com.antiaction.critical
Class Multex

java.lang.Object
  |
  +--com.antiaction.critical.Multex

public class Multex

extends java.lang.Object

Basic counter semaphore, allows for controlled multithreaded access to data. Losely based on a mutex implementation by Scott Oaks & Henry Wong. Java Threads ISBN 1-56592-418-5.

This allows for the management of resources. Several threads can be admitted access to the lock at the same time. For each released resource one can be obtained.

This should be a very robust implementation.

In depth coverage of the subject can be found in the afore mentioned book.

Version:

1.00

Author:

Nicholas Clarke

Constructor Summary

Multex()
Initialize closed multex semaphore.

Multex(int cnt)
Initialize multex semaphore with specified initial open slots.

Method Summary

boolean	attemptSemaphore() Attempt to obtain a free resource, returns either way.
void	obtainSemaphore() This call returns when the current thread has obtained a free resource.
void	releaseSemaphore() Release a resource, increases the amount of open slots.

Methods inherited from class java.lang.Object

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

Constructor Detail

Multex

public Multex()

Initialize closed multex semaphore.

See Also:

Multex(int)

Multex

public Multex(int cnt)

Initialize multex semaphore with specified initial open slots.

Parameters:

cnt - initial open slots.

Throws:

java.lang.IllegalArgumentException - in case a negative argument is passed.

Method Detail

obtainSemaphore

public void obtainSemaphore()

This call returns when the current thread has obtained a free resource.

See Also:

attemptSemaphore(), releaseSemaphore()

attemptSemaphore

public boolean attemptSemaphore()

Attempt to obtain a free resource, returns either way.

Returns:

boolean indicating whether the attempt was successful or not.

See Also:

obtainSemaphore()

releaseSemaphore

public void releaseSemaphore()

Release a resource, increases the amount of open slots.

See Also:

obtainSemaphore()