PerformanceMonitor: UMA alert for high browser CPU usage.

chrome/browser/performance_monitor/process_metrics_history.h

+// Copyright (c) 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.
+
+#ifndef CHROME_BROWSER_PERFORMANCE_MONITOR_PROCESS_METRICS_HISTORY_H_
+#define CHROME_BROWSER_PERFORMANCE_MONITOR_PROCESS_METRICS_HISTORY_H_
+
+#include "base/memory/linked_ptr.h"
+#include "base/process/process_handle.h"
+
+namespace base {
+class ProcessMetrics;
+}
+
+namespace performance_monitor {
+
+class ProcessMetricsHistory {
+ public:
+  ProcessMetricsHistory();
+  ~ProcessMetricsHistory();
+
+  // Configure this to monitor a specific process.
+  void Initialize(base::ProcessHandle process_handle,
+                  int process_type,
+                  int initial_update_sequence);
+
+  // End of a measurement cycle; check for performance issues and reset
+  // accumulated statistics.
+  void EndOfCycle();
+
+  // Gather metrics for the process and accumulate with past data.
+  void SampleMetrics();
+
+  // Used to mark when this object was last updated, so we can cull
+  // dead ones.
+  void SetLastUpdateSequence(int new_update_sequence) {
+    last_update_sequence_ = new_update_sequence;
+  }
+
+  int GetLastUpdateSequence() const { return last_update_sequence_; }
+
+  // Average CPU over all the past sampling points since last reset.
+  double GetAverageCPUUsage() { return accumulated_cpu_usage_ / sample_count_; }
+
+  // // Average mem usage over all the past sampling points since last reset.
+  void GetAverageMemoryBytes(size_t* private_bytes, size_t* shared_bytes) {
+    *private_bytes = accumulated_private_bytes_ / sample_count_;
+    *shared_bytes = accumulated_shared_bytes_ / sample_count_;
+  }
+
+ private:
+  void ResetCounters();
+  void RunPerformanceTriggers();
+
+  base::ProcessHandle process_handle_;
+  int process_type_;
+  linked_ptr<base::ProcessMetrics> process_metrics_;
+  int last_update_sequence_;
+
+  double accumulated_cpu_usage_;
+  double min_cpu_usage_;
+  size_t accumulated_private_bytes_;
+  size_t accumulated_shared_bytes_;
+  int sample_count_;
+};
+
+}  // namespace performance_monitor
+
+#endif  // CHROME_BROWSER_PERFORMANCE_MONITOR_PROCESS_METRICS_HISTORY_H_