| // Copyright 2012 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_PROFILER_CPU_PROFILER_H_ |
| #define V8_PROFILER_CPU_PROFILER_H_ |
| |
| #include <atomic> |
| #include <memory> |
| |
| #include "src/base/platform/condition-variable.h" |
| #include "src/base/platform/mutex.h" |
| #include "src/base/platform/time.h" |
| #include "src/profiler/circular-queue.h" |
| #include "src/profiler/profiler-listener.h" |
| #include "src/profiler/tick-sample.h" |
| #include "src/utils/locked-queue.h" |
| |
| namespace v8 { |
| namespace sampler { |
| class Sampler; |
| } // namespace sampler |
| namespace internal { |
| |
| // Forward declarations. |
| class CodeEntry; |
| class CodeMap; |
| class CpuProfilesCollection; |
| class Isolate; |
| class Symbolizer; |
| |
| #define CODE_EVENTS_TYPE_LIST(V) \ |
| V(CODE_CREATION, CodeCreateEventRecord) \ |
| V(CODE_MOVE, CodeMoveEventRecord) \ |
| V(CODE_DISABLE_OPT, CodeDisableOptEventRecord) \ |
| V(CODE_DEOPT, CodeDeoptEventRecord) \ |
| V(REPORT_BUILTIN, ReportBuiltinEventRecord) |
| |
| class CodeEventRecord { |
| public: |
| #define DECLARE_TYPE(type, ignore) type, |
| enum Type { NONE = 0, CODE_EVENTS_TYPE_LIST(DECLARE_TYPE) }; |
| #undef DECLARE_TYPE |
| |
| Type type; |
| mutable unsigned order; |
| }; |
| |
| |
| class CodeCreateEventRecord : public CodeEventRecord { |
| public: |
| Address instruction_start; |
| CodeEntry* entry; |
| unsigned instruction_size; |
| |
| V8_INLINE void UpdateCodeMap(CodeMap* code_map); |
| }; |
| |
| |
| class CodeMoveEventRecord : public CodeEventRecord { |
| public: |
| Address from_instruction_start; |
| Address to_instruction_start; |
| |
| V8_INLINE void UpdateCodeMap(CodeMap* code_map); |
| }; |
| |
| |
| class CodeDisableOptEventRecord : public CodeEventRecord { |
| public: |
| Address instruction_start; |
| const char* bailout_reason; |
| |
| V8_INLINE void UpdateCodeMap(CodeMap* code_map); |
| }; |
| |
| |
| class CodeDeoptEventRecord : public CodeEventRecord { |
| public: |
| Address instruction_start; |
| const char* deopt_reason; |
| int deopt_id; |
| Address pc; |
| int fp_to_sp_delta; |
| CpuProfileDeoptFrame* deopt_frames; |
| int deopt_frame_count; |
| |
| V8_INLINE void UpdateCodeMap(CodeMap* code_map); |
| }; |
| |
| |
| class ReportBuiltinEventRecord : public CodeEventRecord { |
| public: |
| Address instruction_start; |
| unsigned instruction_size; |
| Builtins::Name builtin_id; |
| |
| V8_INLINE void UpdateCodeMap(CodeMap* code_map); |
| }; |
| |
| // A record type for sending samples from the main thread/signal handler to the |
| // profiling thread. |
| class TickSampleEventRecord { |
| public: |
| // The parameterless constructor is used when we dequeue data from |
| // the ticks buffer. |
| TickSampleEventRecord() = default; |
| explicit TickSampleEventRecord(unsigned order) : order(order) { } |
| |
| unsigned order; |
| TickSample sample; |
| }; |
| |
| // A record type for sending code events (e.g. create, move, delete) to the |
| // profiling thread. |
| class CodeEventsContainer { |
| public: |
| explicit CodeEventsContainer( |
| CodeEventRecord::Type type = CodeEventRecord::NONE) { |
| generic.type = type; |
| } |
| union { |
| CodeEventRecord generic; |
| #define DECLARE_CLASS(ignore, type) type type##_; |
| CODE_EVENTS_TYPE_LIST(DECLARE_CLASS) |
| #undef DECLARE_CLASS |
| }; |
| }; |
| |
| // Maintains the number of active CPU profilers in an isolate, and routes |
| // logging to a given ProfilerListener. |
| class ProfilingScope { |
| public: |
| ProfilingScope(Isolate* isolate, ProfilerListener* listener); |
| ~ProfilingScope(); |
| |
| private: |
| Isolate* const isolate_; |
| ProfilerListener* const listener_; |
| }; |
| |
| class ProfilerCodeObserver; |
| |
| // This class implements both the profile events processor thread and |
| // methods called by event producers: VM and stack sampler threads. |
| class V8_EXPORT_PRIVATE ProfilerEventsProcessor : public base::Thread, |
| public CodeEventObserver { |
| public: |
| ~ProfilerEventsProcessor() override; |
| |
| void CodeEventHandler(const CodeEventsContainer& evt_rec) override; |
| |
| // Thread control. |
| void Run() override = 0; |
| void StopSynchronously(); |
| bool running() { return running_.load(std::memory_order_relaxed); } |
| void Enqueue(const CodeEventsContainer& event); |
| |
