ipc/mojo/ipc_mojo_handle_attachment.h

   1 // Copyright (c) 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef IPC_MOJO_IPC_MOJO_HANDLE_ATTACHMENT_H_
   6 #define IPC_MOJO_IPC_MOJO_HANDLE_ATTACHMENT_H_
   7
   8 #include "base/files/file.h"
   9 #include "ipc/ipc_export.h"
  10 #include "ipc/ipc_message_attachment.h"
  11 #include "third_party/mojo/src/mojo/public/cpp/system/handle.h"
  12
  13 namespace IPC {
  14
  15 namespace internal {
  16
  17 // A MessageAttachment that holds a MojoHandle.
  18 // * On the sending side, every Mojo handle is a MessagePipe. This is because
  19 //   any platform files are wrapped by PlatformFileAttachment.
  20 // * On the receiving side, the handle can be either MessagePipe or wrapped
  21 //   platform file: All files, not only MessagePipes are wrapped as a
  22 //   MojoHandle. The message deserializer should know which type of the object
  23 //   the handle wraps.
  24 class IPC_MOJO_EXPORT MojoHandleAttachment : public MessageAttachment {
  25  public:
  26   explicit MojoHandleAttachment(mojo::ScopedHandle handle);
  27
  28   Type GetType() const override;
  29
  30 #if defined(OS_POSIX)
  31   // Returns wrapped file if it wraps a file, or
  32   // an invalid fd otherwise. The ownership of handle
  33   // is passed to the caller.
  34   base::PlatformFile TakePlatformFile() override;
  35 #endif  // OS_POSIX
  36
  37   // Returns the owning handle transferring the ownership.
  38   mojo::ScopedHandle TakeHandle();
  39
  40  private:
  41   ~MojoHandleAttachment() override;
  42   mojo::ScopedHandle handle_;
  43
  44   DISALLOW_COPY_AND_ASSIGN(MojoHandleAttachment);
  45 };
  46
  47 }  // namespace internal
  48 }  // namespace IPC
  49
  50 #endif  // IPC_MOJO_IPC_MOJO_HANDLE_ATTACHMENT_H_