org.apache.commons.transaction.util
Class TurnBarrier

java.lang.Object
  org.apache.commons.transaction.util.TurnBarrier

public class TurnBarrier

extends Object

Simple turn based barrier to make a sequence of calls from different threads deterministic. This is very useful for testing where you want to have a contious flow throughout different threads. The idea is to have an ordered sequence of steps where step n can not be executed before n-1.

Version:

$Revision$

Field Summary

protected int	currentNumber
static long	DEFAULT_TIMEOUT
protected LoggerFacade	logger
protected String	name
protected int	startNumber
protected long	timeout

Constructor Summary

TurnBarrier(String name, LoggerFacade logger)
Creates a new turn barrier starting with turn 0 with an unlimited timeout.

TurnBarrier(String name, long timeout, LoggerFacade logger)
Creates a new turn barrier starting with turn 0.

TurnBarrier(String name, long timeout, LoggerFacade logger, int startTurn)
Creates a new turn barrier.

Method Summary

void	reset() Starts the barrier over again.
void	signalTurn(int turnNumber) Signals the next turn.
void	waitForTurn(int turnNumber) Blockingly waits for the given turn.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_TIMEOUT

public static final long DEFAULT_TIMEOUT

See Also:

Constant Field Values

name

protected final String name

currentNumber

protected int currentNumber

startNumber

protected final int startNumber

timeout

protected final long timeout

logger

protected LoggerFacade logger

Constructor Detail

TurnBarrier

public TurnBarrier(String name,
                   LoggerFacade logger)

Creates a new turn barrier starting with turn 0 with an unlimited timeout.

Parameters:

name - the name of the barrier

logger - logger for debug output

TurnBarrier

public TurnBarrier(String name,
                   long timeout,
                   LoggerFacade logger)

Creates a new turn barrier starting with turn 0.

Parameters:

name - the name of the barrier

timeout - timeout for threads to wait for their turn

logger - logger for debug output

TurnBarrier

public TurnBarrier(String name,
                   long timeout,
                   LoggerFacade logger,
                   int startTurn)

Creates a new turn barrier.

Parameters:

name - the name of the barrier

timeout - timeout for threads to wait for their turn

logger - logger for debug output

startTurn - the turn to start with

Method Detail

waitForTurn

public void waitForTurn(int turnNumber)
                 throws InterruptedException,
                        RuntimeException

Blockingly waits for the given turn. If a timeout occurs a runtime exception will be thrown.

Parameters:

turnNumber - the turn number to wait for

Throws:

InterruptedException - thrown if the thread is interrupted while waiting

RuntimeException - thrown when timed out

signalTurn

public void signalTurn(int turnNumber)

Signals the next turn. Any thread waiting for the turn will be allowed to continue.

Parameters:

turnNumber - the next turn number

reset

public void reset()

Starts the barrier over again. The next turn will be the one the barrier was started with.