// Copyright 2015 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include <stddef.h> #include "base/trace_event/trace_event_impl.h" #include "base/trace_event/trace_log.h" #include "base/trace_event/trace_sampling_thread.h" namespace base { namespace trace_event { class TraceBucketData { public: TraceBucketData(base::subtle::AtomicWord* bucket, const char* name, TraceSampleCallback callback); ~TraceBucketData(); TRACE_EVENT_API_ATOMIC_WORD* bucket; const char* bucket_name; TraceSampleCallback callback; }; TraceSamplingThread::TraceSamplingThread() : thread_running_(false), waitable_event_for_testing_(false, false) {} TraceSamplingThread::~TraceSamplingThread() {} void TraceSamplingThread::ThreadMain() { PlatformThread::SetName("Sampling Thread"); thread_running_ = true; const int kSamplingFrequencyMicroseconds = 1000; while (!cancellation_flag_.IsSet()) { PlatformThread::Sleep( TimeDelta::FromMicroseconds(kSamplingFrequencyMicroseconds)); GetSamples(); waitable_event_for_testing_.Signal(); } } // static void TraceSamplingThread::DefaultSamplingCallback( TraceBucketData* bucket_data) { TRACE_EVENT_API_ATOMIC_WORD category_and_name = TRACE_EVENT_API_ATOMIC_LOAD(*bucket_data->bucket); if (!category_and_name) return; const char* const combined = reinterpret_cast<const char* const>(category_and_name); const char* category_group; const char* name; ExtractCategoryAndName(combined, &category_group, &name); TRACE_EVENT_API_ADD_TRACE_EVENT( TRACE_EVENT_PHASE_SAMPLE, TraceLog::GetCategoryGroupEnabled(category_group), name, 0, 0, NULL, NULL, NULL, NULL, 0); } void TraceSamplingThread::GetSamples() { for (size_t i = 0; i < sample_buckets_.size(); ++i) { TraceBucketData* bucket_data = &sample_buckets_[i]; bucket_data->callback.Run(bucket_data); } } void TraceSamplingThread::RegisterSampleBucket( TRACE_EVENT_API_ATOMIC_WORD* bucket, const char* const name, TraceSampleCallback callback) { // Access to sample_buckets_ doesn't cause races with the sampling thread // that uses the sample_buckets_, because it is guaranteed that // RegisterSampleBucket is called before the sampling thread is created. DCHECK(!thread_running_); sample_buckets_.push_back(TraceBucketData(bucket, name, callback)); } // static void TraceSamplingThread::ExtractCategoryAndName(const char* combined, const char** category, const char** name) { *category = combined; *name = &combined[strlen(combined) + 1]; } void TraceSamplingThread::Stop() { cancellation_flag_.Set(); } void TraceSamplingThread::WaitSamplingEventForTesting() { waitable_event_for_testing_.Wait(); } TraceBucketData::TraceBucketData(base::subtle::AtomicWord* bucket, const char* name, TraceSampleCallback callback) : bucket(bucket), bucket_name(name), callback(callback) {} TraceBucketData::~TraceBucketData() {} } // namespace trace_event } // namespace base