ThreadStart + * event. * * @throws Exception if the worker cannot complete */ @RetryingTest(3) - public void postStartSleepingThreadLazilyRegistersOwnedBlock() throws Exception { + public void postStartSleepingThreadUsesThreadStartSlot() throws Exception { String threadName = "unfiltered-precheck-post-start"; + long suppressedBefore = suppressedSignals(); assertTrue( runPostStartSleepingWorker(threadName) != 0, - "Expected the owned-block hook to register and arm SLEEPING state"); + "Expected ThreadStart registration to arm SLEEPING state"); stopProfiler(); assertSuppressedSamples(threadName); + assertOwnedBlockSuppressionObserved(suppressedBefore); } @Override @@ -249,19 +243,18 @@ private void assertOwnedBlockSuppressionObserved(long suppressedBefore) { } private long suppressedSignals() { - return profiler.getDebugCounters().getOrDefault(SUPPRESSED_RUN_COUNTER, -1L); - } - - private long unownedSuppressedSignals() { - return profiler.getDebugCounters().getOrDefault(UNOWNED_SUPPRESSED_COUNTER, -1L); + return profiler.getDebugCounters().getOrDefault(SUPPRESSED_OWNED_BLOCK_COUNTER, -1L); } private void assertSuppressedSamples(String threadName) { long sampleCount = samplesForThread(threadName); - assertTrue(sampleCount > 0, "Expected the owned block run to be sampled once"); + assertTrue( + sampleCount >= 1, + "Expected the owned block's first MethodSample to be retained"); assertTrue( sampleCount < 10, - "Expected nearly no samples from owned block thread, got: " + sampleCount); + "Expected samples after the first owned-block sample to be suppressed, got: " + + sampleCount); } private long samplesForThread(String threadName) { diff --git a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/WallclockMitigationsCombinedTest.java b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/WallclockMitigationsCombinedTest.java index 00b51d9ba..77319c13d 100644 --- a/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/WallclockMitigationsCombinedTest.java +++ b/ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/WallclockMitigationsCombinedTest.java @@ -5,6 +5,7 @@ package com.datadoghq.profiler.wallclock; +import static org.junit.jupiter.api.Assertions.assertEquals; import static org.junit.jupiter.api.Assertions.assertTrue; import com.datadoghq.profiler.AbstractProfilerTest; @@ -20,15 +21,12 @@ import java.util.concurrent.CountDownLatch; import java.util.concurrent.atomic.AtomicBoolean; -/** - * Verifies once-per-run suppression ({@code wallprecheck=true}) with a mix of sleeping, - * parked, and runnable threads. - */ +/** Verifies that {@code wallprecheck=true} does not suppress context-scoped threads. */ public class WallclockMitigationsCombinedTest extends AbstractProfilerTest { private static final int OSTHREAD_STATE_SLEEPING = 7; @Test - public void precheckAndParkSuppressionWorkTogether() throws Exception { + public void contextScopedThreadsRemainSampled() throws Exception { Assumptions.assumeTrue(!Platform.isJ9()); Assumptions.assumeTrue( Platform.isJavaVersionAtLeast(11), @@ -36,6 +34,8 @@ public void precheckAndParkSuppressionWorkTogether() throws Exception { CountDownLatch ready = new CountDownLatch(3); AtomicBoolean stop = new AtomicBoolean(false); + long suppressedBefore = profiler.getDebugCounters() + .getOrDefault("wc_signals_suppressed_owned_block", 0L); Thread sleeping = new Thread( @@ -106,20 +106,17 @@ public void precheckAndParkSuppressionWorkTogether() throws Exception { long parkedSamples = samplesByThread.getOrDefault("combined-parked", 0L); long runnableSamples = samplesByThread.getOrDefault("combined-runnable", 0L); - assertTrue(sleepingSamples < 10, - "Expected nearly no samples from owned sleeping thread, got: " + sleepingSamples); + assertTrue(sleepingSamples > 0, + "Expected samples from context-scoped sleeping thread, got: " + sleepingSamples); assertTrue(parkedSamples > 0, "Expected samples from traced parked thread, got: " + parkedSamples); assertTrue(runnableSamples > 0, "Expected samples from runnable thread, got: " + runnableSamples); - // Sleeping thread's suppression counter must have incremented. - Map counters = profiler.getDebugCounters(); - if (counters.containsKey("wc_signals_suppressed_sampled_run")) { - assertTrue( - counters.get("wc_signals_suppressed_sampled_run") > 0, - "Expected once-per-run suppression counter to increase"); - } + long suppressedAfter = profiler.getDebugCounters() + .getOrDefault("wc_signals_suppressed_owned_block", 0L); + assertEquals(suppressedBefore, suppressedAfter, + "Context-scoped blocked threads must not be signal-suppression candidates"); } @Override