[Mesa-dev] [PATCH 05/13] mesa: Replace buffer object locks with atomic inc/dec.

[Matt Turner]

---
 src/mesa/main/bufferobj.c | 17 +++--------------
 src/mesa/main/mtypes.h    |  1 -
 2 files changed, 3 insertions(+), 15 deletions(-)

diff --git a/src/mesa/main/bufferobj.c b/src/mesa/main/bufferobj.c
index cc035ff..78af229 100644
--- a/src/mesa/main/bufferobj.c
+++ b/src/mesa/main/bufferobj.c
@@ -47,6 +47,7 @@
 #include "texstore.h"
 #include "transformfeedback.h"
 #include "dispatch.h"
+#include "util/u_atomic.h"
 
 
 /* Debug flags */
@@ -424,7 +425,6 @@ _mesa_delete_buffer_object(struct gl_context *ctx,
    bufObj->RefCount = -1000;
    bufObj->Name = ~0;
 
-   mtx_destroy(&bufObj->Mutex);
    free(bufObj->Label);
    free(bufObj);
 }
@@ -443,16 +443,9 @@ _mesa_reference_buffer_object_(struct gl_context *ctx,
 {
    if (*ptr) {
       /* Unreference the old buffer */
-      GLboolean deleteFlag = GL_FALSE;
       struct gl_buffer_object *oldObj = *ptr;
 
-      mtx_lock(&oldObj->Mutex);
-      assert(oldObj->RefCount > 0);
-      oldObj->RefCount--;
-      deleteFlag = (oldObj->RefCount == 0);
-      mtx_unlock(&oldObj->Mutex);
-
-      if (deleteFlag) {
+      if (p_atomic_dec_zero(&oldObj->RefCount)) {
 	 assert(ctx->Driver.DeleteBuffer);
          ctx->Driver.DeleteBuffer(ctx, oldObj);
       }
@@ -463,7 +456,6 @@ _mesa_reference_buffer_object_(struct gl_context *ctx,
 
    if (bufObj) {
       /* reference new buffer */
-      mtx_lock(&bufObj->Mutex);
       if (bufObj->RefCount == 0) {
          /* this buffer's being deleted (look just above) */
          /* Not sure this can every really happen.  Warn if it does. */
@@ -471,10 +463,9 @@ _mesa_reference_buffer_object_(struct gl_context *ctx,
          *ptr = NULL;
       }
       else {
-         bufObj->RefCount++;
+         p_atomic_inc(&bufObj->RefCount);
          *ptr = bufObj;
       }
-      mtx_unlock(&bufObj->Mutex);
    }
 }
 
@@ -488,7 +479,6 @@ _mesa_initialize_buffer_object(struct gl_context *ctx,
                                GLuint name)
 {
    memset(obj, 0, sizeof(struct gl_buffer_object));
-   mtx_init(&obj->Mutex, mtx_plain);
    obj->RefCount = 1;
    obj->Name = name;
    obj->Usage = GL_STATIC_DRAW_ARB;
@@ -806,7 +796,6 @@ _mesa_init_buffer_objects( struct gl_context *ctx )
    GLuint i;
 
    memset(&DummyBufferObject, 0, sizeof(DummyBufferObject));
-   mtx_init(&DummyBufferObject.Mutex, mtx_plain);
    DummyBufferObject.RefCount = 1000*1000*1000; /* never delete */
 
    _mesa_reference_buffer_object(ctx, &ctx->Array.ArrayBufferObj,
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 19f65ee..2adfae2 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -1477,7 +1477,6 @@ typedef enum {
  */
 struct gl_buffer_object
 {
-   mtx_t Mutex;
    GLint RefCount;
    GLuint Name;
    GLchar *Label;       /**< GL_KHR_debug */
-- 
2.3.6