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Class simu.util.Semaphore

java.lang.Object
   |
   +----simu.util.Semaphore

public class Semaphore

extends Object

Version:

1.0 27-Mar-97

Author:

Andre Campeau

The Semaphore class implements a simple counting semaphore. All methods are synchronized, meaning that the Semaphore class is actually a monitor. Calling threads wait for access to shared resources, which in this case is the semCount class variable.

The methods are as follows:
- Wait
- Signal
For more information, see the method descriptions included with the methods.

The behaviour of the Semaphore class is that of a counting semaphore, which means that calls to Wait() will cause the caller to block if the semCount is zero, and to decrement the semCount if it is greater than zero. Calls to Signal() will increment the semCount.

Semaphore()

This Semaphore class constructor is called to create an instance of the semaphore class with semCount set initially to zero.

Semaphore(int)

This Semaphore class constructor is called to create an instance of the semaphore class with semCount set initially to the value specified by the SemCount parameter.

Signal()

The Signal method causes the semCount to be incremented.

Wait()

The Wait method causes the caller to block if the semCount is zero, and to decrement the semCount if it is greater than zero.

  public Semaphore()

This Semaphore class constructor is called to create an instance of the semaphore class with semCount set initially to zero.

  public Semaphore(int SemCount)

This Semaphore class constructor is called to create an instance of the semaphore class with semCount set initially to the value specified by the SemCount parameter.

Parameters:

SemCount - The initial semaphore count.

  public synchronized void Wait()

The Wait method causes the caller to block if the semCount is zero, and to decrement the semCount if it is greater than zero. The method is synchronized to provide mutual exclusion protection.

  public synchronized void Signal()

The Signal method causes the semCount to be incremented. If any threads are waiting for a signal, they will be notified and moved to the ready-to-run queue.

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