1/*
2 * libjingle
3 * Copyright 2011, Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 *  1. Redistributions of source code must retain the above copyright notice,
9 *     this list of conditions and the following disclaimer.
10 *  2. Redistributions in binary form must reproduce the above copyright notice,
11 *     this list of conditions and the following disclaimer in the documentation
12 *     and/or other materials provided with the distribution.
13 *  3. The name of the author may not be used to endorse or promote products
14 *     derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#ifndef TALK_XMPP_PINGTASK_H_
29#define TALK_XMPP_PINGTASK_H_
30
31#include "talk/xmpp/xmpptask.h"
32#include "webrtc/base/messagehandler.h"
33#include "webrtc/base/messagequeue.h"
34
35namespace buzz {
36
37// Task to periodically send pings to the server to ensure that the network
38// connection is valid, implementing XEP-0199.
39//
40// This is especially useful on cellular networks because:
41// 1. It keeps the connections alive through the cellular network's NATs or
42//    proxies.
43// 2. It detects when the server has crashed or any other case in which the
44//    connection has broken without a fin or reset packet being sent to us.
45class PingTask : public buzz::XmppTask, private rtc::MessageHandler {
46 public:
47  PingTask(buzz::XmppTaskParentInterface* parent,
48      rtc::MessageQueue* message_queue, uint32 ping_period_millis,
49      uint32 ping_timeout_millis);
50
51  virtual bool HandleStanza(const buzz::XmlElement* stanza);
52  virtual int ProcessStart();
53
54  // Raised if there is no response to a ping within ping_timeout_millis.
55  // The task is automatically aborted after a timeout.
56  sigslot::signal0<> SignalTimeout;
57
58 private:
59  // Implementation of MessageHandler.
60  virtual void OnMessage(rtc::Message* msg);
61
62  rtc::MessageQueue* message_queue_;
63  uint32 ping_period_millis_;
64  uint32 ping_timeout_millis_;
65  uint32 next_ping_time_;
66  uint32 ping_response_deadline_; // 0 if the response has been received
67};
68
69} // namespace buzz
70
71#endif  // TALK_XMPP_PINGTASK_H_
72