让人思来想去的ThreadPool

publicvoidexecute(Runnablecommand) {
if (command==null)
thrownewNullPointerException();
intc=ctl.get();
if (workerCountOf(c) <corePoolSize) {
// 创建核心线程if (addWorker(command, true))
return;
c=ctl.get();
    }
if (isRunning(c) &&workQueue.offer(command)) {
intrecheck=ctl.get();
if (!isRunning(recheck) &&remove(command))
reject(command);
elseif (workerCountOf(recheck) ==0)
// 线程数扩容addWorker(null, false);
    }
elseif (!addWorker(command, false))
reject(command);
}

finalvoidrunWorker(Workerw) {
Threadwt=Thread.currentThread();
Runnabletask=w.firstTask;
w.firstTask=null;
w.unlock(); // allow interruptsbooleancompletedAbruptly=true;
try {
while (task!=null|| (task=getTask()) !=null) {
w.lock();
// If pool is stopping, ensure thread is interrupted;// if not, ensure thread is not interrupted.  This// requires a recheck in second case to deal with// shutdownNow race while clearing interruptif ((runStateAtLeast(ctl.get(), STOP) ||                 (Thread.interrupted() &&runStateAtLeast(ctl.get(), STOP))) &&!wt.isInterrupted())
wt.interrupt();
try {
beforeExecute(wt, task);
try {
task.run();
afterExecute(task, null);
                } catch (Throwableex) {
afterExecute(task, ex);
throwex;
                }
            } finally {
task=null;
w.completedTasks++;
w.unlock();
            }
        }
completedAbruptly=false;
    } finally {
processWorkerExit(w, completedAbruptly);
    }
}