Perform glReadPixels with PBOs in the gpu, if PBOs are available.

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/shared_memory.h"
@@ skipping 161 matching lines @@
     , 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;
 
- protected:
-  virtual ~AsyncPixelTransfersCompletedQuery();
-
   static void MarkAsCompletedThreadSafe(
       uint32 submit_count, const AsyncMemoryParams& mem_params) {
     DCHECK(mem_params.shared_memory);
     DCHECK(mem_params.shared_memory->memory());
     void *data = static_cast<int8*>(mem_params.shared_memory->memory()) +
         mem_params.shm_data_offset;
     QuerySync* sync = static_cast<QuerySync*>(data);
 
     // Need a MemoryBarrier here to ensure that upload completed before
     // submit_count was written to sync->process_count.
     base::subtle::MemoryBarrier();
     sync->process_count = submit_count;
   }
+
+ protected:
+  virtual ~AsyncPixelTransfersCompletedQuery();

[piman, 2013/07/01 22:24:08]

nit: it looks like you didn't end up needing changes to this class. Revert?

[hubbe, 2013/07/01 22:34:41]

Done.

+
 };
 
 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) {
   AsyncMemoryParams mem_params;
   // Get the real shared memory since it might need to be duped to prevent
   // use-after-free of the memory.
   Buffer buffer = manager()->decoder()->GetSharedMemoryBuffer(shm_id());
   if (!buffer.shared_memory)
     return false;
   mem_params.shared_memory = buffer.shared_memory;
   mem_params.shm_size = buffer.size;
   mem_params.shm_data_offset = shm_offset();
   mem_params.shm_data_size = sizeof(QuerySync);
 
   // Ask AsyncPixelTransferDelegate to run completion callback after all
   // previous async transfers are done. No guarantee that callback is run
   // on the current thread.
   manager()->decoder()->GetAsyncPixelTransferManager()->AsyncNotifyCompletion(
       mem_params,
-      base::Bind(AsyncPixelTransfersCompletedQuery::MarkAsCompletedThreadSafe,
+      base::Bind(&AsyncPixelTransfersCompletedQuery::MarkAsCompletedThreadSafe,
                  submit_count));
-
   return AddToPendingTransferQueue(submit_count);
 }
 
 bool AsyncPixelTransfersCompletedQuery::Process() {
   QuerySync* sync = manager()->decoder()->GetSharedMemoryAs<QuerySync*>(
       shm_id(), shm_offset(), sizeof(*sync));
   if (!sync)
     return false;
 
   // Check if completion callback has been run. sync->process_count atomicity
   // is guaranteed as this is already used to notify client of a completed
   // query.
   if (sync->process_count != submit_count())
     return true;
 
   UnmarkAsPending();
   return true;
 }
 
 void AsyncPixelTransfersCompletedQuery::Destroy(bool /* have_context */) {
   if (!IsDeleted()) {
     MarkAsDeleted();
   }
 }
 
 AsyncPixelTransfersCompletedQuery::~AsyncPixelTransfersCompletedQuery() {
 }
 
+///////////////////
+class AsyncReadPixelsCompletedQuery
+    : public QueryManager::Query
+    , public base::SupportsWeakPtr<AsyncReadPixelsCompletedQuery> {

[piman, 2013/07/01 22:24:08]

nit: , on previous line.

[hubbe, 2013/07/01 22:34:41]

Done.

+ public:
+  AsyncReadPixelsCompletedQuery(
+      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;
+
+ protected:
+  void Complete();
+  virtual ~AsyncReadPixelsCompletedQuery();
+};
+
+AsyncReadPixelsCompletedQuery::AsyncReadPixelsCompletedQuery(
+    QueryManager* manager, GLenum target, int32 shm_id, uint32 shm_offset)
+    : Query(manager, target, shm_id, shm_offset) {
+}
+
+bool AsyncReadPixelsCompletedQuery::Begin() {
+  return true;
+}
+
+bool AsyncReadPixelsCompletedQuery::End(uint32 submit_count) {
+  manager()->decoder()->WaitForReadPixels(
+      base::Bind(&AsyncReadPixelsCompletedQuery::Complete,
+                 AsWeakPtr()));
+
+  return AddToPendingTransferQueue(submit_count);
+}
+
+void AsyncReadPixelsCompletedQuery::Complete() {
+  MarkAsCompleted(1);
+}
+
+bool AsyncReadPixelsCompletedQuery::Process() {
+  return !pending();
+}
+
+void AsyncReadPixelsCompletedQuery::Destroy(bool /* have_context */) {
+  if (!IsDeleted()) {
+    MarkAsDeleted();
+  }
+}
+
+AsyncReadPixelsCompletedQuery::~AsyncReadPixelsCompletedQuery() {
+}
+
+
 class GetErrorQuery : public QueryManager::Query {
  public:
   GetErrorQuery(
       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;
 
@@ skipping 71 matching lines @@
     case GL_COMMANDS_ISSUED_CHROMIUM:
       query = new CommandsIssuedQuery(this, target, shm_id, shm_offset);
       break;
     case GL_LATENCY_QUERY_CHROMIUM:
       query = new CommandLatencyQuery(this, target, shm_id, shm_offset);
       break;
     case GL_ASYNC_PIXEL_TRANSFERS_COMPLETED_CHROMIUM:
       query = new AsyncPixelTransfersCompletedQuery(
           this, target, shm_id, shm_offset);
       break;
+    case GL_ASYNC_READ_PIXELS_COMPLETED_CHROMIUM:
+      query = new AsyncReadPixelsCompletedQuery(
+          this, target, shm_id, shm_offset);
+      break;
     case GL_GET_ERROR_QUERY_CHROMIUM:
       query = new GetErrorQuery(this, target, shm_id, shm_offset);
       break;
     default: {
       GLuint service_id = 0;
       glGenQueriesARB(1, &service_id);
       DCHECK_NE(0u, service_id);
       query = new AllSamplesPassedQuery(
           this, target, shm_id, shm_offset, service_id);
       break;
@@ skipping 218 matching lines @@
 bool QueryManager::EndQuery(Query* query, uint32 submit_count) {
   DCHECK(query);
   if (!RemovePendingQuery(query)) {
     return false;
   }
   return query->End(submit_count);
 }
 
 }  // namespace gles2
 }  // namespace gpu