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/base/messagehandler.h" 32 #include "talk/base/messagequeue.h" 33 #include "talk/xmpp/xmpptask.h" 34 35 namespace 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. 45 class PingTask : public buzz::XmppTask, private talk_base::MessageHandler { 46 public: 47 PingTask(buzz::XmppTaskParentInterface* parent, 48 talk_base::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(talk_base::Message* msg); 61 62 talk_base::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