Hold a reference on the context when being set as current on the thread

This should vastly improve efficiency for retrieving the current thread
context, as we can be assured the stored context pointer will always be valid.

1 files changed, 50 insertions, 40 deletions

diff --git a/Alc/ALc.c b/Alc/ALc.c
index ac169eac..0bdd61f5 100644
--- a/Alc/ALc.c
+++ b/Alc/ALc.c
@@ -411,6 +411,7 @@ static pthread_once_t alc_config_once = PTHREAD_ONCE_INIT;
 ///////////////////////////////////////////////////////
 // ALC Related helper functions
 static void ReleaseALC(ALCboolean doclose);
+static void ReleaseThreadCtx(void *ptr);
 
 static void alc_initconfig(void);
 #define DO_INITCONFIG() pthread_once(&alc_config_once, alc_initconfig)
@@ -499,7 +500,7 @@ static void alc_init(void)
     if(str && (strcasecmp(str, "true") == 0 || strtol(str, NULL, 0) == 1))
         ZScale = -1.0;
 
-    pthread_key_create(&LocalContext, NULL);
+    pthread_key_create(&LocalContext, ReleaseThreadCtx);
     InitializeCriticalSection(&ListLock);
     ThunkInit();
 }
@@ -1307,24 +1308,21 @@ ALCvoid UnlockContext(ALCcontext *context)
 */
 ALCcontext *GetLockedContext(void)
 {
-    ALCcontext *pContext = NULL;
+    ALCcontext *context = NULL;
 
-    LockLists();
-
-    pContext = pthread_getspecific(LocalContext);
-    if(pContext && !IsContext(pContext))
+    context = pthread_getspecific(LocalContext);
+    if(context)
+        LockContext(context);
+    else
     {
-        pthread_setspecific(LocalContext, NULL);
-        pContext = NULL;
+        LockLists();
+        context = GlobalContext;
+        if(context)
+            LockContext(context);
+        UnlockLists();
     }
-    if(!pContext)
-        pContext = GlobalContext;
-    if(pContext)
-        LockContext(pContext);
 
-    UnlockLists();
-
-    return pContext;
+    return context;
 }
 
 
@@ -1406,10 +1404,24 @@ static ALCvoid FreeContext(ALCcontext *context)
     free(context);
 }
 
+static void ALCcontext_IncRef(ALCcontext *context)
+{
+    RefCount ref;
+    ref = IncrementRef(&context->ref);
+    TRACE("%p refcount increment to %d\n", context, ref);
+}
+
 static void ALCcontext_DecRef(ALCcontext *context)
 {
-    if(DecrementRef(&context->ref) == 0)
-        FreeContext(context);
+    RefCount ref;
+    ref = DecrementRef(&context->ref);
+    TRACE("%p refcount decrement to %d\n", context, ref);
+    if(ref == 0) FreeContext(context);
+}
+
+static void ReleaseThreadCtx(void *ptr)
+{
+    ALCcontext_DecRef(ptr);
 }
 
 ///////////////////////////////////////////////////////
@@ -2140,16 +2152,13 @@ ALC_API ALCcontext* ALC_APIENTRY alcGetCurrentContext(ALCvoid)
 {
     ALCcontext *Context;
 
-    LockLists();
     Context = pthread_getspecific(LocalContext);
-    if(Context && !IsContext(Context))
-    {
-        pthread_setspecific(LocalContext, NULL);
-        Context = NULL;
-    }
     if(!Context)
+    {
+        LockLists();
         Context = GlobalContext;
-    UnlockLists();
+        UnlockLists();
+    }
 
     return Context;
 }
@@ -2161,20 +2170,9 @@ ALC_API ALCcontext* ALC_APIENTRY alcGetCurrentContext(ALCvoid)
 */
 ALC_API ALCcontext* ALC_APIENTRY alcGetThreadContext(void)
 {
-    ALCcontext *pContext = NULL;
-
-    LockLists();
-
-    pContext = pthread_getspecific(LocalContext);
-    if(pContext && !IsContext(pContext))
-    {
-        pthread_setspecific(LocalContext, NULL);
-        pContext = NULL;
-    }
-
-    UnlockLists();
-
-    return pContext;
+    ALCcontext *Context;
+    Context = pthread_getspecific(LocalContext);
+    return Context;
 }
 
 
@@ -2213,7 +2211,11 @@ ALC_API ALCboolean ALC_APIENTRY alcMakeContextCurrent(ALCcontext *context)
     if(context == NULL || IsContext(context))
     {
         GlobalContext = context;
-        pthread_setspecific(LocalContext, NULL);
+        if((context=pthread_getspecific(LocalContext)) != NULL)
+        {
+            pthread_setspecific(LocalContext, NULL);
+            ALCcontext_DecRef(context);
+        }
     }
     else
     {
@@ -2239,7 +2241,15 @@ ALC_API ALCboolean ALC_APIENTRY alcSetThreadContext(ALCcontext *context)
 
     // context must be a valid Context or NULL
     if(context == NULL || IsContext(context))
-        pthread_setspecific(LocalContext, context);
+    {
+        ALCcontext *old = pthread_getspecific(LocalContext);
+        if(old != context)
+        {
+            if(context) ALCcontext_IncRef(context);
+            pthread_setspecific(LocalContext, context);
+            if(old) ALCcontext_DecRef(old);
+        }
+    }
     else
     {
         alcSetError(NULL, ALC_INVALID_CONTEXT);