Add an option to limit the write size of the ringbuffer

11 files changed, 36 insertions, 36 deletions

diff --git a/Alc/backends/alsa.c b/Alc/backends/alsa.c
index c75749de..d0f0e24e 100644
--- a/Alc/backends/alsa.c
+++ b/Alc/backends/alsa.c
@@ -1124,7 +1124,8 @@ static ALCenum ALCcaptureAlsa_open(ALCcaptureAlsa *self, const ALCchar *name)
     {
         self->ring = ll_ringbuffer_create(
             device->UpdateSize*device->NumUpdates + 1,
-            FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder)
+            FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder),
+            false
         );
         if(!self->ring)
         {
diff --git a/Alc/backends/coreaudio.c b/Alc/backends/coreaudio.c
index 3db0d702..caa01167 100644
--- a/Alc/backends/coreaudio.c
+++ b/Alc/backends/coreaudio.c
@@ -664,7 +664,7 @@ static ALCenum ALCcoreAudioCapture_open(ALCcoreAudioCapture *self, const ALCchar
 
     self->ring = ll_ringbuffer_create(
         device->UpdateSize*self->sampleRateRatio*device->NumUpdates + 1,
-        self->frameSize
+        self->frameSize, false
     );
     if(!self->ring) goto error;
 
diff --git a/Alc/backends/dsound.c b/Alc/backends/dsound.c
index 0040a840..4c52e0f8 100644
--- a/Alc/backends/dsound.c
+++ b/Alc/backends/dsound.c
@@ -857,7 +857,7 @@ static ALCenum ALCdsoundCapture_open(ALCdsoundCapture *self, const ALCchar *devi
     if(SUCCEEDED(hr))
     {
          self->Ring = ll_ringbuffer_create(device->UpdateSize*device->NumUpdates + 1,
-                                           InputType.Format.nBlockAlign);
+                                           InputType.Format.nBlockAlign, false);
          if(self->Ring == NULL)
              hr = DSERR_OUTOFMEMORY;
     }
diff --git a/Alc/backends/jack.c b/Alc/backends/jack.c
index e6f4b435..003877a4 100644
--- a/Alc/backends/jack.c
+++ b/Alc/backends/jack.c
@@ -236,7 +236,8 @@ static int ALCjackPlayback_bufferSizeNotify(jack_nframes_t numframes, void *arg)
 
     ll_ringbuffer_free(self->Ring);
     self->Ring = ll_ringbuffer_create(bufsize,
-        FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder)
+        FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder),
+        true
     );
     if(!self->Ring)
     {
@@ -437,7 +438,8 @@ static ALCboolean ALCjackPlayback_reset(ALCjackPlayback *self)
 
     ll_ringbuffer_free(self->Ring);
     self->Ring = ll_ringbuffer_create(bufsize,
-        FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder)
+        FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder),
+        true
     );
     if(!self->Ring)
     {
diff --git a/Alc/backends/mmdevapi.c b/Alc/backends/mmdevapi.c
index 5f1dbba8..34dcf468 100644
--- a/Alc/backends/mmdevapi.c
+++ b/Alc/backends/mmdevapi.c
@@ -1813,7 +1813,8 @@ static HRESULT ALCmmdevCapture_resetProxy(ALCmmdevCapture *self)
     buffer_len = maxu(device->UpdateSize*device->NumUpdates + 1, buffer_len);
     ll_ringbuffer_free(self->Ring);
     self->Ring = ll_ringbuffer_create(buffer_len,
-        FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder)
+        FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder),
+        false
     );
     if(!self->Ring)
     {
diff --git a/Alc/backends/opensl.c b/Alc/backends/opensl.c
index b20d7841..d930526d 100644
--- a/Alc/backends/opensl.c
+++ b/Alc/backends/opensl.c
@@ -239,7 +239,6 @@ static int ALCopenslPlayback_mixerProc(void *arg)
     ll_ringbuffer_data_t data[2];
     SLPlayItf player;
     SLresult result;
-    size_t padding;
 
