| // 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 IPC_IPC_SYNC_MESSAGE_H_ |
| #define IPC_IPC_SYNC_MESSAGE_H_ |
| |
| #if defined(OS_WIN) |
| #include <windows.h> |
| #endif |
| #include <string> |
| #include "base/basictypes.h" |
| #include "base/memory/scoped_ptr.h" |
| #include "ipc/ipc_message.h" |
| |
| namespace base { |
| class WaitableEvent; |
| } |
| |
| namespace IPC { |
| |
| class MessageReplyDeserializer; |
| |
| class IPC_EXPORT SyncMessage : public Message { |
| public: |
| SyncMessage(int32 routing_id, uint32 type, PriorityValue priority, |
| MessageReplyDeserializer* deserializer); |
| virtual ~SyncMessage(); |
| |
| // Call this to get a deserializer for the output parameters. |
| // Note that this can only be called once, and the caller is responsible |
| // for deleting the deserializer when they're done. |
| MessageReplyDeserializer* GetReplyDeserializer(); |
| |
| // If this message can cause the receiver to block while waiting for user |
| // input (i.e. by calling MessageBox), then the caller needs to pump window |
| // messages and dispatch asynchronous messages while waiting for the reply. |
| // If this event is passed in, then window messages will start being pumped |
| // when it's set. Note that this behavior will continue even if the event is |
| // later reset. The event must be valid until after the Send call returns. |
| void set_pump_messages_event(base::WaitableEvent* event) { |
| pump_messages_event_ = event; |
| if (event) { |
| header()->flags |= PUMPING_MSGS_BIT; |
| } else { |
| header()->flags &= ~PUMPING_MSGS_BIT; |
| } |
| } |
| |
| // Call this if you always want to pump messages. You can call this method |
| // or set_pump_messages_event but not both. |
| void EnableMessagePumping(); |
| |
| base::WaitableEvent* pump_messages_event() const { |
| return pump_messages_event_; |
| } |
| |
| // Returns true if the message is a reply to the given request id. |
| static bool IsMessageReplyTo(const Message& msg, int request_id); |
| |
| // Given a reply message, returns an iterator to the beginning of the data |
| // (i.e. skips over the synchronous specific data). |
| static PickleIterator GetDataIterator(const Message* msg); |
| |
| // Given a synchronous message (or its reply), returns its id. |
| static int GetMessageId(const Message& msg); |
| |
| // Generates a reply message to the given message. |
| static Message* GenerateReply(const Message* msg); |
| |
| private: |
| struct SyncHeader { |
| // unique ID (unique per sender) |
| int message_id; |
| }; |
| |
| static bool ReadSyncHeader(const Message& msg, SyncHeader* header); |
| static bool WriteSyncHeader(Message* msg, const SyncHeader& header); |
| |
| scoped_ptr<MessageReplyDeserializer> deserializer_; |
| base::WaitableEvent* pump_messages_event_; |
| }; |
| |
| // Used to deserialize parameters from a reply to a synchronous message |
| class IPC_EXPORT MessageReplyDeserializer { |
| public: |
| virtual ~MessageReplyDeserializer() {} |
| bool SerializeOutputParameters(const Message& msg); |
| private: |
| // Derived classes need to implement this, using the given iterator (which |
| // is skipped past the header for synchronous messages). |
| virtual bool SerializeOutputParameters(const Message& msg, |
| PickleIterator iter) = 0; |
| }; |
| |
| // When sending a synchronous message, this structure contains an object |
| // that knows how to deserialize the response. |
| struct PendingSyncMsg { |
| PendingSyncMsg(int id, |
| MessageReplyDeserializer* d, |
| base::WaitableEvent* e) |
| : id(id), deserializer(d), done_event(e), send_result(false) { } |
| int id; |
| MessageReplyDeserializer* deserializer; |
| base::WaitableEvent* done_event; |
| bool send_result; |
| }; |
| |
| } // namespace IPC |
| |
| #endif // IPC_IPC_SYNC_MESSAGE_H_ |