public class

AbstractQueuedSynchronizer.ConditionObject

extends Object
implements Serializable Condition
java.lang.Object
   ↳ java.util.concurrent.locks.AbstractQueuedSynchronizer.ConditionObject

Class Overview

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
AbstractQueuedSynchronizer.ConditionObject()
Creates a new ConditionObject instance.
Public Methods
final boolean await(long time, TimeUnit unit)
Implements timed condition wait.
final void await()
Implements interruptible 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.
[Expand]
Inherited Methods
From class java.lang.Object
From interface java.util.concurrent.locks.Condition

Public Constructors

public AbstractQueuedSynchronizer.ConditionObject ()

Creates a new ConditionObject instance.

Public Methods

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 getState()
  3. Invoke 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 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 the maximum time to wait
unit the time unit of the time argument.
Returns
  • false if the waiting time detectably elapsed before return from the method, else true.
Throws
InterruptedException if the current thread is interrupted (and interruption of thread suspension is supported).

public final void await ()

Implements interruptible condition wait.

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

Throws
InterruptedException if the current thread is interrupted (and interruption of thread suspension is supported).

public final long awaitNanos (long nanosTimeout)

Implements timed condition wait.

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

Parameters
nanosTimeout the maximum time to wait, in nanoseconds
Returns
  • A value less than or equal to zero if the wait has timed out; otherwise an estimate, that is strictly less than the nanosTimeout argument, of the time still remaining when this method returned.
Throws
InterruptedException if the current thread is interrupted (and interruption of thread suspension is supported).

public final void awaitUninterruptibly ()

Implements uninterruptible condition wait.

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

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 getState()
  3. Invoke 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 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 the absolute time to wait until
Returns
  • false if the deadline has elapsed upon return, else true.
Throws
InterruptedException if the current thread is interrupted (and interruption of thread suspension is supported).

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 isHeldExclusively() returns false

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 isHeldExclusively() returns false

Protected Methods

protected final int getWaitQueueLength ()

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

Returns
  • the estimated number of waiting threads.
Throws
IllegalMonitorStateException if isHeldExclusively() returns false

protected final Collection<Thread> getWaitingThreads ()

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

Returns
  • the collection of threads
Throws
IllegalMonitorStateException if isHeldExclusively() returns false

protected final boolean hasWaiters ()

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

Returns
  • true if there are any waiting threads.
Throws
IllegalMonitorStateException if isHeldExclusively() returns false