org.jboss.com.sun.corba.se.impl.orbutil.concurrent

Class ReentrantMutex

java.lang.Object

org.jboss.com.sun.corba.se.impl.orbutil.concurrent.ReentrantMutex

All Implemented Interfaces:

Sync

public class ReentrantMutex
extends Object
implements Sync

Field Summary

Fields

Modifier and Type	Field and Description
protected int	counter_ number of times thread has acquired the lock
protected boolean	debug
protected Thread	holder_ The thread holding the lock

Fields inherited from interface org.jboss.com.sun.corba.se.impl.orbutil.concurrent.Sync

ONE_CENTURY, ONE_DAY, ONE_HOUR, ONE_MINUTE, ONE_SECOND, ONE_WEEK, ONE_YEAR

Constructor Summary

Constructors

Constructor and Description
ReentrantMutex()
ReentrantMutex(boolean debug)

Method Summary

Methods

Modifier and Type	Method and Description
void	acquire() Wait (possibly forever) until successful passage.
boolean	attempt(long msecs) Wait at most msecs to pass; report whether passed.
void	release() Potentially enable others to pass.

Methods inherited from class java.lang.Object

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

Field Detail

holder_

protected Thread holder_

The thread holding the lock

counter_

protected int counter_

number of times thread has acquired the lock

debug

protected boolean debug

Constructor Detail

ReentrantMutex

public ReentrantMutex()

ReentrantMutex

public ReentrantMutex(boolean debug)

Method Detail

acquire

public void acquire()
             throws InterruptedException

Description copied from interface: Sync

Wait (possibly forever) until successful passage. Fail only upon interuption. Interruptions always result in `clean' failures. On failure, you can be sure that it has not been acquired, and that no corresponding release should be performed. Conversely, a normal return guarantees that the acquire was successful.

Specified by:

acquire in interface Sync

Throws:

InterruptedException

release

public void release()

Description copied from interface: Sync

Potentially enable others to pass.

Because release does not raise exceptions, it can be used in `finally' clauses without requiring extra embedded try/catch blocks. But keep in mind that as with any java method, implementations may still throw unchecked exceptions such as Error or NullPointerException when faced with uncontinuable errors. However, these should normally only be caught by higher-level error handlers.

Specified by:

release in interface Sync

attempt

public boolean attempt(long msecs)
                throws InterruptedException

Description copied from interface: Sync

Wait at most msecs to pass; report whether passed.

The method has best-effort semantics: The msecs bound cannot be guaranteed to be a precise upper bound on wait time in Java. Implementations generally can only attempt to return as soon as possible after the specified bound. Also, timers in Java do not stop during garbage collection, so timeouts can occur just because a GC intervened. So, msecs arguments should be used in a coarse-grained manner. Further, implementations cannot always guarantee that this method will return at all without blocking indefinitely when used in unintended ways. For example, deadlocks may be encountered when called in an unintended context.

Specified by:

attempt in interface Sync

Parameters:

msecs - the number of milleseconds to wait. An argument less than or equal to zero means not to wait at all. However, this may still require access to a synchronization lock, which can impose unbounded delay if there is a lot of contention among threads.

Returns:

true if acquired

Throws:

InterruptedException