orc.runtime.regions
Class LogicalClock

java.lang.Object
  orc.runtime.regions.Region
      orc.runtime.regions.SubRegion
          orc.runtime.regions.LogicalClock

public final class LogicalClock
extends SubRegion

An event queue for site calls to a logical timer (created by MakeTimer).

According to the semantics of logical time, logical timers can only advance when there are no pending site calls except those to so-called "immediate" sites. However it's not so clear how logical timers should interact with "<<". For the moment clocks are allowed to advance even if there are tokens blocked on a group cell.

Author:

dkitchin, quark

Field Summary

Fields inherited from class orc.runtime.regions.SubRegion

parent

Constructor Summary

LogicalClock(Region parent, LogicalClock parentClock)

Method Summary

void	addEvent(int delay, Token token) Schedule a token to resume at a future time.
int	getCurrentTime()
LogicalClock	getParentClock()
protected void	maybeDeactivate() Advance the logical time.

Methods inherited from class orc.runtime.regions.SubRegion

activate, deactivate, getParent, onClose

Methods inherited from class orc.runtime.regions.Region

add, add, addActive, close, putContainedTokens, remove, remove, removeActive

Methods inherited from class java.lang.Object

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

Constructor Detail

LogicalClock

public LogicalClock(Region parent,
                    LogicalClock parentClock)

Method Detail

addEvent

public final void addEvent(int delay,
                           Token token)

Schedule a token to resume at a future time.

maybeDeactivate

protected void maybeDeactivate()

Advance the logical time. Called when all child tokens and clocks are quiescent.

Overrides:

maybeDeactivate in class Region

getParentClock

public LogicalClock getParentClock()
                            throws SiteException

Throws:

SiteException

getCurrentTime

public int getCurrentTime()