Acquires in exclusive mode, ignoring interrupts.

  Acquires in exclusive mode, ignoring interrupts. Implemented
by invoking at least once AbstractQueuedLongSynchronizer.tryAcquire(long),
returning on success. Otherwise the thread is queued, possibly
repeatedly blocking and unblocking, invoking AbstractQueuedLongSynchronizer.tryAcquire(long) until success. This method can be used
to implement method Lock.lock().
Parameters:
- arg - the acquire argument. This value is conveyed to {@link #tryAcquire} but is otherwise uninterpreted and can represent anything you like.

  Acquires in exclusive mode, aborting if interrupted.

  Acquires in exclusive mode, aborting if interrupted.
Implemented by first checking interrupt status, then invoking
at least once AbstractQueuedLongSynchronizer.tryAcquire(long), returning on
success. Otherwise the thread is queued, possibly repeatedly
blocking and unblocking, invoking AbstractQueuedLongSynchronizer.tryAcquire(long)
until success or the thread is interrupted. This method can be
used to implement method Lock.lockInterruptibly().
Parameters:
- arg - the acquire argument. This value is conveyed to {@link #tryAcquire} but is otherwise uninterpreted and can represent anything you like.
Throws:
- InterruptedException - if the current thread is interrupted

  Acquires in exclusive uninterruptible mode for thread already in queue.

  Acquires in exclusive uninterruptible mode for thread already in
queue. Used by condition wait methods as well as acquire.
Returns: {@code true} if interrupted while waiting
Parameters:
- node - the node
- arg - the acquire argument

  Acquires in shared mode, ignoring interrupts.

  Acquires in shared mode, ignoring interrupts. Implemented by
first invoking at least once AbstractQueuedLongSynchronizer.tryAcquireShared(long),
returning on success. Otherwise the thread is queued, possibly
repeatedly blocking and unblocking, invoking AbstractQueuedLongSynchronizer.tryAcquireShared(long) until success.
Parameters:
- arg - the acquire argument. This value is conveyed to {@link #tryAcquireShared} but is otherwise uninterpreted and can represent anything you like.

  Acquires in shared mode, aborting if interrupted.

  Acquires in shared mode, aborting if interrupted. Implemented
by first checking interrupt status, then invoking at least once
AbstractQueuedLongSynchronizer.tryAcquireShared(long), returning on success. Otherwise the
thread is queued, possibly repeatedly blocking and unblocking,
invoking AbstractQueuedLongSynchronizer.tryAcquireShared(long) until success or the thread
is interrupted.
Parameters:
- arg - the acquire argument. This value is conveyed to {@link #tryAcquireShared} but is otherwise uninterpreted and can represent anything you like.
Throws:
- InterruptedException - if the current thread is interrupted

  Return true if the apparent first queued thread, if one exists, is not waiting in exclusive mode.

  Return true if the apparent first queued thread, if one
exists, is not waiting in exclusive mode. Used only as a heuristic
in ReentrantReadWriteLock.

  Atomically sets synchronization state to the given updated value if the current state value equals the expected value.

  Atomically sets synchronization state to the given updated
value if the current state value equals the expected value.
This operation has memory semantics of a volatile read
and write.
Returns: true if successful. False return indicates that the actual value was not equal to the expected value.
Parameters:
- expect - the expected value
- update - the new value

  Invokes release with current state value; returns saved state.

  Invokes release with current state value; returns saved state.
Cancels node and throws exception on failure.
Returns: previous sync state
Parameters:
- node - the condition node for this wait

  Returns a collection containing threads that may be waiting to acquire in exclusive mode.

  Returns a collection containing threads that may be waiting to
acquire in exclusive mode. This has the same properties
as AbstractQueuedLongSynchronizer.getQueuedThreads() except that it only returns
those threads waiting due to an exclusive acquire.
Returns: the collection of threads

  Returns the first (longest-waiting) thread in the queue, or null if no threads are currently queued.

  Returns the first (longest-waiting) thread in the queue, or null if no threads are currently queued.

In this implementation, this operation normally returns in constant time, but may iterate upon contention if other threads are concurrently modifying the queue.
Returns: the first (longest-waiting) thread in the queue, or {@code null} if no threads are currently queued

  Returns a collection containing threads that may be waiting to acquire.

  Returns a collection containing threads that may be waiting to
acquire. Because the actual set of threads may change
dynamically while constructing this result, the returned
collection is only a best-effort estimate. The elements of the
returned collection are in no particular order. This method is
designed to facilitate construction of subclasses that provide
more extensive monitoring facilities.
Returns: the collection of threads

  Returns an estimate of the number of threads waiting to acquire.

  Returns an estimate of the number of threads waiting to
acquire. The value is only an estimate because the number of
threads may change dynamically while this method traverses
internal data structures. This method is designed for use in
monitoring system state, not for synchronization
control.
Returns: the estimated number of threads waiting to acquire

  Returns a collection containing threads that may be waiting to acquire in shared mode.

  Returns a collection containing threads that may be waiting to
acquire in shared mode. This has the same properties
as AbstractQueuedLongSynchronizer.getQueuedThreads() except that it only returns
those threads waiting due to a shared acquire.
Returns: the collection of threads

  Returns the current value of synchronization state.

  Returns the current value of synchronization state.
This operation has memory semantics of a volatile read.
Returns: current state value

  Returns a collection containing those threads that may be waiting on the given condition associated with this synchronizer.

  Returns a collection containing those threads that may be
waiting on the given condition associated with this
synchronizer. Because the actual set of threads may change
dynamically while constructing this result, the returned
collection is only a best-effort estimate. The elements of the
returned collection are in no particular order.
Returns: the collection of threads
Parameters:
- condition - the condition
Throws:
- IllegalMonitorStateException - if exclusive synchronization is not held
- IllegalArgumentException - if the given condition is not associated with this synchronizer
- NullPointerException - if the condition is null

  Returns an estimate of the number of threads waiting on the given condition associated with this synchronizer.

  Returns an estimate of the number of threads waiting on the
given condition associated with this synchronizer. Note that
because timeouts and interrupts may occur at any time, the
estimate serves only as an upper bound on the actual number of
waiters. This method is designed for use in monitoring of the
system state, not for synchronization control.
Returns: the estimated number of waiting threads
Parameters:
- condition - the condition
Throws:
- IllegalMonitorStateException - if exclusive synchronization is not held
- IllegalArgumentException - if the given condition is not associated with this synchronizer
- NullPointerException - if the condition is null

  Queries whether any threads have ever contended to acquire this synchronizer; that is if an acquire method has ever blocked.

  Queries whether any threads have ever contended to acquire this synchronizer; that is if an acquire method has ever blocked.

In this implementation, this operation returns in constant time.
Returns: {@code true} if there has ever been contention

  Queries whether any threads are waiting to acquire.

  Queries whether any threads are waiting to acquire. Note that because cancellations due to interrupts and timeouts may occur at any time, a true return does not guarantee that any other thread will ever acquire.

In this implementation, this operation returns in constant time.
Returns: {@code true} if there may be other threads waiting to acquire

  Queries whether any threads are waiting on the given condition associated with this synchronizer.

  Queries whether any threads are waiting on the given condition
associated with this synchronizer. Note that because timeouts
and interrupts may occur at any time, a true return
does not guarantee that a future signal will awaken
any threads. This method is designed primarily for use in
monitoring of the system state.
Returns: true if there are any waiting threads
Parameters:
- condition - the condition
Throws:
- IllegalMonitorStateException - if exclusive synchronization is not held
- IllegalArgumentException - if the given condition is not associated with this synchronizer
- NullPointerException - if the condition is null

  Return true if the queue is empty or if the given thread is at the head of the queue.

  Return true if the queue is empty or if the given thread
is at the head of the queue. This is reliable only if
current is actually Thread.currentThread() of caller.

  Returns true if synchronization is held exclusively with respect to the current (calling) thread.

  Returns true if synchronization is held exclusively with respect to the current (calling) thread. This method is invoked upon each call to a non-waiting AbstractQueuedLongSynchronizer.ConditionObject method. (Waiting methods instead invoke AbstractQueuedLongSynchronizer.release(long).)

