app.util

Class Token

java.lang.Object

app.util.Token

public final class Token
extends java.lang.Object

A synchronization Token is essentially a binary semaphore, with acquire() as the potentially blocking P() operation, and release() as the potentially unblocking V() operation.

Method Summary

Modifier and Type	Method and Description
void	acquire() Acquires this token, blocking if necessary until it is available.
static Token	newBlockedToken() Creates and returns a new token, initially "blocked", i.e.
static Token	newUnblockedToken() Creates and returns a new token, initially "unblocked", i.e.
void	release() Releases this token, possibly unblocking a thread currently attempting to acquire() it.

Methods inherited from class java.lang.Object

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

Method Detail

acquire

public final void acquire()
                   throws java.lang.InterruptedException

Acquires this token, blocking if necessary until it is available.

Throws:

java.lang.InterruptedException

release

public final void release()
                   throws java.lang.IllegalStateException

Releases this token, possibly unblocking a thread currently attempting to acquire() it.

Throws:

java.lang.IllegalStateException

newBlockedToken

public static final Token newBlockedToken()

Creates and returns a new token, initially "blocked", i.e. allocated.

newUnblockedToken

public static final Token newUnblockedToken()

Creates and returns a new token, initially "unblocked", i.e. unallocated.