Provide asynchronous property updates for sources

This necessitates a change in how source updates are handled. Rather than just
being able to update sources when a dependent object state is changed (e.g. a
listener gain change), now all source updates must be proactively provided.
Consequently, apps that do not utilize any deferring (AL_SOFT_defer_updates or
alcSuspendContext/alcProcessContext) may utilize more CPU since it'll be
filling out more update containers for the mixer thread to use.

The upside is that there's less blocking between the app's calling thread and
the mixer thread, particularly for vectors and other multi-value properties
(filters and sends). Deferring behavior when used is also improved, since
updates that shouldn't be applied yet are simply not provided. And when they
are provided, the mixer doesn't have to ignore them, meaning the actual
deferring of a context doesn't have to synchrnously force an update -- the
process call will send any pending updates, which the mixer will apply even if
another deferral occurs before the mixer runs, because it'll still be there
waiting on the next mixer invocation.

There is one slight bug introduced by this commit. When a listener change is
made, or changes to multiple sources while updates are being deferred, it is
possible for the mixer to run while the sources are prepping their updates,
causing some of the source updates to be seen before the other. This will be
fixed in short order.

3 files changed, 153 insertions, 181 deletions

diff --git a/Alc/ALc.c b/Alc/ALc.c
index 47aa0f04..e5c18d8c 100644
--- a/Alc/ALc.c
+++ b/Alc/ALc.c
@@ -1558,22 +1558,7 @@ extern inline ALint GetChannelIndex(const enum Channel names[MAX_OUTPUT_CHANNELS
  */
 void ALCcontext_DeferUpdates(ALCcontext *context)
 {
-    ALCdevice *device = context->Device;
-    FPUCtl oldMode;
-
-    SetMixerFPUMode(&oldMode);
-
-    V0(device->Backend,lock)();
-    if(!context->DeferUpdates)
-    {
-        context->DeferUpdates = AL_TRUE;
-
-        /* Make sure all pending updates are performed */
-        UpdateContextSources(context);
-    }
-    V0(device->Backend,unlock)();
-
-    RestoreFPUMode(&oldMode);
+    ATOMIC_STORE(&context->DeferUpdates, AL_TRUE);
 }
 
 /* ALCcontext_ProcessUpdates
@@ -1584,14 +1569,15 @@ void ALCcontext_ProcessUpdates(ALCcontext *context)
 {
     ALCdevice *device = context->Device;
 
-    V0(device->Backend,lock)();
-    if(context->DeferUpdates)
+    ReadLock(&context->PropLock);
+    if(ATOMIC_EXCHANGE(ALenum, &context->DeferUpdates, AL_FALSE))
     {
         ALsizei pos;
 
-        context->DeferUpdates = AL_FALSE;
+        UpdateListenerProps(context);
 
         LockUIntMapRead(&context->SourceMap);
+        V0(device->Backend,lock)();
         for(pos = 0;pos < context->SourceMap.size;pos++)
         {
             ALsource *Source = context->SourceMap.array[pos].value;
@@ -1610,9 +1596,11 @@ void ALCcontext_ProcessUpdates(ALCcontext *context)
             if(new_state)
                 SetSourceState(Source, context, new_state);
         }
+        V0(device->Backend,unlock)();
         UnlockUIntMapRead(&context->SourceMap);
+        UpdateAllSourceProps(context);
     }
-    V0(device->Backend,unlock)();
+    ReadUnlock(&context->PropLock);
 }
 
 
@@ -2052,7 +2040,6 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
     }
 
     SetMixerFPUMode(&oldMode);
-    V0(device->Backend,lock)();
     if(device->DefaultSlot)
     {
         ALeffectslot *slot = device->DefaultSlot;
@@ -2062,7 +2049,6 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
         state->OutChannels = device->Dry.NumChannels;
         if(V(state,deviceUpdate)(device) == AL_FALSE)
         {
-            V0(device->Backend,unlock)();
             RestoreFPUMode(&oldMode);
             return ALC_INVALID_DEVICE;
         }
@@ -2074,6 +2060,7 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
     {
         ALsizei pos;
 
+        ReadLock(&context->PropLock);
         LockUIntMapRead(&context->EffectSlotMap);
         for(pos = 0;pos < context->EffectSlotMap.size;pos++)
         {
@@ -2085,10 +2072,11 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
             if(V(state,deviceUpdate)(device) == AL_FALSE)
             {
                 UnlockUIntMapRead(&context->EffectSlotMap);
-                V0(device->Backend,unlock)();
+                ReadUnlock(&context->PropLock);
                 RestoreFPUMode(&oldMode);
                 return ALC_INVALID_DEVICE;
             }
+
             UpdateEffectSlotProps(slot, AL_FALSE);
         }
         UnlockUIntMapRead(&context->EffectSlotMap);
@@ -2105,38 +2093,19 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
                 source->Send[s].Slot = NULL;
                 source->Send[s].Gain = 1.0f;
                 source->Send[s].GainHF = 1.0f;
+                source->Send[s].HFReference = LOWPASSFREQREF;
+                source->Send[s].GainLF = 1.0f;
+                source->Send[s].LFReference = HIGHPASSFREQREF;
                 s++;
             }
-            ATOMIC_STORE(&source->NeedsUpdate, AL_TRUE);
         }
         UnlockUIntMapRead(&context->SourceMap);
 
-        for(pos = 0;pos < context->VoiceCount;pos++)
-        {
-            ALvoice *voice = &context->Voices[pos];
-            ALsource *source = voice->Source;
-            ALbufferlistitem *BufferListItem;
-
-            if(!source)
-                continue;
-
-            BufferListItem = ATOMIC_LOAD(&source->queue);
-            while(BufferListItem != NULL)
-            {
-                ALbuffer *buffer;
-                if((buffer=BufferListItem->buffer) != NULL)
-                {
-                    ATOMIC_STORE(&source->NeedsUpdate, AL_FALSE);
-                    voice->Update(voice, source, buffer, context);
-                    break;
-                }
-                BufferListItem = BufferListItem->next;
-            }
-        }
+        UpdateAllSourceProps(context);
+        ReadUnlock(&context->PropLock);
 
         context = context->next;
     }
-    V0(device->Backend,unlock)();
     RestoreFPUMode(&oldMode);
 
     if(!(device->Flags&DEVICE_PAUSED))
@@ -2308,7 +2277,7 @@ static ALvoid InitContext(ALCcontext *Context)
     Context->DopplerFactor = 1.0f;
     Context->DopplerVelocity = 1.0f;
     Context->SpeedOfSound = SPEEDOFSOUNDMETRESPERSEC;
-    Context->DeferUpdates = AL_FALSE;
+    ATOMIC_INIT(&Context->DeferUpdates, AL_FALSE);
 
     Context->ExtensionList = alExtList;
 }
diff --git a/Alc/ALu.c b/Alc/ALu.c
index 4a9a59cf..2fffdcd9 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -266,7 +266,7 @@ static ALboolean BsincPrepare(const ALuint increment, BsincState *state)
 }
 
 
-static ALboolean CalcListenerParams(ALCcontext *Context)
+static void CalcListenerParams(ALCcontext *Context)
 {
     ALlistener *Listener = Context->Listener;
     ALdouble N[3], V[3], U[3], P[3];
@@ -275,7 +275,7 @@ static ALboolean CalcListenerParams(ALCcontext *Context)
     aluVector vel;
 
     props = ATOMIC_EXCHANGE(struct ALlistenerProps*, &Listener->Update, NULL, almemory_order_acq_rel);
-    if(!props) return AL_FALSE;
+    if(!props) return;
 
     /* AT then UP */
     N[0] = ATOMIC_LOAD(&props->Forward[0], almemory_order_relaxed);
@@ -330,17 +330,15 @@ static ALboolean CalcListenerParams(ALCcontext *Context)
         ATOMIC_STORE(&props->next, first, almemory_order_relaxed);
     } while(ATOMIC_COMPARE_EXCHANGE_WEAK(struct ALlistenerProps*,
             &Listener->FreeList, &first, props) == 0);
-
-    return AL_TRUE;
 }
 
