gpu: Implement idle async pixel transfers.

gpu/command_buffer/service/gles2_cmd_decoder.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.
 
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <stdio.h>
 
 #include <algorithm>
 #include <list>
@@ skipping 555 matching lines @@
   virtual void RestoreFramebufferBindings() const OVERRIDE;
   virtual void RestoreTextureState(unsigned service_id) const OVERRIDE;
 
   virtual QueryManager* GetQueryManager() OVERRIDE {
     return query_manager_.get();
   }
   virtual VertexArrayManager* GetVertexArrayManager() OVERRIDE {
     return vertex_array_manager_.get();
   }
   virtual bool ProcessPendingQueries() OVERRIDE;
+  virtual bool HasMoreWork() OVERRIDE;
+  virtual bool PerformIdleWork() OVERRIDE;
 
   virtual void SetResizeCallback(
       const base::Callback<void(gfx::Size)>& callback) OVERRIDE;
 
   virtual void SetMsgCallback(const MsgCallback& callback) OVERRIDE;
   virtual void SetWaitSyncPointCallback(
       const WaitSyncPointCallback& callback) OVERRIDE;
 
   virtual void SetStreamTextureManager(StreamTextureManager* manager) OVERRIDE;
 
@@ skipping 8522 matching lines @@
 bool GLES2DecoderImpl::ProcessPendingQueries() {
   if (query_manager_.get() == NULL) {
     return false;
   }
   if (!query_manager_->ProcessPendingQueries()) {
     current_decoder_error_ = error::kOutOfBounds;
   }
   return query_manager_->HavePendingQueries();
 }
 
+bool GLES2DecoderImpl::HasMoreWork() {
+  return ProcessPendingQueries() ||
+      async_pixel_transfer_delegate_->CanProcessPendingTransfers();
+}
+
+bool GLES2DecoderImpl::PerformIdleWork() {
+  if (!async_pixel_transfer_delegate_->CanProcessPendingTransfers())
+    return false;
+  async_pixel_transfer_delegate_->ProcessPendingTransfers();
+  RestoreCurrentTexture2DBindings();

[greggman, 2013/03/08 21:06:21]

What do think about moving RestoreCurrentTexture2DBindings inside
ProcessPendingTransfers?

I've made all the state restore functions public from GLES2Decoder so you can
pass 'this' into ProcessPendingTransfers.

In this particular case you really want to call

decoder->RestoreTextureUnitBindings(0);
decoder->RestoreActiveTexture();

The advantage is ProcessPendingTransfers can clean up after itself. The caller
doesn't need to know what happens inside like it does here.

I did this for DoCopyTextureCHROMIUM recently.
see http://goo.gl/XfXlE

[reveman, 2013/03/12 00:31:42]

Makes sense. The latest patch calls ProcessFinishedAsyncTransfers() here instead
as that's more appropriate. ProcessFinishedAsyncTransfers() calls
RestoreCurrentTexture2DBindings() and we probably want to clean that up as you
described but I would prefer to do that in a follow up patch. Latest patch at
least doesn't make things worse.

+  return async_pixel_transfer_delegate_->CanProcessPendingTransfers();
+}
+
 error::Error GLES2DecoderImpl::HandleBeginQueryEXT(
     uint32 immediate_data_size, const cmds::BeginQueryEXT& c) {
   GLenum target = static_cast<GLenum>(c.target);
   GLuint client_id = static_cast<GLuint>(c.id);
   int32 sync_shm_id = static_cast<int32>(c.sync_data_shm_id);
   uint32 sync_shm_offset = static_cast<uint32>(c.sync_data_shm_offset);
 
   switch (target) {
     case GL_COMMANDS_ISSUED_CHROMIUM:
     case GL_LATENCY_QUERY_CHROMIUM:
@@ skipping 1044 matching lines @@
   return error::kNoError;
 }
 
 // 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/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu