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diff --git a/o3d/gpu/command_buffer/service/cmd_parser.cc b/o3d/gpu/command_buffer/service/cmd_parser.cc
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+++ b/o3d/gpu/command_buffer/service/cmd_parser.cc
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+/*
+ * Copyright 2009, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+// This file contains the implementation of the command parser.
+
+#include "gpu/command_buffer/service/precompile.h"
+#include "gpu/command_buffer/service/cmd_parser.h"
+// TODO(gman): remove this so we can use this code for different formats.
+#include "gpu/command_buffer/common/o3d_cmd_format.h"
+
+namespace command_buffer {
+
+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),
+      handler_(handler) {
+  // 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);
+  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.
+parse_error::ParseError CommandParser::ProcessCommand() {
+  CommandBufferOffset get = get_;
+  if (get == put_) return parse_error::kParseNoError;
+
+  CommandHeader header = buffer_[get].value_header;
+  if (header.size == 0) {
+    DLOG(INFO) << "Error: zero sized command in command buffer";
+    return parse_error::kParseInvalidSize;
+  }
+
+  if (header.size + get > entry_count_) {
+    DLOG(INFO) << "Error: get offset out of bounds";
+    return parse_error::kParseOutOfBounds;
+  }
+
+  parse_error::ParseError result = handler_->DoCommand(
+      header.command, header.size - 1, buffer_ + get);
+  // TODO(gman): If you want to log errors this is the best place to catch them.
+  //     It seems like we need an official way to turn on a debug mode and
+  //     get these errors.
+  if (result != parse_error::kParseNoError) {
+    ReportError(header.command, result);
+  }
+  get_ = (get + header.size) % entry_count_;
+  return result;
+}
+
+void CommandParser::ReportError(unsigned int command_id,
+                                parse_error::ParseError result) {
+  DLOG(INFO) << "Error: " << result << " for Command "
+             << handler_->GetCommandName(command_id);
+}
+
+// Processes all the commands, while the buffer is not empty. Stop if an error
+// is encountered.
+parse_error::ParseError CommandParser::ProcessAllCommands() {
+  while (!IsEmpty()) {
+    parse_error::ParseError error = ProcessCommand();
+    if (error) return error;
+  }
+  return parse_error::kParseNoError;
+}
+
+}  // namespace command_buffer