Mac Energy Test Harness/Framework

base/test/energy_monitor_mac.h

+// 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.
+
+#ifndef BASE_TEST_ENERGY_MONITOR_MAC_H_
+#define BASE_TEST_ENERGY_MONITOR_MAC_H_
+
+#include <stdint.h>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/time/time.h"
+
+namespace base {
+
+class FilePath;
+
+namespace test {
+
+// Class that executes a base::RunLoop on the current thread, sampling power
+// draw from Intel Machine-Specific Registers at regular intervals.
+class EnergyMonitorMac {
+ public:
+  enum EnergyType { PROCESSOR, IA, NUM_ENERGY_TYPES };
+
+  EnergyMonitorMac();
+  ~EnergyMonitorMac();
+
+  // Executes a run loop on the current thread. Starts taking samples after
+  // |warmup_delay|, and quits the runloop after taking num_samples.
+  void Run(const base::TimeDelta& warmup_delay, size_t num_samples);
+
+  // Set the sampling frequency. By default, each sample is taken after a 50
+  // millisecond delay by posting an event to the RunLoop.
+  void SetSampleDelay(const base::TimeDelta& sample_delay);
+
+  double GetAverageWatts(EnergyType type) const;
+  double GetStdDevWatts(EnergyType type) const;
+
+  void WriteTimeSeries(const base::FilePath& file);
+
+ private:
+  void ReadNextSample();
+  void TakeSample();
+
+  base::TimeDelta sample_delay_;
+  size_t target_sample_count_ = ~0;
+  base::Closure quit_closure_;
+
+  struct {
+    int msr_index = -1;
+    std::vector<double> watts;
+  } samples_[NUM_ENERGY_TYPES];
+
+  std::vector<uint64_t> rdtsc_values_;
+
+  DISALLOW_COPY_AND_ASSIGN(EnergyMonitorMac);
+};
+
+}  // namespace test
+}  // namespace base
+
+#endif  // BASE_TEST_ENERGY_MONITOR_MAC_H_