Implement suspend() and resume() for OfflineAudioContext

third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp

 /*
  * 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
@@ skipping 10 matching lines @@
  * (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 "modules/webaudio/DeferredTaskHandler.h"
 
 #include "modules/webaudio/AudioNode.h"
 #include "modules/webaudio/AudioNodeOutput.h"
+#include "modules/webaudio/OfflineAudioContext.h"
 #include "platform/ThreadSafeFunctional.h"
 #include "public/platform/Platform.h"
 #include "wtf/MainThread.h"
 
 namespace blink {
 
 void DeferredTaskHandler::lock()
 {
     // Don't allow regular lock in real-time audio thread.
     ASSERT(isMainThread());
@@ skipping 12 matching lines @@
         return true;
     }
     return m_contextGraphMutex.tryLock();
 }
 
 void DeferredTaskHandler::unlock()
 {
     m_contextGraphMutex.unlock();
 }
 
+void DeferredTaskHandler::offlineLock()
+{
+    // It is safe to lock the audio thread for offline rendering, but
+    // let us have RELEASE_ASSERT here to make sure to explicitly crash rather
+    // than accidentally blocking the audio thread.
+    RELEASE_ASSERT_WITH_MESSAGE(isAudioThread(),
+        "DeferredTaskHandler::offlineLock() should be called within the audio thread.");
+
+    m_contextGraphMutex.lock();
+}

[Raymond Toy, 2015/10/21 23:14:18]

As discussed, we should just move all of this into the OfflineAutoLocker.

+
 #if ENABLE(ASSERT)
 bool DeferredTaskHandler::isGraphOwner()
 {
     return m_contextGraphMutex.locked();
 }
 #endif
 
 void DeferredTaskHandler::addDeferredBreakConnection(AudioHandler& node)
 {
     ASSERT(isAudioThread());
@@ skipping 146 matching lines @@
 void DeferredTaskHandler::contextWillBeDestroyed()
 {
     for (auto& handler : m_renderingOrphanHandlers)
         handler->clearContext();
     for (auto& handler : m_deletableOrphanHandlers)
         handler->clearContext();
     clearHandlersToBeDeleted();
     // Some handlers might live because of their cross thread tasks.
 }
 
+
 DeferredTaskHandler::AutoLocker::AutoLocker(AbstractAudioContext* context)
     : m_handler(context->deferredTaskHandler())
 {
     m_handler.lock();
 }
 
+DeferredTaskHandler::OfflineAutoLocker::OfflineAutoLocker(OfflineAudioContext* context)
+    : m_handler(context->deferredTaskHandler())
+{
+    m_handler.offlineLock();
+}
+
 void DeferredTaskHandler::addRenderingOrphanHandler(PassRefPtr<AudioHandler> handler)
 {
     ASSERT(handler);
     ASSERT(!m_renderingOrphanHandlers.contains(handler));
     m_renderingOrphanHandlers.append(handler);
 }
 
 void DeferredTaskHandler::requestToDeleteHandlersOnMainThread()
 {
     ASSERT(isGraphOwner());
@@ skipping 16 matching lines @@
 {
     ASSERT(isMainThread());
     AutoLocker locker(*this);
     m_renderingOrphanHandlers.clear();
     m_deletableOrphanHandlers.clear();
 }
 
 } // namespace blink
 
 #endif // ENABLE(WEB_AUDIO)