Class StampedLongAdderLockManager

java.lang.Object

org.eclipse.rdf4j.common.concurrent.locks.StampedLongAdderLockManager

public class StampedLongAdderLockManager
extends Object

A lightweight read/write lock manager that avoids allocating per-lock objects. Readers are tracked using two LongAdders while writers rely on a StampedLock. The read-lock method returns a constant stamp (READ_LOCK_STAMP) and writers receive the stamp produced by the underlying StampedLock.

Field Summary

Fields

Modifier and Type	Field	Description
static final long	READ_LOCK_STAMP	Stamp returned to callers holding a read lock.

Constructor Summary

Constructors

Constructor	Description
StampedLongAdderLockManager()
StampedLongAdderLockManager(int writePreference, int tryWriteLockMillis)

Method Summary

Modifier and Type	Method	Description
boolean	isReaderActive()
boolean	isWriterActive()
long	readLock()
long	tryReadLock()
long	tryWriteLock()
void	unlockRead(long stamp)
void	unlockWrite(long stamp)
void	waitForActiveReaders()
void	waitForActiveWriter()
long	writeLock()

Methods inherited from class Object

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

Field Details

READ_LOCK_STAMP

public static final long READ_LOCK_STAMP

Stamp returned to callers holding a read lock. Passing any other value to unlockRead(long) is considered an illegal monitor state.

See Also:

• Constant Field Values

Constructor Details

StampedLongAdderLockManager

public StampedLongAdderLockManager()

StampedLongAdderLockManager

public StampedLongAdderLockManager(int writePreference,
 int tryWriteLockMillis)

Method Details

isWriterActive

public boolean isWriterActive()

isReaderActive

public boolean isReaderActive()

waitForActiveWriter

public void waitForActiveWriter()
                         throws InterruptedException

Throws:

InterruptedException

waitForActiveReaders

public void waitForActiveReaders()
                          throws InterruptedException

Throws:

InterruptedException

readLock

public long readLock()
              throws InterruptedException

Throws:

InterruptedException

tryReadLock

public long tryReadLock()

unlockRead

public void unlockRead(long stamp)

writeLock

public long writeLock()
               throws InterruptedException

Throws:

InterruptedException

tryWriteLock

public long tryWriteLock()

unlockWrite

public void unlockWrite(long stamp)