Early wait on texture resource sync points in gl_renderer.

cc/output/gl_renderer.cc

 // Copyright 2010 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.
 
 #include "cc/output/gl_renderer.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 #include <string>
@@ skipping 458 matching lines @@
 
   // TODO(enne): Do we need to reinitialize all of this state per frame?
   ReinitializeGLState();
 }
 
 void GLRenderer::DoNoOp() {
   GLC(gl_, gl_->BindFramebuffer(GL_FRAMEBUFFER, 0));
   GLC(gl_, gl_->Flush());
 }
 
+void GLRenderer::DoPrelockQuad(DrawingFrame* frame, const DrawQuad* quad) {
+  switch (quad->material) {
+    case DrawQuad::TILED_CONTENT: {
+      const TileDrawQuad* q = TileDrawQuad::MaterialCast(quad);
+      ResourceProvider::ScopedReadLockGL lock(resource_provider_,

[enne (OOO), 2014/08/13 00:20:54]

I'm not sure that I follow what this is trying to do.  A scoped read lock will
lock and unlock right here.  Is that intentional?

[vmiura, 2014/08/13 01:01:32]

Yes it's intentional, in this case taking the lock is taken temporarily to force
any pending mailbox sync point to be checked.

Here:

ResourceProvider::LockForRead(ResourceId id) {
...
    DCHECK(gl);
    if (resource->mailbox.sync_point()) {
      GLC(gl, gl->WaitSyncPointCHROMIUM(resource->mailbox.sync_point()));
      resource->mailbox.set_sync_point(0);
    }
}

[vmiura, 2014/08/13 22:50:39]

No longer applicable.

+                                              q->resource_id);
+    } break;
+    default:
+      break;
+  }
+}
+
 void GLRenderer::DoDrawQuad(DrawingFrame* frame, const DrawQuad* quad) {
   DCHECK(quad->rect.Contains(quad->visible_rect));
   if (quad->material != DrawQuad::TEXTURE_CONTENT) {
     FlushTextureQuadCache();
   }
 
   switch (quad->material) {
     case DrawQuad::INVALID:
       NOTREACHED();
       break;
@@ skipping 2682 matching lines @@
     context_support_->ScheduleOverlayPlane(
         overlay.plane_z_order,
         overlay.transform,
         pending_overlay_resources_.back()->texture_id(),
         overlay.display_rect,
         overlay.uv_rect);
   }
 }
 
 }  // namespace cc