Avoid separate updates to sources that should apply together

3 files changed, 18 insertions, 3 deletions

diff --git a/OpenAL32/Include/alMain.h b/OpenAL32/Include/alMain.h
index a624e078..f709e9bd 100644
--- a/OpenAL32/Include/alMain.h
+++ b/OpenAL32/Include/alMain.h
@@ -699,6 +699,12 @@ struct ALCcontext_struct {
 
     RWLock PropLock;
 
+    /* Counter for the pre-mixing updates, in 31.1 fixed point (lowest bit
+     * indicates if updates are currently happening).
+     */
+    RefCount UpdateCount;
+    ATOMIC(ALenum) HoldUpdates;
+
     struct ALvoice *Voices;
     ALsizei VoiceCount;
     ALsizei MaxVoices;
diff --git a/OpenAL32/Include/alu.h b/OpenAL32/Include/alu.h
index 8e93dc6e..fc58bfb1 100644
--- a/OpenAL32/Include/alu.h
+++ b/OpenAL32/Include/alu.h
@@ -374,8 +374,6 @@ void ComputeFirstOrderGainsMC(const ChannelConfig *chancoeffs, ALuint numchans,
 void ComputeFirstOrderGainsBF(const BFChannelConfig *chanmap, ALuint numchans, const ALfloat mtx[4], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);
 
 
-ALvoid UpdateContextSources(ALCcontext *context);
-
 ALvoid CalcAttnSourceParams(struct ALvoice *voice, const struct ALsourceProps *props, const struct ALbuffer *buffer, const ALCcontext *ALContext);
 ALvoid CalcNonAttnSourceParams(struct ALvoice *voice, const struct ALsourceProps *props, const struct ALbuffer *buffer, const ALCcontext *ALContext);
 
diff --git a/OpenAL32/alSource.c b/OpenAL32/alSource.c
index e2d6ca4f..1124c9c3 100644
--- a/OpenAL32/alSource.c
+++ b/OpenAL32/alSource.c
@@ -2848,7 +2848,15 @@ void UpdateSourceProps(ALsource *source, ALuint num_sends)
 void UpdateAllSourceProps(ALCcontext *context)
 {
     ALuint num_sends = context->Device->NumAuxSends;
+    uint updates;
     ALsizei pos;
+
+    /* Tell the mixer to stop applying updates, then wait for any active
+     * updating to finish, before providing source updates.
+     */
+    ATOMIC_STORE(&context->HoldUpdates, AL_TRUE);
+    while(((updates=ReadRef(&context->UpdateCount))&1) != 0)
+        althrd_yield();
     for(pos = 0;pos < context->VoiceCount;pos++)
     {
         ALvoice *voice = &context->Voices[pos];
@@ -2857,7 +2865,10 @@ void UpdateAllSourceProps(ALCcontext *context)
                               source->state == AL_PAUSED))
             UpdateSourceProps(source, num_sends);
     }
-
+    /* Now with all updates declared, let the mixer continue applying them so
+     * they all happen at once.
+     */
+    ATOMIC_STORE(&context->HoldUpdates, AL_FALSE);
 }