-static ALboolean CalcEffectSlotParams(ALeffectslot *slot, ALCdevice *device)
+static void CalcEffectSlotParams(ALeffectslot *slot, ALCdevice *device)
 {
     struct ALeffectslotProps *first;
     struct ALeffectslotProps *props;
 
     props = ATOMIC_EXCHANGE(struct ALeffectslotProps*, &slot->Update, NULL, almemory_order_acq_rel);
-    if(!props) return AL_FALSE;
+    if(!props) return;
 
     slot->Params.Gain = ATOMIC_LOAD(&props->Gain, almemory_order_relaxed);
     slot->Params.AuxSendAuto = ATOMIC_LOAD(&props->AuxSendAuto, almemory_order_relaxed);
@@ -377,11 +375,43 @@ static ALboolean CalcEffectSlotParams(ALeffectslot *slot, ALCdevice *device)
         ATOMIC_STORE(&props->next, first, almemory_order_relaxed);
     } while(ATOMIC_COMPARE_EXCHANGE_WEAK(struct ALeffectslotProps*,
             &slot->FreeList, &first, props) == 0);
+}
+
+static void CalcSourceParams(ALvoice *voice, ALCcontext *context)
+{
+    ALsource *source = voice->Source;
+    ALbufferlistitem *BufferListItem;
+    struct ALsourceProps *first;
+    struct ALsourceProps *props;
+
+    props = ATOMIC_EXCHANGE(struct ALsourceProps*, &source->Update, NULL, almemory_order_acq_rel);
+    if(!props) return;
+
+    BufferListItem = ATOMIC_LOAD(&source->queue, almemory_order_relaxed);
+    while(BufferListItem != NULL)
+    {
+        ALbuffer *buffer;
+        if((buffer=BufferListItem->buffer) != NULL)
+        {
+            voice->Update(voice, props, buffer, context);
+            break;
+        }
+        BufferListItem = BufferListItem->next;
+    }
 
-    return AL_TRUE;
+    /* WARNING: A livelock is theoretically possible if another thread keeps
+     * changing the freelist head without giving this a chance to actually swap
+     * in the old container (practically impossible with this little code,
+     * but...).
+     */
+    first = ATOMIC_LOAD(&source->FreeList);
+    do {
+        ATOMIC_STORE(&props->next, first, almemory_order_relaxed);
+    } while(ATOMIC_COMPARE_EXCHANGE_WEAK(struct ALsourceProps*,
+            &source->FreeList, &first, props) == 0);
 }
 
-ALvoid CalcNonAttnSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer *ALBuffer, const ALCcontext *ALContext)
+ALvoid CalcNonAttnSourceParams(ALvoice *voice, const struct ALsourceProps *props, const ALbuffer *ALBuffer, const ALCcontext *ALContext)
 {
     static const struct ChanMap MonoMap[1] = {
         { FrontCenter, 0.0f, 0.0f }
@@ -448,22 +478,22 @@ ALvoid CalcNonAttnSourceParams(ALvoice *voice, const ALsource *ALSource, const A
     ListenerGain = Listener->Params.Gain;
 
     /* Get source properties */
-    SourceVolume    = ALSource->Gain;
-    MinVolume       = ALSource->MinGain;
-    MaxVolume       = ALSource->MaxGain;
-    Pitch           = ALSource->Pitch;
-    Relative        = ALSource->HeadRelative;
-    DirectChannels  = ALSource->DirectChannels;
+    SourceVolume   = ATOMIC_LOAD(&props->Gain, almemory_order_relaxed);
+    MinVolume      = ATOMIC_LOAD(&props->MinGain, almemory_order_relaxed);
+    MaxVolume      = ATOMIC_LOAD(&props->MaxGain, almemory_order_relaxed);
+    Pitch          = ATOMIC_LOAD(&props->Pitch, almemory_order_relaxed);
+    Relative       = ATOMIC_LOAD(&props->HeadRelative, almemory_order_relaxed);
+    DirectChannels = ATOMIC_LOAD(&props->DirectChannels, almemory_order_relaxed);
 
