java.lang.Object java.util.concurrent.locks.ReentrantReadWriteLock.ReadLock
public static class ReentrantReadWriteLock.ReadLock
The lock returned by method ReentrantReadWriteLock.readLock() .
Constructor Summary | |
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protected |
ReentrantReadWriteLock.ReadLock
(
ReentrantReadWriteLock
lock) Constructor for use by subclasses |
Method Summary | |
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void |
lock
() Acquires the read lock. |
void |
lockInterruptibly
() Acquires the read lock unless the current thread is interrupted . |
Condition |
newCondition
() Throws UnsupportedOperationException because ReadLocks do not support conditions. |
String |
toString
() Returns a string identifying this lock, as well as its lock state. |
boolean |
tryLock
() Acquires the read lock only if the write lock is not held by another thread at the time of invocation. |
boolean |
tryLock
(long timeout,
TimeUnit
unit) Acquires the read lock if the write lock is not held by another thread within the given waiting time and the current thread has not been interrupted . |
void |
unlock
() Attempts to release this lock. |
Methods inherited from class java.lang. Object |
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clone , equals , finalize , getClass , hashCode , notify , notifyAll , wait , wait , wait |
Constructor Detail |
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protected ReentrantReadWriteLock.ReadLock(ReentrantReadWriteLock lock)
Method Detail |
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public void lock()
Acquires the read lock if the write lock is not held by another thread and returns immediately.
If the write lock is held by another thread then the current thread becomes disabled for thread scheduling purposes and lies dormant until the read lock has been acquired.
public void lockInterruptibly() throws InterruptedException
Acquires the read lock if the write lock is not held by another thread and returns immediately.
If the write 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 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.
public boolean tryLock()
Acquires the read lock if the write lock is not held by another thread and returns immediately with the value
true.
true
.
Even when this lock has been set to use a fair ordering policy, a call to
tryLock()
will immediately acquire the read lock if it is available, whether or not other threads are currently waiting for the read 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 write lock is held by another thread then this method will return immediately with the value
false.
false
.
public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException
Acquires the read lock if the write lock is not held by another thread and returns immediately with the value
true.
true
.
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 lock. This is in contrast to the
tryLock()
method. If you want a timed
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 write 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 read lock is acquired then the value true is returned.
If the current thread:
If the specified waiting time elapses then the value 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.
public void unlock()
If the number of readers is now zero then the lock is made available for write lock attempts.
public Condition newCondition()
public String toString()