Added support for allowing a parent GGL context to be destroyed before all of...

chrome/renderer/ggl/ggl.cc

 // Copyright (c) 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 "build/build_config.h"
 
 #include "base/ref_counted.h"
 #include "base/singleton.h"
 #include "base/thread_local.h"
+#include "base/weak_ptr.h"
 #include "chrome/renderer/command_buffer_proxy.h"
 #include "chrome/renderer/ggl/ggl.h"
 #include "chrome/renderer/gpu_channel_host.h"
 #include "chrome/renderer/render_widget.h"
 #include "ipc/ipc_channel_handle.h"
 
 #if defined(ENABLE_GPU)
 #include "gpu/command_buffer/client/gles2_cmd_helper.h"
 #include "gpu/command_buffer/client/gles2_implementation.h"
 #include "gpu/command_buffer/client/gles2_lib.h"
@@ skipping 24 matching lines @@
   ~GLES2Initializer() {
     gles2::Terminate();
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GLES2Initializer);
 };
 }  // namespace anonymous
 
 // Manages a GL context.
-class Context {
+class Context : public base::SupportsWeakPtr<Context> {
  public:
   Context(GpuChannelHost* channel, Context* parent);
   ~Context();
 
   // Initialize a GGL context that can be used in association with a a GPU
   // channel acquired from a RenderWidget or RenderView.
   bool Initialize(gfx::NativeViewId view, const gfx::Size& size);
 
   // Asynchronously resizes an offscreen frame buffer.
   void ResizeOffscreen(const gfx::Size& size);
@@ skipping 16 matching lines @@
   bool SwapBuffers();
 
   // Get the current error code.
   Error GetError();
 
   // TODO(gman): Remove this.
   void DisableShaderTranslation();
 
  private:
   scoped_refptr<GpuChannelHost> channel_;
-  Context* parent_;
+  base::WeakPtr<Context> parent_;
   uint32 parent_texture_id_;
   CommandBufferProxy* command_buffer_;
   gpu::gles2::GLES2CmdHelper* gles2_helper_;
   int32 transfer_buffer_id_;
   gpu::gles2::GLES2Implementation* gles2_implementation_;
 
   DISALLOW_COPY_AND_ASSIGN(Context);
 };
 
 Context::Context(GpuChannelHost* channel, Context* parent)
     : channel_(channel),
-      parent_(parent),
+      parent_(parent ? parent->AsWeakPtr() : base::WeakPtr<Context>()),
       parent_texture_id_(0),
       command_buffer_(NULL),
       gles2_helper_(NULL),
       transfer_buffer_id_(0),
       gles2_implementation_(NULL) {
   DCHECK(channel);
 }
 
 Context::~Context() {
   Destroy();
 }
 
 bool Context::Initialize(gfx::NativeViewId view, const gfx::Size& size) {
   DCHECK(size.width() >= 0 && size.height() >= 0);
 
   if (!channel_->ready())
     return false;
 
   // Ensure the gles2 library is initialized first in a thread safe way.
   Singleton<GLES2Initializer>::get();
 
   // Allocate a frame buffer ID with respect to the parent.
-  if (parent_) {
+  if (parent_.get()) {
     // Flush any remaining commands in the parent context to make sure the
     // texture id accounting stays consistent.
     int32 token = parent_->gles2_helper_->InsertToken();
     parent_->gles2_helper_->WaitForToken(token);
     parent_texture_id_ = parent_->gles2_implementation_->MakeTextureId();
   }
 
   // Create a proxy to a command buffer in the GPU process.
   if (view) {
     command_buffer_ = channel_->CreateViewCommandBuffer(view);
   } else {
     CommandBufferProxy* parent_command_buffer =
-        parent_ ? parent_->command_buffer_ : NULL;
+        parent_.get() ? parent_->command_buffer_ : NULL;
     command_buffer_ = channel_->CreateOffscreenCommandBuffer(
         parent_command_buffer,
         size,
         parent_texture_id_);
   }
   if (!command_buffer_) {
     Destroy();
     return false;
   }
 
@@ skipping 37 matching lines @@
 
   return true;
 }
 
 void Context::ResizeOffscreen(const gfx::Size& size) {
   DCHECK(size.width() > 0 && size.height() > 0);
   command_buffer_->ResizeOffscreenFrameBuffer(size);
 }
 
 void Context::Destroy() {
-  if (parent_ && parent_texture_id_ != 0)
+  if (parent_.get() && parent_texture_id_ != 0)
     parent_->gles2_implementation_->FreeTextureId(parent_texture_id_);
 
   delete gles2_implementation_;
   gles2_implementation_ = NULL;
 
   if (command_buffer_ && transfer_buffer_id_ != 0) {
     command_buffer_->DestroyTransferBuffer(transfer_buffer_id_);
     transfer_buffer_id_ = 0;
   }
 
@@ skipping 151 matching lines @@
 
 // TODO(gman): Remove This
 void DisableShaderTranslation(Context* context) {
 #if defined(ENABLE_GPU)
   if (context) {
     context->DisableShaderTranslation();
   }
 #endif
 }
 }  // namespace ggl