     /* Convert counter-clockwise to clockwise. */
-    StereoMap[0].angle = -ALSource->StereoPan[0];
-    StereoMap[1].angle = -ALSource->StereoPan[1];
+    StereoMap[0].angle = -ATOMIC_LOAD(&props->StereoPan[0], almemory_order_relaxed);
+    StereoMap[1].angle = -ATOMIC_LOAD(&props->StereoPan[1], almemory_order_relaxed);
 
     voice->Direct.OutBuffer = Device->Dry.Buffer;
     voice->Direct.OutChannels = Device->Dry.NumChannels;
     for(i = 0;i < NumSends;i++)
     {
-        SendSlots[i] = ALSource->Send[i].Slot;
+        SendSlots[i] = ATOMIC_LOAD(&props->Send[i].Slot, almemory_order_relaxed);
         if(!SendSlots[i] && i == 0)
             SendSlots[i] = Device->DefaultSlot;
         if(!SendSlots[i] || SendSlots[i]->Params.EffectType == AL_EFFECT_NULL)
@@ -489,15 +519,15 @@ ALvoid CalcNonAttnSourceParams(ALvoice *voice, const ALsource *ALSource, const A
 
     /* Calculate gains */
     DryGain  = clampf(SourceVolume, MinVolume, MaxVolume);
-    DryGain  *= ALSource->Direct.Gain * ListenerGain;
-    DryGainHF = ALSource->Direct.GainHF;
-    DryGainLF = ALSource->Direct.GainLF;
+    DryGain  *= ATOMIC_LOAD(&props->Direct.Gain, almemory_order_relaxed) * ListenerGain;
+    DryGainHF = ATOMIC_LOAD(&props->Direct.GainHF, almemory_order_relaxed);
+    DryGainLF = ATOMIC_LOAD(&props->Direct.GainLF, almemory_order_relaxed);
     for(i = 0;i < NumSends;i++)
     {
         WetGain[i] = clampf(SourceVolume, MinVolume, MaxVolume);
-        WetGain[i]  *= ALSource->Send[i].Gain * ListenerGain;
-        WetGainHF[i] = ALSource->Send[i].GainHF;
-        WetGainLF[i] = ALSource->Send[i].GainLF;
+        WetGain[i]  *= ATOMIC_LOAD(&props->Send[i].Gain, almemory_order_relaxed) * ListenerGain;
+        WetGainHF[i] = ATOMIC_LOAD(&props->Send[i].GainHF, almemory_order_relaxed);
+        WetGainLF[i] = ATOMIC_LOAD(&props->Send[i].GainLF, almemory_order_relaxed);
     }
 
     switch(ALBuffer->FmtChannels)
@@ -557,13 +587,13 @@ ALvoid CalcNonAttnSourceParams(ALvoice *voice, const ALsource *ALSource, const A
         ALfloat scale;
 
         /* AT then UP */
-        N[0] = ALSource->Orientation[0][0];
-        N[1] = ALSource->Orientation[0][1];
-        N[2] = ALSource->Orientation[0][2];
+        N[0] = ATOMIC_LOAD(&props->Orientation[0][0], almemory_order_relaxed);
+        N[1] = ATOMIC_LOAD(&props->Orientation[0][1], almemory_order_relaxed);
+        N[2] = ATOMIC_LOAD(&props->Orientation[0][2], almemory_order_relaxed);
         aluNormalize(N);
-        V[0] = ALSource->Orientation[1][0];
-        V[1] = ALSource->Orientation[1][1];
-        V[2] = ALSource->Orientation[1][2];
+        V[0] = ATOMIC_LOAD(&props->Orientation[1][0], almemory_order_relaxed);
+        V[1] = ATOMIC_LOAD(&props->Orientation[1][1], almemory_order_relaxed);
+        V[2] = ATOMIC_LOAD(&props->Orientation[1][2], almemory_order_relaxed);
         aluNormalize(V);
         if(!Relative)
         {
@@ -779,8 +809,10 @@ ALvoid CalcNonAttnSourceParams(ALvoice *voice, const ALsource *ALSource, const A
     }
 
     {
-        ALfloat hfscale = ALSource->Direct.HFReference / Frequency;
-        ALfloat lfscale = ALSource->Direct.LFReference / Frequency;
+        ALfloat hfscale = ATOMIC_LOAD(&props->Direct.HFReference, almemory_order_relaxed) /
+                          Frequency;
+        ALfloat lfscale = ATOMIC_LOAD(&props->Direct.LFReference, almemory_order_relaxed) /
+                          Frequency;
         DryGainHF = maxf(DryGainHF, 0.0001f);
         DryGainLF = maxf(DryGainLF, 0.0001f);
         for(c = 0;c < num_channels;c++)
@@ -800,8 +832,10 @@ ALvoid CalcNonAttnSourceParams(ALvoice *voice, const ALsource *ALSource, const A
     }
     for(i = 0;i < NumSends;i++)
     {
-        ALfloat hfscale = ALSource->Send[i].HFReference / Frequency;
-        ALfloat lfscale = ALSource->Send[i].LFReference / Frequency;
+        ALfloat hfscale = ATOMIC_LOAD(&props->Send[i].HFReference, almemory_order_relaxed) /
+                          Frequency;
+        ALfloat lfscale = ATOMIC_LOAD(&props->Send[i].LFReference, almemory_order_relaxed) /
+                          Frequency;
         WetGainHF[i] = maxf(WetGainHF[i], 0.0001f);
         WetGainLF[i] = maxf(WetGainLF[i], 0.0001f);
         for(c = 0;c < num_channels;c++)
@@ -821,7 +855,7 @@ ALvoid CalcNonAttnSourceParams(ALvoice *voice, const ALsource *ALSource, const A
     }
 }
 
-ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer *ALBuffer, const ALCcontext *ALContext)
+ALvoid CalcAttnSourceParams(ALvoice *voice, const struct ALsourceProps *props, const ALbuffer *ALBuffer, const ALCcontext *ALContext)
 {
     const ALCdevice *Device = ALContext->Device;
     const ALlistener *Listener = ALContext->Listener;
@@ -862,7 +896,7 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
     }
 
     /* Get context/device properties */
-    DopplerFactor = Listener->Params.DopplerFactor * ALSource->DopplerFactor;
+    DopplerFactor = Listener->Params.DopplerFactor;
     SpeedOfSound  = Listener->Params.SpeedOfSound;
     NumSends      = Device->NumAuxSends;
     Frequency     = Device->Frequency;
@@ -872,29 +906,39 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
     MetersPerUnit = Listener->Params.MetersPerUnit;
 
     /* Get source properties */
-    SourceVolume   = ALSource->Gain;
-    MinVolume      = ALSource->MinGain;
-    MaxVolume      = ALSource->MaxGain;
-    Pitch          = ALSource->Pitch;
-    Position       = ALSource->Position;
-    Direction      = ALSource->Direction;
-    Velocity       = ALSource->Velocity;
-    MinDist        = ALSource->RefDistance;
-    MaxDist        = ALSource->MaxDistance;
-    Rolloff        = ALSource->RollOffFactor;
-    InnerAngle     = ALSource->InnerAngle;
-    OuterAngle     = ALSource->OuterAngle;
-    AirAbsorptionFactor = ALSource->AirAbsorptionFactor;
-    DryGainHFAuto   = ALSource->DryGainHFAuto;
-    WetGainAuto     = ALSource->WetGainAuto;
-    WetGainHFAuto   = ALSource->WetGainHFAuto;
-    RoomRolloffBase = ALSource->RoomRolloffFactor;
+    SourceVolume   = ATOMIC_LOAD(&props->Gain, almemory_order_relaxed);
+    MinVolume      = ATOMIC_LOAD(&props->MinGain, almemory_order_relaxed);
+    MaxVolume      = ATOMIC_LOAD(&props->MaxGain, almemory_order_relaxed);
+    Pitch          = ATOMIC_LOAD(&props->Pitch, almemory_order_relaxed);
+    aluVectorSet(&Position, ATOMIC_LOAD(&props->Position[0], almemory_order_relaxed),
+                            ATOMIC_LOAD(&props->Position[1], almemory_order_relaxed),
+                            ATOMIC_LOAD(&props->Position[2], almemory_order_relaxed),
+                            1.0f);
+    aluVectorSet(&Direction, ATOMIC_LOAD(&props->Direction[0], almemory_order_relaxed),
+                             ATOMIC_LOAD(&props->Direction[1], almemory_order_relaxed),
+                             ATOMIC_LOAD(&props->Direction[2], almemory_order_relaxed),
+                             0.0f);
+    aluVectorSet(&Velocity, ATOMIC_LOAD(&props->Velocity[0], almemory_order_relaxed),
+                            ATOMIC_LOAD(&props->Velocity[1], almemory_order_relaxed),
+                            ATOMIC_LOAD(&props->Velocity[2], almemory_order_relaxed),
+                            0.0f);
+    MinDist        = ATOMIC_LOAD(&props->RefDistance, almemory_order_relaxed);
+    MaxDist        = ATOMIC_LOAD(&props->MaxDistance, almemory_order_relaxed);
+    Rolloff        = ATOMIC_LOAD(&props->RollOffFactor, almemory_order_relaxed);
+    DopplerFactor *= ATOMIC_LOAD(&props->DopplerFactor, almemory_order_relaxed);
+    InnerAngle     = ATOMIC_LOAD(&props->InnerAngle, almemory_order_relaxed);
+    OuterAngle     = ATOMIC_LOAD(&props->OuterAngle, almemory_order_relaxed);
+    AirAbsorptionFactor = ATOMIC_LOAD(&props->AirAbsorptionFactor, almemory_order_relaxed);
+    DryGainHFAuto   = ATOMIC_LOAD(&props->DryGainHFAuto, almemory_order_relaxed);
+    WetGainAuto     = ATOMIC_LOAD(&props->WetGainAuto, almemory_order_relaxed);
+    WetGainHFAuto   = ATOMIC_LOAD(&props->WetGainHFAuto, almemory_order_relaxed);
+    RoomRolloffBase = ATOMIC_LOAD(&props->RoomRolloffFactor, almemory_order_relaxed);
 