The default implementation throws UnsupportedOperationException. This method is invoked internally only within AbstractQueuedLongSynchronizer.ConditionObject methods, so need not be defined if conditions are not used.
Returns: {@code true} if synchronization is held exclusively; {@code false} otherwise
Throws:
- UnsupportedOperationException - if conditions are not supported

  Returns true if a node, always one that was initially placed on a condition queue, is now waiting to reacquire on sync queue.

  Returns true if a node, always one that was initially placed on
a condition queue, is now waiting to reacquire on sync queue.
Returns: true if is reacquiring
Parameters:
- node - the node

  Returns true if the given thread is currently queued.

  Returns true if the given thread is currently queued.

This implementation traverses the queue to determine presence of the given thread.
Returns: {@code true} if the given thread is on the queue
Parameters:
- thread - the thread
Throws:
- NullPointerException - if the thread is null

  Queries whether the given ConditionObject uses this synchronizer as its lock.

  Queries whether the given ConditionObject
uses this synchronizer as its lock.
Returns: true if owned
Parameters:
- condition - the condition
Throws:
- NullPointerException - if the condition is null

  Releases in exclusive mode.

  Releases in exclusive mode. Implemented by unblocking one or
more threads if AbstractQueuedLongSynchronizer.tryRelease(long) returns true.
This method can be used to implement method Lock.unlock().
Returns: the value returned from {@link #tryRelease}
Parameters:
- arg - the release argument. This value is conveyed to {@link #tryRelease} but is otherwise uninterpreted and can represent anything you like.

  Releases in shared mode.

  Releases in shared mode. Implemented by unblocking one or more
threads if AbstractQueuedLongSynchronizer.tryReleaseShared(long) returns true.
Returns: the value returned from {@link #tryReleaseShared}
Parameters:
- arg - the release argument. This value is conveyed to {@link #tryReleaseShared} but is otherwise uninterpreted and can represent anything you like.

  Sets the value of synchronization state.

  Sets the value of synchronization state.
This operation has memory semantics of a volatile write.
Parameters:
- newState - the new state value

  Returns a string identifying this synchronizer, as well as its state.

  Returns a string identifying this synchronizer, as well as its state.
The state, in brackets, includes the String "State ="
followed by the current value of AbstractQueuedLongSynchronizer.getState(), and either
"nonempty" or "empty" depending on whether the
queue is empty.
Returns: a string identifying this synchronizer, as well as its state

  Transfers node, if necessary, to sync queue after a cancelled wait.

  Transfers node, if necessary, to sync queue after a cancelled
wait. Returns true if thread was cancelled before being
signalled.
Returns: true if cancelled before the node was signalled.
Parameters:
- current - the waiting thread
- node - its node

  Transfers a node from a condition queue onto sync queue.

  Transfers a node from a condition queue onto sync queue.
Returns true if successful.
Returns: true if successfully transferred (else the node was cancelled before signal).
Parameters:
- node - the node

  Attempts to acquire in exclusive mode.

  Attempts to acquire in exclusive mode. This method should query if the state of the object permits it to be acquired in the exclusive mode, and if so to acquire it.

This method is always invoked by the thread performing acquire. If this method reports failure, the acquire method may queue the thread, if it is not already queued, until it is signalled by a release from some other thread. This can be used to implement method Lock.tryLock().

The default implementation throws UnsupportedOperationException.
Returns: {@code true} if successful. Upon success, this object has been acquired.
Parameters:
- arg - the acquire argument. This value is always the one passed to an acquire method, or is the value saved on entry to a condition wait. The value is otherwise uninterpreted and can represent anything you like.
Throws:
- IllegalMonitorStateException - if acquiring would place this synchronizer in an illegal state. This exception must be thrown in a consistent fashion for synchronization to work correctly.
- UnsupportedOperationException - if exclusive mode is not supported

  Attempts to acquire in exclusive mode, aborting if interrupted, and failing if the given timeout elapses.

