ThreadPool

HashSet<Worker> workers.add(w)

t.start(); -> workerStarted = true;

runStateOf(c) != rs

! isRunning(recheck) && remove(command)reject(command)

count.getAndIncrement()if (c + 1 < capacity)                   notFull.signal();

if (!started) {                group.threadStartFailed(this);}

compareAndIncrementWorkerCountCAS 更新+1线程数

w.thread.isAlive()

isRunning(c) && workQueue.offer(command)

if (c == 0)signalNotEmpty();    return c >= 0

ThreadPoolExcutor.excute(Runable)

 false

CallerRunsPolicy如果线程池没有Shutdown，则直接调用Runnable任务的run()方法。AbortPolicy丢掉这个任务并抛出 RejectedExecutionException异常。DiscardPolicy忽略这个任务，什么也不做。DiscardOldestPolicy这个策略从字面上也很好理解，丢弃最老的。也就是说如果队列满了，会将最早进入队列的任务删掉腾出空间，再尝试加入队列。因为队列是队尾进，队头出，所以队头元素是最老的，因此每次都是移除对头元素后再尝试入队.

workerCountOf >= (core ? corePoolSize : maximumPoolSize)

return false

group.add(this）started = falsetry{start0()started = true}

if (! workerStarted) addWorkerFailed(w);

new Node<E>(command)enqueue(node) 放入队列末尾

workerAdded == true

w=new work() setstate=-1 new thread()ReentrantLock.lock

largestPoolSize = self<workers?workers.sizeworkerAdded = trueunlock

throw IllegalThreadStateException