gpu: Add async pixel transfer interface, stub and tests.

gpu/command_buffer/service/query_manager.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 "gpu/command_buffer/service/query_manager.h"
 #include "base/atomicops.h"
+#include "base/bind.h"
 #include "base/logging.h"
 #include "base/time.h"
 #include "gpu/command_buffer/common/gles2_cmd_format.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 #include "gpu/command_buffer/service/feature_info.h"
+#include "ui/gl/async_pixel_transfer_delegate.h"
 
 namespace gpu {
 namespace gles2 {
 
 class AllSamplesPassedQuery : public QueryManager::Query {
  public:
   AllSamplesPassedQuery(
       QueryManager* manager, GLenum target, int32 shm_id, uint32 shm_offset,
       GLuint service_id);
   virtual bool Begin() OVERRIDE;
@@ skipping 133 matching lines @@
 
 void CommandLatencyQuery::Destroy(bool /* have_context */) {
   if (!IsDeleted()) {
     MarkAsDeleted();
   }
 }
 
 CommandLatencyQuery::~CommandLatencyQuery() {
 }
 
-class AsyncPixelTransfersCompletedQuery : public QueryManager::Query {
+class AsyncPixelTransfersCompletedQuery
+    : public QueryManager::Query
+    , public base::SupportsWeakPtr<AsyncPixelTransfersCompletedQuery> {
  public:
   AsyncPixelTransfersCompletedQuery(
       QueryManager* manager, GLenum target, int32 shm_id, uint32 shm_offset);
 
   virtual bool Begin() OVERRIDE;
   virtual bool End(uint32 submit_count) OVERRIDE;
   virtual bool Process() OVERRIDE;
   virtual void Destroy(bool have_context) OVERRIDE;
 
+  void MarkAsCompletedCallback() { MarkAsCompleted(1); }
+
  protected:
   virtual ~AsyncPixelTransfersCompletedQuery();
 };
 
 AsyncPixelTransfersCompletedQuery::AsyncPixelTransfersCompletedQuery(
     QueryManager* manager, GLenum target, int32 shm_id, uint32 shm_offset)
     : Query(manager, target, shm_id, shm_offset) {
 }
 
 bool AsyncPixelTransfersCompletedQuery::Begin() {
   return true;
 }
 
 bool AsyncPixelTransfersCompletedQuery::End(uint32 submit_count) {
-  // TODO(epenner): Mark completion via an async task.
-  // TODO(epenner): This will be a boolean to start, indicating
-  // completion of all tasks in the query. We could change this
-  // to return a count of tasks completed instead.
   MarkAsPending(submit_count);
-  return MarkAsCompleted(1);
+
+  // This will call MarkAsCompleted(1) as a reply to a task on
+  // the async upload thread, such that it occurs after all previous
+  // async transfers have completed.
+  gfx::AsyncPixelTransferDelegate::Get()->AsyncNotifyCompletion(
+      base::Bind(
+          &AsyncPixelTransfersCompletedQuery::MarkAsCompletedCallback,
+          AsWeakPtr()));
+
+  // TODO: Could we possibly trigger the completion on
+  // the upload thread by writing to the query shared memory
+  // directly?
+
+  // TODO: Confirm if the above async task is sufficient.
+  // Since it is an async task, the bool return value is
+  // disregarded. It is also called outside the normal
+  // flow, and never called if this object is destroyed.
+  return true;
 }
 
 bool AsyncPixelTransfersCompletedQuery::Process() {
   NOTREACHED();
   return true;
 }
 
 void AsyncPixelTransfersCompletedQuery::Destroy(bool /* have_context */) {
   if (!IsDeleted()) {
     MarkAsDeleted();
@@ skipping 268 matching lines @@
   if (!RemovePendingQuery(query)) {
     return false;
   }
   return query->End(submit_count);
 }
 
 }  // namespace gles2
 }  // namespace gpu