chrome/browser/task_management/task_manager_observer.h

   1 // Copyright 2015 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_TASK_MANAGEMENT_TASK_MANAGER_OBSERVER_H_
   6 #define CHROME_BROWSER_TASK_MANAGEMENT_TASK_MANAGER_OBSERVER_H_
   7
   8 #include <vector>
   9
  10 #include "base/time/time.h"
  11
  12 namespace task_management {
  13
  14 class TaskManagerInterface;
  15
  16 typedef int64 TaskId;
  17 typedef std::vector<TaskId> TaskIdList;
  18
  19 // Defines a list of types of resources that an observer needs to be refreshed
  20 // on every task manager refresh cycle.
  21 enum RefreshType {
  22   REFRESH_TYPE_NONE              = 0,
  23   REFRESH_TYPE_CPU               = 1,
  24   REFRESH_TYPE_MEMORY            = 1 << 1,
  25   REFRESH_TYPE_GPU_MEMORY        = 1 << 2,
  26   REFRESH_TYPE_V8_MEMORY         = 1 << 3,
  27   REFRESH_TYPE_SQLITE_MEMORY     = 1 << 4,
  28   REFRESH_TYPE_WEBCACHE_STATS    = 1 << 5,
  29   REFRESH_TYPE_NETWORK_USAGE     = 1 << 6,
  30   REFRESH_TYPE_NACL              = 1 << 7,
  31   REFRESH_TYPE_IDLE_WAKEUPS      = 1 << 8,
  32   REFRESH_TYPE_HANDLES           = 1 << 9,
  33 };
  34
  35 // Defines the interface for observers of the task manager.
  36 class TaskManagerObserver {
  37  public:
  38   // Constructs a TaskManagerObserver given the minimum |refresh_time| that it
  39   // it requires the task manager to be refreshing the values at, along with the
  40   // |resources_flags| that it needs to be calculated on each refresh cycle of
  41   // the task manager (use the above flags in |ResourceType|).
  42   //
  43   // Notes:
  44   // 1- The task manager will refresh at least once every |refresh_time| as
  45   // long as this observer is added to it. There might be other observers that
  46   // require more frequent refreshes.
  47   // 2- Refresh time values less than 1 second will be considered as 1 second.
  48   // 3- Depending on the other observers, the task manager may refresh more
  49   // resources than those defined in |resources_flags|.
  50   // 4- Upon the removal of the observer from the task manager, the task manager
  51   // will update its refresh time and the calculated resources to be the minimum
  52   // required value of all the remaining observers.
  53   TaskManagerObserver(base::TimeDelta refresh_time, int64 resources_flags);
  54   virtual ~TaskManagerObserver();
  55
  56   // Notifies the observer that a chrome task with |id| has started and the task
  57   // manager is now monitoring it. The resource usage of this newly-added task
  58   // will remain invalid until the next refresh cycle of the task manager.
  59   virtual void OnTaskAdded(TaskId id) = 0;
  60
  61   // Notifies the observer that a chrome task with |id| is about to be destroyed
  62   // and removed from the task manager right after this call. Observers which
  63   // are interested in doing some calculations related to the resource usage of
  64   // this task upon its removal may do so inside this call.
  65   virtual void OnTaskToBeRemoved(TaskId id) = 0;
  66
  67   // Notifies the observer that the task manager has just finished a refresh
  68   // cycle to calculate the resources usage of all tasks whose IDs are given in
  69   // |task_ids|. |task_ids| will be sorted such that the task representing the
  70   // browser process is at the top of the list and the rest of the IDs will be
  71   // sorted by the process IDs on which the tasks are running, then by the task
  72   // IDs themselves.
  73   virtual void OnTasksRefreshed(const TaskIdList& task_ids) = 0;
  74
  75   const base::TimeDelta& desired_refresh_time() const {
  76     return desired_refresh_time_;
  77   }
  78
  79   int64 desired_resources_flags() const { return desired_resources_flags_; }
  80
  81  protected:
  82   TaskManagerInterface* observed_task_manager() const {
  83     return observed_task_manager_;
  84   }
  85
  86   // Add or Remove a refresh |type|.
  87   void AddRefreshType(RefreshType type);
  88   void RemoveRefreshType(RefreshType type);
  89
  90  private:
  91   friend class TaskManagerInterface;
  92
  93   // The currently observed task Manager.
  94   TaskManagerInterface* observed_task_manager_;
  95
  96   // The minimum update time of the task manager that this observer needs to
  97   // do its job.
  98   base::TimeDelta desired_refresh_time_;
  99
 100   // The flags that contain the resources that this observer needs to be
 101   // calculated on each refresh.
 102   int64 desired_resources_flags_;
 103
 104   DISALLOW_COPY_AND_ASSIGN(TaskManagerObserver);
 105 };
 106
 107 }  // namespace task_management
 108
 109
 110 #endif  // CHROME_BROWSER_TASK_MANAGEMENT_TASK_MANAGER_OBSERVER_H_