com.sleepycat.je.latch

Class LatchImpl

java.lang.Object

java.util.concurrent.locks.ReentrantLock

com.sleepycat.je.latch.LatchImpl

All Implemented Interfaces:

Latch, SharedLatch, Serializable, Lock

Direct Known Subclasses:

TimingLatch

public class LatchImpl
extends ReentrantLock
implements SharedLatch

An exclusive latch without stats. SharedLatch (not just Latch) is implemented to support exclusive-only BIN latches.

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
void	acquireExclusive() Acquires a latch for exclusive/write access.
boolean	acquireExclusiveNoWait() Acquires a latch for exclusive/write access, but do not block if it's not available.
void	acquireShared() Acquires a latch for shared/read access.
void	clearStats() Resets collected stat values to zero.
String	debugString() Returns the same information as Latch.toString() plus all known debug info.
Thread	getExclusiveOwner() Returns the thread that currently holds the latch for exclusive access.
int	getNWaiters() Returns an estimate of the number of threads waiting.
StatGroup	getStats() Returns a stats group with information about this latch.
boolean	isExclusiveOnly() Returns whether this latch is exclusive-only.
boolean	isExclusiveOwner() Returns true if the current thread holds this latch for exclusive/write access.
boolean	isOwner() Returns true if the current thread holds this latch.
void	release() Releases the latch.
void	releaseIfOwner() Releases the latch.
String	toString() Returns the latch name and exclusive owner info.

Methods inherited from class java.util.concurrent.locks.ReentrantLock

getHoldCount, getOwner, getQueuedThreads, getQueueLength, getWaitingThreads, getWaitQueueLength, hasQueuedThread, hasQueuedThreads, hasWaiters, isFair, isHeldByCurrentThread, isLocked, lock, lockInterruptibly, newCondition, tryLock, tryLock, unlock

Methods inherited from class java.lang.Object

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

Method Detail

isExclusiveOnly

public boolean isExclusiveOnly()

Description copied from interface: SharedLatch

Returns whether this latch is exclusive-only.

Specified by:

isExclusiveOnly in interface SharedLatch

acquireExclusive

public void acquireExclusive()

Description copied from interface: Latch

Acquires a latch for exclusive/write access.

Specified by:

acquireExclusive in interface Latch

acquireExclusiveNoWait

public boolean acquireExclusiveNoWait()

Description copied from interface: Latch

Acquires a latch for exclusive/write access, but do not block if it's not available.

Specified by:

acquireExclusiveNoWait in interface Latch

Returns:

true if the latch was acquired, false if it is not available.

acquireShared

public void acquireShared()

Description copied from interface: SharedLatch

Acquires a latch for shared/read access. In exclusive-only mode, calling this method is equivalent to calling Latch.acquireExclusive().

Specified by:

acquireShared in interface SharedLatch

release

public void release()

Description copied from interface: Latch

Releases the latch. If there are other thread(s) waiting for the latch, they are woken up and granted the latch.

Specified by:

release in interface Latch

releaseIfOwner

public void releaseIfOwner()

Description copied from interface: Latch

Releases the latch. If there are other thread(s) waiting for the latch, one is woken up and granted the latch. If the latch was not owned by the caller, just return.

Specified by:

releaseIfOwner in interface Latch

isOwner

public boolean isOwner()

Description copied from interface: Latch

Returns true if the current thread holds this latch. For an exclusive latch, is equivalent to calling Latch.isExclusiveOwner().

Specified by:

isOwner in interface Latch

isExclusiveOwner

public boolean isExclusiveOwner()

Description copied from interface: Latch

Returns true if the current thread holds this latch for exclusive/write access.

Specified by:

isExclusiveOwner in interface Latch

getExclusiveOwner

public Thread getExclusiveOwner()

Description copied from interface: Latch

Returns the thread that currently holds the latch for exclusive access.

Specified by:

getExclusiveOwner in interface Latch

getNWaiters

public int getNWaiters()

Description copied from interface: Latch

Returns an estimate of the number of threads waiting.

Specified by:

getNWaiters in interface Latch

getStats

public StatGroup getStats()

Description copied from interface: Latch

Returns a stats group with information about this latch.

Specified by:

getStats in interface Latch

clearStats

public void clearStats()

Description copied from interface: Latch

Resets collected stat values to zero.

Specified by:

clearStats in interface Latch

toString

public String toString()

Description copied from interface: Latch

Returns the latch name and exclusive owner info.

Specified by:

toString in interface Latch

Overrides:

toString in class ReentrantLock

debugString

public String debugString()

Description copied from interface: Latch

Returns the same information as Latch.toString() plus all known debug info.

Specified by:

debugString in interface Latch