下面是一个示例代码,展示了如何使用isEmpty()方法来判断一个队列是否为空: importjava.util.LinkedList;importjava.util.Queue;publicclassQueueExample{publicstaticvoidmain(String[]args){Queue<Integer>queue=newLinkedList<>();queue.offer(1);queue.offer(2);queue.offer(3);if(queue.isEmpty()){System.out....
// Check if queue empty only if necessary. if (rs >= SHUTDOWN && ! (rs == SHUTDOWN && firstTask == null && ! workQueue.isEmpty())) return false; for (;;) { int wc = workerCountOf(c); if (wc >= CAPACITY || wc >= (core ? corePoolSize : maximumPoolSize)) return false;...
retry:for(;;) {intc =ctl.get();intrs =runStateOf(c);//Check if queue empty only if necessary.if(rs >= SHUTDOWN && ! (rs == SHUTDOWN &&firstTask==null&& !workQueue.isEmpty()))returnfalse;for(;;) {intwc =workerCountOf(c);if(wc >= CAPACITY ||wc>= (core ?corePoolSize : ...
for(;;) {intc=ctl.get();intrs=runStateOf(c);// Check if queue empty only if necessary.// 判断:// 1.rs >= SHUTDOWN,线程池状态至少是SHUTDOWN// 2.在满足条件1的情况下,rs >= STOP 线程池的状态已经至少是stop了,stop状态不需要继续处理队列中的任务了;workQueue.isEmpty()说明队列已经空了,...
// Check if queue empty only if necessary. if (rs >= SHUTDOWN && ! (rs == SHUTDOWN && firstTask == null && ! workQueue.isEmpty())) return false; for (;;) { int wc = workerCountOf(c); if (wc >= CAPACITY || wc >= (core ? corePoolSize : maximumPoolSize)) ...
(c);// Check if queue empty only if necessary.// 这个逻辑判断有点绕可以改成// rs >= shutdown && (rs != shutdown || firstTask != null || workQueue.isEmpty())// 逻辑判断成立可以分为以下几种情况均不接受新任务// 1、rs > shutdown:--不接受新任务// 2、rs >= shutdown && ...
public ThreadPoolExecutor(int corePoolSize,int maximumPoolSize,long keepAliveTime,TimeUnit unit, BlockingQueue<Runnable> workQueue,ThreadFactory threadFactory,RejectedExecutionHandler handler); } 下面解释下一下构造器中各个参数的含义: corePoolSize:线程池容量,这个参数跟后面讲述的线程池的实现原理有非常大的关...
重新进入 for 循环,自然会有部分线程会返回 null int c = ctl.get(); int rs = runStateOf(c); // Check if queue empty only if necessary. if (rs >= SHUTDOWN && (rs >= STOP || workQueue.isEmpty())) { // CAS 操作,减少工作线程数 decrementWorkerCount(); return null; } int wc =...
-// If the estimated time to complete a cms collection (cms_duration())// is less than the estimated time remaining until the cms generation// is full, start a collection.if(!UseCMSInitiatingOccupancyOnly) {if(stats().valid()) {if(stats().time_until_cms_start() ==0.0) {returntrue...
Assert.isTrue(Object object,"object must be true")-对象必须为trueAssert.notEmpty(Collection collection,"collection must not be empty")-集合非空 Assert.hasLength(String text,"text must be specified")-字符不为null且字符长度不为0Assert.hasText(String text,"text must not be empty")-text 不为nu...