monq.stuff

Class Semaphore

java.lang.Object

monq.stuff.Semaphore

public class Semaphore
extends java.lang.Object

implements multi-slot semaphore. (This is somewhere available in the jdk and I just missed it, right?)

Version:

$Revision: 1.3 $, $Date: 2005-02-14 10:23:39 $

Author:

© 2004 Harald Kirsch

Constructor Summary

Constructors

Constructor and Description
Semaphore(int slots) creates a semaphore with the given number of slots.

Method Summary

Modifier and Type	Method and Description
int	acquire() blocks the calling thread until a free slot is available.
void	release(int slot) releases the given slot and thereby allows other threads to acquire it.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Semaphore

public Semaphore(int slots)

creates a semaphore with the given number of slots.

Method Detail

acquire

public int acquire()

blocks the calling thread until a free slot is available. The slot number as a value starting from zero is returned. It will typically be used by the caller as and index into an array of resources. Once the caller does not need the resource anymore, it should call release() to free the slot for others.

release

public void release(int slot)

releases the given slot and thereby allows other threads to acquire it. No check is and can be made as to whether it is ok to release the slot. To assure this is completely the responsibility of the caller.