components/power_metrics/system_power_monitor.h

   1 // Copyright 2023 The Chromium Authors
   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 COMPONENTS_POWER_METRICS_SYSTEM_POWER_MONITOR_H_
   6 #define COMPONENTS_POWER_METRICS_SYSTEM_POWER_MONITOR_H_
   7
   8 #include <memory>
   9 #include <vector>
  10
  11 #include "base/threading/sequence_bound.h"
  12 #include "base/time/time.h"
  13 #include "base/timer/timer.h"
  14 #include "base/trace_event/trace_log.h"
  15 #include "components/power_metrics/energy_metrics_provider.h"
  16
  17 namespace power_metrics {
  18
  19 // A delegate to isolate System Power Monitor functionality mainly for
  20 // testing.
  21 class SystemPowerMonitorDelegate {
  22  public:
  23   SystemPowerMonitorDelegate();
  24
  25   SystemPowerMonitorDelegate(const SystemPowerMonitorDelegate&) = delete;
  26   SystemPowerMonitorDelegate& operator=(const SystemPowerMonitorDelegate&) =
  27       delete;
  28
  29   virtual ~SystemPowerMonitorDelegate();
  30
  31   // Emits trace counter. The metric string stands for trace counter name,
  32   // timestamp is the counter timestamp, power is the corresponding counter
  33   // value of system power consumption in units of milliwatts.
  34   virtual void RecordSystemPower(const char* metric,
  35                                  base::TimeTicks timestamp,
  36                                  int64_t power);
  37
  38   // Returns whether the tracing category is enabled to determine if we should
  39   // record.
  40   virtual bool IsTraceCategoryEnabled() const;
  41 };
  42
  43 // Manages a timer to regularly sample and emit trace events, whose start and
  44 // stop are controlled by System Power Monitor.
  45 class SystemPowerMonitorHelper {
  46  public:
  47   // Default sampling interval, which should be set to larger or equal to 50 ms.
  48   static constexpr base::TimeDelta kDefaultSampleInterval =
  49       base::Milliseconds(50);
  50
  51   SystemPowerMonitorHelper(
  52       std::unique_ptr<EnergyMetricsProvider> provider,
  53       std::unique_ptr<SystemPowerMonitorDelegate> delegate);
  54
  55   SystemPowerMonitorHelper(const SystemPowerMonitorHelper&) = delete;
  56   SystemPowerMonitorHelper& operator=(const SystemPowerMonitorHelper&) = delete;
  57
  58   ~SystemPowerMonitorHelper();
  59
  60   void Start();
  61   void Stop();
  62   void Sample();
  63
  64   bool IsTimerRunningForTesting();
  65
  66  private:
  67   std::vector<const char*> valid_metrics_;
  68   EnergyMetricsProvider::EnergyMetrics last_sample_;
  69   base::TimeTicks last_timestamp_;
  70   base::RepeatingTimer timer_;
  71
  72   // Used to derive instant system energy metrics.
  73   std::unique_ptr<EnergyMetricsProvider> provider_;
  74   std::unique_ptr<SystemPowerMonitorDelegate> delegate_;
  75 };
  76
  77 // Monitors system-wide power consumption. Gets data from EnergyMetricsProvider.
  78 class SystemPowerMonitor
  79     : public base::trace_event::TraceLog::EnabledStateObserver {
  80  public:
  81   SystemPowerMonitor();
  82
  83   SystemPowerMonitor(const SystemPowerMonitor&) = delete;
  84   SystemPowerMonitor& operator=(const SystemPowerMonitor&) = delete;
  85
  86   ~SystemPowerMonitor() override;
  87
  88   static SystemPowerMonitor* GetInstance();
  89
  90   // TraceLog::EnabledStateObserver.
  91   void OnTraceLogEnabled() override;
  92   void OnTraceLogDisabled() override;
  93
  94  private:
  95   friend class SystemPowerMonitorTest;
  96
  97   SystemPowerMonitor(std::unique_ptr<EnergyMetricsProvider> provider,
  98                      std::unique_ptr<SystemPowerMonitorDelegate> delegate);
  99
 100   base::SequenceBound<SystemPowerMonitorHelper>* GetHelperForTesting();
 101
 102   base::SequenceBound<SystemPowerMonitorHelper> helper_;
 103 };
 104
 105 }  // namespace power_metrics
 106
 107 #endif  // COMPONENTS_POWER_METRICS_SYSTEM_POWER_MONITOR_H_