audio_node.h | Explore in Territory

/*
 * Copyright (C) 2010, Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *    notice, this list of conditions and the following disclaimer in the
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 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
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#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_AUDIO_NODE_H_
#define THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_AUDIO_NODE_H_

#include "base/memory/scoped_refptr.h"
#include "third_party/blink/renderer/modules/event_target_modules.h"
#include "third_party/blink/renderer/modules/modules_export.h"
#include "third_party/blink/renderer/modules/webaudio/audio_handler.h"
#include "third_party/blink/renderer/modules/webaudio/inspector_helper_mixin.h"
#include "third_party/blink/renderer/platform/heap/collection_support/heap_hash_set.h"
#include "third_party/blink/renderer/platform/heap/prefinalizer.h"

namespace blink {

class BaseAudioContext;
class AudioHandler;
class AudioNodeOptions;
class AudioParam;
class DeferredTaskHandler;
class ExceptionState;

// An AudioNode is the basic building block for handling audio within an
// BaseAudioContext.  It may be an audio source, an intermediate processing
// module, or an audio destination.  Each AudioNode can have inputs and/or
// outputs. An AudioSourceNode has no inputs and a single output.
// An AudioDestinationNode has one input and no outputs and represents the final
// destination to the audio hardware.  Most processing nodes such as filters
// will have one input and one output, although multiple inputs and outputs are
// possible.

// Each of AudioNode objects owns its dedicated AudioHandler object. AudioNode
// is responsible to provide IDL-accessible interface and its lifetime is
// managed by Oilpan GC. AudioHandler is responsible for anything else. We must
// not touch AudioNode objects in an audio rendering thread.

// AudioHandler is created and owned by an AudioNode almost all the time. When
// the AudioNode is about to die, the ownership of its AudioHandler is
// transferred to DeferredTaskHandler, and it does deref the AudioHandler on the
// main thread.
//
// Be careful to avoid reference cycles. If an AudioHandler has a reference
// cycle including the owner AudioNode, objects in the cycle are never
// collected.
class MODULES_EXPORT AudioNode : public EventTarget,
                                 public InspectorHelperMixin { … };

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_AUDIO_NODE_H_
chromium/third_party/blink/renderer/modules/webaudio/audio_node.h
