Verify resource provider sync tokens before sending to parent.

gpu/command_buffer/client/gles2_implementation.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // A class to emulate GLES2 over command buffers.
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
@@ skipping 5571 matching lines @@
 
   // Copy the data over after setting the data to ensure alignment.
   SyncToken sync_token_data(gpu_control_->GetNamespaceID(),
                             gpu_control_->GetExtraCommandBufferData(),
                             gpu_control_->GetCommandBufferID(), fence_sync);
   memcpy(sync_token, &sync_token_data, sizeof(sync_token_data));
 }
 
 void GLES2Implementation::VerifySyncTokensCHROMIUM(GLbyte **sync_tokens,
                                                    GLsizei count) {
-  bool sync_tokens_verified = false;
+  bool requires_synchronization = false;
   for (GLsizei i = 0; i < count; ++i) {
     if (sync_tokens[i]) {
       SyncToken sync_token;
       memcpy(&sync_token, sync_tokens[i], sizeof(sync_token));
 
       if (!sync_token.verified_flush()) {
         if (!gpu_control_->CanWaitUnverifiedSyncToken(&sync_token)) {
           SetGLError(GL_INVALID_VALUE, "glVerifySyncTokensCHROMIUM",
                      "Cannot verify sync token using this context.");
           return;
         }
-        if (!sync_tokens_verified) {
-          // Insert a fence sync here and ensure it is received immediately.
-          // This will require a flush but simplifies things a bit because
-          // unverified sync tokens only need an ordering barrier.
-          const uint64_t release = gpu_control_->GenerateFenceSyncRelease();
-          FlushHelper();
-          const bool verified = gpu_control_->IsFenceSyncFlushReceived(release);
-          DCHECK(verified);
+        requires_synchronization = true;
+      }
+    }
+  }
 
-          sync_tokens_verified = true;
-        }
+  // This step must be done after all unverified tokens have finished processing
+  // CanWaitUnverifiedSyncToken(), command buffers use that to do any necessary
+  // flushes.
+  if (requires_synchronization) {
+    // Make sure we have no pending ordering barriers by flushing now.
+    FlushHelper();
 
+    // Ensure all the fence syncs are visible on GPU service.
+    gpu_control_->EnsureWorkVisible();
+
+    // We can automatically mark everything as verified now.
+    for (GLsizei i = 0; i < count; ++i) {
+      SyncToken sync_token;
+      memcpy(&sync_token, sync_tokens[i], sizeof(sync_token));
+      if (!sync_token.verified_flush()) {
         sync_token.SetVerifyFlush();
         memcpy(sync_tokens[i], &sync_token, sizeof(sync_token));
       }
     }
   }
 }
 
 void GLES2Implementation::WaitSyncTokenCHROMIUM(const GLbyte* sync_token) {
   if (sync_token) {
     // Copy the data over before data access to ensure alignment.
@@ skipping 915 matching lines @@
   CheckGLError();
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/client/gles2_implementation_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu