tomcat7 servlet 3异步请求AsyncContext AsyncListener超时问题

最近在用tomcat来搞servlet异步化请求，当然异步化下异常处理也很重要，servlet3默认带一个监听器，可以监听onComplete，onError，onStartAsync，onTimeout事件，当然onTimeout可以选择在系统server.xml当中Connector 设置asyncTimeout="100"单位是毫秒，如果不设置，默认就是10秒，当然

AsyncContext asyncContext = request.startAsync();
asyncContext.setTimeout(100);

 在代码中也可以去设置，tomcat会以此为准，当然你必须得addListener，

 

 

可调试中发现这100毫秒怎么也不会生效，当服务端返回超过100ms，可以请求就是不会报超时，这是为什么呢？看tomcat源码了

找啊找啊找，一切都明了了，原来超时线程在那sleep（1000）呢，因此要得到很短的超时并且能够生效，要么自己搞，要么改tomcat的源码吧

 

 bio && apr

实现

 /**
     * Async timeout thread
     */
    protected class AsyncTimeout implements Runnable {
        /**
         * The background thread that checks async requests and fires the
         * timeout if there has been no activity.
         */
        @Override
        public void run() {

            // Loop until we receive a shutdown command
            while (running) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    // Ignore
                }
                long now = System.currentTimeMillis();
                Iterator<SocketWrapper<Socket>> sockets =
                    waitingRequests.iterator();
                while (sockets.hasNext()) {
                    SocketWrapper<Socket> socket = sockets.next();
                    long access = socket.getLastAccess();
                    if (socket.getTimeout() > 0 &&
                            (now-access)>socket.getTimeout()) {
                        processSocketAsync(socket,SocketStatus.TIMEOUT);
                    }
                }

                // Loop if endpoint is paused
                while (paused && running) {
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        // Ignore
                    }
                }

            }
        }
    }

 

 nio实现

 

  Poller线程当中，存在
             //process timeouts
                    timeout(keyCount,hasEvents);
因此也是在有新的事件到来，或者selectorTimeout=1000ms超时后，都会去触发





                          // Async requests with a timeout of 0 or less never timeout
                            long delta = now - ka.getLastAccess();
                            long timeout = (ka.getTimeout()==-1)?((long) socketProperties.getSoTimeout()):(ka.getTimeout());
                            boolean isTimedout = delta > timeout;
                            if (isTimedout) {
                                // Prevent subsequent timeouts if the timeout event takes a while to process
                                ka.access(Long.MAX_VALUE);
                                processSocket(ka.getChannel(), SocketStatus.TIMEOUT, true);
                            }