/*
* 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
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#if ENABLE(WEB_AUDIO)
#include "AudioNode.h"
#include "AudioContext.h"
#include "AudioNodeInput.h"
#include "AudioNodeOutput.h"
#include <wtf/Atomics.h>
namespace WebCore {
AudioNode::AudioNode(AudioContext* context, double sampleRate)
: m_isInitialized(false)
, m_type(NodeTypeUnknown)
, m_context(context)
, m_sampleRate(sampleRate)
, m_lastProcessingTime(-1.0)
, m_normalRefCount(1) // start out with normal refCount == 1 (like WTF::RefCounted class)
, m_connectionRefCount(0)
, m_disabledRefCount(0)
, m_isMarkedForDeletion(false)
, m_isDisabled(false)
{
#if DEBUG_AUDIONODE_REFERENCES
if (!s_isNodeCountInitialized) {
s_isNodeCountInitialized = true;
atexit(AudioNode::printNodeCounts);
}
#endif
}
AudioNode::~AudioNode()
{
#if DEBUG_AUDIONODE_REFERENCES
--s_nodeCount[type()];
printf("%p: %d: AudioNode::~AudioNode() %d %d %d\n", this, type(), m_normalRefCount, m_connectionRefCount, m_disabledRefCount);
#endif
}
void AudioNode::initialize()
{
m_isInitialized = true;
}
void AudioNode::uninitialize()
{
m_isInitialized = false;
}
void AudioNode::setType(NodeType type)
{
m_type = type;
#if DEBUG_AUDIONODE_REFERENCES
++s_nodeCount[type];
#endif
}
void AudioNode::lazyInitialize()
{
if (!isInitialized())
initialize();
}
void AudioNode::addInput(PassOwnPtr<AudioNodeInput> input)
{
m_inputs.append(input);
}
void AudioNode::addOutput(PassOwnPtr<AudioNodeOutput> output)
{
m_outputs.append(output);
}
AudioNodeInput* AudioNode::input(unsigned i)
{
return m_inputs[i].get();
}
AudioNodeOutput* AudioNode::output(unsigned i)
{
return m_outputs[i].get();
}
bool AudioNode::connect(AudioNode* destination, unsigned outputIndex, unsigned inputIndex)
{
ASSERT(isMainThread());
AudioContext::AutoLocker locker(context());
// Sanity check input and output indices.
if (outputIndex >= numberOfOutputs())
return false;
if (destination && inputIndex >= destination->numberOfInputs())
return false;
AudioNodeOutput* output = this->output(outputIndex);
if (!destination) {
// Disconnect output from any inputs it may be currently connected to.
output->disconnectAllInputs();
return true;
}
AudioNodeInput* input = destination->input(inputIndex);
input->connect(output);
// Let context know that a connection has been made.
context()->incrementConnectionCount();
return true;
}
bool AudioNode::disconnect(unsigned outputIndex)
{
ASSERT(isMainThread());
AudioContext::AutoLocker locker(context());
return connect(0, outputIndex);
}
void AudioNode::processIfNecessary(size_t framesToProcess)
{
ASSERT(context()->isAudioThread());
if (!isInitialized())
return;
// Ensure that we only process once per rendering quantum.
// This handles the "fanout" problem where an output is connected to multiple inputs.
// The first time we're called during this time slice we process, but after that we don't want to re-process,
// instead our output(s) will already have the results cached in their bus;
double currentTime = context()->currentTime();
if (m_lastProcessingTime != currentTime) {
m_lastProcessingTime = currentTime; // important to first update this time because of feedback loops in the rendering graph
pullInputs(framesToProcess);
process(framesToProcess);
}
}
void AudioNode::pullInputs(size_t framesToProcess)
{
ASSERT(context()->isAudioThread());
// Process all of the AudioNodes connected to our inputs.
for (unsigned i = 0; i < m_inputs.size(); ++i)
input(i)->pull(0, framesToProcess);
}
void AudioNode::ref(RefType refType)
{
switch (refType) {
case RefTypeNormal:
atomicIncrement(&m_normalRefCount);
break;
case RefTypeConnection:
atomicIncrement(&m_connectionRefCount);
break;
case RefTypeDisabled:
atomicIncrement(&m_disabledRefCount);
break;
default:
ASSERT_NOT_REACHED();
}
#if DEBUG_AUDIONODE_REFERENCES
printf("%p: %d: AudioNode::ref(%d) %d %d %d\n", this, type(), refType, m_normalRefCount, m_connectionRefCount, m_disabledRefCount);
#endif
if (m_connectionRefCount == 1 && refType == RefTypeConnection) {
// FIXME: implement wake-up - this is an advanced feature and is not necessary in a simple implementation.
