ca.odell.glazedlists.util.concurrent
Class J2SE14ReadWriteLock.ReadLock

java.lang.Object
  ca.odell.glazedlists.util.concurrent.J2SE14ReadWriteLock.ReadLock

All Implemented Interfaces:

Lock, Serializable

Enclosing class:

J2SE14ReadWriteLock

public static class J2SE14ReadWriteLock.ReadLock
extends Object
implements Lock, Serializable

The lock returned by method J2SE14ReadWriteLock.readLock().

See Also:

Serialized Form

Constructor Summary

protected

J2SE14ReadWriteLock.ReadLock(J2SE14ReadWriteLock lock) Constructor for use by subclasses

Method Summary

void	lock() Acquires the read lock.
void	lockInterruptibly() Acquires the read lock unless the current thread is interrupted.
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.
void	unlock() Attempts to release this lock.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

J2SE14ReadWriteLock.ReadLock

protected J2SE14ReadWriteLock.ReadLock(J2SE14ReadWriteLock lock)

Constructor for use by subclasses

Parameters:

lock - the outer lock object

Throws:

NullPointerException - if the lock is null

Method Detail

lock

public void lock()

Acquires the read 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.

Specified by:

lock in interface Lock

lockInterruptibly

public void lockInterruptibly()
                       throws InterruptedException

Acquires the read lock unless the current thread is interrupted.

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:

• The read lock is acquired by the current thread; or
• Some other thread interrupts the current thread.

If the current thread:

• has its interrupted status set on entry to this method; or
• is interrupted while acquiring the read lock,

then InterruptedException is thrown and the current thread's interrupted status is cleared.

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

tryLock

public boolean tryLock()

Acquires the read lock only if the write lock is not held by another thread at the time of invocation.

Acquires the read lock if the write lock is not held by another thread and returns immediately with the value 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.

Specified by:

tryLock in interface Lock

Returns:

true if the read lock was acquired

unlock

public void unlock()

Attempts to release this lock.

If the number of readers is now zero then the lock is made available for write lock attempts.

Specified by:

unlock in interface Lock

toString

public String toString()

Returns a string identifying this lock, as well as its lock state. The state, in brackets, includes the String "Read locks =" followed by the number of held read locks.

Overrides:

toString in class Object

Returns:

a string identifying this lock, as well as its lock state