Added a unique command buffer ID for command buffers.

gpu/command_buffer/common/command_buffer.h

 // 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.
 
 #ifndef GPU_COMMAND_BUFFER_COMMON_COMMAND_BUFFER_H_
 #define GPU_COMMAND_BUFFER_COMMON_COMMAND_BUFFER_H_
 
+#include "base/logging.h"
 #include "gpu/command_buffer/common/buffer.h"
 #include "gpu/command_buffer/common/constants.h"
 #include "gpu/gpu_export.h"
 
 namespace base {
 class SharedMemory;
 }
 
 namespace gpu {
 
+enum CommandBufferNamespace {
+  kCommandBufferNamespace_Invalid = -1,
+
+  kCommandBufferNamespace_GpuIO,
+  kCommandBufferNamespace_InProcess,
+
+  NUM_COMMAND_BUFFER_NAMESPACES
+};
+
 // Common interface for CommandBuffer implementations.
 class GPU_EXPORT CommandBuffer {
  public:
   struct State {
     State()
         : get_offset(0),
           token(-1),
           error(error::kNoError),
           context_lost_reason(error::kUnknown),
           generation(0) {
@@ skipping 21 matching lines @@
     uint32 generation;
   };
 
   struct ConsoleMessage {
     // An user supplied id.
     int32 id;
     // The message.
     std::string message;
   };
 
-  CommandBuffer() {
+  explicit CommandBuffer(CommandBufferNamespace namespace_id,
+                uint64_t command_buffer_id)
+    : namespace_id_(namespace_id),
+      command_buffer_id_(command_buffer_id) {
   }
 
   virtual ~CommandBuffer() {
   }
 
   // Check if a value is between a start and end value, inclusive, allowing
   // for wrapping if start > end.
   static bool InRange(int32 start, int32 end, int32 value) {
     if (start <= end)
       return start <= value && value <= end;
@@ skipping 49 matching lines @@
 // GetLastError declared would mean we'd have to also define it, and pull more
 // of gpu in to the NaCl Win64 build.
 #if !defined(NACL_WIN64)
   // TODO(apatrick): this is a temporary optimization while skia is calling
   // RendererGLContext::MakeCurrent prior to every GL call. It saves returning 6
   // ints redundantly when only the error is needed for the CommandBufferProxy
   // implementation.
   virtual error::Error GetLastError();
 #endif
 
+  // The namespace and command buffer ID forms a unique pair for all existing
+  // command buffers in a single process. Intermediate command buffers
+  // (such as CommandBufferService) should assign have an invalid namespace
+  // to signify that they should not be queried. Command Buffers that forward
+  // messages to other command buffers should identify as the command buffer
+  // which actually does the executions.
+  CommandBufferNamespace namespace_id() const {
+    DCHECK_NE(namespace_id_, kCommandBufferNamespace_Invalid);
+    return namespace_id_;
+  }
+
+  uint64_t command_buffer_id() const {
+    DCHECK_NE(namespace_id_, kCommandBufferNamespace_Invalid);
+    return command_buffer_id_;
+  }
+
  private:
+  const CommandBufferNamespace namespace_id_;
+  const uint64_t command_buffer_id_;
+
   DISALLOW_COPY_AND_ASSIGN(CommandBuffer);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_COMMON_COMMAND_BUFFER_H_