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_IPC_MESSAGE_ATTACHMENT_H_
6 #define IPC_IPC_MESSAGE_ATTACHMENT_H_
7 
8 #include "base/files/file.h"
9 #include "base/macros.h"
10 #include "base/memory/ref_counted.h"
11 #include "base/pickle.h"
12 #include "build/build_config.h"
13 #include "ipc/ipc_export.h"
14 
15 namespace IPC {
16 
17 // Auxiliary data sent with |Message|. This can be a platform file descriptor
18 // or a mojo |MessagePipe|. |GetType()| returns the type of the subclass.
19 class IPC_EXPORT MessageAttachment : public base::Pickle::Attachment {
20  public:
21   enum Type {
22     TYPE_PLATFORM_FILE,          // The instance is |PlatformFileAttachment|.
23     TYPE_MOJO_HANDLE,            // The instance is |MojoHandleAttachment|.
24     TYPE_BROKERABLE_ATTACHMENT,  // The instance is |BrokerableAttachment|.
25   };
26 
27   virtual Type GetType() const = 0;
28 
29 #if defined(OS_POSIX)
30   virtual base::PlatformFile TakePlatformFile() = 0;
31 #endif  // OS_POSIX
32 
33  protected:
34   friend class base::RefCountedThreadSafe<MessageAttachment>;
35   MessageAttachment();
36   ~MessageAttachment() override;
37 
38   DISALLOW_COPY_AND_ASSIGN(MessageAttachment);
39 };
40 
41 }  // namespace IPC
42 
43 #endif  // IPC_IPC_MESSAGE_ATTACHMENT_H_
44