/* * Copyright (C) 2011 The Android Open Source Project * * 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. */ #ifndef ART_RUNTIME_TRACE_H_ #define ART_RUNTIME_TRACE_H_ #include #include #include #include #include #include #include #include #include "base/atomic.h" #include "base/locks.h" #include "base/macros.h" #include "base/os.h" #include "base/safe_map.h" #include "instrumentation.h" #include "runtime_globals.h" namespace unix_file { class FdFile; } // namespace unix_file namespace art { class ArtField; class ArtMethod; class DexFile; class LOCKABLE Mutex; class ShadowFrame; class Thread; using DexIndexBitSet = std::bitset<65536>; constexpr size_t kMaxThreadIdNumber = kIsTargetBuild ? 65536U : 1048576U; using ThreadIDBitSet = std::bitset; enum TracingMode { kTracingInactive, kMethodTracingActive, // Trace activity synchronous with method progress. kSampleProfilingActive, // Trace activity captured by sampling thread. }; std::ostream& operator<<(std::ostream& os, const TracingMode& rhs); // File format: // header // record 0 // record 1 // ... // // Header format: // u4 magic ('SLOW') // u2 version // u2 offset to data // u8 start date/time in usec // u2 record size in bytes (version >= 2 only) // ... padding to 32 bytes // // Record format v1: // u1 thread ID // u4 method ID | method action // u4 time delta since start, in usec // // Record format v2: // u2 thread ID // u4 method ID | method action // u4 time delta since start, in usec // // Record format v3: // u2 thread ID // u4 method ID | method action // u4 time delta since start, in usec // u4 wall time since start, in usec (when clock == "dual" only) // // 32 bits of microseconds is 70 minutes. // // All values are stored in little-endian order. enum TraceAction { kTraceMethodEnter = 0x00, // method entry kTraceMethodExit = 0x01, // method exit kTraceUnroll = 0x02, // method exited by exception unrolling // 0x03 currently unused kTraceMethodActionMask = 0x03, // two bits }; // Class for recording event traces. Trace data is either collected // synchronously during execution (TracingMode::kMethodTracingActive), // or by a separate sampling thread (TracingMode::kSampleProfilingActive). class Trace final : public instrumentation::InstrumentationListener { public: enum TraceFlag { kTraceCountAllocs = 1, }; enum class TraceOutputMode { kFile, kDDMS, kStreaming }; enum class TraceMode { kMethodTracing, kSampling }; ~Trace(); static void SetDefaultClockSource(TraceClockSource clock_source); static void Start(const char* trace_filename, size_t buffer_size, int flags, TraceOutputMode output_mode, TraceMode trace_mode, int interval_us) REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_, !Locks::trace_lock_); static void Start(int trace_fd, size_t buffer_size, int flags, TraceOutputMode output_mode, TraceMode trace_mode, int interval_us) REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_, !Locks::trace_lock_); static void Start(std::unique_ptr&& file, size_t buffer_size, int flags, TraceOutputMode output_mode, TraceMode trace_mode, int interval_us) REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_, !Locks::trace_lock_); static void StartDDMS(size_t buffer_size, int flags, TraceMode trace_mode, int interval_us) REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_, !Locks::trace_lock_); // Stop tracing. This will finish the trace and write it to file/send it via DDMS. static void Stop() REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_); // Abort tracing. This will just stop tracing and *not* write/send the collected data. static void Abort() REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_); static void Shutdown() REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_); static TracingMode GetMethodTracingMode() REQUIRES(!Locks::trace_lock_); bool UseWallClock(); bool UseThreadCpuClock(); void MeasureClockOverhead(); uint32_t GetClockOverheadNanoSeconds(); void CompareAndUpdateStackTrace(Thread* thread, std::vector* stack_trace) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_, !streaming_lock_); // InstrumentationListener implementation. void MethodEntered(Thread* thread, Handle this_object, ArtMethod* method, uint32_t dex_pc) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_, !streaming_lock_) override; void MethodExited(Thread* thread, Handle this_object, ArtMethod* method, uint32_t dex_pc, const JValue& return_value) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_, !streaming_lock_) override; void MethodUnwind(Thread* thread, Handle this_object, ArtMethod* method, uint32_t dex_pc) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_, !streaming_lock_) override; void DexPcMoved(Thread* thread, Handle this_object, ArtMethod* method, uint32_t new_dex_pc) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_, !streaming_lock_) override; void FieldRead(Thread* thread, Handle this_object, ArtMethod* method, uint32_t dex_pc, ArtField* field) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_) override; void FieldWritten(Thread* thread, Handle this_object, ArtMethod* method, uint32_t dex_pc, ArtField* field, const JValue& field_value) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_) override; void ExceptionThrown(Thread* thread, Handle exception_object) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_) override; void ExceptionHandled(Thread* thread, Handle exception_object) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_) override; void Branch(Thread* thread, ArtMethod* method, uint32_t dex_pc, int32_t dex_pc_offset) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_) override; void WatchedFramePop(Thread* thread, const ShadowFrame& frame) REQUIRES_SHARED(Locks::mutator_lock_) override; // Reuse an old stack trace if it exists, otherwise allocate a new one. static std::vector* AllocStackTrace(); // Clear and store an old stack trace for later use. static void FreeStackTrace(std::vector* stack_trace); // Save id and name of a thread before it exits. static void StoreExitingThreadInfo(Thread* thread); static TraceOutputMode GetOutputMode() REQUIRES(!Locks::trace_lock_); static TraceMode GetMode() REQUIRES(!Locks::trace_lock_); static size_t GetBufferSize() REQUIRES(!Locks::trace_lock_); // Used by class linker to prevent class unloading. static bool IsTracingEnabled() REQUIRES(!Locks::trace_lock_); private: Trace(File* trace_file, size_t buffer_size, int flags, TraceOutputMode output_mode, TraceMode trace_mode); // The sampling interval in microseconds is passed as an argument. static void* RunSamplingThread(void* arg) REQUIRES(!Locks::trace_lock_); static void StopTracing(bool finish_tracing, bool flush_file) REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_) // There is an annoying issue with static functions that create a new object and call into // that object that causes them to not be able to tell that we don't currently hold the lock. // This causes the negative annotations to incorrectly have a false positive. TODO: Figure out // how to annotate this. NO_THREAD_SAFETY_ANALYSIS; void FinishTracing() REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_, !streaming_lock_); void ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff); void LogMethodTraceEvent(Thread* thread, ArtMethod* method, instrumentation::Instrumentation::InstrumentationEvent event, uint32_t thread_clock_diff, uint32_t wall_clock_diff) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_, !streaming_lock_); // Methods to output traced methods and threads. void GetVisitedMethods(size_t end_offset, std::set* visited_methods) REQUIRES(!unique_methods_lock_); void DumpMethodList(std::ostream& os, const std::set& visited_methods) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_); void DumpThreadList(std::ostream& os) REQUIRES(!Locks::thread_list_lock_); // Methods to register seen entitites in streaming mode. The methods return true if the entity // is newly discovered. bool RegisterMethod(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(streaming_lock_); bool RegisterThread(Thread* thread) REQUIRES(streaming_lock_); // Copy a temporary buffer to the main buffer. Used for streaming. Exposed here for lock // annotation. void WriteToBuf(const uint8_t* src, size_t src_size) REQUIRES(streaming_lock_); // Flush the main buffer to file. Used for streaming. Exposed here for lock annotation. void FlushBuf() REQUIRES(streaming_lock_); uint32_t EncodeTraceMethod(ArtMethod* method) REQUIRES(!unique_methods_lock_); uint32_t EncodeTraceMethodAndAction(ArtMethod* method, TraceAction action) REQUIRES(!unique_methods_lock_); ArtMethod* DecodeTraceMethod(uint32_t tmid) REQUIRES(!unique_methods_lock_); std::string GetMethodLine(ArtMethod* method) REQUIRES(!unique_methods_lock_) REQUIRES_SHARED(Locks::mutator_lock_); void DumpBuf(uint8_t* buf, size_t buf_size, TraceClockSource clock_source) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!unique_methods_lock_); // Singleton instance of the Trace or null when no method tracing is active. static Trace* volatile the_trace_ GUARDED_BY(Locks::trace_lock_); // The default profiler clock source. static TraceClockSource default_clock_source_; // Sampling thread, non-zero when sampling. static pthread_t sampling_pthread_; // Used to remember an unused stack trace to avoid re-allocation during sampling. static std::unique_ptr> temp_stack_trace_; // File to write trace data out to, null if direct to ddms. std::unique_ptr trace_file_; // Buffer to store trace data. In streaming mode, this is protected // by the streaming_lock_. In non-streaming mode, reserved regions // are atomically allocated (using cur_offset_) for log entries to // be written. std::unique_ptr buf_; // Flags enabling extra tracing of things such as alloc counts. const int flags_; // The kind of output for this tracing. const TraceOutputMode trace_output_mode_; // The tracing method. const TraceMode trace_mode_; const TraceClockSource clock_source_; // Size of buf_. const size_t buffer_size_; // Time trace was created. const uint64_t start_time_; // Clock overhead. const uint32_t clock_overhead_ns_; // Offset into buf_. The field is atomic to allow multiple writers // to concurrently reserve space in the buffer. The newly written // buffer contents are not read without some other form of thread // synchronization, such as suspending all potential writers or // acquiring *streaming_lock_. Reading cur_offset_ is thus never // used to ensure visibility of any other objects, and all accesses // are memory_order_relaxed. // // All accesses to buf_ in streaming mode occur whilst holding the // streaming lock. In streaming mode, the buffer may be written out // so cur_offset_ can move forwards and backwards. // // When not in streaming mode, the buf_ writes can come from // multiple threads when the trace mode is kMethodTracing. When // trace mode is kSampling, writes only come from the sampling // thread. // // Reads to the buffer happen after the event sources writing to the // buffer have been shutdown and all stores have completed. The // stores are made visible in StopTracing() when execution leaves // the ScopedSuspendAll block. AtomicInteger cur_offset_; // Did we overflow the buffer recording traces? bool overflow_; // Map of thread ids and names that have already exited. SafeMap exited_threads_; // Sampling profiler sampling interval. int interval_us_; // Streaming mode data. Mutex* streaming_lock_; std::map seen_methods_ GUARDED_BY(streaming_lock_); std::unique_ptr seen_threads_ GUARDED_BY(streaming_lock_); // Bijective map from ArtMethod* to index. // Map from ArtMethod* to index in unique_methods_; Mutex* unique_methods_lock_ ACQUIRED_AFTER(streaming_lock_); std::unordered_map art_method_id_map_ GUARDED_BY(unique_methods_lock_); std::vector unique_methods_ GUARDED_BY(unique_methods_lock_); DISALLOW_COPY_AND_ASSIGN(Trace); }; } // namespace art #endif // ART_RUNTIME_TRACE_H_