gecko-dev/dom/media/MediaDecoderStateMachineSch...

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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 MediaDecoderStateMachineScheduler_h__
#define MediaDecoderStateMachineScheduler_h__
#include "nsCOMPtr.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/DebugOnly.h"
class nsITimer;
class nsIEventTarget;
namespace mozilla {
class ReentrantMonitor;
class MediaDecoderStateMachineScheduler {
enum State {
SCHEDULER_STATE_NONE,
SCHEDULER_STATE_FROZEN,
SCHEDULER_STATE_FROZEN_WITH_PENDING_TASK,
SCHEDULER_STATE_SHUTDOWN
};
public:
MediaDecoderStateMachineScheduler(ReentrantMonitor& aMonitor,
nsresult (*aTimeoutCallback)(void*),
void* aClosure, bool aRealTime);
~MediaDecoderStateMachineScheduler();
nsresult Init();
nsresult Schedule(int64_t aUsecs = 0);
void ScheduleAndShutdown();
nsresult TimeoutExpired(int aTimerId);
void FreezeScheduling();
void ThawScheduling();
bool OnStateMachineThread() const;
bool IsScheduled() const;
bool IsRealTime() const {
return mRealTime;
}
nsIEventTarget* GetStateMachineThread() const {
return mEventTarget;
}
bool IsFrozen() const {
return mState == SCHEDULER_STATE_FROZEN ||
mState == SCHEDULER_STATE_FROZEN_WITH_PENDING_TASK;
}
private:
void ResetTimer();
// Callback function provided by MediaDecoderStateMachine to run
// state machine cycles.
nsresult (*const mTimeoutCallback)(void*);
// Since StateMachineScheduler will never outlive the state machine,
// it is safe to keep a raw pointer only to avoid reference cycles.
void* const mClosure;
// True is we are decoding a realtime stream, like a camera stream
const bool mRealTime;
// Monitor of the decoder
ReentrantMonitor& mMonitor;
// State machine thread
const nsCOMPtr<nsIEventTarget> mEventTarget;
// Timer to schedule callbacks to run the state machine cycles.
nsCOMPtr<nsITimer> mTimer;
// Timestamp at which the next state machine cycle will run.
TimeStamp mTimeout;
// The id of timer tasks, timer callback will only run if id matches.
int mTimerId;
// No more state machine cycles in shutdown state.
State mState;
// Used to check if state machine cycles are running in sequence.
DebugOnly<bool> mInRunningStateMachine;
};
} // namespace mozilla
#endif // MediaDecoderStateMachineScheduler_h__