Socket.close 卡住了 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 dataoutput/input 流。在我的主线程循环中，我有一个方法可以通过连接映射并关闭连接（不活动踢、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，我在另一个线程中打印出一个堆栈跟踪以及主线程有多少个循环运行。

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)]

由此我可以看出我的服务器在尝试关闭连接时卡住了：

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

这是它被卡住的浓缩方法运行ning（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);
    }
}

我最近重写了我的连接代码以尝试修复挂起，我终于找到了根本原因 - 但我不确定如何解决它。

Answer 1

对于任何可能在此处找到此问题的人，我都是如何解决它的。我不能仅仅依赖 setSoTimeout 方法，因为我想要临时踢球员的能力。

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();

Socket.close 卡住了 15 分钟

Socket.close stuck for 15 minutes

java

sockets

sslsocketfactory