1 // Copyright (c) 2012 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.
5 #ifndef IPC_IPC_SYNC_MESSAGE_H_
6 #define IPC_IPC_SYNC_MESSAGE_H_
12 #include "base/basictypes.h"
13 #include "base/memory/scoped_ptr.h"
14 #include "ipc/ipc_message.h"
22 class MessageReplyDeserializer
;
24 class IPC_EXPORT SyncMessage
: public Message
{
26 SyncMessage(int32 routing_id
, uint32 type
,
27 MessageReplyDeserializer
* deserializer
);
28 virtual ~SyncMessage();
30 // Call this to get a deserializer for the output parameters.
31 // Note that this can only be called once, and the caller is responsible
32 // for deleting the deserializer when they're done.
33 MessageReplyDeserializer
* GetReplyDeserializer();
35 // If this message can cause the receiver to block while waiting for user
36 // input (i.e. by calling MessageBox), then the caller needs to pump window
37 // messages and dispatch asynchronous messages while waiting for the reply.
38 // If this event is passed in, then window messages will start being pumped
39 // when it's set. Note that this behavior will continue even if the event is
40 // later reset. The event must be valid until after the Send call returns.
41 void set_pump_messages_event(base::WaitableEvent
* event
) {
42 pump_messages_event_
= event
;
44 header()->flags
|= PUMPING_MSGS_BIT
;
46 header()->flags
&= ~PUMPING_MSGS_BIT
;
50 // Call this if you always want to pump messages. You can call this method
51 // or set_pump_messages_event but not both.
52 void EnableMessagePumping();
54 base::WaitableEvent
* pump_messages_event() const {
55 return pump_messages_event_
;
58 // Returns true if the message is a reply to the given request id.
59 static bool IsMessageReplyTo(const Message
& msg
, int request_id
);
61 // Given a reply message, returns an iterator to the beginning of the data
62 // (i.e. skips over the synchronous specific data).
63 static PickleIterator
GetDataIterator(const Message
* msg
);
65 // Given a synchronous message (or its reply), returns its id.
66 static int GetMessageId(const Message
& msg
);
68 // Generates a reply message to the given message.
69 static Message
* GenerateReply(const Message
* msg
);
73 // unique ID (unique per sender)
77 static bool ReadSyncHeader(const Message
& msg
, SyncHeader
* header
);
78 static bool WriteSyncHeader(Message
* msg
, const SyncHeader
& header
);
80 scoped_ptr
<MessageReplyDeserializer
> deserializer_
;
81 base::WaitableEvent
* pump_messages_event_
;
84 // Used to deserialize parameters from a reply to a synchronous message
85 class IPC_EXPORT MessageReplyDeserializer
{
87 virtual ~MessageReplyDeserializer() {}
88 bool SerializeOutputParameters(const Message
& msg
);
90 // Derived classes need to implement this, using the given iterator (which
91 // is skipped past the header for synchronous messages).
92 virtual bool SerializeOutputParameters(const Message
& msg
,
93 PickleIterator iter
) = 0;
96 // When sending a synchronous message, this structure contains an object
97 // that knows how to deserialize the response.
98 struct PendingSyncMsg
{
99 PendingSyncMsg(int id
,
100 MessageReplyDeserializer
* d
,
101 base::WaitableEvent
* e
)
102 : id(id
), deserializer(d
), done_event(e
), send_result(false) { }
104 MessageReplyDeserializer
* deserializer
;
105 base::WaitableEvent
* done_event
;
111 #endif // IPC_IPC_SYNC_MESSAGE_H_