Package com.oracle.coherence.common.base

Class ConcurrentNotifier

java.lang.Object

com.oracle.coherence.common.base.ConcurrentNotifier

All Implemented Interfaces:

Notifier

public abstract class ConcurrentNotifier
extends Object
implements Notifier

A Condition-like object, usable by multiple threads to both wait and signal.

Note that no synchronization is needed to use this class; i.e. clients must not synchronize on this class prior to calling await() or signal(), nor should the use any of the primitive wait() or notify() methods.

Unlike the SingleWaiterMultiNotifier, this notifier implementation requires the notion of a ready check. When the notifier is ready then a call to await because a no-op. An example ready check for a notifier based queue removal would be !queue.isEmpty();

Author:

mf 2018.04.13

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	ConcurrentNotifier.Link	A link in a stack of waiting threads.

Field Summary

Fields

Modifier and Type	Field	Description
protected Object	m_oWaitHead	The head of a stack of waiting threads.

Constructor Summary

Constructors

Constructor	Description
ConcurrentNotifier()

Method Summary

Modifier and Type	Method	Description
void	await(long cMillis)	Wait for a notification.
protected abstract boolean	isReady()	Return true if the notifier is ready, i.e. threads entering await cant return without blocking.
protected ConcurrentNotifier.Link	makeSelfLink(Thread threadThis, long lBitThis, Object oHead)	Make a link for the calling thread, checking if one already exists for this notifier.
protected void	park(long cMillis)	Block the calling thread if the notifier is not ready.
void	signal()	Notifies the waiting thread(s), waking them up if awaiting.
protected void	signalInternal()	Full version of signal.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.oracle.coherence.common.base.Notifier

await

Field Detail

m_oWaitHead

protected volatile Object m_oWaitHead

The head of a stack of waiting threads. The head can be either a Thread, or a Link.

Constructor Detail

ConcurrentNotifier

public ConcurrentNotifier()

Method Detail

await

public void await(long cMillis)
           throws InterruptedException

Description copied from interface: Notifier

Wait for a notification. Note that spurious wake-ups are possible.

Specified by:

await in interface Notifier

Parameters:

cMillis - the maximum wait time in milliseconds, or zero for indefinite

Throws:

InterruptedException - if the calling thread is interrupted while it is waiting

signal

public void signal()

Description copied from interface: Notifier

Notifies the waiting thread(s), waking them up if awaiting.

Specified by:

signal in interface Notifier

signalInternal

protected void signalInternal()

Full version of signal.

park

protected void park(long cMillis)
             throws InterruptedException

Block the calling thread if the notifier is not ready.

Parameters:

cMillis - the time to block for

Throws:

InterruptedException - if the calling thread is interrupted

makeSelfLink

protected ConcurrentNotifier.Link makeSelfLink(Thread threadThis,
                                               long lBitThis,
                                               Object oHead)

Make a link for the calling thread, checking if one already exists for this notifier.

Parameters:

threadThis - the calling thread

lBitThis - this thread's contribution to the bloom filter

oHead - the current head

Returns:

this thread's link, or null if we should not block

isReady

protected abstract boolean isReady()

Return true if the notifier is ready, i.e. threads entering await cant return without blocking.

Returns:

true if the notifier is ready