void AudioContext::stopRendering()
{
ASSERT(isMainThread());
ASSERT(destination());
if (contextState() == Running) {
destination()->audioDestinationHandler().stopRendering();
setContextState(Suspended);
deferredTaskHandler().clearHandlersToBeDeleted();
}
}
ScriptPromise OfflineAudioContext::resumeContext(ScriptState* scriptState)
{
ASSERT(isMainThread());
ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
ScriptPromise promise = resolver->promise();
// If the rendering has not started, reject the promise.
if (!m_isRenderingStarted) {
resolver->reject(DOMException::create(InvalidStateError,
"cannot resume an offline context that has not started"));
return promise;
}
// If the context is in a closed state, reject the promise.
if (contextState() == AudioContextState::Closed) {
resolver->reject(DOMException::create(InvalidStateError,
"cannot resume a closed offline context"));
return promise;
}
// If the context is already running, resolve the promise without altering
// the current state or starting the rendering loop.
if (contextState() == AudioContextState::Running) {
resolver->resolve();
return promise;
}
ASSERT(contextState() == AudioContextState::Suspended);
// If the context is suspended, resume rendering by setting the state to
// "Running". and calling startRendering(). Note that resuming is possible
// only after the rendering started.
setContextState(Running);
destinationHandler().startRendering();
// Resolve the promise immediately.
resolver->resolve();
return promise;
}
ScriptPromise OfflineAudioContext::startOfflineRendering(ScriptState* scriptState)
{
ASSERT(isMainThread());
// Calling close() on an OfflineAudioContext is not supported/allowed,
// but it might well have been stopped by its execution context.
//
// See: crbug.com/435867
if (isContextClosed()) {
return ScriptPromise::rejectWithDOMException(
scriptState,
DOMException::create(
InvalidStateError,
"cannot call startRendering on an OfflineAudioContext in a stopped state."));
}
// If the context is not in the suspended state (i.e. running), reject the promise.
if (contextState() != AudioContextState::Suspended) {
return ScriptPromise::rejectWithDOMException(
scriptState,
DOMException::create(
InvalidStateError,
"cannot startRendering when an OfflineAudioContext is " + state()));
}
// Can't call startRendering more than once. Return a rejected promise now.
if (m_isRenderingStarted) {
return ScriptPromise::rejectWithDOMException(
scriptState,
DOMException::create(
InvalidStateError,
"cannot call startRendering more than once"));
}
ASSERT(!m_isRenderingStarted);
m_completeResolver = ScriptPromiseResolver::create(scriptState);
// Start rendering and return the promise.
m_isRenderingStarted = true;
setContextState(Running);
destinationHandler().startRendering();
return m_completeResolver->promise();
}
ScriptPromise AudioContext::suspendContext(ScriptState* scriptState)
{
ASSERT(isMainThread());
AutoLocker locker(this);
ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
ScriptPromise promise = resolver->promise();
if (contextState() == Closed) {
resolver->reject(
DOMException::create(InvalidStateError, "Cannot suspend a context that has been closed"));
} else {
// Stop rendering now.
if (destination())
stopRendering();
// Since we don't have any way of knowing when the hardware actually stops, we'll just
// resolve the promise now.
resolver->resolve();
}
return promise;
}