What is java's equivalent of ManualResetEvent? [duplicate]

Question

What is java's equivalent of ManualResetEvent?

Answer 1

class ManualResetEvent {    private final Object monitor = new Object();   private volatile boolean open = false;    public ManualResetEvent(boolean open) {     this.open = open;   }    public void waitOne() throws InterruptedException {     synchronized (monitor) {       while (open==false) {           monitor.wait();       }     }   }    public boolean waitOne(long milliseconds) throws InterruptedException {     synchronized (monitor) {       if (open)          return true;       monitor.wait(milliseconds);         return open;     }   }    public void set() {//open start     synchronized (monitor) {       open = true;       monitor.notifyAll();     }   }    public void reset() {//close stop     open = false;   } } 

Answer 2

The closest I know of is the Semaphore. Just use it with a "permit" count of 1, and aquire/release will be pretty much the same as what you know from the ManualResetEvent.

A semaphore initialized to one, and which is used such that it only has at most one permit available, can serve as a mutual exclusion lock. This is more commonly known as a binary semaphore, because it only has two states: one permit available, or zero permits available. When used in this way, the binary semaphore has the property (unlike many Lock implementations), that the "lock" can be released by a thread other than the owner (as semaphores have no notion of ownership). This can be useful in some specialized contexts, such as deadlock recovery.

Answer 3

Try CountDownLatch with count of one.

CountDownLatch startSignal = new CountDownLatch(1);

Answer 4

Based on:

ManualResetEvent allows threads to communicate with each other by signaling. Typically, this communication concerns a task which one thread must complete before other threads can proceed.

from here:

http://msdn.microsoft.com/en-us/library/system.threading.manualresetevent.aspx

you possibly want to look at the Barriers in the Java concurrency package - specifically CyclicBarrier I believe:

http://java.sun.com/j2se/1.5.0/docs/api/java/util/concurrent/CyclicBarrier.html

It blocks a fixed number of threads until a particular event has occured. All the threads must come together at a barrier point.