     voice->Direct.OutBuffer = Device->Dry.Buffer;
     voice->Direct.OutChannels = Device->Dry.NumChannels;
     for(i = 0;i < NumSends;i++)
     {
-        SendSlots[i] = ALSource->Send[i].Slot;
+        SendSlots[i] = ATOMIC_LOAD(&props->Send[i].Slot, almemory_order_relaxed);
 
         if(!SendSlots[i] && i == 0)
             SendSlots[i] = Device->DefaultSlot;
@@ -905,7 +949,7 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
             DecayDistance[i] = 0.0f;
             RoomAirAbsorption[i] = 1.0f;
         }
-        else if(SendSlots[i]->AuxSendAuto)
+        else if(SendSlots[i]->Params.AuxSendAuto)
         {
             RoomRolloff[i] = SendSlots[i]->Params.RoomRolloff + RoomRolloffBase;
             DecayDistance[i] = SendSlots[i]->Params.DecayTime *
@@ -934,7 +978,7 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
     }
 
     /* Transform source to listener space (convert to head relative) */
-    if(ALSource->HeadRelative == AL_FALSE)
+    if(ATOMIC_LOAD(&props->HeadRelative, almemory_order_relaxed) == AL_FALSE)
     {
         const aluMatrixd *Matrix = &Listener->Params.Matrix;
         /* Transform source vectors */
@@ -964,8 +1008,9 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
     Attenuation = 1.0f;
     for(i = 0;i < NumSends;i++)
         RoomAttenuation[i] = 1.0f;
-    switch(Listener->Params.SourceDistanceModel ? ALSource->DistanceModel :
-                                                  Listener->Params.DistanceModel)
+    switch(Listener->Params.SourceDistanceModel ?
+           ATOMIC_LOAD(&props->DistanceModel, almemory_order_relaxed) :
+           Listener->Params.DistanceModel)
     {
         case InverseDistanceClamped:
             ClampedDist = clampf(ClampedDist, MinDist, MaxDist);
@@ -1059,13 +1104,15 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
     if(Angle > InnerAngle && Angle <= OuterAngle)
     {
         ALfloat scale = (Angle-InnerAngle) / (OuterAngle-InnerAngle);
-        ConeVolume = lerp(1.0f, ALSource->OuterGain, scale);
-        ConeHF = lerp(1.0f, ALSource->OuterGainHF, scale);
+        ConeVolume = lerp(1.0f, ATOMIC_LOAD(&props->OuterGain, almemory_order_relaxed),
+                          scale);
+        ConeHF = lerp(1.0f, ATOMIC_LOAD(&props->OuterGainHF, almemory_order_relaxed),
+                      scale);
     }
     else if(Angle > OuterAngle)
     {
-        ConeVolume = ALSource->OuterGain;
-        ConeHF = ALSource->OuterGainHF;
+        ConeVolume = ATOMIC_LOAD(&props->OuterGain, almemory_order_relaxed);
+        ConeHF = ATOMIC_LOAD(&props->OuterGainHF, almemory_order_relaxed);
     }
     else
     {
@@ -1093,14 +1140,14 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
         WetGain[i] = clampf(WetGain[i], MinVolume, MaxVolume);
 
