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25 #ifndef AudioSummingJunction_h
26 #define AudioSummingJunction_h
28 #include "platform/audio/AudioBus.h"
29 #include "platform/heap/Handle.h"
30 #include "wtf/HashSet.h"
31 #include "wtf/Vector.h"
36 class AudioNodeOutput;
38 // An AudioSummingJunction represents a point where zero, one, or more AudioNodeOutputs connect.
40 class AudioSummingJunction : public GarbageCollectedFinalized<AudioSummingJunction> {
42 virtual ~AudioSummingJunction();
43 virtual void trace(Visitor*);
46 // Can be called from any thread.
47 AudioContext* context() { return m_context.get(); }
49 // This must be called whenever we modify m_outputs.
50 void changedOutputs();
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();
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; }
61 virtual void didUpdate() = 0;
64 explicit AudioSummingJunction(AudioContext*);
66 Member<AudioContext> m_context;
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;
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;
84 // m_renderingStateNeedUpdating keeps track if m_outputs is modified.
85 bool m_renderingStateNeedUpdating;
87 bool m_didCallDispose;
92 #endif // AudioSummingJunction_h