Socket.close卡滞15分钟

Question

我使用SSLSockets开发了自己的MMORPG游戏客户端和服务器。新连接在它们自己的线程中获得数据输出/输入流。在我的主线程循环中，我有一个方法，它遍历连接映射并关闭连接(非活动踢、请求注销等(

我的游戏服务器随机挂起15分钟，所以每隔60秒，我就会在另一个线程中打印出一个堆栈竞赛以及主线程运行了多少个循环。

main: [sun.misc.Unsafe.park(Native Method),
java.util.concurrent.locks.LockSupport.park(LockSupport.java:175),
java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836),
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870),
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199),
java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209),
java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285),
sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:863),
sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:735),
sun.security.ssl.SSLSocketImpl.sendAlert(SSLSocketImpl.java:2087),
sun.security.ssl.SSLSocketImpl.warning(SSLSocketImpl.java:1914),
sun.security.ssl.SSLSocketImpl.closeInternal(SSLSocketImpl.java:1677),
sun.security.ssl.SSLSocketImpl.close(SSLSocketImpl.java:1615),
com.jayavon.game.server.MyServer.processClientConnectionMapV2(MyServer.java:6427),
com.jayavon.game.server.MyServer.main(MyServer.java:708)]

从这一点我可以看出，我的服务器在试图关闭连接时被卡住了：

clientConnectionEntry.getValue().getSocket().close();

以下是它被困在运行中的精简方法(挂起整个服务器(：

private void processClientConnectionMapV2(boolean disconnectAll) {
try {
Iterator<Entry<String, ClientConnectionV2>> it = MyServer.ClientConnectionMapV2.entrySet().iterator();
while (it.hasNext()) {
Entry<String, ClientConnectionV2> clientConnectionEntry = it.next();

if (clientConnectionEntry.getValue().isToDisconnect()
|| disconnectAll){ //this connection should be disconnected
if (!hasOutstandingBacklogMessagesV2(MyServer.ClientConnectionMapV2.get(clientConnectionEntry.getKey()))
|| clientConnectionEntry.getValue().getDisconnectLoopsSkipped() > 4
|| disconnectAll) {
MyServer.LOGGER.warn("----REMOVE CONNECTION----<processClientConnectionMapV2>----    " + clientConnectionEntry);

//close the actual connection here
try {
clientConnectionEntry.getValue().getSocket().close();
clientConnectionEntry.getValue().getDataInputStream().close();
clientConnectionEntry.getValue().getDataOutputStream().close();
clientConnectionEntry.getValue().getCommandHandlerV2().loggedOut = true;
serverConnectionNumber--;
} catch (Exception e1) {
LOGGER.warn("unable to close in Server processClientConnectionsV2", e1);
LOGGER.warn("connection was already closed on client side");
}
//remove from iterator and ClientConnectionMapV2
it.remove();
} else {
clientConnectionEntry.getValue().setDisconnectLoopsSkipped(clientConnectionEntry.getValue().getDisconnectLoopsSkipped() + 1);
MyServer.LOGGER.warn("----SKIP REMOVE CONNECTION----<processClientConnectionMapV2>----    " + clientConnectionEntry);
}
}
}
} catch (Exception e) {
LOGGER.fatal("MAIN LOOP: processClientConnectionsV2: ", e);
}
}

我最近重写了很多连接代码，试图修复挂起的问题，我终于找到了根本原因，但我不确定如何解决。

Answer 1

对于任何可能发现这一点的人来说，这里是我解决它的方法。我不能仅仅依靠setSoTimeout方法，因为我希望能够临时踢球员。

Thread closerThread = new Thread(){
public void run(){
//close the actual connection here
try {
Thread.currentThread().setName("closerThread-" + clientConnectionEntry.getKey() + "-" + tmpAccountName + "|" + tmpCharacterName);
clientConnectionEntry.getValue().getCommandHandlerV2().outgoingMessageBacklog.clear();
clientConnectionEntry.getValue().getCommandHandlerV2().loggedOut = true;
serverConnectionNumber--;
clientConnectionEntry.getValue().getSocket().close();
clientConnectionEntry.getValue().getDataInputStream().close();
clientConnectionEntry.getValue().getDataOutputStream().close();
} catch (Exception e1) {
LOGGER.warn("unable to close in Server processClientConnectionsV2", e1);
}
}
};
closerThread.start();