Queue是先进先出(FIFO)的单向队列,只允许在表的前端进行删除操作,在表的后端进行插入操作。 LinkedList类实现了Queue接口,因此可以把LinkedList当成Queue来用。 Queue实现通常不允许插入null元素,尽管某些实现(比如LinkedList)并不禁止插入null,但即使在允许插入null的实现中也不应该这样做,因为null也作为poll()等方法的一...
讲讲Queue/Deque对应的并发类 PriorityQueue优先队列没有对应的并发类。可是Queue接口有对应的并发实现类:java.util.concurrent.ConcurrentLinkedQueue类。 Deque接口有对应的并发实现类:java.util.concurrent.ConcurrentLinkedDeque类。 Collection集合下的Queue/Deque 从类图来看,实现了Queue接口的类就是PriorityQueue,但要注意...
}Queue queue2=newPriorityQueue(); queue2.offer(newUser(32)); queue2.offer(newUser(12)); queue2.offer(newUser(48)); queue2.offer(newUser(8)); System.out.println(queue2);//[User{age=8}, User{age=12}, User{age=48}, User{age=32}]} } Deque接口和ArrayDeque实现类: Deque接口是Qu...
Queue<String> myQueue = new LinkedList<String>(); boolean offerSuccess; // offer method tries to enqueue. // A boolean is returned telling you if the // attempt to add to the queue was successful or not offerSuccess=myQueue.offer("Add Me"); offerSuccess=myQueue.offer("Add Me Too")...
* Inserts the specified element at the tail of this queue if it is * possible to do so immediately without exceeding the queue's capacity, * returning {@code true} upon success and {@code false} if this queue * is full. This method is generally preferable to method {@link #add}, ...
This method is equivalent toaddLast(E). Specified by: addin interfaceCollection<E> Specified by: addin interfaceQueue<E> Parameters: e- the element to add Returns: true(as specified byCollection.add(E)) Throws: IllegalStateException- if the element cannot be added at this time due to capacit...
This method is equivalent toDeque.getFirst(). Specified by: elementin interfaceDeque<E> Specified by: elementin interfaceQueue<E> Returns: the head of the queue represented by this deque Throws: NoSuchElementException- if this deque is empty ...
Unlike typical queues in which the elements are data items, the elements of condition queue are the threads waiting for condition. 这是java并发编程实战里的解释,wait set是什么?感觉没怎么说清楚。另一种解释是说条件队列可以协同不同线程之间的工作(太抽象)。条件队列的定义暂且放下,先了解一下如何使用...
java -XX:+PrintAssembly -XX:CompileCommand=dontinline,Count.testMethod -XX:CompileCommand=compileonly,Count.testMethod Hello > out 这里解释一下上面的命令,首先我们使用 -XX:+PrintAssembly 参数使用 hsdis 插件获取 JIT 机器码,然后通过 XX:CompileCommand 参数指定不要将我们的代码内联优化,并且只编译 Count.tes...
一.JDK 中基于数组的阻塞队列 ArrayBlockingQueue 原理剖析,ArrayBlockingQueue 内部如何基于一把独占锁以及对应的两个条件变量实现出入队操作的线程安全? 首先我们先大概的浏览一下ArrayBlockingQueue 的内部构造,如下类图: 如类图所示,可以看到ArrayBlockingQueue 内部有个数组items 用来存放队列元素,putIndex变量标示入队元...