     SetRTPriority();
     althrd_setname(althrd_current(), MIXER_THREAD_NAME);
@@ -260,18 +259,13 @@ static int ALCopenslPlayback_mixerProc(void *arg)
         return 1;
     }
 
-    /* NOTE: The ringbuffer will be larger than the desired buffer metrics.
-     * Calculate the amount of extra space so we know how much to keep unused.
-     */
-    padding = ll_ringbuffer_write_space(self->mRing) - device->NumUpdates;
-
     ALCopenslPlayback_lock(self);
     while(!ATOMIC_LOAD(&self->mKillNow, almemory_order_acquire) &&
           ATOMIC_LOAD(&device->Connected, almemory_order_acquire))
     {
         size_t todo, len0, len1;
 
-        if(ll_ringbuffer_write_space(self->mRing) <= padding)
+        if(ll_ringbuffer_write_space(self->mRing) == 0)
         {
             SLuint32 state = 0;
 
@@ -288,7 +282,7 @@ static int ALCopenslPlayback_mixerProc(void *arg)
                 break;
             }
 
-            if(ll_ringbuffer_write_space(self->mRing) <= padding)
+            if(ll_ringbuffer_write_space(self->mRing) == 0)
             {
                 ALCopenslPlayback_unlock(self);
                 alsem_wait(&self->mSem);
@@ -298,7 +292,7 @@ static int ALCopenslPlayback_mixerProc(void *arg)
         }
 
         ll_ringbuffer_get_write_vector(self->mRing, data);
-        todo = data[0].len+data[1].len - padding;
+        todo = data[0].len+data[1].len;
 
         len0 = minu(todo, data[0].len);
         len1 = minu(todo-len0, data[1].len);
@@ -577,7 +571,7 @@ static ALCboolean ALCopenslPlayback_start(ALCopenslPlayback *self)
      * buffer will not be writeable, and we only write in period-sized chunks.
      */
     self->mRing = ll_ringbuffer_create(device->NumUpdates + 1,
-                                       self->mFrameSize*device->UpdateSize);
+                                       self->mFrameSize*device->UpdateSize, true);
 
     result = VCALL(self->mBufferQueueObj,GetInterface)(SL_IID_ANDROIDSIMPLEBUFFERQUEUE,
                                                        &bufferQueue);
@@ -854,7 +848,7 @@ static ALCenum ALCopenslCapture_open(ALCopenslCapture *self, const ALCchar *name
     if(SL_RESULT_SUCCESS == result)
     {
         self->mRing = ll_ringbuffer_create(device->NumUpdates + 1,
-                                           device->UpdateSize * self->mFrameSize);
+                                           device->UpdateSize * self->mFrameSize, false);
 
         result = VCALL(self->mRecordObj,GetInterface)(SL_IID_ANDROIDSIMPLEBUFFERQUEUE,
                                                       &bufferQueue);
diff --git a/Alc/backends/oss.c b/Alc/backends/oss.c
index faf3ee99..61d25476 100644
--- a/Alc/backends/oss.c
+++ b/Alc/backends/oss.c
@@ -729,7 +729,7 @@ static ALCenum ALCcaptureOSS_open(ALCcaptureOSS *self, const ALCchar *name)
         return ALC_INVALID_VALUE;
     }
 
-    self->ring = ll_ringbuffer_create(device->UpdateSize*device->NumUpdates + 1, frameSize);
+    self->ring = ll_ringbuffer_create(device->UpdateSize*device->NumUpdates + 1, frameSize, false);
     if(!self->ring)
     {
         ERR("Ring buffer create failed\n");
diff --git a/Alc/backends/portaudio.c b/Alc/backends/portaudio.c
index fdc8a2a5..9b0d3487 100644
--- a/Alc/backends/portaudio.c
+++ b/Alc/backends/portaudio.c
@@ -395,7 +395,7 @@ static ALCenum ALCportCapture_open(ALCportCapture *self, const ALCchar *name)
     samples = maxu(samples, 100 * device->Frequency / 1000);
     frame_size = FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder);
 
