关于java:线程池的状态

RUNNING

能接管新工作并解决已增加的工作
线程池一旦创立，就处于RUNNING状态，此时线程池中的工作数为0

SHUTDOWN

不接管新工作，但能解决已增加的工作
调用线程池的shutdown()接口，线程池由 RUNNING 》 SHUTDOWN

STOP

线程池处于STOP状态，不接管新工作，不解决已增加的工作，并且会中断正在解决的工作
调用线程池的shutdownNow()接口，线程池由 RUNNING or SHUTDOWN 》 STOP

TIDYING

当所有工作已终止，ctl记录的工作数为0，线程池的状态会变为TIDYING
当线程池的状态变为TIDYING状态时，会调用钩子函数terminated()，该办法在ThreadPoolExecutor中是空的，若用户想在线程池变为TIDYING时进行相应的解决，就须要重载terminated()函数
当线程池状态为SHUTDOWN，阻塞队列为空，线程池中执行的工作也为空时，由 SHUTDOWN 》 TIDYING
当线程池状态为STOP，线程池中执行的工作为空时，由 STOP》 TIDYING

TERMINATED

线程池彻底终止
线程池处于TIDYING状态，调用terminated()时，由 TIDYING 》 TERMINATED

ThreadPoolExecutor 源码正文

  * The runState provides the main lifecycle control, taking on values: * *   RUNNING:  Accept new tasks and process queued tasks *   SHUTDOWN: Don't accept new tasks, but process queued tasks *   STOP:     Don't accept new tasks, don't process queued tasks, *             and interrupt in-progress tasks *   TIDYING:  All tasks have terminated, workerCount is zero, *             the thread transitioning to state TIDYING *             will run the terminated() hook method *   TERMINATED: terminated() has completed * * The numerical order among these values matters, to allow * ordered comparisons. The runState monotonically increases over * time, but need not hit each state. The transitions are: * * RUNNING -> SHUTDOWN *    On invocation of shutdown(), perhaps implicitly in finalize() * (RUNNING or SHUTDOWN) -> STOP *    On invocation of shutdownNow() * SHUTDOWN -> TIDYING *    When both queue and pool are empty * STOP -> TIDYING *    When pool is empty * TIDYING -> TERMINATED *    When the terminated() hook method has completed * * Threads waiting in awaitTermination() will return when the * state reaches TERMINATED.