gecko-dev/dom/media/MediaTimer.h
Ehsan Akhgari e5e885ae31 Bug 1521000 - Part 2: Adjust our clang-format rules to include spaces after the hash for nested preprocessor directives r=sylvestre
# ignore-this-changeset

--HG--
extra : amend_source : 7221c8d15a765df71171099468e7c7faa648f37c
extra : histedit_source : a0cce6015636202bff09e35a13f72e03257a7695
2019-01-18 10:16:18 +01:00

165 lines
5.3 KiB
C++

/* -*- 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/. */
#if !defined(MediaTimer_h_)
# define MediaTimer_h_
# include "mozilla/AbstractThread.h"
# include "mozilla/IntegerPrintfMacros.h"
# include "mozilla/Monitor.h"
# include "mozilla/MozPromise.h"
# include "mozilla/RefPtr.h"
# include "mozilla/TimeStamp.h"
# include "mozilla/Unused.h"
# include "nsITimer.h"
# include <queue>
namespace mozilla {
extern LazyLogModule gMediaTimerLog;
# define TIMER_LOG(x, ...) \
MOZ_ASSERT(gMediaTimerLog); \
MOZ_LOG(gMediaTimerLog, LogLevel::Debug, \
("[MediaTimer=%p relative_t=%" PRId64 "]" x, this, \
RelativeMicroseconds(TimeStamp::Now()), ##__VA_ARGS__))
// This promise type is only exclusive because so far there isn't a reason for
// it not to be. Feel free to change that.
typedef MozPromise<bool, bool, /* IsExclusive = */ true> MediaTimerPromise;
// Timers only know how to fire at a given thread, which creates an impedence
// mismatch with code that operates with TaskQueues. This class solves
// that mismatch with a dedicated (but shared) thread and a nice MozPromise-y
// interface.
class MediaTimer {
public:
explicit MediaTimer(bool aFuzzy = false);
// We use a release with a custom Destroy().
NS_IMETHOD_(MozExternalRefCountType) AddRef(void);
NS_IMETHOD_(MozExternalRefCountType) Release(void);
RefPtr<MediaTimerPromise> WaitFor(const TimeDuration& aDuration,
const char* aCallSite);
RefPtr<MediaTimerPromise> WaitUntil(const TimeStamp& aTimeStamp,
const char* aCallSite);
void Cancel(); // Cancel and reject any unresolved promises with false.
private:
virtual ~MediaTimer() { MOZ_ASSERT(OnMediaTimerThread()); }
void DispatchDestroy(); // Invoked by Release on an arbitrary thread.
void Destroy(); // Runs on the timer thread.
bool OnMediaTimerThread();
void ScheduleUpdate();
void Update();
void UpdateLocked();
bool IsExpired(const TimeStamp& aTarget, const TimeStamp& aNow);
void Reject();
static void TimerCallback(nsITimer* aTimer, void* aClosure);
void TimerFired();
void ArmTimer(const TimeStamp& aTarget, const TimeStamp& aNow);
bool TimerIsArmed() { return !mCurrentTimerTarget.IsNull(); }
void CancelTimerIfArmed() {
MOZ_ASSERT(OnMediaTimerThread());
if (TimerIsArmed()) {
TIMER_LOG("MediaTimer::CancelTimerIfArmed canceling timer");
mTimer->Cancel();
mCurrentTimerTarget = TimeStamp();
}
}
struct Entry {
TimeStamp mTimeStamp;
RefPtr<MediaTimerPromise::Private> mPromise;
explicit Entry(const TimeStamp& aTimeStamp, const char* aCallSite)
: mTimeStamp(aTimeStamp),
mPromise(new MediaTimerPromise::Private(aCallSite)) {}
// Define a < overload that reverses ordering because std::priority_queue
// provides access to the largest element, and we want the smallest
// (i.e. the soonest).
bool operator<(const Entry& aOther) const {
return mTimeStamp > aOther.mTimeStamp;
}
};
ThreadSafeAutoRefCnt mRefCnt;
NS_DECL_OWNINGTHREAD
nsCOMPtr<nsIEventTarget> mThread;
std::priority_queue<Entry> mEntries;
Monitor mMonitor;
nsCOMPtr<nsITimer> mTimer;
TimeStamp mCurrentTimerTarget;
// Timestamps only have relative meaning, so we need a base timestamp for
// logging purposes.
TimeStamp mCreationTimeStamp;
int64_t RelativeMicroseconds(const TimeStamp& aTimeStamp) {
return (int64_t)(aTimeStamp - mCreationTimeStamp).ToMicroseconds();
}
bool mUpdateScheduled;
const bool mFuzzy;
};
// Class for managing delayed dispatches on target thread.
class DelayedScheduler {
public:
explicit DelayedScheduler(AbstractThread* aTargetThread, bool aFuzzy = false)
: mTargetThread(aTargetThread), mMediaTimer(new MediaTimer(aFuzzy)) {
MOZ_ASSERT(mTargetThread);
}
bool IsScheduled() const { return !mTarget.IsNull(); }
void Reset() {
MOZ_ASSERT(mTargetThread->IsCurrentThreadIn(),
"Must be on target thread to disconnect");
if (IsScheduled()) {
mRequest.Disconnect();
mTarget = TimeStamp();
}
}
template <typename ResolveFunc, typename RejectFunc>
void Ensure(mozilla::TimeStamp& aTarget, ResolveFunc&& aResolver,
RejectFunc&& aRejector) {
MOZ_ASSERT(mTargetThread->IsCurrentThreadIn());
if (IsScheduled() && mTarget <= aTarget) {
return;
}
Reset();
mTarget = aTarget;
mMediaTimer->WaitUntil(mTarget, __func__)
->Then(mTargetThread, __func__, std::forward<ResolveFunc>(aResolver),
std::forward<RejectFunc>(aRejector))
->Track(mRequest);
}
void CompleteRequest() {
MOZ_ASSERT(mTargetThread->IsCurrentThreadIn());
mRequest.Complete();
mTarget = TimeStamp();
}
private:
RefPtr<AbstractThread> mTargetThread;
RefPtr<MediaTimer> mMediaTimer;
MozPromiseRequestHolder<mozilla::MediaTimerPromise> mRequest;
TimeStamp mTarget;
};
} // namespace mozilla
#endif