// Copyright 2013 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 "chrome/browser/performance_monitor/process_metrics_history.h"

#include <limits>

#include "base/logging.h"
#include "base/metrics/histogram.h"
#include "base/process/process_metrics.h"
#include "build/build_config.h"
#include "content/public/common/process_type.h"

#if defined(OS_MACOSX)
#include "content/public/browser/browser_child_process_host.h"
#endif

namespace performance_monitor {

namespace {

const char kBrowserProcessTrigger[] =
    "ProcessMetricsHistory.BrowserProcess.HighCPU";
const char kGPUProcessTrigger[] = "ProcessMetricsHistory.GPUProcess.HighCPU";
const char kExtensionPersistentProcessTrigger[] =
    "ProcessMetricsHistory.ExtensionPersistentProcess.HighCPU";

}  // namespace

// If a process is consistently above this CPU utilization percentage over time,
// we consider it as high and may take action.
const float kHighCPUUtilizationThreshold = 90.0f;

ProcessMetricsHistory::ProcessMetricsHistory()
    : last_update_sequence_(0), cpu_usage_(0.0), trace_trigger_handle_(-1) {
}

ProcessMetricsHistory::ProcessMetricsHistory(
    const ProcessMetricsHistory& other) = default;

ProcessMetricsHistory::~ProcessMetricsHistory() {
}

void ProcessMetricsHistory::Initialize(
    const ProcessMetricsMetadata& process_data,
    int initial_update_sequence) {
  DCHECK_EQ(base::kNullProcessHandle, process_data_.handle);
  process_data_ = process_data;
  last_update_sequence_ = initial_update_sequence;

#if defined(OS_MACOSX)
  process_metrics_.reset(base::ProcessMetrics::CreateProcessMetrics(
      process_data_.handle,
      content::BrowserChildProcessHost::GetPortProvider()));
#else
  process_metrics_.reset(
      base::ProcessMetrics::CreateProcessMetrics(process_data_.handle));
#endif

  const char* trigger_name = NULL;
  switch (process_data_.process_type) {
    case content::PROCESS_TYPE_BROWSER:
      trigger_name = kBrowserProcessTrigger;
      break;
    case content::PROCESS_TYPE_GPU:
      trigger_name = kGPUProcessTrigger;
      break;
  }
  switch (process_data_.process_subtype) {
    case kProcessSubtypeExtensionPersistent:
      trigger_name = kExtensionPersistentProcessTrigger;
      break;
    default:
      break;
  }
  if (trigger_name) {
    trace_trigger_handle_ =
        content::BackgroundTracingManager::GetInstance()->RegisterTriggerType(
            trigger_name);
  }
}

void ProcessMetricsHistory::SampleMetrics() {
  cpu_usage_ = process_metrics_->GetPlatformIndependentCPUUsage();
}

void ProcessMetricsHistory::RunPerformanceTriggers() {
  // We scale up to the equivalent of 64 CPU cores fully loaded. More than this
  // doesn't really matter, as we're already in a terrible place.
  const int kHistogramMin = 0;
  const int kHistogramMax = 6400;
  const int kHistogramBucketCount = 50;

  // The histogram macros don't support variables as histogram names,
  // hence the macro duplication for each process type.
  switch (process_data_.process_type) {
    case content::PROCESS_TYPE_BROWSER:
      UMA_HISTOGRAM_CUSTOM_COUNTS(
          "PerformanceMonitor.AverageCPU.BrowserProcess", cpu_usage_,
          kHistogramMin, kHistogramMax, kHistogramBucketCount);
      // If CPU usage has consistently been above our threshold,
      // we *may* have an issue.
      if (cpu_usage_ > kHighCPUUtilizationThreshold) {
        UMA_HISTOGRAM_BOOLEAN("PerformanceMonitor.HighCPU.BrowserProcess",
                              true);
      }
      break;
    case content::PROCESS_TYPE_RENDERER:
      UMA_HISTOGRAM_CUSTOM_COUNTS(
          "PerformanceMonitor.AverageCPU.RendererProcess", cpu_usage_,
          kHistogramMin, kHistogramMax, kHistogramBucketCount);
      if (cpu_usage_ > kHighCPUUtilizationThreshold) {
        UMA_HISTOGRAM_BOOLEAN("PerformanceMonitor.HighCPU.RendererProcess",
                              true);
      }
      break;
    case content::PROCESS_TYPE_GPU:
      UMA_HISTOGRAM_CUSTOM_COUNTS("PerformanceMonitor.AverageCPU.GPUProcess",
                                  cpu_usage_, kHistogramMin, kHistogramMax,
                                  kHistogramBucketCount);
      if (cpu_usage_ > kHighCPUUtilizationThreshold)
        UMA_HISTOGRAM_BOOLEAN("PerformanceMonitor.HighCPU.GPUProcess", true);
      break;
    case content::PROCESS_TYPE_PPAPI_PLUGIN:
      UMA_HISTOGRAM_CUSTOM_COUNTS("PerformanceMonitor.AverageCPU.PPAPIProcess",
                                  cpu_usage_, kHistogramMin, kHistogramMax,
                                  kHistogramBucketCount);
      if (cpu_usage_ > kHighCPUUtilizationThreshold)
        UMA_HISTOGRAM_BOOLEAN("PerformanceMonitor.HighCPU.PPAPIProcess", true);
      break;
    default:
      break;
  }

  switch (process_data_.process_subtype) {
    case kProcessSubtypeUnknown:
      break;
    case kProcessSubtypePPAPIFlash:
      UMA_HISTOGRAM_CUSTOM_COUNTS(
          "PerformanceMonitor.AverageCPU.PPAPIFlashProcess", cpu_usage_,
          kHistogramMin, kHistogramMax, kHistogramBucketCount);
      if (cpu_usage_ > kHighCPUUtilizationThreshold) {
        UMA_HISTOGRAM_BOOLEAN("PerformanceMonitor.HighCPU.PPAPIFlashProcess",
                              true);
      }
      break;
    case kProcessSubtypeExtensionPersistent:
      UMA_HISTOGRAM_CUSTOM_COUNTS(
          "PerformanceMonitor.AverageCPU.RendererExtensionPersistentProcess",
          cpu_usage_, kHistogramMin, kHistogramMax, kHistogramBucketCount);
      if (cpu_usage_ > kHighCPUUtilizationThreshold) {
        UMA_HISTOGRAM_BOOLEAN(
            "PerformanceMonitor.HighCPU.RendererExtensionPersistentProcess",
            true);
      }
      break;
    case kProcessSubtypeExtensionEvent:
      UMA_HISTOGRAM_CUSTOM_COUNTS(
          "PerformanceMonitor.AverageCPU.RendererExtensionEventProcess",
          cpu_usage_, kHistogramMin, kHistogramMax, kHistogramBucketCount);
      if (cpu_usage_ > kHighCPUUtilizationThreshold) {
        UMA_HISTOGRAM_BOOLEAN(
            "PerformanceMonitor.HighCPU.RendererExtensionEventProcess", true);
      }
      break;
  }

  if (cpu_usage_ > kHighCPUUtilizationThreshold &&
      trace_trigger_handle_ != -1) {
    content::BackgroundTracingManager::GetInstance()->TriggerNamedEvent(
        trace_trigger_handle_,
        content::BackgroundTracingManager::StartedFinalizingCallback());
  }
}

}  // namespace performance_monitor