Reference count HRTFs and unload them when unused

5 files changed, 90 insertions, 9 deletions

diff --git a/Alc/ALc.c b/Alc/ALc.c
index ed2c5e8e..0cc36cad 100644
--- a/Alc/ALc.c
+++ b/Alc/ALc.c
@@ -2049,7 +2049,7 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
 
         if(hrtf_userreq == Hrtf_Enable || (hrtf_userreq != Hrtf_Disable && hrtf_appreq == Hrtf_Enable))
         {
-            const struct Hrtf *hrtf = NULL;
+            struct Hrtf *hrtf = NULL;
             if(VECTOR_SIZE(device->HrtfList) == 0)
             {
                 VECTOR_DEINIT(device->HrtfList);
@@ -2068,6 +2068,9 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
                 device->FmtChans = DevFmtStereo;
                 device->Frequency = hrtf->sampleRate;
                 device->Flags |= DEVICE_CHANNELS_REQUEST | DEVICE_FREQUENCY_REQUEST;
+                if(device->HrtfHandle)
+                    Hrtf_DecRef(device->HrtfHandle);
+                device->HrtfHandle = hrtf;
             }
             else
             {
@@ -2338,6 +2341,9 @@ static ALCvoid FreeDevice(ALCdevice *device)
 
     AL_STRING_DEINIT(device->HrtfName);
     FreeHrtfList(&device->HrtfList);
+    if(device->HrtfHandle)
+        Hrtf_DecRef(device->HrtfHandle);
+    device->HrtfHandle = NULL;
     al_free(device->Hrtf);
     device->Hrtf = NULL;
 
@@ -3755,6 +3761,7 @@ ALC_API ALCdevice* ALC_APIENTRY alcOpenDevice(const ALCchar *deviceName)
     device->Bs2b = NULL;
     device->Uhj_Encoder = NULL;
     device->Hrtf = NULL;
+    device->HrtfHandle = NULL;
     VECTOR_INIT(device->HrtfList);
     AL_STRING_INIT(device->HrtfName);
     device->Render_Mode = NormalRender;
@@ -4062,6 +4069,7 @@ ALC_API ALCdevice* ALC_APIENTRY alcCaptureOpenDevice(const ALCchar *deviceName,
     device->Type = Capture;
 
     device->Hrtf = NULL;
+    device->HrtfHandle = NULL;
     VECTOR_INIT(device->HrtfList);
     AL_STRING_INIT(device->HrtfName);
 
@@ -4272,6 +4280,7 @@ ALC_API ALCdevice* ALC_APIENTRY alcLoopbackOpenDeviceSOFT(const ALCchar *deviceN
 
     device->Flags = 0;
     device->Hrtf = NULL;
+    device->HrtfHandle = NULL;
     VECTOR_INIT(device->HrtfList);
     AL_STRING_INIT(device->HrtfName);
     device->Bs2b = NULL;
diff --git a/Alc/hrtf.c b/Alc/hrtf.c
index 35be4dc3..32a6357e 100644
--- a/Alc/hrtf.c
+++ b/Alc/hrtf.c
@@ -59,6 +59,7 @@ static const ALchar magicMarker01[8] = "MinPHR01";
  * directional sounds. */
 static const ALfloat PassthruCoeff = 0.707106781187f/*sqrt(0.5)*/;
 
+static ATOMIC_FLAG LoadedHrtfLock = ATOMIC_FLAG_INIT;
 static struct HrtfEntry *LoadedHrtfs = NULL;
 
 
@@ -272,6 +273,7 @@ static struct Hrtf *CreateHrtfStore(ALuint rate, ALsizei irSize, ALsizei evCount
         ALfloat *_coeffs;
         ALsizei i;
 
+        InitRef(&Hrtf->ref, 0);
         Hrtf->sampleRate = rate;
         Hrtf->irSize = irSize;
         Hrtf->evCount = evCount;
@@ -973,7 +975,6 @@ void FreeHrtfList(vector_EnumeratedHrtf *list)
 
 struct Hrtf *GetLoadedHrtf(struct HrtfEntry *entry)
 {
-    static ATOMIC_FLAG LoadLock = ATOMIC_FLAG_INIT;
     struct Hrtf *hrtf = NULL;
     struct FileMapping fmap;
     const ALubyte *rdata;
@@ -982,12 +983,13 @@ struct Hrtf *GetLoadedHrtf(struct HrtfEntry *entry)
     size_t rsize;
     char ch;
 
