Implemented new fence syncs which replaces the old sync points.

gpu/command_buffer/client/cmd_buffer_helper.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.
 
 // This file contains the implementation of the command buffer helper class.
 
 #include "gpu/command_buffer/client/cmd_buffer_helper.h"
 
 #include <algorithm>
 #include "base/logging.h"
@@ skipping 13 matching lines @@
 CommandBufferHelper::CommandBufferHelper(CommandBuffer* command_buffer)
     : command_buffer_(command_buffer),
       ring_buffer_id_(-1),
       ring_buffer_size_(0),
       entries_(NULL),
       total_entry_count_(0),
       immediate_entry_count_(0),
       token_(0),
       put_(0),
       last_put_sent_(0),
+      next_fence_sync_release_(1),
+      flushed_fence_sync_release_(0),
 #if defined(CMD_HELPER_PERIODIC_FLUSH_CHECK)
       commands_issued_(0),
 #endif
       usable_(true),
       context_lost_(false),
       flush_automatically_(true),
       flush_generation_(0) {
   // In certain cases, ThreadTaskRunnerHandle isn't set (Android Webview).
   // Don't register a dump provider in these cases.
   // TODO(ericrk): Get this working in Android Webview. crbug.com/517156
@@ skipping 95 matching lines @@
     ring_buffer_ = nullptr;
   }
 }
 
 void CommandBufferHelper::FreeRingBuffer() {
   CHECK((put_ == get_offset()) ||
       error::IsError(command_buffer_->GetLastState().error));
   FreeResources();
 }
 
+uint32_t CommandBufferHelper::GenerateFenceSyncRelease() {
+  // Enforce fence syncs generated are always inserted in the command buffer.
+  const uint32_t release = next_fence_sync_release_++;
+  return release;
+}
+
 bool CommandBufferHelper::Initialize(int32 ring_buffer_size) {
   ring_buffer_size_ = ring_buffer_size;
   return AllocateRingBuffer();
 }
 
 CommandBufferHelper::~CommandBufferHelper() {
   base::trace_event::MemoryDumpManager::GetInstance()->UnregisterDumpProvider(
       this);
   FreeResources();
 }
@@ skipping 10 matching lines @@
   // Wrap put_ before flush.
   if (put_ == total_entry_count_)
     put_ = 0;
 
   if (usable()) {
     last_flush_time_ = base::TimeTicks::Now();
     last_put_sent_ = put_;
     command_buffer_->Flush(put_);
     ++flush_generation_;
     CalcImmediateEntries(0);
+
+    flushed_fence_sync_release_ = next_fence_sync_release_ - 1;
   }
 }
 
 void CommandBufferHelper::OrderingBarrier() {
   // Wrap put_ before setting the barrier.
   if (put_ == total_entry_count_)
     put_ = 0;
 
   if (usable()) {
     command_buffer_->OrderingBarrier(put_);
@@ skipping 164 matching lines @@
                   GetTotalFreeEntriesNoWaiting() * sizeof(CommandBufferEntry));
   auto guid = GetBufferGUIDForTracing(tracing_process_id, ring_buffer_id_);
   const int kImportance = 2;
   pmd->CreateSharedGlobalAllocatorDump(guid);
   pmd->AddOwnershipEdge(dump->guid(), guid, kImportance);
 
   return true;
 }
 
 }  // namespace gpu