com.ibm.commons.util
Class ThreadLockManager

java.lang.Object
  com.ibm.commons.util.ThreadLockManager

public class ThreadLockManager
extends java.lang.Object

Read write lock acquisition.

Locking strategies can be defined by overriding some of the protected methods (who has priority, how many concurrent thread can run simultaneously...). Also note that JRE 5 now has a concurrent package which can be used to replace this class.

Inspired from 'Concurrent programming in Java, 2nd edition'

Field Summary

protected int	activeReaders
protected int	activeWriters
protected int	waitingReaders
protected int	waitingWriters

Constructor Summary

ThreadLockManager()

Method Summary

protected void	afterRead(java.lang.Object param)
protected void	afterWrite(java.lang.Object param)
protected boolean	allowReader(java.lang.Object param)
protected boolean	allowWriter(java.lang.Object param)
protected void	beforeRead(java.lang.Object param)
protected void	beforeWrite(java.lang.Object param)
protected void	doRead()
protected void	doWrite()
ThreadLock	getReadLock() Get a lock used to read data.
ThreadLock	getReadLock(java.lang.Object param) Get a lock used to read data.
ThreadLock	getWriteLock() Get a lock used to write data.
ThreadLock	getWriteLock(java.lang.Object param) Get a lock used to write data.
void	read()
void	read(java.lang.Object param)
protected boolean	tryBeforeRead(java.lang.Object param)
protected boolean	tryBeforeWrite(java.lang.Object param)
protected void	waitForRead(java.lang.Object param)
protected void	waitForWrite(java.lang.Object param)
void	write()
void	write(java.lang.Object param)

Methods inherited from class java.lang.Object

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

Field Detail

activeReaders

protected int activeReaders

activeWriters

protected int activeWriters

waitingReaders

protected int waitingReaders

waitingWriters

protected int waitingWriters

Constructor Detail

ThreadLockManager

public ThreadLockManager()

Method Detail

allowReader

protected boolean allowReader(java.lang.Object param)

allowWriter

protected boolean allowWriter(java.lang.Object param)

beforeRead

protected void beforeRead(java.lang.Object param)
                   throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

waitForRead

protected void waitForRead(java.lang.Object param)
                    throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

tryBeforeRead

protected boolean tryBeforeRead(java.lang.Object param)
                         throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

afterRead

protected void afterRead(java.lang.Object param)

beforeWrite

protected void beforeWrite(java.lang.Object param)
                    throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

waitForWrite

protected void waitForWrite(java.lang.Object param)
                     throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

tryBeforeWrite

protected boolean tryBeforeWrite(java.lang.Object param)
                          throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

afterWrite

protected void afterWrite(java.lang.Object param)

read

public void read()
          throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

read

public void read(java.lang.Object param)
          throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

write

public void write()
           throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

write

public void write(java.lang.Object param)
           throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

doRead

protected void doRead()

doWrite

protected void doWrite()

getReadLock

public ThreadLock getReadLock()

Get a lock used to read data.

getReadLock

public ThreadLock getReadLock(java.lang.Object param)

Get a lock used to read data.

getWriteLock

public ThreadLock getWriteLock()

Get a lock used to write data.

getWriteLock

public ThreadLock getWriteLock(java.lang.Object param)

Get a lock used to write data.