1 /** 2 * Copyright 2012-2013 Florian Schmaus 3 * 4 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package org.jivesoftware.smackx.ping; 18 19 import java.lang.ref.WeakReference; 20 import java.util.Set; 21 22 import org.jivesoftware.smack.Connection; 23 24 class ServerPingTask implements Runnable { 25 26 // This has to be a weak reference because IIRC all threads are roots 27 // for objects and we have a new thread here that should hold a strong 28 // reference to connection so that it can be GCed. 29 private WeakReference<Connection> weakConnection; 30 31 private int delta = 1000; // 1 seconds 32 private int tries = 3; // 3 tries 33 ServerPingTask(Connection connection)34 protected ServerPingTask(Connection connection) { 35 this.weakConnection = new WeakReference<Connection>(connection); 36 } 37 run()38 public void run() { 39 Connection connection = weakConnection.get(); 40 if (connection == null) { 41 // connection has been collected by GC 42 // which means we can stop the thread by breaking the loop 43 return; 44 } 45 if (connection.isAuthenticated()) { 46 PingManager pingManager = PingManager.getInstanceFor(connection); 47 boolean res = false; 48 49 for (int i = 0; i < tries; i++) { 50 if (i != 0) { 51 try { 52 Thread.sleep(delta); 53 } catch (InterruptedException e) { 54 // We received an interrupt 55 // This only happens if we should stop pinging 56 return; 57 } 58 } 59 res = pingManager.pingMyServer(); 60 // stop when we receive a pong back 61 if (res) { 62 pingManager.lastSuccessfulPingByTask = System.currentTimeMillis(); 63 break; 64 } 65 } 66 if (!res) { 67 Set<PingFailedListener> pingFailedListeners = pingManager.getPingFailedListeners(); 68 for (PingFailedListener l : pingFailedListeners) { 69 l.pingFailed(); 70 } 71 } else { 72 // Ping was successful, wind-up the periodic task again 73 pingManager.maybeSchedulePingServerTask(); 74 } 75 } 76 } 77 } 78