AbstractQueuedSynchronizer.ConditionObject

public class AbstractQueuedSynchronizer.ConditionObject
extends Object implements Condition, Serializable

java.lang.Object
   ↳ java.util.concurrent.locks.AbstractQueuedSynchronizer.ConditionObject


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.

Summary

Public constructors

ConditionObject()

Creates a new ConditionObject instance.

Public methods

final void await()

Implements interruptible condition wait.

final boolean await(long time, TimeUnit unit)

Implements timed condition wait.

final long awaitNanos(long nanosTimeout)

Implements timed condition wait.

final void awaitUninterruptibly()

Implements uninterruptible condition wait.

final boolean awaitUntil(Date deadline)

Implements absolute timed condition wait.

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.

final void signalAll()

Moves all threads from the wait queue for this condition to the wait queue for the owning lock.

Protected methods

final int getWaitQueueLength()

Returns an estimate of the number of threads waiting on this condition.

final Collection<Thread> getWaitingThreads()

Returns a collection containing those threads that may be waiting on this Condition.

final boolean hasWaiters()

Queries whether any threads are waiting on this condition.

Inherited methods

Public constructors

ConditionObject

Added in API level 1
public ConditionObject ()

Creates a new ConditionObject instance.

Public methods

await

Added in API level 1
public final void await ()

Implements interruptible condition wait.

  1. If current thread is interrupted, throw InterruptedException.
  2. Save lock state returned by AbstractQueuedSynchronizer.getState().
  3. Invoke AbstractQueuedSynchronizer.release(int) with saved state as argument, throwing IllegalMonitorStateException if it fails.
  4. Block until signalled or interrupted.
  5. Reacquire by invoking specialized version of AbstractQueuedSynchronizer.acquire(int) with saved state as argument.
  6. If interrupted while blocked in step 4, throw InterruptedException.

Throws
InterruptedException

await

Added in API level 1
public final boolean await (long time, 
                TimeUnit unit)

Implements timed condition wait.

  1. If current thread is interrupted, throw InterruptedException.
  2. Save lock state returned by AbstractQueuedSynchronizer.getState().
  3. Invoke AbstractQueuedSynchronizer.release(int) 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.acquire(int) 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.

Parameters
time long: the maximum time to wait

unit TimeUnit: the time unit of the time argument

Returns
boolean false if the waiting time detectably elapsed before return from the method, else true

Throws
InterruptedException

awaitNanos

Added in API level 1
public final long awaitNanos (long nanosTimeout)

Implements timed condition wait.

  1. If current thread is interrupted, throw InterruptedException.
  2. Save lock state returned by AbstractQueuedSynchronizer.getState().
  3. Invoke AbstractQueuedSynchronizer.release(int) 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.acquire(int) with saved state as argument.
  6. If interrupted while blocked in step 4, throw InterruptedException.

Parameters
nanosTimeout long: the maximum time to wait, in nanoseconds

Returns
long an estimate of the nanosTimeout value minus the time spent waiting upon return from this method. A positive value may be used as the argument to a subsequent call to this method to finish waiting out the desired time. A value less than or equal to zero indicates that no time remains.

Throws
InterruptedException

awaitUninterruptibly

Added in API level 1
public final void awaitUninterruptibly ()

Implements uninterruptible condition wait.

  1. Save lock state returned by AbstractQueuedSynchronizer.getState().
  2. Invoke AbstractQueuedSynchronizer.release(int) with saved state as argument, throwing IllegalMonitorStateException if it fails.
  3. Block until signalled.
  4. Reacquire by invoking specialized version of AbstractQueuedSynchronizer.acquire(int) with saved state as argument.

awaitUntil

Added in API level 1
public final boolean awaitUntil (Date deadline)

Implements absolute timed condition wait.

  1. If current thread is interrupted, throw InterruptedException.
  2. Save lock state returned by AbstractQueuedSynchronizer.getState().
  3. Invoke AbstractQueuedSynchronizer.release(int) 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.acquire(int) 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.

Parameters
deadline Date: the absolute time to wait until

Returns
boolean false if the deadline has elapsed upon return, else true

Throws
InterruptedException

signal

Added in API level 1
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.

Throws
IllegalMonitorStateException if AbstractQueuedSynchronizer.isHeldExclusively() returns false

signalAll

Added in API level 1
public final void signalAll ()

Moves all threads from the wait queue for this condition to the wait queue for the owning lock.

Throws
IllegalMonitorStateException if AbstractQueuedSynchronizer.isHeldExclusively() returns false

Protected methods

getWaitQueueLength

Added in API level 1
protected final int getWaitQueueLength ()

Returns an estimate of the number of threads waiting on this condition. Implements AbstractQueuedSynchronizer.getWaitQueueLength(ConditionObject).

Returns
int the estimated number of waiting threads

Throws
IllegalMonitorStateException if AbstractQueuedSynchronizer.isHeldExclusively() returns false

getWaitingThreads

Added in API level 1
protected final Collection<Thread> getWaitingThreads ()

Returns a collection containing those threads that may be waiting on this Condition. Implements AbstractQueuedSynchronizer.getWaitingThreads(ConditionObject).

Returns
Collection<Thread> the collection of threads

Throws
IllegalMonitorStateException if AbstractQueuedSynchronizer.isHeldExclusively() returns false

hasWaiters

Added in API level 1
protected final boolean hasWaiters ()

Queries whether any threads are waiting on this condition. Implements AbstractQueuedSynchronizer.hasWaiters(ConditionObject).

Returns
boolean true if there are any waiting threads

Throws
IllegalMonitorStateException if AbstractQueuedSynchronizer.isHeldExclusively() returns false