Avoid sending duplicate flushes

content/common/gpu/client/command_buffer_proxy.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/common/gpu/client/command_buffer_proxy.h"
 
 #include "base/callback.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/process_util.h"
@@ skipping 10 matching lines @@
 #include "gpu/command_buffer/common/command_buffer_shared.h"
 #include "ui/gfx/size.h"
 
 using gpu::Buffer;
 
 CommandBufferProxy::CommandBufferProxy(
     GpuChannelHost* channel,
     int route_id)
     : channel_(channel),
       route_id_(route_id),
-      flush_count_(0) {
+      flush_count_(0),
+      last_put_offset_(-1) {
 }
 
 CommandBufferProxy::~CommandBufferProxy() {
   // Delete all the locally cached shared memory objects, closing the handle
   // in this process.
   for (TransferBufferMap::iterator it = transfer_buffers_.begin();
        it != transfer_buffers_.end();
        ++it) {
     delete it->second.shared_memory;
     it->second.shared_memory = NULL;
@@ skipping 123 matching lines @@
 gpu::CommandBuffer::State CommandBufferProxy::GetLastState() {
   return last_state_;
 }
 
 void CommandBufferProxy::Flush(int32 put_offset) {
   if (last_state_.error != gpu::error::kNoError)
     return;
 
   TRACE_EVENT1("gpu", "CommandBufferProxy::Flush", "put_offset", put_offset);
 
+  if (last_put_offset_ == put_offset)
+    return;
+
+  last_put_offset_ = put_offset;
+
   Send(new GpuCommandBufferMsg_AsyncFlush(route_id_,
                                           put_offset,
                                           ++flush_count_));
 }
 
 gpu::CommandBuffer::State CommandBufferProxy::FlushSync(int32 put_offset,
                                                         int32 last_known_get) {
   TRACE_EVENT1("gpu", "CommandBufferProxy::FlushSync", "put_offset",
                put_offset);
   Flush(put_offset);
@@ skipping 10 matching lines @@
   }
 
   return last_state_;
 }
 
 void CommandBufferProxy::SetGetBuffer(int32 shm_id) {
   if (last_state_.error != gpu::error::kNoError)
     return;
 
   Send(new GpuCommandBufferMsg_SetGetBuffer(route_id_, shm_id));
+  last_put_offset_ = -1;
 }
 
 void CommandBufferProxy::SetGetOffset(int32 get_offset) {
   // Not implemented in proxy.
   NOTREACHED();
 }
 
 int32 CommandBufferProxy::CreateTransferBuffer(size_t size, int32 id_request) {
   if (last_state_.error != gpu::error::kNoError)
     return -1;
@@ skipping 232 matching lines @@
 
 void CommandBufferProxy::SetOnConsoleMessageCallback(
     const GpuConsoleMessageCallback& callback) {
   console_message_callback_ = callback;
 }
 
 void CommandBufferProxy::TryUpdateState() {
   if (last_state_.error == gpu::error::kNoError)
     shared_state_->Read(&last_state_);
 }