Package org.eclipse.ui.internal

Class UILockListener

java.lang.Object

org.eclipse.core.runtime.jobs.LockListener

org.eclipse.ui.internal.UILockListener

public class UILockListener
extends LockListener

The UI lock listener is used to prevent the UI thread from deadlocking on a lock when the thread owning the lock is attempting to syncExec.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	UILockListener.Queue	The Queue is the construct that keeps track of Semaphores.

Field Summary

Fields

Modifier and Type	Field	Description
protected PendingSyncExec	currentWork
protected Display	display
protected final UILockListener.Queue	pendingWork
protected Thread	ui	Points to the UI thread if it is currently waiting on a lock or null

Constructor Summary

Constructors

Constructor	Description
UILockListener(Display display)	Create a new instance of the receiver.

Method Summary

Modifier and Type	Method	Description
void	aboutToRelease()	Notification that a thread is about to release a lock.
boolean	aboutToWait(Thread lockOwner)	Notification that a thread is about to block on an attempt to acquire a lock.
boolean	canBlock()	Returns if it is safe for the calling thread to block while waiting to obtain a lock.

Methods inherited from class org.eclipse.core.runtime.jobs.LockListener

isLockOwnerThread

Methods inherited from class java.lang.Object

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

Field Details

display

protected Display display

pendingWork

protected final UILockListener.Queue pendingWork

currentWork

protected PendingSyncExec currentWork

ui

protected volatile Thread ui

Points to the UI thread if it is currently waiting on a lock or null

Constructor Details

UILockListener

public UILockListener(Display display)

Create a new instance of the receiver.

Method Details

aboutToRelease

public void aboutToRelease()

Description copied from class: LockListener

Notification that a thread is about to release a lock.

This default implementation does nothing. Subclasses may override.

Overrides:

aboutToRelease in class LockListener

aboutToWait

public boolean aboutToWait(Thread lockOwner)

Description copied from class: LockListener

Notification that a thread is about to block on an attempt to acquire a lock. Returns whether the thread should be granted immediate access to the lock.

This default implementation always returns false. Subclasses may override.

Overrides:

aboutToWait in class LockListener

Parameters:

lockOwner - the thread that currently owns the lock this thread is waiting for, or null if unknown.

Returns:

true if the thread should be granted immediate access, and false if it should wait for the lock to be available

canBlock

public boolean canBlock()

Description copied from class: LockListener

Returns if it is safe for the calling thread to block while waiting to obtain a lock. When blocking in the calling thread is not safe, the caller will ensure that the thread is kept alive and responsive to cancellation while waiting.

Overrides:

canBlock in class LockListener

Returns:

true if this thread can block, and false otherwise.