gpu: Reuse transfer buffers more aggresively

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 "base/logging.h"
 #include "gpu/command_buffer/common/command_buffer.h"
@@ skipping 151 matching lines @@
     if (token_ == 0) {
       TRACE_EVENT0("gpu", "CommandBufferHelper::InsertToken(wrapped)");
       // we wrapped
       Finish();
       DCHECK_EQ(token_, last_token_read());
     }
   }
   return token_;
 }
 
+bool CommandBufferHelper::HasTokenPassed(int32 token) {
+  if (token > token_)
+    return true;  // we wrapped
+  return last_token_read() >= token;
+}
+
 // Waits until the current token value is greater or equal to the value passed
 // in argument.
 void CommandBufferHelper::WaitForToken(int32 token) {
   if (!usable() || !HaveRingBuffer()) {
     return;
   }
   // Return immediately if corresponding InsertToken failed.
   if (token < 0)
     return;
   if (token > token_) return;  // we wrapped
@@ skipping 88 matching lines @@
   CommandBufferEntry* space = &entries_[put_];
   put_ += entries;
   DCHECK_LE(put_, total_entry_count_);
   if (put_ == total_entry_count_) {
     put_ = 0;
   }
   return space;
 }
 
 }  // namespace gpu