Revert "Revert 113479 - Revert "Revert 113250 - Add CommandBuffer::SetGetBuffer""

gpu/command_buffer/service/cmd_parser.cc

 // Copyright (c) 2011 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 parser.
 
 #include "gpu/command_buffer/service/cmd_parser.h"
 
 #include "base/logging.h"
 
 namespace gpu {
 
-CommandParser::CommandParser(void *shm_address,
-                             size_t shm_size,
-                             ptrdiff_t offset,
-                             size_t size,
-                             CommandBufferOffset start_get,
-                             AsyncAPIInterface *handler)
-    : get_(start_get),
-      put_(start_get),
+CommandParser::CommandParser(AsyncAPIInterface* handler)
+    : get_(0),
+      put_(0),
+      buffer_(NULL),
+      entry_count_(0),
       handler_(handler) {
+}
+
+void CommandParser::SetBuffer(
+    void* shm_address,
+    size_t shm_size,
+    ptrdiff_t offset,
+    size_t size) {
   // check proper alignments.
   DCHECK_EQ(0, (reinterpret_cast<intptr_t>(shm_address)) % 4);
   DCHECK_EQ(0, offset % 4);
   DCHECK_EQ(0u, size % 4);
   // check that the command buffer fits into the memory buffer.
   DCHECK_GE(shm_size, offset + size);
-  char * buffer_begin = static_cast<char *>(shm_address) + offset;
-  buffer_ = reinterpret_cast<CommandBufferEntry *>(buffer_begin);
+  get_ = 0;
+  put_ = 0;
+  char* buffer_begin = static_cast<char*>(shm_address) + offset;
+  buffer_ = reinterpret_cast<CommandBufferEntry*>(buffer_begin);
   entry_count_ = size / 4;
 }
 
 // Process one command, reading the header from the command buffer, and
 // forwarding the command index and the arguments to the handler.
 // Note that:
 // - validation needs to happen on a copy of the data (to avoid race
 // conditions). This function only validates the header, leaving the arguments
 // validation to the handler, so it can pass a reference to them.
 // - get_ is modified *after* the command has been executed.
@@ skipping 40 matching lines @@
 error::Error CommandParser::ProcessAllCommands() {
   while (!IsEmpty()) {
     error::Error error = ProcessCommand();
     if (error)
       return error;
   }
   return error::kNoError;
 }
 
 }  // namespace gpu