  Attempts to acquire in exclusive mode, aborting if interrupted,
and failing if the given timeout elapses. Implemented by first
checking interrupt status, then invoking at least once AbstractQueuedLongSynchronizer.tryAcquire(long), returning on success. Otherwise, the thread is
queued, possibly repeatedly blocking and unblocking, invoking
AbstractQueuedLongSynchronizer.tryAcquire(long) until success or the thread is interrupted
or the timeout elapses. This method can be used to implement
method Lock.tryLock(long, TimeUnit).
Returns: {@code true} if acquired; {@code false} if timed out
Parameters:
- arg - the acquire argument. This value is conveyed to {@link #tryAcquire} but is otherwise uninterpreted and can represent anything you like.
- nanosTimeout - the maximum number of nanoseconds to wait
Throws:
- InterruptedException - if the current thread is interrupted

  Attempts to acquire in shared mode.

  Attempts to acquire in shared mode. This method should query if the state of the object permits it to be acquired in the shared mode, and if so to acquire it.

This method is always invoked by the thread performing acquire. If this method reports failure, the acquire method may queue the thread, if it is not already queued, until it is signalled by a release from some other thread.

The default implementation throws UnsupportedOperationException.
Returns: a negative value on failure; zero if acquisition in shared mode succeeded but no subsequent shared-mode acquire can succeed; and a positive value if acquisition in shared mode succeeded and subsequent shared-mode acquires might also succeed, in which case a subsequent waiting thread must check availability. (Support for three different return values enables this method to be used in contexts where acquires only sometimes act exclusively.) Upon success, this object has been acquired.
Parameters:
- arg - the acquire argument. This value is always the one passed to an acquire method, or is the value saved on entry to a condition wait. The value is otherwise uninterpreted and can represent anything you like.
Throws:
- IllegalMonitorStateException - if acquiring would place this synchronizer in an illegal state. This exception must be thrown in a consistent fashion for synchronization to work correctly.
- UnsupportedOperationException - if shared mode is not supported

  Attempts to acquire in shared mode, aborting if interrupted, and failing if the given timeout elapses.

  Attempts to acquire in shared mode, aborting if interrupted, and
failing if the given timeout elapses. Implemented by first
checking interrupt status, then invoking at least once AbstractQueuedLongSynchronizer.tryAcquireShared(long), returning on success. Otherwise, the
thread is queued, possibly repeatedly blocking and unblocking,
invoking AbstractQueuedLongSynchronizer.tryAcquireShared(long) until success or the thread
is interrupted or the timeout elapses.
Returns: {@code true} if acquired; {@code false} if timed out
Parameters:
- arg - the acquire argument. This value is conveyed to {@link #tryAcquireShared} but is otherwise uninterpreted and can represent anything you like.
- nanosTimeout - the maximum number of nanoseconds to wait
Throws:
- InterruptedException - if the current thread is interrupted

  Attempts to set the state to reflect a release in exclusive mode.

  Attempts to set the state to reflect a release in exclusive mode.

This method is always invoked by the thread performing release.

The default implementation throws UnsupportedOperationException.
Returns: {@code true} if this object is now in a fully released state, so that any waiting threads may attempt to acquire; and {@code false} otherwise.
Parameters:
- arg - the release argument. This value is always the one passed to a release method, or the current state value upon entry to a condition wait. The value is otherwise uninterpreted and can represent anything you like.
Throws:
- IllegalMonitorStateException - if releasing would place this synchronizer in an illegal state. This exception must be thrown in a consistent fashion for synchronization to work correctly.
- UnsupportedOperationException - if exclusive mode is not supported

  Attempts to set the state to reflect a release in shared mode.

  Attempts to set the state to reflect a release in shared mode.

This method is always invoked by the thread performing release.

The default implementation throws UnsupportedOperationException.
Returns: {@code true} if this release of shared mode may permit a waiting acquire (shared or exclusive) to succeed; and {@code false} otherwise
Parameters:
- arg - the release argument. This value is always the one passed to a release method, or the current state value upon entry to a condition wait. The value is otherwise uninterpreted and can represent anything you like.
Throws:
- IllegalMonitorStateException - if releasing would place this synchronizer in an illegal state. This exception must be thrown in a consistent fashion for synchronization to work correctly.
- UnsupportedOperationException - if shared mode is not supported