支持生产阻塞的线程池

 1     public void execute(Runnable command) {
 2         if (command == null)
 3             throw new NullPointerException();
 4         /*
 5          * Proceed in 3 steps:
 6          *
 7          * 1. If fewer than corePoolSize threads are running, try to
 8          * start a new thread with the given command as its first
 9          * task.  The call to addWorker atomically checks runState and
10          * workerCount, and so prevents false alarms that would add
11          * threads when it shouldn‘t, by returning false.
12          *
13          * 2. If a task can be successfully queued, then we still need
14          * to double-check whether we should have added a thread
15          * (because existing ones died since last checking) or that
16          * the pool shut down since entry into this method. So we
17          * recheck state and if necessary roll back the enqueuing if
18          * stopped, or start a new thread if there are none.
19          *
20          * 3. If we cannot queue task, then we try to add a new
21          * thread.  If it fails, we know we are shut down or saturated
22          * and so reject the task.
23          */
24         int c = ctl.get();
25         if (workerCountOf(c) < corePoolSize) {
26             if (addWorker(command, true))
27                 return;
28             c = ctl.get();
29         }
30         if (isRunning(c) && workQueue.offer(command)) {
31             int recheck = ctl.get();
32             if (! isRunning(recheck) && remove(command))
33                 reject(command);
34             else if (workerCountOf(recheck) == 0)
35                 addWorker(null, false);
36         }
37         else if (!addWorker(command, false))
38             reject(command);
39     }

 1         int corePoolSize = 30;
 2         int waitQueueSize = 100000;
 3         ExecutorService pool = new ThreadPoolExecutor(corePoolSize, corePoolSize, 1, TimeUnit.DAYS,
 4                 new LinkedBlockingQueue<Runnable>(waitQueueSize), new RejectedExecutionHandler() {
 5             @Override
 6             public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
 7                 if (!executor.isShutdown()) {
 8                     try {
 9                         executor.getQueue().put(r);
10                     } catch (InterruptedException e) {
11                         // should not be interrupted
12                     }
13                 }
14             }
15         });