jade.util
Class SynchList

java.lang.Object
  jade.util.RWLock
      jade.util.SynchList

public class SynchList
extends RWLock

Implementation of a list of objects providing methods to synchronize threads acting on the list in such a way to prevent concurrent modifications (addition/remotion of elements) and concurrent scanning/modification. Concurrent scannings are allowed instead.

Author:

Giovanni Caire - TILab

Constructor Summary

SynchList()
Default constructor.

Method Summary

protected void	onWriteEnd() This placeholder method is called every time a thread actually releases the protected resource with writing privileges (this means that, in case of multiple recursive unlocking by the same thread, this method is called only the last time).
protected void	onWriteStart() This placeholder method is called every time a thread actually acquires the protected resource with writing privileges (this means that, in case of multiple recursive locking by the same thread, this method is called only the first time).
List	startModifying() This method grants writing privileges to the calling thread and grants access to the protected list.
List	startScanning() This method grants reading privileges to the calling thread and grants access to the protected list.
void	stopModifying() This method must be called when a writer thread has finished modifying the list, so that the associated readers-writer lock can be relinquished.
void	stopScanning() This method must be called when a reader thread has finished accessing the list, so that the associated readers-writer lock can be relinquished.

Methods inherited from class jade.util.RWLock

readLock, readUnlock, writeLock, writeUnlock

Methods inherited from class java.lang.Object

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

Constructor Detail

SynchList

public SynchList()

Default constructor.

Method Detail

startModifying

public List startModifying()

This method grants writing privileges to the calling thread and grants access to the protected list.

Returns:

The inner, protected list.

stopModifying

public void stopModifying()

This method must be called when a writer thread has finished modifying the list, so that the associated readers-writer lock can be relinquished.

startScanning

public List startScanning()

This method grants reading privileges to the calling thread and grants access to the protected list.

Returns:

The inner, protected list.

stopScanning

public void stopScanning()

This method must be called when a reader thread has finished accessing the list, so that the associated readers-writer lock can be relinquished.

onWriteStart

protected void onWriteStart()

Description copied from class: RWLock

This placeholder method is called every time a thread actually acquires the protected resource with writing privileges (this means that, in case of multiple recursive locking by the same thread, this method is called only the first time). Subclasses can exploit this to transparently trigger a resource acquisition prolog.

Overrides:

onWriteStart in class RWLock

onWriteEnd

protected void onWriteEnd()

Description copied from class: RWLock

This placeholder method is called every time a thread actually releases the protected resource with writing privileges (this means that, in case of multiple recursive unlocking by the same thread, this method is called only the last time). Subclasses can exploit this to transparently trigger a resource release epilog.

Overrides:

onWriteEnd in class RWLock