cc: Dedup IPCs to return resources to client

content/renderer/gpu/compositor_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/compositor_output_surface.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/location.h"
@@ skipping 122 matching lines @@
 }
 
 void CompositorOutputSurface::OnMessageReceived(const IPC::Message& message) {
   DCHECK(client_thread_checker_.CalledOnValidThread());
   if (!HasClient())
     return;
   IPC_BEGIN_MESSAGE_MAP(CompositorOutputSurface, message)
     IPC_MESSAGE_HANDLER(ViewMsg_UpdateVSyncParameters,
                         OnUpdateVSyncParametersFromBrowser);
     IPC_MESSAGE_HANDLER(ViewMsg_SwapCompositorFrameAck, OnSwapAck);
-    IPC_MESSAGE_HANDLER(ViewMsg_ReclaimCompositorResources, OnReclaimResources);
   IPC_END_MESSAGE_MAP()
 }
 
 void CompositorOutputSurface::OnUpdateVSyncParametersFromBrowser(
     base::TimeTicks timebase,
     base::TimeDelta interval) {
   DCHECK(client_thread_checker_.CalledOnValidThread());
   TRACE_EVENT2("cc",
                "CompositorOutputSurface::OnUpdateVSyncParametersFromBrowser",
                "timebase", (timebase - base::TimeTicks()).InSecondsF(),
                "interval", interval.InSecondsF());
   client_->CommitVSyncParameters(timebase, interval);
 }
 
 void CompositorOutputSurface::OnSwapAck(uint32_t 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_)
     return;
   ReclaimResources(&ack);
   client_->DidSwapBuffersComplete();

[dcheng, 2016/07/13 14:26:58]

Does it matter that OnReclaimResources didn't call this?

[Fady Samuel, 2016/07/13 15:29:48]

piman@ can better answer this question. I could add a bool to the IPC to do this
if necessary.

It looks to me that we unref resources in response to a new compositorframe
anyway, and so this is effectively marking the end of a swapbuffers. I don't
really yet understand the implication of calling this more than before yet.

[danakj, 2016/07/13 18:40:20]

This is what unthrottles the compositor to produce another frame. Calling it a
different number of times would be bad, it needs to match with SwapBuffers.

 }
 
-void CompositorOutputSurface::OnReclaimResources(
-    uint32_t 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_)
-    return;
-  ReclaimResources(&ack);
-}
-
 bool CompositorOutputSurface::Send(IPC::Message* message) {
   return message_sender_->Send(message);
 }
 
 }  // namespace content