org.eclipse.xtext.util.concurrent

Class AbstractReadWriteAcces<P>

java.lang.Object

org.eclipse.xtext.util.concurrent.AbstractReadWriteAcces<P>

All Implemented Interfaces:

IReadAccess<P>

public abstract class AbstractReadWriteAcces<P>
extends Object
implements IReadAccess<P>

Author:

Sven Efftinge - Initial contribution and API, Jan Koehnlein

Nested Class Summary

Nested classes/interfaces inherited from interface org.eclipse.xtext.util.concurrent.IReadAccess

IReadAccess.Priority<P>

Field Summary

Fields

Modifier and Type	Field and Description
protected Lock	readLock This field should be private.
protected ReentrantReadWriteLock	rwLock This field should be private.
protected Lock	writeLock This field should be private.

Constructor Summary

Constructors

Constructor and Description
AbstractReadWriteAcces()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	afterModify(P state, Object result, IUnitOfWork<?,P> work) is executed within the transaction right after the unit of work has been executed and delivered the result.
protected void	afterReadOnly(P state, Object result, IUnitOfWork<?,P> work) is executed within the transaction right after the unit of work has been executed and delivered the result.
protected void	beforeModify(P state, IUnitOfWork<?,P> work) Is called before a write lock is obtained
protected void	beforeReadOnly(P state, IUnitOfWork<?,P> work) is called before a read lock is obtained
protected int	getReadHoldCount() Queries the number of reentrant read holds on this lock by the current thread.
protected abstract P	getState()
protected int	getWriteHoldCount() Queries the number of reentrant write holds on this lock by the current thread.
<T> T	modify(IUnitOfWork<T,P> work)
<T> T	process(IUnitOfWork<T,P> work) Upgrades a read transaction to a write transaction, executes the work then downgrades to a read transaction again.
<T> T	readOnly(IUnitOfWork<T,P> work)

Methods inherited from class java.lang.Object

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

Field Detail

rwLock

protected final ReentrantReadWriteLock rwLock

This field should be private. It is protected for API compatibility only. Never access this from the outside.

writeLock

protected final Lock writeLock

This field should be private. It is protected for API compatibility only. Never access this from the outside.

readLock

protected final Lock readLock

This field should be private. It is protected for API compatibility only. Never access this from the outside.

Constructor Detail

AbstractReadWriteAcces

public AbstractReadWriteAcces()

Method Detail

getState

protected abstract P getState()

readOnly

public <T> T readOnly(IUnitOfWork<T,P> work)

Specified by:

readOnly in interface IReadAccess<P>

modify

public <T> T modify(IUnitOfWork<T,P> work)

process

public <T> T process(IUnitOfWork<T,P> work)

Upgrades a read transaction to a write transaction, executes the work then downgrades to a read transaction again.

Since:

2.4

beforeModify

protected void beforeModify(P state,
                IUnitOfWork<?,P> work)

Is called before a write lock is obtained

Parameters:

work - - the unit of work to be processed

beforeReadOnly

protected void beforeReadOnly(P state,
                  IUnitOfWork<?,P> work)

is called before a read lock is obtained

Parameters:

work - - the unit of work to be processed

afterModify

protected void afterModify(P state,
               Object result,
               IUnitOfWork<?,P> work)

is executed within the transaction right after the unit of work has been executed and delivered the result.

Parameters:

result - - delivered result

work - - the unit of work to be processed

afterReadOnly

protected void afterReadOnly(P state,
                 Object result,
                 IUnitOfWork<?,P> work)

is executed within the transaction right after the unit of work has been executed and delivered the result.

Parameters:

result - - delivered result

work - - the unit of work to be processed

getWriteHoldCount

protected int getWriteHoldCount()

Queries the number of reentrant write holds on this lock by the current thread. Delegates to ReentrantReadWriteLock.getWriteHoldCount().

Returns:

the number of holds on the write lock by the current thread, or zero if the write lock is not held by the current thread

Since:

2.4

getReadHoldCount

protected int getReadHoldCount()

Queries the number of reentrant read holds on this lock by the current thread. A reader thread has a hold on a lock for each lock action that is not matched by an unlock action. That functionality is implemented in ReentrantReadWriteLock as well, but not before version 1.6. This is why we have to find our own way to work around it.

Returns:

the number of holds on the read lock by the current thread, or zero if the read lock is not held by the current thread

Since:

2.4