1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_DEBUG_TRACE_EVENT_SYSTEM_STATS_MONITOR_H_ 6 #define BASE_DEBUG_TRACE_EVENT_SYSTEM_STATS_MONITOR_H_ 7 8 #include "base/base_export.h" 9 #include "base/debug/trace_event_impl.h" 10 #include "base/gtest_prod_util.h" 11 #include "base/memory/ref_counted.h" 12 #include "base/memory/weak_ptr.h" 13 #include "base/process/process_metrics.h" 14 #include "base/timer/timer.h" 15 16 namespace base { 17 18 class SingleThreadTaskRunner; 19 20 namespace debug { 21 22 // Watches for chrome://tracing to be enabled or disabled. When tracing is 23 // enabled, also enables system events profiling. This class is the preferred 24 // way to turn system tracing on and off. 25 class BASE_EXPORT TraceEventSystemStatsMonitor 26 : public TraceLog::EnabledStateObserver { 27 public: 28 // Length of time interval between stat profiles. 29 static const int kSamplingIntervalMilliseconds = 2000; 30 31 // |task_runner| must be the primary thread for the client 32 // process, e.g. the UI thread in a browser. 33 explicit TraceEventSystemStatsMonitor( 34 scoped_refptr<SingleThreadTaskRunner> task_runner); 35 36 virtual ~TraceEventSystemStatsMonitor(); 37 38 // base::debug::TraceLog::EnabledStateChangedObserver overrides: 39 virtual void OnTraceLogEnabled() OVERRIDE; 40 virtual void OnTraceLogDisabled() OVERRIDE; 41 42 // Retrieves system profiling at the current time. 43 void DumpSystemStats(); 44 45 private: 46 FRIEND_TEST_ALL_PREFIXES(TraceSystemStatsMonitorTest, 47 TraceEventSystemStatsMonitor); 48 49 bool IsTimerRunningForTest() const; 50 51 void StartProfiling(); 52 53 void StopProfiling(); 54 55 // Ensures the observer starts and stops tracing on the primary thread. 56 scoped_refptr<SingleThreadTaskRunner> task_runner_; 57 58 // Timer to schedule system profile dumps. 59 RepeatingTimer<TraceEventSystemStatsMonitor> dump_timer_; 60 61 WeakPtrFactory<TraceEventSystemStatsMonitor> weak_factory_; 62 63 DISALLOW_COPY_AND_ASSIGN(TraceEventSystemStatsMonitor); 64 }; 65 66 // Converts system memory profiling stats in |input| to 67 // trace event compatible JSON and appends to |output|. Visible for testing. 68 BASE_EXPORT void AppendSystemProfileAsTraceFormat(const SystemMetrics& 69 system_stats, 70 std::string* output); 71 72 } // namespace debug 73 } // namespace base 74 75 #endif // BASE_DEBUG_TRACE_EVENT_SYSTEM_STATS_MONITOR_H_ 76