-    while(ATOMIC_FLAG_TEST_AND_SET(&LoadLock, almemory_order_seq_cst))
+    while(ATOMIC_FLAG_TEST_AND_SET(&LoadedHrtfLock, almemory_order_seq_cst))
         althrd_yield();
 
     if(entry->handle)
     {
         hrtf = entry->handle;
+        Hrtf_IncRef(hrtf);
         goto done;
     }
 
@@ -1047,18 +1049,55 @@ struct Hrtf *GetLoadedHrtf(struct HrtfEntry *entry)
         ERR("Failed to load %s\n", name);
         goto done;
     }
+    entry->handle = hrtf;
+    Hrtf_IncRef(hrtf);
 
     TRACE("Loaded HRTF support for format: %s %uhz\n",
           DevFmtChannelsString(DevFmtStereo), hrtf->sampleRate);
 
-    entry->handle = hrtf;
-
 done:
-    ATOMIC_FLAG_CLEAR(&LoadLock, almemory_order_seq_cst);
+    ATOMIC_FLAG_CLEAR(&LoadedHrtfLock, almemory_order_seq_cst);
     return hrtf;
 }
 
 
+void Hrtf_IncRef(struct Hrtf *hrtf)
+{
+    uint ref = IncrementRef(&hrtf->ref);
+    TRACEREF("%p increasing refcount to %u\n", hrtf, ref);
+}
+
+void Hrtf_DecRef(struct Hrtf *hrtf)
+{
+    struct HrtfEntry *Hrtf;
+    uint ref = DecrementRef(&hrtf->ref);
+    TRACEREF("%p decreasing refcount to %u\n", hrtf, ref);
+    if(ref == 0)
+    {
+        while(ATOMIC_FLAG_TEST_AND_SET(&LoadedHrtfLock, almemory_order_seq_cst))
+            althrd_yield();
+
+        Hrtf = LoadedHrtfs;
+        while(Hrtf != NULL)
+        {
+            /* Need to double-check that it's still unused, as another device
+             * could've reacquired this HRTF after its reference went to 0 and
+             * before the lock was taken.
+             */
+            if(hrtf == Hrtf->handle && ReadRef(&hrtf->ref) == 0)
+            {
+                al_free(Hrtf->handle);
+                Hrtf->handle = NULL;
+                TRACE("Unloaded unused HRTF %s\n", Hrtf->filename);
+            }
+            Hrtf = Hrtf->next;
+        }
+
+        ATOMIC_FLAG_CLEAR(&LoadedHrtfLock, almemory_order_seq_cst);
+    }
+}
+
+
 void FreeHrtfs(void)
 {
     struct HrtfEntry *Hrtf = LoadedHrtfs;
diff --git a/Alc/hrtf.h b/Alc/hrtf.h
index 4e25dde3..3ec3e19e 100644
--- a/Alc/hrtf.h
+++ b/Alc/hrtf.h
@@ -6,6 +6,7 @@
 
 #include "alMain.h"
 #include "alstring.h"
+#include "atomic.h"
 
 
 #define HRTFDELAY_BITS    (20)
@@ -21,6 +22,8 @@
 struct HrtfEntry;
 
 struct Hrtf {
+    RefCount ref;
+
     ALuint sampleRate;
     ALsizei irSize;
     ALubyte evCount;
@@ -37,6 +40,8 @@ void FreeHrtfs(void);
 vector_EnumeratedHrtf EnumerateHrtf(const_al_string devname);
 void FreeHrtfList(vector_EnumeratedHrtf *list);
 struct Hrtf *GetLoadedHrtf(struct HrtfEntry *entry);
+void Hrtf_IncRef(struct Hrtf *hrtf);
+void Hrtf_DecRef(struct Hrtf *hrtf);
 
 void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat (*coeffs)[2], ALsizei *delays);
 
diff --git a/Alc/panning.c b/Alc/panning.c
index bd550b32..8a8840fb 100644
--- a/Alc/panning.c
+++ b/Alc/panning.c
@@ -997,6 +997,8 @@ static void InitUhjPanning(ALCdevice *device)
 
