edu.rice.cs.plt.concurrent
Class CompletionMonitor

java.lang.Object
  edu.rice.cs.plt.concurrent.CompletionMonitor

All Implemented Interfaces:

Condition

public class CompletionMonitor
extends Object
implements Condition

Provides a convenient facility for blocking until a boolean flag is signaled. Typically, this is used for communication in which one thread must complete a task before other threads can proceed.

Constructor Summary

CompletionMonitor()
Create an unsignaled completion monitor.

CompletionMonitor(boolean signaled)
Create a completion monitor in the given initial state.

Method Summary

boolean	attemptEnsureSignaled() Tries to ensure that the monitor has been signaled before continuing.
boolean	attemptEnsureSignaled(long timeout) Tries to ensure that the monitor has been signaled before continuing.
boolean	attemptEnsureSignaled(long timeout, TimeUnit unit) Tries to ensure that the monitor has been signaled before continuing.
void	ensureSignaled() Ensures that the monitor has been signaled before continuing.
void	ensureSignaled(long timeout) Ensures that the monitor has been signaled before continuing.
void	ensureSignaled(long timeout, TimeUnit unit) Ensures that the monitor has been signaled before continuing.
boolean	isSignaled() Returns whether the flag is currently set
boolean	isTrue() Returns whether the flag is currently set
void	reset() Revert to the unsignaled state
void	signal() Sets the state to signaled and alerts all blocked threads

Methods inherited from class java.lang.Object

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

Constructor Detail

CompletionMonitor

public CompletionMonitor()

Create an unsignaled completion monitor.

CompletionMonitor

public CompletionMonitor(boolean signaled)

Create a completion monitor in the given initial state. If signaled is true, invocations of ensureSignaled() will not block until reset() is invoked.

Method Detail

isSignaled

public boolean isSignaled()

Returns whether the flag is currently set

isTrue

public boolean isTrue()

Returns whether the flag is currently set

Specified by:

isTrue in interface Condition

reset

public void reset()

Revert to the unsignaled state

signal

public void signal()

Sets the state to signaled and alerts all blocked threads

ensureSignaled

public void ensureSignaled()
                    throws InterruptedException

Ensures that the monitor has been signaled before continuing. Blocks if necessary.

Throws:

InterruptedException

ensureSignaled

public void ensureSignaled(long timeout)
                    throws InterruptedException,
                           TimeoutException

Ensures that the monitor has been signaled before continuing. Blocks if necessary; fails if the the timeout is reached.

Parameters:

timeout - Maximum wait time, in milliseconds.

Throws:

InterruptedException

TimeoutException

ensureSignaled

public void ensureSignaled(long timeout,
                           TimeUnit unit)
                    throws InterruptedException,
                           TimeoutException

Ensures that the monitor has been signaled before continuing. Blocks if necessary; fails if the the timeout is reached.

Parameters:

timeout - Maximum wait time, in unit units.

unit - Units for timeout.

Throws:

InterruptedException

TimeoutException

attemptEnsureSignaled

public boolean attemptEnsureSignaled()

Tries to ensure that the monitor has been signaled before continuing. Blocks if necessary. If the wait is interrupted, returns false.

attemptEnsureSignaled

public boolean attemptEnsureSignaled(long timeout)

Tries to ensure that the monitor has been signaled before continuing. Blocks if necessary. If the wait is interrupted or the timeout is reached, returns false.

Parameters:

timeout - Maximum wait time, in milliseconds.

attemptEnsureSignaled

public boolean attemptEnsureSignaled(long timeout,
                                     TimeUnit unit)

Tries to ensure that the monitor has been signaled before continuing. Blocks if necessary. If the wait is interrupted or the timeout is reached, returns false.

Parameters:

timeout - Maximum wait time, in unit units.

unit - Units for timeout.