commit f8a1041e99af4b86f7c550b736f87e8586df1a74
author Jiawei Shao <jiawei.shao@intel.com> Mon May 06 01:10:16 2019 +0000
committer Commit Bot service account <commit-bot@chromium.org> Mon May 06 01:10:16 2019 +0000
tree 7a9cb4a5d9ad921d402974ab20eab79c7e0626be
parent f54bb68f47ec718ab9175a9956e44959d2976301

Check OpenGL passed fences with glClientWaitSync()

This patch fixes an issue in the check of passed OpenGL fences.
Currently Dawn checks if an OpenGL fence is passed with glGetSynciv(sync,
GL_SYNC_CONDITION, sizeof(GLint), &length, &status), which always returns
GL_SYNC_GPU_COMMANDS_COMPLETE and is meaningless. This patch uses
glClientWaitSync() to check if a fence is passed instead.

BUG=dawn:137

Change-Id: Iff6b18bcc7155b06bde98ff68c7ed104a27bfe55
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/6800
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>

src/dawn_native/opengl/DeviceGL.cpp

diff --git a/src/dawn_native/opengl/DeviceGL.cpp b/src/dawn_native/opengl/DeviceGL.cpp
index dcaf916..a287f48 100644
--- a/src/dawn_native/opengl/DeviceGL.cpp
+++ b/src/dawn_native/opengl/DeviceGL.cpp
@@ -125,15 +125,11 @@
             GLsync sync = mFencesInFlight.front().first;
             Serial fenceSerial = mFencesInFlight.front().second;
 
-            GLint status = 0;
-            GLsizei length;
-            glGetSynciv(sync, GL_SYNC_CONDITION, sizeof(GLint), &length, &status);
-            ASSERT(length == 1);
-
             // Fence are added in order, so we can stop searching as soon
             // as we see one that's not ready.
-            if (!status) {
-                return;
+            GLenum result = glClientWaitSync(sync, GL_SYNC_FLUSH_COMMANDS_BIT, 0);
+            if (result == GL_TIMEOUT_EXPIRED) {
+                continue;
             }
 
             glDeleteSync(sync);