[Mesa-dev] [PATCH] mesa: don't wait in _mesa_ClientWaitSync if timeout is 0

[Vadim Girlin]

>From ARB_sync spec:

    If the value of <timeout> is zero, then ClientWaitSync does not
    block, but simply tests the current state of <sync>. TIMEOUT_EXPIRED
    will be returned in this case if <sync> is not signaled, even though
    no actual wait was performed.

Fixes random fails of the arb_sync-timeout-zero piglit test on r600g.

Signed-off-by: Vadim Girlin <vadimgirlin at gmail.com>
---
 src/mesa/main/syncobj.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/mesa/main/syncobj.c b/src/mesa/main/syncobj.c
index e1a5c6c..9f5a27e 100644
--- a/src/mesa/main/syncobj.c
+++ b/src/mesa/main/syncobj.c
@@ -326,9 +326,13 @@ _mesa_ClientWaitSync(GLsync sync, GLbitfield flags, GLuint64 timeout)
    if (syncObj->StatusFlag) {
       ret = GL_ALREADY_SIGNALED;
    } else {
-      ctx->Driver.ClientWaitSync(ctx, syncObj, flags, timeout);
+      if (timeout == 0) {
+         ret = GL_TIMEOUT_EXPIRED;
+      } else {
+         ctx->Driver.ClientWaitSync(ctx, syncObj, flags, timeout);
 
-      ret = syncObj->StatusFlag ? GL_CONDITION_SATISFIED : GL_TIMEOUT_EXPIRED;
+         ret = syncObj->StatusFlag ? GL_CONDITION_SATISFIED : GL_TIMEOUT_EXPIRED;
+      }
    }
 
    _mesa_unref_sync_object(ctx, syncObj);
-- 
1.7.11.4