gecko-dev/content/media/webaudio/PlayingRefChangeHandler.h

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1.6 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/. */
#ifndef PlayingRefChangeHandler_h__
#define PlayingRefChangeHandler_h__
#include "nsThreadUtils.h"
#include "AudioNodeStream.h"
namespace mozilla {
namespace dom {
template<class NodeType>
class PlayingRefChangeHandler : public nsRunnable
{
public:
enum ChangeType { ADDREF, RELEASE };
PlayingRefChangeHandler(AudioNodeStream* aStream, ChangeType aChange)
: mLastProcessedGraphUpdateIndex(aStream->GetProcessingGraphUpdateIndex())
, mStream(aStream)
, mChange(aChange)
{
}
NS_IMETHOD Run()
{
nsRefPtr<NodeType> node;
{
// No need to keep holding the lock for the whole duration of this
// function, since we're holding a strong reference to it, so if
// we can obtain the reference, we will hold the node alive in
// this function.
MutexAutoLock lock(mStream->Engine()->NodeMutex());
node = static_cast<NodeType*>(mStream->Engine()->Node());
}
if (node) {
if (mChange == ADDREF) {
node->mPlayingRef.Take(node);
} else if (mChange == RELEASE &&
node->AcceptPlayingRefRelease(mLastProcessedGraphUpdateIndex)) {
node->mPlayingRef.Drop(node);
}
}
return NS_OK;
}
private:
int64_t mLastProcessedGraphUpdateIndex;
nsRefPtr<AudioNodeStream> mStream;
ChangeType mChange;
};
}
}
#endif