// We should not be "actively" connected to anything, but now we're "waking up"
// For example, a note which has finished playing, but is now being played again.
// Note that if this is considered a worthwhile feature to add, then an evaluation of the locking considerations must be made.
}
}
void AudioNode::deref(RefType refType)
{
// The actually work for deref happens completely within the audio context's graph lock.
// In the case of the audio thread, we must use a tryLock to avoid glitches.
bool hasLock = false;
bool mustReleaseLock = false;
if (context()->isAudioThread()) {
// Real-time audio thread must not contend lock (to avoid glitches).
hasLock = context()->tryLock(mustReleaseLock);
} else {
context()->lock(mustReleaseLock);
hasLock = true;
}
if (hasLock) {
// This is where the real deref work happens.
finishDeref(refType);
if (mustReleaseLock)
context()->unlock();
} else {
// We were unable to get the lock, so put this in a list to finish up later.
ASSERT(context()->isAudioThread());
context()->addDeferredFinishDeref(this, refType);
}
// Once AudioContext::uninitialize() is called there's no more chances for deleteMarkedNodes() to get called, so we call here.
// We can't call in AudioContext::~AudioContext() since it will never be called as long as any AudioNode is alive
// because AudioNodes keep a reference to the context.
if (context()->isAudioThreadFinished())
context()->deleteMarkedNodes();
}
void AudioNode::finishDeref(RefType refType)
{
ASSERT(context()->isGraphOwner());
switch (refType) {
case RefTypeNormal:
ASSERT(m_normalRefCount > 0);
atomicDecrement(&m_normalRefCount);
break;
case RefTypeConnection:
ASSERT(m_connectionRefCount > 0);
atomicDecrement(&m_connectionRefCount);
break;
case RefTypeDisabled:
ASSERT(m_disabledRefCount > 0);
atomicDecrement(&m_disabledRefCount);
break;
default:
ASSERT_NOT_REACHED();
}
#if DEBUG_AUDIONODE_REFERENCES
printf("%p: %d: AudioNode::deref(%d) %d %d %d\n", this, type(), refType, m_normalRefCount, m_connectionRefCount, m_disabledRefCount);
#endif
if (!m_connectionRefCount) {
if (!m_normalRefCount && !m_disabledRefCount) {
if (!m_isMarkedForDeletion) {
// All references are gone - we need to go away.
for (unsigned i = 0; i < m_outputs.size(); ++i)
output(i)->disconnectAllInputs(); // this will deref() nodes we're connected to...
// Mark for deletion at end of each render quantum or when context shuts down.
context()->markForDeletion(this);
m_isMarkedForDeletion = true;
}
} else if (refType == RefTypeConnection) {
if (!m_isDisabled) {
// Still may have JavaScript references, but no more "active" connection references, so put all of our outputs in a "dormant" disabled state.
// Garbage collection may take a very long time after this time, so the "dormant" disabled nodes should not bog down the rendering...
// As far as JavaScript is concerned, our outputs must still appear to be connected.
// But internally our outputs should be disabled from the inputs they're connected to.
// disable() can recursively deref connections (and call disable()) down a whole chain of connected nodes.
// FIXME: we special case the convolver and delay since they have a significant tail-time and shouldn't be disconnected simply
// because they no longer have any input connections. This needs to be handled more generally where AudioNodes have
// a tailTime attribute. Then the AudioNode only needs to remain "active" for tailTime seconds after there are no
// longer any active connections.
if (type() != NodeTypeConvolver && type() != NodeTypeDelay) {
m_isDisabled = true;
for (unsigned i = 0; i < m_outputs.size(); ++i)
output(i)->disable();
}
}
}
}
}
#if DEBUG_AUDIONODE_REFERENCES
bool AudioNode::s_isNodeCountInitialized = false;
int AudioNode::s_nodeCount[NodeTypeEnd];
void AudioNode::printNodeCounts()
{
printf("\n\n");
printf("===========================\n");
printf("AudioNode: reference counts\n");
printf("===========================\n");
for (unsigned i = 0; i < NodeTypeEnd; ++i)
printf("%d: %d\n", i, s_nodeCount[i]);
printf("===========================\n\n\n");
}
#endif // DEBUG_AUDIONODE_REFERENCES
} // namespace WebCore
#endif // ENABLE(WEB_AUDIO)