Mesa (master): mesa: Make _mesa_share_state thread safe.

[Keith Whitwell]

Module: Mesa
Branch: master
Commit: b25168c34c60760a33ca9e8336ac76cf1219f143
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=b25168c34c60760a33ca9e8336ac76cf1219f143

Author: José Fonseca <jfonseca at vmware.com>
Date:   Fri May  1 18:52:54 2009 +0100

mesa: Make _mesa_share_state thread safe.

---

 src/mesa/main/context.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 1a290f2..ddbc631 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -1394,14 +1394,21 @@ _mesa_share_state(GLcontext *ctx, GLcontext *ctxToShare)
 {
    if (ctx && ctxToShare && ctx->Shared && ctxToShare->Shared) {
       struct gl_shared_state *oldSharedState = ctx->Shared;
+      GLint RefCount;
 
       ctx->Shared = ctxToShare->Shared;
+      
+      _glthread_LOCK_MUTEX(ctx->Shared->Mutex);
       ctx->Shared->RefCount++;
+      _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);
 
       update_default_objects(ctx);
 
-      oldSharedState->RefCount--;
-      if (oldSharedState->RefCount == 0) {
+      _glthread_LOCK_MUTEX(oldSharedState->Mutex);
+      RefCount = --oldSharedState->RefCount;
+      _glthread_UNLOCK_MUTEX(oldSharedState->Mutex);
+
+      if (RefCount == 0) {
          _mesa_free_shared_state(ctx, oldSharedState);
       }