Associate an id with the output surface to handle lost contexts

content/renderer/gpu/mailbox_output_surface.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 "content/renderer/gpu/mailbox_output_surface.h"
 
 #include "base/logging.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
 #include "cc/output/gl_frame_data.h"
 #include "third_party/WebKit/public/platform/WebGraphicsContext3D.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/khronos/GLES2/gl2ext.h"
 
 using cc::CompositorFrame;
 using cc::GLFrameData;
 using gpu::Mailbox;
 
 namespace content {
 
 MailboxOutputSurface::MailboxOutputSurface(
     int32 routing_id,
+    uint32 output_surface_id,
     WebGraphicsContext3DCommandBufferImpl* context3D,
     cc::SoftwareOutputDevice* software_device)
-    : CompositorOutputSurface(routing_id, context3D, software_device, true),
+    : CompositorOutputSurface(routing_id,
+                              output_surface_id,
+                              context3D,
+                              software_device,
+                              true),
       fbo_(0),
       is_backbuffer_discarded_(false) {
   pending_textures_.push_back(TransferableFrame());
   capabilities_.max_frames_pending = 1;
 }
 
 MailboxOutputSurface::~MailboxOutputSurface() {
   DiscardBackbuffer();
   while (!pending_textures_.empty()) {
     if (pending_textures_.front().texture_id)
@@ skipping 80 matching lines @@
   DCHECK(current_backing_.texture_id);
 
   if (!fbo_)
     fbo_ = context3d_->createFramebuffer();
   context3d_->bindFramebuffer(GL_FRAMEBUFFER, fbo_);
   context3d_->framebufferTexture2D(
       GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
       current_backing_.texture_id, 0);
 }
 
-void MailboxOutputSurface::OnSwapAck(const cc::CompositorFrameAck& ack) {
+void MailboxOutputSurface::OnSwapAck(uint32 output_surface_id,
+                                     const cc::CompositorFrameAck& ack) {
+  // Ignore message if it's a stale one coming from a different output surface
+  // (e.g. after a lost context).
+  if (output_surface_id != output_surface_id_) {
+    CompositorOutputSurface::OnSwapAck(output_surface_id, ack);
+    return;
+  }
   if (!ack.gl_frame_data->mailbox.IsZero()) {
     DCHECK(!ack.gl_frame_data->size.IsEmpty());
     // The browser could be returning the oldest or any other pending texture
     // if it decided to skip a frame.
     std::deque<TransferableFrame>::iterator it;
     for (it = pending_textures_.begin(); it != pending_textures_.end(); it++) {
       DCHECK(!it->mailbox.IsZero());
       if (!memcmp(it->mailbox.name,
                   ack.gl_frame_data->mailbox.name,
                   sizeof(it->mailbox.name))) {
@@ skipping 14 matching lines @@
   } else {
     DCHECK(!pending_textures_.empty());
     // The browser always keeps one texture as the frontbuffer.
     // If it does not return a mailbox, it discarded the frontbuffer which is
     // the oldest texture we sent.
     uint32 texture_id = pending_textures_.front().texture_id;
     if (texture_id)
       context3d_->deleteTexture(texture_id);
     pending_textures_.pop_front();
   }
-  CompositorOutputSurface::OnSwapAck(ack);
+  CompositorOutputSurface::OnSwapAck(output_surface_id, ack);
 }
 
 void MailboxOutputSurface::SwapBuffers(cc::CompositorFrame* frame) {
   DCHECK(frame->gl_frame_data);
   DCHECK(!surface_size_.IsEmpty());
   DCHECK(surface_size_ == current_backing_.size);
   DCHECK(frame->gl_frame_data->size == current_backing_.size);
   DCHECK(!current_backing_.mailbox.IsZero());
 
   frame->gl_frame_data->mailbox = current_backing_.mailbox;
   context3d_->flush();
   frame->gl_frame_data->sync_point = context3d_->insertSyncPoint();
   CompositorOutputSurface::SwapBuffers(frame);
 
   pending_textures_.push_back(current_backing_);
   current_backing_ = TransferableFrame();
 }
 
 size_t MailboxOutputSurface::GetNumAcksPending() {
   DCHECK(pending_textures_.size());
   return pending_textures_.size() - 1;
 }
 
 }  // namespace content