-    self->ring = ll_ringbuffer_create(samples, frame_size);
+    self->ring = ll_ringbuffer_create(samples, frame_size, false);
     if(self->ring == NULL) return ALC_INVALID_VALUE;
 
     self->params.device = -1;
diff --git a/Alc/backends/winmm.c b/Alc/backends/winmm.c
index d6ecd7a9..787ba8e4 100644
--- a/Alc/backends/winmm.c
+++ b/Alc/backends/winmm.c
@@ -626,7 +626,7 @@ static ALCenum ALCwinmmCapture_open(ALCwinmmCapture *self, const ALCchar *name)
     if(CapturedDataSize < (self->Format.nSamplesPerSec / 10))
         CapturedDataSize = self->Format.nSamplesPerSec / 10;
 
-    self->Ring = ll_ringbuffer_create(CapturedDataSize+1, self->Format.nBlockAlign);
+    self->Ring = ll_ringbuffer_create(CapturedDataSize+1, self->Format.nBlockAlign, false);
     if(!self->Ring) goto failure;
 
     InitRef(&self->WaveBuffersCommitted, 0);
diff --git a/Alc/ringbuffer.c b/Alc/ringbuffer.c
index c594331e..02fa857c 100644
--- a/Alc/ringbuffer.c
+++ b/Alc/ringbuffer.c
@@ -48,7 +48,7 @@ struct ll_ringbuffer {
 
 /* Create a new ringbuffer to hold at least `sz' elements of `elem_sz' bytes.
  * The number of elements is rounded up to the next power of two. */
-ll_ringbuffer_t *ll_ringbuffer_create(size_t sz, size_t elem_sz)
+ll_ringbuffer_t *ll_ringbuffer_create(size_t sz, size_t elem_sz, int limit_writes)
 {
     ll_ringbuffer_t *rb;
     size_t power_of_two = 0;
@@ -73,8 +73,8 @@ ll_ringbuffer_t *ll_ringbuffer_create(size_t sz, size_t elem_sz)
 
     ATOMIC_INIT(&rb->write_ptr, 0);
     ATOMIC_INIT(&rb->read_ptr, 0);
-    rb->size = power_of_two;
-    rb->size_mask = rb->size - 1;
+    rb->size = limit_writes ? sz : power_of_two;
+    rb->size_mask = power_of_two - 1;
     rb->elem_size = elem_sz;
     return rb;
 }
@@ -90,7 +90,7 @@ void ll_ringbuffer_reset(ll_ringbuffer_t *rb)
 {
     ATOMIC_STORE(&rb->write_ptr, 0, almemory_order_release);
     ATOMIC_STORE(&rb->read_ptr, 0, almemory_order_release);
-    memset(rb->buf, 0, rb->size*rb->elem_size);
+    memset(rb->buf, 0, (rb->size_mask+1)*rb->elem_size);
 }
 
 /* Return the number of elements available for reading. This is the number of
@@ -107,7 +107,8 @@ size_t ll_ringbuffer_write_space(const ll_ringbuffer_t *rb)
 {
     size_t w = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->write_ptr, almemory_order_acquire);
     size_t r = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->read_ptr, almemory_order_acquire);
-    return (r-w-1) & rb->size_mask;
+    w = (r-w-1) & rb->size_mask;
+    return (w > rb->size) ? rb->size : w;
 }
 
