Create a broker interface for the new Mojo EDK so that the browser can create and duplicate messa...

mojo/edk/system/parent_token_serializer_win.h

+// Copyright 2015 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 MOJO_EDK_SYSTEM_PARENT_TOKEN_SERIALIZER_WIN_H_
+#define MOJO_EDK_SYSTEM_PARENT_TOKEN_SERIALIZER_WIN_H_
+
+#include <vector>
+
+#include "base/compiler_specific.h"
+#include "base/message_loop/message_loop.h"
+#include "mojo/edk/embedder/scoped_platform_handle.h"
+#include "mojo/edk/system/system_impl_export.h"
+
+namespace mojo {
+namespace edk {
+
+// Responds to requests from a child process to exchange handles to tokens and
+// vice versa. There is one object of this class per child process host object.
+// This object will delete itself when it notices that the pipe is broken.
+class MOJO_SYSTEM_IMPL_EXPORT ParentTokenSerializer
+    : NON_EXPORTED_BASE(public base::MessageLoopForIO::IOHandler) {
+ public:
+  // |child_process| is a handle to the child process. It's not owned by this
+  // class but is guaranteed to be alive as long as the child process is
+  // running. |pipe| is a handle to the communication pipe to the child process,
+  // which is generated inside mojo::edk::ChildProcessLaunched. It is owned by
+  // this class.
+  ParentTokenSerializer(HANDLE child_process, ScopedPlatformHandle pipe);
+
+ private:
+  virtual ~ParentTokenSerializer();
+
+  void RegisterIOHandler();
+  void BeginRead();
+
+  void OnIOCompleted(base::MessageLoopForIO::IOContext* context,
+                     DWORD bytes_transferred,
+                     DWORD error) override;
+
+  // Helper wrappers around DuplicateHandle.
+  HANDLE DuplicateToChild(HANDLE handle);
+  HANDLE DuplicateFromChild(HANDLE handle);
+
+  HANDLE child_process_;
+  ScopedPlatformHandle pipe_;
+  base::MessageLoopForIO::IOContext read_context_;
+  base::MessageLoopForIO::IOContext write_context_;
+
+  std::vector<char> read_data_;
+  // How many bytes in read_data_ we already read.
+  uint32_t num_bytes_read_;
+  std::vector<char> write_data_;
+};
+
+}  // namespace edk
+}  // namespace mojo
+
+#endif  // MOJO_EDK_SYSTEM_PARENT_TOKEN_SERIALIZER_WIN_H_