java.util.concurrent.locks

Class AbstractQueuedSynchronizer.ConditionObject

Enclosing Class:
AbstractQueuedSynchronizer
Implemented Interfaces:
Condition, Serializable

public class AbstractQueuedSynchronizer.ConditionObject
extends Object
implements Condition, Serializable

Condition implementation for a AbstractQueuedSynchronizer serving as the basis of a Lock implementation.

Method documentation for this class describes mechanics, not behavioral specifications from the point of view of Lock and Condition users. Exported versions of this class will in general need to be accompanied by documentation describing condition semantics that rely on those of the associated AbstractQueuedSynchronizer.

This class is Serializable, but all fields are transient, so deserialized conditions have no waiters.

See Also:
Serialized Form

Constructor Summary

ConditionObject()
Creates a new ConditionObject instance.

Method Summary

void
await()
Implements interruptible condition wait.
boolean
await(long time, TimeUnit unit)
Implements timed condition wait.
long
awaitNanos(long nanosTimeout)
Implements timed condition wait.
void
awaitUninterruptibly()
Implements uninterruptible condition wait.
boolean
awaitUntil(Date deadline)
Implements absolute timed condition wait.
protected int
getWaitQueueLength()
Returns an estimate of the number of threads waiting on this condition.
protected Collection
getWaitingThreads()
Returns a collection containing those threads that may be waiting on this Condition.
protected boolean
hasWaiters()
Queries whether any threads are waiting on this condition.
void
signal()
Moves the longest-waiting thread, if one exists, from the wait queue for this condition to the wait queue for the owning lock.
void
signalAll()
Moves all threads from the wait queue for this condition to the wait queue for the owning lock.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ConditionObject

public ConditionObject()
Creates a new ConditionObject instance.

Method Details

await

public final void await()
            throws InterruptedException
Implements interruptible condition wait.
  1. If current thread is interrupted, throw InterruptedException
  2. Save lock state returned by AbstractQueuedSynchronizer.ConditionObject
  3. Invoke AbstractQueuedSynchronizer.ConditionObject with saved state as argument, throwing IllegalMonitorStateException if it fails.
  4. Block until signalled or interrupted
  5. Reacquire by invoking specialized version of AbstractQueuedSynchronizer.ConditionObject with saved state as argument.
  6. If interrupted while blocked in step 4, throw exception
Specified by:
await in interface Condition

await

public final boolean await(long time,
                           TimeUnit unit)
            throws InterruptedException
Implements timed condition wait.
  1. If current thread is interrupted, throw InterruptedException
  2. Save lock state returned by AbstractQueuedSynchronizer.ConditionObject
  3. Invoke AbstractQueuedSynchronizer.ConditionObject with saved state as argument, throwing IllegalMonitorStateException if it fails.
  4. Block until signalled, interrupted, or timed out
  5. Reacquire by invoking specialized version of AbstractQueuedSynchronizer.ConditionObject with saved state as argument.
  6. If interrupted while blocked in step 4, throw InterruptedException
  7. If timed out while blocked in step 4, return false, else true
Specified by:
await in interface Condition

awaitNanos

public final long awaitNanos(long nanosTimeout)
            throws InterruptedException
Implements timed condition wait.
  1. If current thread is interrupted, throw InterruptedException
  2. Save lock state returned by AbstractQueuedSynchronizer.ConditionObject
  3. Invoke AbstractQueuedSynchronizer.ConditionObject with saved state as argument, throwing IllegalMonitorStateException if it fails.
  4. Block until signalled, interrupted, or timed out
  5. Reacquire by invoking specialized version of AbstractQueuedSynchronizer.ConditionObject with saved state as argument.
  6. If interrupted while blocked in step 4, throw InterruptedException
Specified by:
awaitNanos in interface Condition

awaitUninterruptibly

public final void awaitUninterruptibly()
Implements uninterruptible condition wait.
  1. Save lock state returned by AbstractQueuedSynchronizer.ConditionObject
  2. Invoke AbstractQueuedSynchronizer.ConditionObject with saved state as argument, throwing IllegalMonitorStateException if it fails.
  3. Block until signalled
  4. Reacquire by invoking specialized version of AbstractQueuedSynchronizer.ConditionObject with saved state as argument.
Specified by:
awaitUninterruptibly in interface Condition

awaitUntil

public final boolean awaitUntil(Date deadline)
            throws InterruptedException
Implements absolute timed condition wait.
  1. If current thread is interrupted, throw InterruptedException
  2. Save lock state returned by AbstractQueuedSynchronizer.ConditionObject
  3. Invoke AbstractQueuedSynchronizer.ConditionObject with saved state as argument, throwing IllegalMonitorStateException if it fails.
  4. Block until signalled, interrupted, or timed out
  5. Reacquire by invoking specialized version of AbstractQueuedSynchronizer.ConditionObject with saved state as argument.
  6. If interrupted while blocked in step 4, throw InterruptedException
  7. If timed out while blocked in step 4, return false, else true
Specified by:
awaitUntil in interface Condition

getWaitQueueLength

protected final int getWaitQueueLength()
Returns an estimate of the number of threads waiting on this condition. Implements AbstractQueuedSynchronizer.getWaitQueueLength(AbstractQueuedSynchronizer.ConditionObject).
Returns:
the estimated number of waiting threads
Throws:
IllegalMonitorStateException - if AbstractQueuedSynchronizer.ConditionObject returns false

getWaitingThreads

protected final Collection getWaitingThreads()
Returns a collection containing those threads that may be waiting on this Condition. Implements AbstractQueuedSynchronizer.getWaitingThreads(AbstractQueuedSynchronizer.ConditionObject).
Returns:
the collection of threads
Throws:
IllegalMonitorStateException - if AbstractQueuedSynchronizer.ConditionObject returns false

hasWaiters

protected final boolean hasWaiters()
Queries whether any threads are waiting on this condition. Implements AbstractQueuedSynchronizer.hasWaiters(AbstractQueuedSynchronizer.ConditionObject).
Returns:
true if there are any waiting threads
Throws:
IllegalMonitorStateException - if AbstractQueuedSynchronizer.ConditionObject returns false

signal

public final void signal()
Moves the longest-waiting thread, if one exists, from the wait queue for this condition to the wait queue for the owning lock.
Specified by:
signal in interface Condition
Throws:
IllegalMonitorStateException - if AbstractQueuedSynchronizer.ConditionObject returns false

signalAll

public final void signalAll()
Moves all threads from the wait queue for this condition to the wait queue for the owning lock.
Specified by:
signalAll in interface Condition
Throws:
IllegalMonitorStateException - if AbstractQueuedSynchronizer.ConditionObject returns false