Provide (mostly) lockless updates for effect slots

Similar to the listener, separate containers are provided atomically for the
mixer thread to apply updates without needing to block, and a free-list is used
to reuse container objects.

A couple things to note. First, the lock is still used when the effect state's
deviceUpdate method is called to prevent asynchronous calls to reset the device
from interfering. This can be fixed by using the list lock in ALc.c instead.

Secondly, old effect states aren't immediately deleted when the effect type
changes (the actual type, not just its properties). This is because the mixer
thread is intended to be real-time safe, and so can't be freeing anything. They
are cleared away when updates reuse the container they were kept in, and they
don't incur any extra processing cost, but there may be cases where the memory
is kept around until the effect slot is deleted.

1 files changed, 17 insertions, 12 deletions

diff --git a/Alc/effects/equalizer.c b/Alc/effects/equalizer.c
index e0fa010e..94ee1853 100644
--- a/Alc/effects/equalizer.c
+++ b/Alc/effects/equalizer.c
@@ -87,8 +87,9 @@ typedef struct ALequalizerState {
     ALfloat SampleBuffer[4][MAX_EFFECT_CHANNELS][MAX_UPDATE_SAMPLES];
 } ALequalizerState;
 
-static ALvoid ALequalizerState_Destruct(ALequalizerState *UNUSED(state))
+static ALvoid ALequalizerState_Destruct(ALequalizerState *state)
 {
+    ALeffectState_Destruct(STATIC_CAST(ALeffectState,state));
 }
 
 static ALboolean ALequalizerState_deviceUpdate(ALequalizerState *UNUSED(state), ALCdevice *UNUSED(device))
@@ -113,15 +114,15 @@ static ALvoid ALequalizerState_update(ALequalizerState *state, const ALCdevice *
     STATIC_CAST(ALeffectState,state)->OutBuffer = device->FOAOut.Buffer;
     STATIC_CAST(ALeffectState,state)->OutChannels = device->FOAOut.NumChannels;
     for(i = 0;i < MAX_EFFECT_CHANNELS;i++)
-        ComputeFirstOrderGains(device->FOAOut, matrix.m[i], slot->Gain,
+        ComputeFirstOrderGains(device->FOAOut, matrix.m[i], slot->Params.Gain,
                                state->Gain[i]);
 
     /* Calculate coefficients for the each type of filter. Note that the shelf
      * filters' gain is for the reference frequency, which is the centerpoint
      * of the transition band.
      */
-    gain = sqrtf(slot->EffectProps.Equalizer.LowGain);
-    freq_mult = slot->EffectProps.Equalizer.LowCutoff/frequency;
+    gain = sqrtf(slot->Params.EffectProps.Equalizer.LowGain);
+    freq_mult = slot->Params.EffectProps.Equalizer.LowCutoff/frequency;
     ALfilterState_setParams(&state->filter[0][0], ALfilterType_LowShelf,
         gain, freq_mult, calc_rcpQ_from_slope(gain, 0.75f)
     );
@@ -136,10 +137,12 @@ static ALvoid ALequalizerState_update(ALequalizerState *state, const ALCdevice *
         state->filter[0][i].process = state->filter[0][0].process;
     }
 
-    gain = slot->EffectProps.Equalizer.Mid1Gain;
-    freq_mult = slot->EffectProps.Equalizer.Mid1Center/frequency;
+    gain = slot->Params.EffectProps.Equalizer.Mid1Gain;
+    freq_mult = slot->Params.EffectProps.Equalizer.Mid1Center/frequency;
     ALfilterState_setParams(&state->filter[1][0], ALfilterType_Peaking,
-        gain, freq_mult, calc_rcpQ_from_bandwidth(freq_mult, slot->EffectProps.Equalizer.Mid1Width)
+        gain, freq_mult, calc_rcpQ_from_bandwidth(
+            freq_mult, slot->Params.EffectProps.Equalizer.Mid1Width
+        )
     );
     for(i = 1;i < MAX_EFFECT_CHANNELS;i++)
     {
@@ -151,10 +154,12 @@ static ALvoid ALequalizerState_update(ALequalizerState *state, const ALCdevice *
         state->filter[1][i].process = state->filter[1][0].process;
     }
 
-    gain = slot->EffectProps.Equalizer.Mid2Gain;
-    freq_mult = slot->EffectProps.Equalizer.Mid2Center/frequency;
+    gain = slot->Params.EffectProps.Equalizer.Mid2Gain;
+    freq_mult = slot->Params.EffectProps.Equalizer.Mid2Center/frequency;
     ALfilterState_setParams(&state->filter[2][0], ALfilterType_Peaking,
-        gain, freq_mult, calc_rcpQ_from_bandwidth(freq_mult, slot->EffectProps.Equalizer.Mid2Width)
+        gain, freq_mult, calc_rcpQ_from_bandwidth(
+            freq_mult, slot->Params.EffectProps.Equalizer.Mid2Width
+        )
     );
     for(i = 1;i < MAX_EFFECT_CHANNELS;i++)
     {
@@ -166,8 +171,8 @@ static ALvoid ALequalizerState_update(ALequalizerState *state, const ALCdevice *
         state->filter[2][i].process = state->filter[2][0].process;
     }
 
-    gain = sqrtf(slot->EffectProps.Equalizer.HighGain);
-    freq_mult = slot->EffectProps.Equalizer.HighCutoff/frequency;
+    gain = sqrtf(slot->Params.EffectProps.Equalizer.HighGain);
+    freq_mult = slot->Params.EffectProps.Equalizer.HighCutoff/frequency;
     ALfilterState_setParams(&state->filter[3][0], ALfilterType_HighShelf,
         gain, freq_mult, calc_rcpQ_from_slope(gain, 0.75f)
     );