Mac Energy Test Harness/Framework

base/test/energy_monitor_mac.cc

+// 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 "base/test/energy_monitor_mac.h"
+
+#include <IntelPowerGadget/EnergyLib.h>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/files/file_util.h"
+#include "base/logging.h"
+#include "base/run_loop.h"
+
+namespace base {
+namespace test {
+namespace {
+
+enum {
+  POWER_DATA_AVERAGE_WATTS = 0,
+  POWER_DATA_CUMULATIVE_JOULES = 1,
+  POWER_DATA_CUMULATIVE_MILLIWATT_HOURS = 2
+};
+
+const int kDefaultDelayMs = 50;
+
+void CheckResult(int result) {
+  CHECK_NE(0, result) << "Intel API call failed.";
+}
+
+}  // namespace
+
+EnergyMonitorMac::EnergyMonitorMac()
+    : sample_delay_(base::TimeDelta::FromMilliseconds(kDefaultDelayMs)) {
+  static int initialize_once = IntelEnergyLibInitialize();
+  CHECK_NE(0, initialize_once) << "Failed to initialize.";
+
+  int num_nodes = 0;
+  CheckResult(GetNumNodes(&num_nodes));
+  CHECK_EQ(1, num_nodes) << "Only supports 1 node for now.";
+
+  int num_msrs = 0;
+  CheckResult(GetNumMsrs(&num_msrs));
+
+  for (int msr = 0; msr < num_msrs; ++msr) {
+    int msr_func = 0;
+    CheckResult(GetMsrFunc(msr, &msr_func));
+    if (msr_func != MSR_FUNC_POWER)
+      continue;  // Ignore frequency and temperature MSRs.
+
+    char msr_name[4096];  // The API doesn't document a max length for this.
+    CheckResult(GetMsrName(msr, msr_name));
+
+    if (strcmp(msr_name, "IA") == 0) {
+      DCHECK_EQ(-1, samples_[IA].msr_index) << "Multiple IA MSRs";
+      samples_[IA].msr_index = msr;
+    }
+
+    if (strcmp(msr_name, "Processor") == 0) {
+      DCHECK_EQ(-1, samples_[PROCESSOR].msr_index) << "Multiple Processor MSRs";
+      samples_[PROCESSOR].msr_index = msr;
+    }
+  }
+}
+
+EnergyMonitorMac::~EnergyMonitorMac() {}
+
+void EnergyMonitorMac::Run(const base::TimeDelta& warmup_delay,
+                           size_t num_samples) {
+  DCHECK_LT(1u, num_samples) << "Need at least 2 samples.";
+  target_sample_count_ = num_samples;
+
+  // First step is to read a sample, but record nothing. This allows
+  // measurements such as watts to establish the first time interval.
+  MessageLoop::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&EnergyMonitorMac::ReadNextSample, base::Unretained(this)),
+      warmup_delay);
+
+  base::RunLoop run_loop;
+  quit_closure_ = run_loop.QuitClosure();
+  run_loop.Run();
+}
+
+void EnergyMonitorMac::SetSampleDelay(const base::TimeDelta& sample_delay) {}
+
+double EnergyMonitorMac::GetAverageWatts(EnergyType type) const {
+  DCHECK_EQ(target_sample_count_, samples_[type].watts.size());
+  double sum = 0;
+  for (double v : samples_[type].watts)
+    sum += v;
+  return sum / samples_[type].watts.size();
+}
+
+double EnergyMonitorMac::GetStdDevWatts(EnergyType type) const {
+  DCHECK_EQ(target_sample_count_, samples_[type].watts.size());
+  const double mean = GetAverageWatts(type);
+  double sum = 0;
+  for (double v : samples_[type].watts) {
+    v -= mean;
+    sum += v * v;
+  }
+  return sqrt(sum / (samples_[type].watts.size() - 1));
+}
+
+void EnergyMonitorMac::WriteTimeSeries(const base::FilePath& file) {
+  DCHECK_EQ(target_sample_count_, rdtsc_values_.size());
+  DCHECK_EQ(target_sample_count_, samples_[PROCESSOR].watts.size());
+  DCHECK_EQ(target_sample_count_, samples_[IA].watts.size());
+
+  std::ostringstream csv;
+  csv << "RDTSC,Processor_Watts,IA_Watts\n";
+  for (size_t i = 0; i < rdtsc_values_.size(); ++i) {
+    csv << rdtsc_values_[i] - rdtsc_values_[0];  // Always relative to start.
+    for (int j = 0; j < NUM_ENERGY_TYPES; ++j)
+      csv << ',' << samples_[j].watts[i];
+    csv << '\n';
+  }
+
+  WriteFile(file, csv.str().data(), csv.str().size());
+}
+
+void EnergyMonitorMac::ReadNextSample() {
+  CheckResult(ReadSample());
+  if (samples_[0].watts.size() + 1 >= target_sample_count_) {
+    MessageLoop::current()->PostTask(FROM_HERE, quit_closure_);
+    return;
+  }
+  MessageLoop::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&EnergyMonitorMac::TakeSample, base::Unretained(this)),
+      sample_delay_);
+}
+
+void EnergyMonitorMac::TakeSample() {
+  ReadNextSample();
+
+  const int node = 0;
+  for (int i = 0; i < NUM_ENERGY_TYPES; ++i) {
+    int num_data;
+    double data[3];
+
+    CheckResult(GetPowerData(node, samples_[i].msr_index, data, &num_data));
+    DCHECK_EQ(static_cast<int>(arraysize(data)), num_data);
+
+    samples_[i].watts.push_back(data[POWER_DATA_AVERAGE_WATTS]);
+  }
+  uint64_t timestamp;
+  CheckResult(GetRDTSC(&timestamp));
+  rdtsc_values_.push_back(timestamp);
+}
+
+}  // namespace test
+}  // namespace base