TimeoutExecutor.h - mozsearch

Enable keyboard shortcuts

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_timeoutexecutor_h

#define mozilla_dom_timeoutexecutor_h

#include "mozilla/TimeStamp.h"

#include "nsCOMPtr.h"

#include "nsIRunnable.h"

#include "nsITimer.h"

#include "nsINamed.h"

namespace mozilla::dom {

class TimeoutManager;

class TimeoutExecutor final : public nsIRunnable,

                              public nsITimerCallback,

                              public nsINamed {

  TimeoutManager* mOwner;

  bool mIsIdleQueue;

  nsCOMPtr<nsITimer> mTimer;

  TimeStamp mDeadline;

  uint32_t mMaxIdleDeferMS;

  // Limits how far we allow timers to fire into the future from their

  // deadline.  Starts off at zero, but is then adjusted when we start

  // using nsITimer.  The nsITimer implementation may sometimes fire

  // early and we should allow that to minimize additional wakeups.

  TimeDuration mAllowedEarlyFiringTime;

  // The TimeoutExecutor is repeatedly scheduled by the TimeoutManager

  // to fire for the next soonest Timeout.  Since the executor is re-used

  // it needs to handle switching between a few states.

  enum class Mode {

    // None indicates the executor is idle.  It may be scheduled or shutdown.

    None,

    // Immediate means the executor is scheduled to run a Timeout with a

    // deadline that has already expired.

    Immediate,

    // Delayed means the executor is scheduled to run a Timeout with a

    // deadline in the future.

    Delayed,

    // Shutdown means the TimeoutManager has been destroyed.  Once this

    // state is reached the executor cannot be scheduled again.  If the

    // executor is already dispatched as a runnable or held by a timer then

    // we may still get a Run()/Notify() call which will be ignored.

    Shutdown

};

  Mode mMode;

  ~TimeoutExecutor();

  nsresult ScheduleImmediate(const TimeStamp& aDeadline, const TimeStamp& aNow);

  nsresult ScheduleDelayed(const TimeStamp& aDeadline, const TimeStamp& aNow,

                           const TimeDuration& aMinDelay);

  nsresult Schedule(const TimeStamp& aDeadline, const TimeDuration& aMinDelay);

  nsresult MaybeReschedule(const TimeStamp& aDeadline,

                           const TimeDuration& aMinDelay);

  MOZ_CAN_RUN_SCRIPT void MaybeExecute();

 public:

  TimeoutExecutor(TimeoutManager* aOwner, bool aIsIdleQueue,

                  uint32_t aMaxIdleDeferMS);

  void Shutdown();

  nsresult MaybeSchedule(const TimeStamp& aDeadline,

                         const TimeDuration& aMinDelay);

  void Cancel();

  NS_DECL_ISUPPORTS

  NS_DECL_NSIRUNNABLE

  NS_DECL_NSITIMERCALLBACK

  NS_DECL_NSINAMED

};

}  // namespace mozilla::dom

#endif  // mozilla_dom_timeoutexecutor_h