static void DispatchSuspendResume(MediaDecoderReader* aSuspend,
MediaDecoderReader* aResume)
{
RefPtr<MediaDecoderReader> suspend = aSuspend;
RefPtr<MediaDecoderReader> resume = aResume;
nsCOMPtr<nsIRunnable> task = NS_NewRunnableFunction(
[suspend, resume] () {
Suspend(suspend);
DispatchResume(resume);
});
suspend->OwnerThread()->Dispatch(task.forget());
}
void Add(MediaDecoderReader* aReader)
{
MutexAutoLock lock(mMutex);
if (mActive.Length() < mNumMaxActive) {
// Below active limit, resume the new reader.
mActive.AppendElement(aReader);
DispatchResume(aReader);
} else if (mActive.IsEmpty()) {
MOZ_ASSERT(mNumMaxActive == 0);
mSuspended.AppendElement(aReader);
} else {
// We're past the active limit, suspend an old reader and resume the new.
mActive.AppendElement(aReader);
MediaDecoderReader* suspendReader = mActive.ElementAt(0);
mSuspended.AppendElement(suspendReader);
mActive.RemoveElementAt(0);
DispatchSuspendResume(suspendReader, aReader);
}
}
void Remove(MediaDecoderReader* aReader)
{
MutexAutoLock lock(mMutex);
// Remove the reader from the queue. Note that the reader's IsSuspended
// state is updated on the task queue, so we cannot depend on it here to
// determine the factual suspension state.
DebugOnly<bool> suspended = mSuspended.RemoveElement(aReader);
bool active = mActive.RemoveElement(aReader);
MOZ_ASSERT(suspended || active, "Reader must be in the queue");
if (active && !mSuspended.IsEmpty()) {
// For each removed active reader, we resume a suspended one.
MediaDecoderReader* resumeReader = mSuspended.LastElement();
mActive.AppendElement(resumeReader);
mSuspended.RemoveElementAt(mSuspended.Length() - 1);
DispatchResume(resumeReader);
}
}
void Remove(MediaDecoderReader* aReader)
{
MutexAutoLock lock(mMutex);
if (aReader->IsSuspended()) {
// Removing suspended readers has no immediate side-effects.
DebugOnly<bool> result = mSuspended.RemoveElement(aReader);
MOZ_ASSERT(result, "Suspended reader must be in mSuspended");
} else {
// For each removed active reader, we resume a suspended one.
DebugOnly<bool> result = mActive.RemoveElement(aReader);
MOZ_ASSERT(result, "Non-suspended reader must be in mActive");
if (mSuspended.IsEmpty()) {
return;
}
MediaDecoderReader* resumeReader = mSuspended.LastElement();
mActive.AppendElement(resumeReader);
mSuspended.RemoveElementAt(mSuspended.Length() - 1);
DispatchResume(resumeReader);
}
}