com.oracle.svm.core.thread

Class ParkEvent

java.lang.Object

com.oracle.svm.core.thread.ParkEvent

public abstract class ParkEvent
extends Object

Each thread has several of these on which to wait. Instances are usually expensive objects because they encapsulate native resources. Therefore, lazy initialization is supported using ParkEvent.initializeOnce(com.oracle.svm.core.jdk.UninterruptibleUtils.AtomicReference<com.oracle.svm.core.thread.ParkEvent>, boolean) and ParkEvent.detach(com.oracle.svm.core.jdk.UninterruptibleUtils.AtomicReference<com.oracle.svm.core.thread.ParkEvent>) with three states and atomic transitions:

1. uninitialized: the UninterruptibleUtils.AtomicReference is null.
2. used: A concrete platform-specific subclass of ParkEvent that allows wait and unpark operations.
3. detached: The thread has exited (or was manually detached from the VM). The DetachedParkEvent singleton.

The allowed transitions are uninitialized->used (wait or park is called on an active thread); used->detached; and uninitialized->detached.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ParkEvent.ParkEventFactory

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	isSleepEvent Currently required by legacy code.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ParkEvent() Constructor for subclasses.

Method Summary

Modifier and Type	Method and Description
protected abstract void	condTimedWait(long delayNanos) cond_timedwait, similar to ParkEvent.condWait() but with a timeout in nanoseconds.
protected abstract void	condWait()
protected abstract void	reset() Resets a pending ParkEvent.unpark() at the time of the call.
protected abstract void	unpark() Notify anyone waiting on this event.

Methods inherited from class java.lang.Object

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

Field Detail

isSleepEvent

protected boolean isSleepEvent

Currently required by legacy code.

Constructor Detail

ParkEvent

protected ParkEvent()

Constructor for subclasses.

Method Detail

reset

protected abstract void reset()

Resets a pending ParkEvent.unpark() at the time of the call. This must synchronize in a way that prevents it from being reordered with regard to setting the thread's interrupted status.

condWait

protected abstract void condWait()

condTimedWait

protected abstract void condTimedWait(long delayNanos)

cond_timedwait, similar to ParkEvent.condWait() but with a timeout in nanoseconds.

unpark

protected abstract void unpark()

Notify anyone waiting on this event.