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