1 /* 2 * Copyright (C) 2012, Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY 17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25 #ifndef AudioSummingJunction_h 26 #define AudioSummingJunction_h 27 28 #include "platform/audio/AudioBus.h" 29 #include "platform/heap/Handle.h" 30 #include "wtf/HashSet.h" 31 #include "wtf/Vector.h" 32 33 namespace blink { 34 35 class AudioContext; 36 class AudioNodeOutput; 37 38 // An AudioSummingJunction represents a point where zero, one, or more AudioNodeOutputs connect. 39 40 class AudioSummingJunction : public GarbageCollectedFinalized<AudioSummingJunction> { 41 public: 42 virtual ~AudioSummingJunction(); 43 virtual void trace(Visitor*); 44 void dispose(); 45 46 // Can be called from any thread. 47 AudioContext* context() { return m_context.get(); } 48 49 // This must be called whenever we modify m_outputs. 50 void changedOutputs(); 51 52 // This copies m_outputs to m_renderingOutputs. Please see comments for these lists below. 53 // This must be called when we own the context's graph lock in the audio thread at the very start or end of the render quantum. 54 void updateRenderingState(); 55 56 // Rendering code accesses its version of the current connections here. 57 unsigned numberOfRenderingConnections() const { return m_renderingOutputs.size(); } 58 AudioNodeOutput* renderingOutput(unsigned i) { return m_renderingOutputs[i]; } 59 bool isConnected() const { return numberOfRenderingConnections() > 0; } 60 61 virtual void didUpdate() = 0; 62 63 protected: 64 explicit AudioSummingJunction(AudioContext*); 65 66 Member<AudioContext> m_context; 67 68 // m_outputs contains the AudioNodeOutputs representing current connections which are not disabled. 69 // The rendering code should never use this directly, but instead uses m_renderingOutputs. 70 // Oilpan: Since items are added to the hash set by the audio thread (not registered to Oilpan), 71 // we cannot use a HeapHashSet. 72 GC_PLUGIN_IGNORE("http://crbug.com/404527") 73 HashSet<AudioNodeOutput*> m_outputs; 74 75 // m_renderingOutputs is a copy of m_outputs which will never be modified during the graph rendering on the audio thread. 76 // This is the list which is used by the rendering code. 77 // Whenever m_outputs is modified, the context is told so it can later update m_renderingOutputs from m_outputs at a safe time. 78 // Most of the time, m_renderingOutputs is identical to m_outputs. 79 // Oilpan: Since items are added to the vector by the audio thread (not registered to Oilpan), 80 // we cannot use a HeapVector. 81 GC_PLUGIN_IGNORE("http://crbug.com/404527") 82 Vector<AudioNodeOutput*> m_renderingOutputs; 83 84 // m_renderingStateNeedUpdating keeps track if m_outputs is modified. 85 bool m_renderingStateNeedUpdating; 86 87 bool m_didCallDispose; 88 }; 89 90 } // namespace blink 91 92 #endif // AudioSummingJunction_h 93
