edu.emory.mathcs.backport.java.util.concurrent.locks
public static class ReentrantReadWriteLock.WriteLock extends Object implements Lock, CondVar.ExclusiveLock, Serializable
Constructor Summary | |
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protected | WriteLock(ReentrantReadWriteLock lock)
Constructor for use by subclasses
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Method Summary | |
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int | getHoldCount()
Queries the number of holds on this write lock by the current
thread. |
boolean | isHeldByCurrentThread()
Queries if this write lock is held by the current thread.
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void | lock()
Acquires the write lock.
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void | lockInterruptibly()
Acquires the write lock unless the current thread is
Thread#interrupt interrupted.
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Condition | newCondition() |
String | toString()
Returns a string identifying this lock, as well as its lock
state. |
boolean | tryLock()
Acquires the write lock only if it is not held by another thread
at the time of invocation.
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boolean | tryLock(long timeout, TimeUnit unit)
Acquires the write lock if it is not held by another thread
within the given waiting time and the current thread has
not been Thread#interrupt interrupted.
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void | unlock()
Attempts to release this lock.
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Parameters: lock the outer lock object
Throws: NullPointerException if the lock is null
Returns: the number of holds on this lock by the current thread, or zero if this lock is not held by the current thread
Since: 1.6
Returns: {@code true} if the current thread holds this lock and {@code false} otherwise
Since: 1.6
Acquires the write lock if neither the read nor write lock are held by another thread and returns immediately, setting the write lock hold count to one.
If the current thread already holds the write lock then the hold count is incremented by one and the method returns immediately.
If the lock is held by another thread then the current thread becomes disabled for thread scheduling purposes and lies dormant until the write lock has been acquired, at which time the write lock hold count is set to one.
Acquires the write lock if neither the read nor write lock are held by another thread and returns immediately, setting the write lock hold count to one.
If the current thread already holds this lock then the hold count is incremented by one and the method returns immediately.
If the lock is held by another thread then the current thread becomes disabled for thread scheduling purposes and lies dormant until one of two things happens:
If the write lock is acquired by the current thread then the lock hold count is set to one.
If the current thread:
In this implementation, as this method is an explicit interruption point, preference is given to responding to the interrupt over normal or reentrant acquisition of the lock.
Throws: InterruptedException if the current thread is interrupted
The returned Condition instance supports the same
usages as do the Object monitor methods ( Object#wait() wait
, Object#notify notify
, and Object#notifyAll notifyAll
) when used with the built-in
monitor lock.
Returns: the Condition object
Returns: a string identifying this lock, as well as its lock state
Acquires the write lock if neither the read nor write lock
are held by another thread
and returns immediately with the value {@code true},
setting the write lock hold count to one. Even when this lock has
been set to use a fair ordering policy, a call to
{@code tryLock()} will immediately acquire the
lock if it is available, whether or not other threads are
currently waiting for the write lock. This "barging"
behavior can be useful in certain circumstances, even
though it breaks fairness. If you want to honor the
fairness setting for this lock, then use tryLock(0, TimeUnit.SECONDS)
which is almost equivalent (it also detects interruption).
If the current thread already holds this lock then the hold count is incremented by one and the method returns {@code true}.
If the lock is held by another thread then this method will return immediately with the value {@code false}.
Returns: {@code true} if the lock was free and was acquired by the current thread, or the write lock was already held by the current thread; and {@code false} otherwise.
Acquires the write lock if neither the read nor write lock are held by another thread and returns immediately with the value {@code true}, setting the write lock hold count to one. If this lock has been set to use a fair ordering policy then an available lock will not be acquired if any other threads are waiting for the write lock. This is in contrast to the tryLock method. If you want a timed {@code tryLock} that does permit barging on a fair lock then combine the timed and un-timed forms together:
if (lock.tryLock() || lock.tryLock(timeout, unit) ) { ... }
If the current thread already holds this lock then the hold count is incremented by one and the method returns {@code true}.
If the lock is held by another thread then the current thread becomes disabled for thread scheduling purposes and lies dormant until one of three things happens:
If the write lock is acquired then the value {@code true} is returned and the write lock hold count is set to one.
If the current thread:
If the specified waiting time elapses then the value {@code false} is returned. If the time is less than or equal to zero, the method will not wait at all.
In this implementation, as this method is an explicit interruption point, preference is given to responding to the interrupt over normal or reentrant acquisition of the lock, and over reporting the elapse of the waiting time.
Parameters: timeout the time to wait for the write lock unit the time unit of the timeout argument
Returns: {@code true} if the lock was free and was acquired by the current thread, or the write lock was already held by the current thread; and {@code false} if the waiting time elapsed before the lock could be acquired.
Throws: InterruptedException if the current thread is interrupted NullPointerException if the time unit is null
If the current thread is the holder of this lock then the hold count is decremented. If the hold count is now zero then the lock is released. If the current thread is not the holder of this lock then IllegalMonitorStateException is thrown.
Throws: IllegalMonitorStateException if the current thread does not hold this lock.