 /* The copying data reader. Copy at most `cnt' elements from `rb' to `dest'.
@@ -127,9 +128,9 @@ size_t ll_ringbuffer_read(ll_ringbuffer_t *rb, char *dest, size_t cnt)
     read_ptr = ATOMIC_LOAD(&rb->read_ptr, almemory_order_relaxed) & rb->size_mask;
 
     cnt2 = read_ptr + to_read;
-    if(cnt2 > rb->size)
+    if(cnt2 > rb->size_mask+1)
     {
-        n1 = rb->size - read_ptr;
+        n1 = rb->size_mask+1 - read_ptr;
         n2 = cnt2 & rb->size_mask;
     }
     else
@@ -168,9 +169,9 @@ size_t ll_ringbuffer_peek(ll_ringbuffer_t *rb, char *dest, size_t cnt)
     read_ptr = ATOMIC_LOAD(&rb->read_ptr, almemory_order_relaxed) & rb->size_mask;
 
     cnt2 = read_ptr + to_read;
-    if(cnt2 > rb->size)
+    if(cnt2 > rb->size_mask+1)
     {
-        n1 = rb->size - read_ptr;
+        n1 = rb->size_mask+1 - read_ptr;
         n2 = cnt2 & rb->size_mask;
     }
     else
@@ -206,9 +207,9 @@ size_t ll_ringbuffer_write(ll_ringbuffer_t *rb, const char *src, size_t cnt)
     write_ptr = ATOMIC_LOAD(&rb->write_ptr, almemory_order_relaxed) & rb->size_mask;
 
     cnt2 = write_ptr + to_write;
-    if(cnt2 > rb->size)
+    if(cnt2 > rb->size_mask+1)
     {
-        n1 = rb->size - write_ptr;
+        n1 = rb->size_mask+1 - write_ptr;
         n2 = cnt2 & rb->size_mask;
     }
     else
@@ -257,12 +258,12 @@ void ll_ringbuffer_get_read_vector(const ll_ringbuffer_t *rb, ll_ringbuffer_data
     free_cnt = (w-r) & rb->size_mask;
 
     cnt2 = r + free_cnt;
-    if(cnt2 > rb->size)
+    if(cnt2 > rb->size_mask+1)
     {
         /* Two part vector: the rest of the buffer after the current write ptr,
          * plus some from the start of the buffer. */
         vec[0].buf = (char*)&rb->buf[r*rb->elem_size];
-        vec[0].len = rb->size - r;
+        vec[0].len = rb->size_mask+1 - r;
         vec[1].buf = (char*)rb->buf;
         vec[1].len = cnt2 & rb->size_mask;
     }
@@ -290,14 +291,15 @@ void ll_ringbuffer_get_write_vector(const ll_ringbuffer_t *rb, ll_ringbuffer_dat
     w &= rb->size_mask;
     r &= rb->size_mask;
     free_cnt = (r-w-1) & rb->size_mask;
+    if(free_cnt > rb->size) free_cnt = rb->size;
 
     cnt2 = w + free_cnt;
-    if(cnt2 > rb->size)
+    if(cnt2 > rb->size_mask+1)
     {
         /* Two part vector: the rest of the buffer after the current write ptr,
          * plus some from the start of the buffer. */
         vec[0].buf = (char*)&rb->buf[w*rb->elem_size];
-        vec[0].len = rb->size - w;
+        vec[0].len = rb->size_mask+1 - w;
         vec[1].buf = (char*)rb->buf;
         vec[1].len = cnt2 & rb->size_mask;
     }
diff --git a/Alc/ringbuffer.h b/Alc/ringbuffer.h
index f764c20f..c1a7a6fa 100644
--- a/Alc/ringbuffer.h
+++ b/Alc/ringbuffer.h
@@ -10,7 +10,7 @@ typedef struct ll_ringbuffer_data {
     size_t len;
 } ll_ringbuffer_data_t;
 
-ll_ringbuffer_t *ll_ringbuffer_create(size_t sz, size_t elem_sz);
+ll_ringbuffer_t *ll_ringbuffer_create(size_t sz, size_t elem_sz, int limit_writes);
 void ll_ringbuffer_free(ll_ringbuffer_t *rb);
 void ll_ringbuffer_reset(ll_ringbuffer_t *rb);