 void aluInitRenderer(ALCdevice *device, ALint hrtf_id, enum HrtfRequestMode hrtf_appreq, enum HrtfRequestMode hrtf_userreq)
 {
+    /* Hold the HRTF the device last used, in case it's used again. */
+    struct Hrtf *old_hrtf = device->HrtfHandle;
     const char *mode;
     bool headphones;
     int bs2blevel;
@@ -1028,6 +1030,9 @@ void aluInitRenderer(ALCdevice *device, ALint hrtf_id, enum HrtfRequestMode hrtf
         const char *devname, *layout = NULL;
         AmbDecConf conf, *pconf = NULL;
 
+        if(old_hrtf)
+            Hrtf_DecRef(old_hrtf);
+        old_hrtf = NULL;
         if(hrtf_appreq == Hrtf_Enable)
             device->HrtfStatus = ALC_HRTF_UNSUPPORTED_FORMAT_SOFT;
 
@@ -1151,29 +1156,49 @@ void aluInitRenderer(ALCdevice *device, ALint hrtf_id, enum HrtfRequestMode hrtf
     if(hrtf_id >= 0 && (size_t)hrtf_id < VECTOR_SIZE(device->HrtfList))
     {
         const EnumeratedHrtf *entry = &VECTOR_ELEM(device->HrtfList, hrtf_id);
-        const struct Hrtf *hrtf = GetLoadedHrtf(entry->hrtf);
+        struct Hrtf *hrtf = GetLoadedHrtf(entry->hrtf);
         if(hrtf && hrtf->sampleRate == device->Frequency)
         {
             device->HrtfHandle = hrtf;
             alstr_copy(&device->HrtfName, entry->name);
         }
+        else if(hrtf)
+            Hrtf_DecRef(hrtf);
+    }
+
+    /* Reuse the old HRTF if its compatible and any desired HRTF isn't
+     * compatible.
+     */
+    if(!device->HrtfHandle && old_hrtf)
+    {
+        if(old_hrtf->sampleRate == device->Frequency)
+        {
+            device->HrtfHandle = old_hrtf;
+            old_hrtf = NULL;
+        }
     }
 
     for(i = 0;!device->HrtfHandle && i < VECTOR_SIZE(device->HrtfList);i++)
     {
         const EnumeratedHrtf *entry = &VECTOR_ELEM(device->HrtfList, i);
-        const struct Hrtf *hrtf = GetLoadedHrtf(entry->hrtf);
+        struct Hrtf *hrtf = GetLoadedHrtf(entry->hrtf);
         if(hrtf && hrtf->sampleRate == device->Frequency)
         {
             device->HrtfHandle = hrtf;
             alstr_copy(&device->HrtfName, entry->name);
         }
+        else if(hrtf)
+            Hrtf_DecRef(hrtf);
     }
 
     if(device->HrtfHandle)
     {
         bool hoa_mode;
 
+        if(old_hrtf)
+            Hrtf_DecRef(old_hrtf);
+        old_hrtf = NULL;
+
         device->Render_Mode = HrtfRender;
         if(ConfigValueStr(alstr_get_cstr(device->DeviceName), NULL, "hrtf-mode", &mode))
         {
@@ -1211,6 +1236,9 @@ void aluInitRenderer(ALCdevice *device, ALint hrtf_id, enum HrtfRequestMode hrtf
     device->HrtfStatus = ALC_HRTF_UNSUPPORTED_FORMAT_SOFT;
 
 no_hrtf:
+    if(old_hrtf)
+        Hrtf_DecRef(old_hrtf);
+    old_hrtf = NULL;
     TRACE("HRTF disabled\n");
 
     device->Render_Mode = StereoPair;
diff --git a/OpenAL32/Include/alMain.h b/OpenAL32/Include/alMain.h
index 4807e07d..7add9310 100644
--- a/OpenAL32/Include/alMain.h
+++ b/OpenAL32/Include/alMain.h
@@ -702,7 +702,7 @@ struct ALCdevice_struct
     /* HRTF state and info */
     DirectHrtfState *Hrtf;
     al_string HrtfName;
-    const struct Hrtf *HrtfHandle;
+    struct Hrtf *HrtfHandle;
     vector_EnumeratedHrtf HrtfList;
     ALCenum HrtfStatus;