chrome/browser/performance_monitor/constants.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   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 CHROME_BROWSER_PERFORMANCE_MONITOR_CONSTANTS_H_
   6 #define CHROME_BROWSER_PERFORMANCE_MONITOR_CONSTANTS_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/time/time.h"
  10
  11 namespace performance_monitor {
  12
  13 // Constants which are used by the PerformanceMonitor and its related classes.
  14 // The constants should be documented alongside the definition of their values
  15 // in the .cc file.
  16
  17 extern const char kMetricNotFoundError[];
  18 extern const char kProcessChromeAggregate[];
  19
  20 // State tokens
  21 extern const char kStateChromeVersion[];
  22 extern const char kStateProfilePrefix[];
  23
  24 // The interval the watched processes are sampled for performance metrics.
  25 const int kSampleIntervalInSeconds = 10;
  26 // The default interval at which PerformanceMonitor performs its timed
  27 // collections; this can be overridden by using the kPerformanceMonitorGathering
  28 // switch with an associated (positive integer) value.
  29 const int kDefaultGatherIntervalInSeconds = 120;
  30
  31 // Unit values (for use in metric, and on the UI side).
  32
  33 // Memory measurements
  34 const int64 kBytesPerKilobyte = 1 << 10;
  35 const int64 kBytesPerMegabyte = kBytesPerKilobyte * (1 << 10);
  36 const int64 kBytesPerGigabyte = kBytesPerMegabyte * (1 << 10);
  37 const int64 kBytesPerTerabyte = kBytesPerGigabyte * (1 << 10);
  38
  39 // Time measurements - Most of these are imported from base/time/time.h
  40 // These units are used for display (and it's related calculations), not for
  41 // any mathematical analysis. Thus we can estimate for values without an exact
  42 // conversion.
  43 const int64 kMicrosecondsPerMonth = base::Time::kMicrosecondsPerDay * 30;
  44 const int64 kMicrosecondsPerYear = base::Time::kMicrosecondsPerDay * 365;
  45
  46 // Performance alert thresholds
  47
  48 // If a process is consistently above this CPU utilization percentage over time,
  49 // we consider it as high and may take action.
  50 const float kHighCPUUtilizationThreshold = 90.0f;
  51 }  // namespace performance_monitor
  52
  53 #endif  // CHROME_BROWSER_PERFORMANCE_MONITOR_CONSTANTS_H_