| // Puts current stack into the tick sample events buffer. |
| void AddCurrentStack(bool update_stats = false); |
| void AddDeoptStack(Address from, int fp_to_sp_delta); |
| // Add a sample into the tick sample events buffer. Used for testing. |
| void AddSample(TickSample sample); |
| |
| virtual void SetSamplingInterval(base::TimeDelta) {} |
| |
| protected: |
| ProfilerEventsProcessor(Isolate* isolate, Symbolizer* symbolizer, |
| ProfilerCodeObserver* code_observer); |
| |
| // Called from events processing thread (Run() method.) |
| bool ProcessCodeEvent(); |
| |
| enum SampleProcessingResult { |
| OneSampleProcessed, |
| FoundSampleForNextCodeEvent, |
| NoSamplesInQueue |
| }; |
| virtual SampleProcessingResult ProcessOneSample() = 0; |
| |
| Symbolizer* symbolizer_; |
| ProfilerCodeObserver* code_observer_; |
| std::atomic_bool running_{true}; |
| base::ConditionVariable running_cond_; |
| base::Mutex running_mutex_; |
| LockedQueue<CodeEventsContainer> events_buffer_; |
| LockedQueue<TickSampleEventRecord> ticks_from_vm_buffer_; |
| std::atomic<unsigned> last_code_event_id_; |
| unsigned last_processed_code_event_id_; |
| Isolate* isolate_; |
| }; |
| |
| class V8_EXPORT_PRIVATE SamplingEventsProcessor |
| : public ProfilerEventsProcessor { |
| public: |
| SamplingEventsProcessor(Isolate* isolate, Symbolizer* symbolizer, |
| ProfilerCodeObserver* code_observer, |
| CpuProfilesCollection* profiles, |
| base::TimeDelta period, bool use_precise_sampling); |
| ~SamplingEventsProcessor() override; |
| |
| // SamplingCircularQueue has stricter alignment requirements than a normal new |
| // can fulfil, so we need to provide our own new/delete here. |
| void* operator new(size_t size); |
| void operator delete(void* ptr); |
| |
| void Run() override; |
| |
| void SetSamplingInterval(base::TimeDelta period) override; |
| |
| // Tick sample events are filled directly in the buffer of the circular |
| // queue (because the structure is of fixed width, but usually not all |
| // stack frame entries are filled.) This method returns a pointer to the |
| // next record of the buffer. |
| // These methods are not thread-safe and should only ever be called by one |
| // producer (from CpuSampler::SampleStack()). For testing, use AddSample. |
| inline TickSample* StartTickSample(); |
| inline void FinishTickSample(); |
| |
| sampler::Sampler* sampler() { return sampler_.get(); } |
| base::TimeDelta period() const { return period_; } |
| |
| private: |
| SampleProcessingResult ProcessOneSample() override; |
| void SymbolizeAndAddToProfiles(const TickSampleEventRecord* record); |
| |
| static const size_t kTickSampleBufferSize = 512 * KB; |
| static const size_t kTickSampleQueueLength = |
| kTickSampleBufferSize / sizeof(TickSampleEventRecord); |
| SamplingCircularQueue<TickSampleEventRecord, |
| kTickSampleQueueLength> ticks_buffer_; |
| std::unique_ptr<sampler::Sampler> sampler_; |
| CpuProfilesCollection* profiles_; |
| base::TimeDelta period_; // Samples & code events processing period. |
| const bool use_precise_sampling_; // Whether or not busy-waiting is used for |
| // low sampling intervals on Windows. |
| }; |
| |
| // Builds and maintains a CodeMap tracking code objects on the VM heap. While |
| // alive, logs generated code, callbacks, and builtins from the isolate. |
| // Redirects events to the profiler events processor when present. |
| class V8_EXPORT_PRIVATE ProfilerCodeObserver : public CodeEventObserver { |
| public: |
| explicit ProfilerCodeObserver(Isolate*); |
| |
| void CodeEventHandler(const CodeEventsContainer& evt_rec) override; |
| |
| CodeMap* code_map() { return &code_map_; } |
| void ClearCodeMap(); |
| |
| private: |
| friend class ProfilerEventsProcessor; |
| |
| void CodeEventHandlerInternal(const CodeEventsContainer& evt_rec); |
| |
| void CreateEntriesForRuntimeCallStats(); |
| void LogBuiltins(); |
| |
| ProfilerEventsProcessor* processor() { return processor_; } |
| |
| // Redirects code events to be enqueued on the given events processor. |
| void set_processor(ProfilerEventsProcessor* processor) { |
| processor_ = processor; |
| } |
| |
| // Stops redirection of code events onto an events processor. |
| void clear_processor() { processor_ = nullptr; } |
| |
| Isolate* const isolate_; |
| CodeMap code_map_; |
