Implement proper synchronization between HW video decode IPC and CommandBuffer.

ppapi/examples/gles2/gles2.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 <string.h>
 
 #include <iostream>
 #include <map>
 #include <set>
 #include <vector>
@@ skipping 55 matching lines @@
   enum { kNumConcurrentDecodes = 7 };
 
   // Helper struct that stores data used by the shader program.
   struct ShaderInfo {
     GLint pos_location;
     GLint tc_location;
     GLint tex_location;
     GLuint vertex_buffers[2];
   };
 
-  // Serialize PPB_Video_Decoder_Dev operations w.r.t. GPU command buffer.
-  // TODO(fischman): figure out how much of this is actually necessary.
-  // Probably any necessary serialization ought to be happening in the
-  // PPAPI implementation, not in the plugin!
-  void FinishGL() {
-    gles2_if_->Finish(context_->pp_resource());
-  }
-
   // Initialize Video Decoder.
   void InitializeDecoder();
 
   // Callbacks passed into pp:VideoDecoder_Dev functions.
   void DecoderInitDone(int32_t result);
   void DecoderBitstreamDone(int32_t result, int bitstream_buffer_id);
   void DecoderFlushDone(int32_t result);
   void DecoderAbortDone(int32_t result);
 
   // Decode helpers.
@@ skipping 171 matching lines @@
     PP_PictureBufferType_Dev type) {
   std::vector<PP_GLESBuffer_Dev> buffers;
   for (uint32_t i = 0; i < req_num_of_bufs; i++) {
     PP_GLESBuffer_Dev buffer;
     buffer.texture_id = CreateTexture(dimensions.width, dimensions.height);
     int id = ++next_picture_buffer_id_;
     buffer.info.id= id;
     buffers.push_back(buffer);
     assert(buffers_by_id_.insert(std::make_pair(id, buffer)).second);
   }
-  FinishGL();
   video_decoder_->AssignGLESBuffers(buffers);
 }
 
 void GLES2DemoInstance::DismissPictureBuffer(
     pp::VideoDecoder_Dev decoder, int32_t picture_buffer_id) {
   PictureBufferMap::iterator it = buffers_by_id_.find(picture_buffer_id);
   assert(it != buffers_by_id_.end());
   DeleteTexture(it->second.texture_id);
   buffers_by_id_.erase(it);
-
-  FinishGL();
 }
 
 void GLES2DemoInstance::PictureReady(
     pp::VideoDecoder_Dev decoder, const PP_Picture_Dev& picture) {
   PictureBufferMap::iterator it =
       buffers_by_id_.find(picture.picture_buffer_id);
   assert(it != buffers_by_id_.end());
   Render(it->second);
 }
 
@@ skipping 36 matching lines @@
 
   // Set viewport window size and clear color bit.
   gles2_if_->Clear(context_->pp_resource(), GL_COLOR_BUFFER_BIT);
   gles2_if_->Viewport(context_->pp_resource(), 0, 0,
                       position_size_.width(), position_size_.height());
 
   assert(BindGraphics(*surface_));
   assertNoGLError();
 
   CreateGLObjects();
-
-  FinishGL();
 }
 
 void GLES2DemoInstance::Render(const PP_GLESBuffer_Dev& buffer) {
   if (is_painting_) {
     // We are dropping frames if we don't render fast enough -
     // that is why sometimes the last frame rendered is < 249.
-    if (video_decoder_) {
-      FinishGL();
+    if (video_decoder_)
       video_decoder_->ReusePictureBuffer(buffer.info.id);
-    }
     return;
   }
   is_painting_ = true;
   gles2_if_->ActiveTexture(context_->pp_resource(), GL_TEXTURE0);
   gles2_if_->BindTexture(
       context_->pp_resource(), GL_TEXTURE_2D, buffer.texture_id);
   gles2_if_->Uniform1i(context_->pp_resource(), program_data_.tex_location, 0);
   gles2_if_->DrawArrays(context_->pp_resource(), GL_TRIANGLE_STRIP, 0, 4);
   pp::CompletionCallback cb =
       callback_factory_.NewCallback(
           &GLES2DemoInstance::PaintFinished, buffer.info.id);
   assert(surface_->SwapBuffers(cb) == PP_ERROR_WOULDBLOCK);
   assertNoGLError();
 }
 
 void GLES2DemoInstance::PaintFinished(int32_t result, int picture_buffer_id) {
   is_painting_ = false;
-  FinishGL();
   if (video_decoder_)
     video_decoder_->ReusePictureBuffer(picture_buffer_id);
 }
 
 GLuint GLES2DemoInstance::CreateTexture(int32_t width, int32_t height) {
   GLuint texture_id;
   gles2_if_->GenTextures(context_->pp_resource(), 1, &texture_id);
   assertNoGLError();
   // Assign parameters.
   gles2_if_->ActiveTexture(context_->pp_resource(), GL_TEXTURE0);
@@ skipping 124 matching lines @@
   gles2_if_->DeleteShader(context_->pp_resource(), shader);
 }
 }  // anonymous namespace
 
 namespace pp {
 // Factory function for your specialization of the Module object.
 Module* CreateModule() {
   return new GLES2DemoModule();
 }
 }  // namespace pp