     /* Apply gain and frequency filters */
-    DryGain   *= ALSource->Direct.Gain * ListenerGain;
-    DryGainHF *= ALSource->Direct.GainHF;
-    DryGainLF *= ALSource->Direct.GainLF;
+    DryGain   *= ATOMIC_LOAD(&props->Direct.Gain, almemory_order_relaxed) * ListenerGain;
+    DryGainHF *= ATOMIC_LOAD(&props->Direct.GainHF, almemory_order_relaxed);
+    DryGainLF *= ATOMIC_LOAD(&props->Direct.GainLF, almemory_order_relaxed);
     for(i = 0;i < NumSends;i++)
     {
-        WetGain[i]   *= ALSource->Send[i].Gain * ListenerGain;
-        WetGainHF[i] *= ALSource->Send[i].GainHF;
-        WetGainLF[i] *= ALSource->Send[i].GainLF;
+        WetGain[i]   *= ATOMIC_LOAD(&props->Send[i].Gain, almemory_order_relaxed) * ListenerGain;
+        WetGainHF[i] *= ATOMIC_LOAD(&props->Send[i].GainHF, almemory_order_relaxed);
+        WetGainLF[i] *= ATOMIC_LOAD(&props->Send[i].GainLF, almemory_order_relaxed);
     }
 
     /* Calculate velocity-based doppler effect */
@@ -1139,7 +1186,7 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
          */
         ALfloat dir[3] = { 0.0f, 0.0f, -1.0f };
         ALfloat ev = 0.0f, az = 0.0f;
-        ALfloat radius = ALSource->Radius;
+        ALfloat radius = ATOMIC_LOAD(&props->Radius, almemory_order_relaxed);
         ALfloat coeffs[MAX_AMBI_COEFFS];
         ALfloat spread = 0.0f;
 
@@ -1193,7 +1240,7 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
     {
         /* Non-HRTF rendering. */
         ALfloat dir[3] = { 0.0f, 0.0f, -1.0f };
-        ALfloat radius = ALSource->Radius;
+        ALfloat radius = ATOMIC_LOAD(&props->Radius, almemory_order_relaxed);
         ALfloat coeffs[MAX_AMBI_COEFFS];
         ALfloat spread = 0.0f;
 
@@ -1247,8 +1294,10 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
     }
 
     {
-        ALfloat hfscale = ALSource->Direct.HFReference / Frequency;
-        ALfloat lfscale = ALSource->Direct.LFReference / Frequency;
+        ALfloat hfscale = ATOMIC_LOAD(&props->Direct.HFReference, almemory_order_relaxed) /
+                          Frequency;
+        ALfloat lfscale = ATOMIC_LOAD(&props->Direct.LFReference, almemory_order_relaxed) /
+                          Frequency;
         DryGainHF = maxf(DryGainHF, 0.0001f);
         DryGainLF = maxf(DryGainLF, 0.0001f);
         voice->Direct.Filters[0].ActiveType = AF_None;
@@ -1265,8 +1314,10 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
     }
     for(i = 0;i < NumSends;i++)
     {
-        ALfloat hfscale = ALSource->Send[i].HFReference / Frequency;
-        ALfloat lfscale = ALSource->Send[i].LFReference / Frequency;
+        ALfloat hfscale = ATOMIC_LOAD(&props->Send[i].HFReference, almemory_order_relaxed) /
+                          Frequency;
+        ALfloat lfscale = ATOMIC_LOAD(&props->Send[i].LFReference, almemory_order_relaxed) /
+                          Frequency;
         WetGainHF[i] = maxf(WetGainHF[i], 0.0001f);
         WetGainLF[i] = maxf(WetGainLF[i], 0.0001f);
         voice->Send[i].Filters[0].ActiveType = AF_None;
@@ -1287,69 +1338,22 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALbuffer
 void UpdateContextSources(ALCcontext *ctx)
 {
     ALvoice *voice, *voice_end;
-    ALboolean fullupdate;
     ALsource *source;
 