| ProfilerEventsProcessor* processor_; |
| }; |
| |
| // The CpuProfiler is a sampling CPU profiler for JS frames. It corresponds to |
| // v8::CpuProfiler at the API level. It spawns an additional thread which is |
| // responsible for triggering samples and then symbolizing the samples with |
| // function names. To symbolize on a background thread, the profiler copies |
| // metadata about generated code off-heap. |
| // |
| // Sampling is done using posix signals (except on Windows). The profiling |
| // thread sends a signal to the main thread, based on a timer. The signal |
| // handler can interrupt the main thread between any abitrary instructions. |
| // This means we are very careful about reading stack values during the signal |
| // handler as we could be in the middle of an operation that is modifying the |
| // stack. |
| // |
| // The story on Windows is similar except we use thread suspend and resume. |
| // |
| // Samples are passed to the profiling thread via a circular buffer. The |
| // profiling thread symbolizes the samples by looking up the code pointers |
| // against its own list of code objects. The profiling thread also listens for |
| // code creation/move/deletion events (from the GC), to maintain its list of |
| // code objects accurately. |
| class V8_EXPORT_PRIVATE CpuProfiler { |
| public: |
| explicit CpuProfiler(Isolate* isolate, CpuProfilingNamingMode = kDebugNaming, |
| CpuProfilingLoggingMode = kLazyLogging); |
| |
| CpuProfiler(Isolate* isolate, CpuProfilingNamingMode naming_mode, |
| CpuProfilingLoggingMode logging_mode, |
| CpuProfilesCollection* profiles, Symbolizer* test_symbolizer, |
| ProfilerEventsProcessor* test_processor); |
| |
| ~CpuProfiler(); |
| |
| static void CollectSample(Isolate* isolate); |
| |
| using ProfilingMode = v8::CpuProfilingMode; |
| using NamingMode = v8::CpuProfilingNamingMode; |
| using LoggingMode = v8::CpuProfilingLoggingMode; |
| using StartProfilingStatus = CpuProfilingStatus; |
| |
| base::TimeDelta sampling_interval() const { return base_sampling_interval_; } |
| void set_sampling_interval(base::TimeDelta value); |
| void set_use_precise_sampling(bool); |
| void CollectSample(); |
| StartProfilingStatus StartProfiling(const char* title, |
| CpuProfilingOptions options = {}); |
| StartProfilingStatus StartProfiling(String title, |
| CpuProfilingOptions options = {}); |
| |
| CpuProfile* StopProfiling(const char* title); |
| CpuProfile* StopProfiling(String title); |
| int GetProfilesCount(); |
| CpuProfile* GetProfile(int index); |
| void DeleteAllProfiles(); |
| void DeleteProfile(CpuProfile* profile); |
| |
| bool is_profiling() const { return is_profiling_; } |
| |
| Symbolizer* symbolizer() const { return symbolizer_.get(); } |
| ProfilerEventsProcessor* processor() const { return processor_.get(); } |
| Isolate* isolate() const { return isolate_; } |
| |
| ProfilerListener* profiler_listener_for_test() const { |
| return profiler_listener_.get(); |
| } |
| CodeMap* code_map_for_test() { return code_observer_.code_map(); } |
| |
| private: |
| void StartProcessorIfNotStarted(); |
| void StopProcessorIfLastProfile(const char* title); |
| void StopProcessor(); |
| void ResetProfiles(); |
| |
| void EnableLogging(); |
| void DisableLogging(); |
| |
| // Computes a sampling interval sufficient to accomodate attached profiles. |
| base::TimeDelta ComputeSamplingInterval() const; |
| // Dynamically updates the sampler to use a sampling interval sufficient for |
| // child profiles. |
| void AdjustSamplingInterval(); |
| |
| Isolate* const isolate_; |
| const NamingMode naming_mode_; |
| const LoggingMode logging_mode_; |
| bool use_precise_sampling_ = true; |
| // Sampling interval to which per-profile sampling intervals will be clamped |
| // to a multiple of, or used as the default if unspecified. |
| base::TimeDelta base_sampling_interval_; |
| std::unique_ptr<CpuProfilesCollection> profiles_; |
| std::unique_ptr<Symbolizer> symbolizer_; |
| std::unique_ptr<ProfilerEventsProcessor> processor_; |
| std::unique_ptr<ProfilerListener> profiler_listener_; |
| std::unique_ptr<ProfilingScope> profiling_scope_; |
| ProfilerCodeObserver code_observer_; |
| bool is_profiling_; |
| |
| DISALLOW_COPY_AND_ASSIGN(CpuProfiler); |
| }; |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_PROFILER_CPU_PROFILER_H_ |