Commit Pepper backing texture immediately on swapbuffers.

webkit/plugins/ppapi/ppb_graphics_3d_impl.cc

 // Copyright (c) 2011 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 "webkit/plugins/ppapi/ppb_graphics_3d_impl.h"
 
 #include "base/bind.h"
 #include "base/message_loop.h"
 #include "gpu/command_buffer/client/gles2_implementation.h"
 #include "webkit/plugins/ppapi/plugin_module.h"
@@ skipping 147 matching lines @@
   return platform_context_->GetCommandBuffer();
 }
 
 int32 PPB_Graphics3D_Impl::DoSwapBuffers() {
   // We do not have a GLES2 implementation when using an OOP proxy.
   // The plugin-side proxy is responsible for adding the SwapBuffers command
   // to the command buffer in that case.
   if (gles2_impl())
     gles2_impl()->SwapBuffers();
 
-  platform_context_->Echo(base::Bind(&PPB_Graphics3D_Impl::OnSwapBuffers,
-                                     weak_ptr_factory_.GetWeakPtr()));
+  if (bound_to_instance_) {
+    // If we are bound to the instance, we need to ask the compositor
+    // to commit our backing texture so that the graphics appears on the page.
+    // When the backing texture will be committed we get notified via
+    // ViewFlushedPaint().
+    //
+    // Don't need to check for NULL from GetPluginInstance since when we're
+    // bound, we know our instance is valid.
+    ResourceHelper::GetPluginInstance(this)->CommitBackingTexture();

[piman, 2011/11/23 06:41:49]

This part is good, but you'll want to fix
ppapi::proxy::Graphics3D::DoSwapBuffers to send the command buffer swap *before*
the swap buffers message, otherwise you have a race.
(note, it looks like the current code already has a race, that was introduced by
the switch to Echo. Hmm...).

+    commit_pending_ = true;
+  } else {
+    // Wait for the command to complete on the GPU to allow for throttling.
+    platform_context_->Echo(base::Bind(&PPB_Graphics3D_Impl::OnSwapBuffers,
+                                       weak_ptr_factory_.GetWeakPtr()));
+  }
+
 
   return PP_OK_COMPLETIONPENDING;
 }
 
 bool PPB_Graphics3D_Impl::Init(PP_Resource share_context,
                                const int32_t* attrib_list) {
   if (!InitRaw(share_context, attrib_list))
     return false;
 
   gpu::CommandBuffer* command_buffer = GetCommandBuffer();
@@ skipping 21 matching lines @@
   if (!platform_context_->Init(attrib_list))
     return false;
 
   platform_context_->SetContextLostCallback(
       base::Bind(&PPB_Graphics3D_Impl::OnContextLost,
                  weak_ptr_factory_.GetWeakPtr()));
   return true;
 }
 
 void PPB_Graphics3D_Impl::OnSwapBuffers() {
-  if (bound_to_instance_) {
-    // If we are bound to the instance, we need to ask the compositor
-    // to commit our backing texture so that the graphics appears on the page.
-    // When the backing texture will be committed we get notified via
-    // ViewFlushedPaint().
-    //
-    // Don't need to check for NULL from GetPluginInstance since when we're
-    // bound, we know our instance is valid.
-    ResourceHelper::GetPluginInstance(this)->CommitBackingTexture();
-    commit_pending_ = true;
-  } else if (HasPendingSwap()) {
+  if (HasPendingSwap()) {
     // If we're off-screen, no need to trigger and wait for compositing.
     // Just send the swap-buffers ACK to the plugin immediately.
     commit_pending_ = false;
     SwapBuffersACK(PP_OK);
   }
 }
 
 void PPB_Graphics3D_Impl::OnContextLost() {
   // Don't need to check for NULL from GetPluginInstance since when we're
   // bound, we know our instance is valid.
@@ skipping 17 matching lines @@
   const PPP_Graphics3D* ppp_graphics_3d =
       static_cast<const PPP_Graphics3D*>(
           instance->module()->GetPluginInterface(
               PPP_GRAPHICS_3D_INTERFACE));
   if (ppp_graphics_3d)
     ppp_graphics_3d->Graphics3DContextLost(pp_instance());
 }
 
 }  // namespace ppapi
 }  // namespace webkit