xpcom/threads/IdleTaskRunner.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef IdleTaskRunner_h
   8 #define IdleTaskRunner_h
   9
  10 #include "mozilla/TimeStamp.h"
  11 #include "mozilla/TaskCategory.h"
  12 #include "nsThreadUtils.h"
  13 #include <functional>
  14
  15 namespace mozilla {
  16
  17 // A general purpose repeating callback runner (it can be configured
  18 // to a one-time runner, too.) If it is running repeatedly,
  19 // one has to either explicitly Cancel() the runner or have
  20 // MayContinueProcessing() callback return false to completely remove
  21 // the runner.
  22 class IdleTaskRunner final : public IdleRunnable {
  23  public:
  24   // Return true if some meaningful work was done.
  25   using CallbackType = std::function<bool(TimeStamp aDeadline)>;
  26
  27   // A callback for "stop processing" decision. Return true to
  28   // stop processing. This can be an alternative to Cancel() or
  29   // work together in different way.
  30   using MayStopProcessingCallbackType = std::function<bool()>;
  31
  32  public:
  33   static already_AddRefed<IdleTaskRunner> Create(
  34       const CallbackType& aCallback, const char* aRunnableName, uint32_t aDelay,
  35       int64_t aBudget, bool aRepeating,
  36       const MayStopProcessingCallbackType& aMayStopProcessing,
  37       TaskCategory aTaskCategory = TaskCategory::Count);
  38
  39   NS_IMETHOD Run() override;
  40
  41   void SetDeadline(mozilla::TimeStamp aDeadline) override;
  42   void SetTimer(uint32_t aDelay, nsIEventTarget* aTarget) override;
  43
  44   nsresult Cancel() override;
  45   void Schedule(bool aAllowIdleDispatch);
  46
  47  private:
  48   explicit IdleTaskRunner(
  49       const CallbackType& aCallback, const char* aRunnableName, uint32_t aDelay,
  50       int64_t aBudget, bool aRepeating,
  51       const MayStopProcessingCallbackType& aMayStopProcessing,
  52       TaskCategory aTaskCategory);
  53   ~IdleTaskRunner();
  54   void CancelTimer();
  55   void SetTimerInternal(uint32_t aDelay);
  56
  57   nsCOMPtr<nsITimer> mTimer;
  58   nsCOMPtr<nsITimer> mScheduleTimer;
  59   CallbackType mCallback;
  60   uint32_t mDelay;
  61   TimeStamp mDeadline;
  62   TimeDuration mBudget;
  63   bool mRepeating;
  64   bool mTimerActive;
  65   MayStopProcessingCallbackType mMayStopProcessing;
  66   const TaskCategory mTaskCategory;
  67   const char* mName;
  68 };
  69
  70 }  // end of namespace mozilla.
  71
  72 #endif