-    fullupdate = CalcListenerParams(ctx);
-#define UPDATE_SLOT(iter) do {                                         \
-    if(CalcEffectSlotParams(*iter, ctx->Device))                       \
-        fullupdate = AL_TRUE;                                          \
-} while(0)
+    CalcListenerParams(ctx);
+#define UPDATE_SLOT(iter) CalcEffectSlotParams(*iter, ctx->Device)
     VECTOR_FOR_EACH(ALeffectslot*, ctx->ActiveAuxSlots, UPDATE_SLOT);
 #undef UPDATE_SLOT
 
-    if(fullupdate)
+    voice = ctx->Voices;
+    voice_end = voice + ctx->VoiceCount;
+    for(;voice != voice_end;++voice)
     {
-        voice = ctx->Voices;
-        voice_end = voice + ctx->VoiceCount;
-        for(;voice != voice_end;++voice)
-        {
-            if(!(source=voice->Source)) continue;
-            if(source->state != AL_PLAYING && source->state != AL_PAUSED)
-                voice->Source = NULL;
-            else
-            {
-                ALbufferlistitem *BufferListItem;
-                BufferListItem = ATOMIC_LOAD(&source->queue);
-                while(BufferListItem != NULL)
-                {
-                    ALbuffer *buffer;
-                    if((buffer=BufferListItem->buffer) != NULL)
-                    {
-                        ATOMIC_STORE(&source->NeedsUpdate, AL_FALSE);
-                        voice->Update(voice, source, buffer, ctx);
-                        break;
-                    }
-                    BufferListItem = BufferListItem->next;
-                }
-            }
-        }
-    }
-    else
-    {
-        voice = ctx->Voices;
-        voice_end = voice + ctx->VoiceCount;
-        for(;voice != voice_end;++voice)
-        {
-            if(!(source=voice->Source)) continue;
-            if(source->state != AL_PLAYING && source->state != AL_PAUSED)
-                voice->Source = NULL;
-            else if(ATOMIC_EXCHANGE(ALenum, &source->NeedsUpdate, AL_FALSE))
-            {
-                ALbufferlistitem *BufferListItem;
-                BufferListItem = ATOMIC_LOAD(&source->queue);
-                while(BufferListItem != NULL)
-                {
-                    ALbuffer *buffer;
-                    if((buffer=BufferListItem->buffer) != NULL)
-                    {
-                        voice->Update(voice, source, buffer, ctx);
-                        break;
-                    }
-                    BufferListItem = BufferListItem->next;
-                }
-            }
-        }
+        if(!(source=voice->Source)) continue;
+        if(source->state != AL_PLAYING && source->state != AL_PAUSED)
+            voice->Source = NULL;
+        else
+            CalcSourceParams(voice, ctx);
     }
 }
 
@@ -1447,8 +1451,7 @@ ALvoid aluMixData(ALCdevice *device, ALvoid *buffer, ALsizei size)
         ctx = ATOMIC_LOAD(&device->ContextList);
         while(ctx)
         {
-            if(!ctx->DeferUpdates)
-                UpdateContextSources(ctx);
+            UpdateContextSources(ctx);
 #define CLEAR_WET_BUFFER(iter) do {                                    \
     for(i = 0;i < (*iter)->NumChannels;i++)                            \
         memset((*iter)->WetBuffer[i], 0, SamplesToDo*sizeof(ALfloat)); \
diff --git a/Alc/mixer.c b/Alc/mixer.c
index 44495d72..38ec295c 100644
--- a/Alc/mixer.c
+++ b/Alc/mixer.c
@@ -388,9 +388,9 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam
     BufferListItem = ATOMIC_LOAD(&Source->current_buffer);
     DataPosInt     = Source->position;
     DataPosFrac    = Source->position_fraction;
-    Looping        = Source->Looping;
     NumChannels    = Source->NumChannels;
     SampleSize     = Source->SampleSize;
+    Looping        = voice->Looping;
     increment      = voice->Step;
 
     IrSize = (Device->Hrtf ? GetHrtfIrSize(Device->Hrtf) : 0);