thread
Class Semaphore

java.lang.Object
  thread.Semaphore

All Implemented Interfaces:

java.io.Serializable

public class Semaphore
extends java.lang.Object
implements java.io.Serializable

Semaphore. This class is safe against Thread InterruptedException.

Author:

Akitoshi Yoshida, Heinz Kredel.

See Also:

Serialized Form

Field Summary

private int	del
private int	init
private static Logger	logger
private int	s

Constructor Summary

Semaphore()
Constructs a default semaphore.

Semaphore(int i)
Constructs a semaphore with the given upper limit value.

Method Summary

protected void	finalize() Finalizes this object.
boolean	isPositive() Checks if Semaphore is positive.
void	P() Performs the P operation.
boolean	P(int m) Performs the time limited P operation.
void	V() Performs the V operation.

Methods inherited from class java.lang.Object

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

Field Detail

init

private int init

s

private int s

del

private int del

logger

private static Logger logger

Constructor Detail

Semaphore

public Semaphore()

Constructs a default semaphore.

Semaphore

public Semaphore(int i)

Constructs a semaphore with the given upper limit value.

Parameters:

i - initial limit.

Method Detail

finalize

protected void finalize()
                 throws java.lang.Throwable

Finalizes this object.

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable

P

public void P()
       throws java.lang.InterruptedException

Performs the P operation.

Throws:

InterruptedException.

java.lang.InterruptedException

P

public boolean P(int m)
          throws java.lang.InterruptedException

Performs the time limited P operation.

Parameters:

m - time to wait.

Returns:

true if P succeeded, else false.

Throws:

InterruptedException.

java.lang.InterruptedException

V

public void V()

Performs the V operation.

isPositive

public boolean isPositive()

Checks if Semaphore is positive.

Returns:

true if Semaphore is positive, else false.