vona.time

Class SuperClock

java.lang.Object

vona.time.Clock

vona.time.SuperClock

public class SuperClock
extends Clock

Vona's utils: accelerateable, stoppable clock with extended sleep semantics.

Copyright (C) 2004 Marsette A. Vona, III

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

Author:

Marsette (Marty) A. Vona, III

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	SuperClock.SleepState Encapsulates thread-specific sleep state.

Field Summary

Fields

Modifier and Type	Field and Description
protected float	accel The time acceleration factor.
protected boolean	accumulateSleep Whether to accumulate sleep, default DEFAULT_ACCUMULATE_SLEEP.
private static java.lang.String	cvsid CVS id.
static boolean	DEFAULT_ACCUMULATE_SLEEP Whether to accumulate sleep by default.
static boolean	DEFAULT_SLEEP_TO_DEADLINE Whether to sleep to deadline by default.
protected double	lastWallTime The last wall time.
static double	MIN_SLEEP Minimum accumulated sleep.
protected boolean	paused Whethere we've been pause()d.
protected double	pausedAt The wall time at which we were paused in seconds if paused.
protected java.util.Vector<PeriodicThread>	periodicThreads All current active PeriodicThreads, lazily consed.
static double	SLEEP_GRANULARITY Real-world sleep granularity, see CompatTime.getSleepGranularity().
protected static java.lang.ThreadLocal	sleepState Holds thread-specific SuperClock.SleepState.
protected boolean	sleepToDeadline Whether we're sleeping to deadline, default DEFAULT_SLEEP_TO_DEADLINE.
protected double	time The current (accel) time.

Constructor Summary

Constructors

Constructor and Description
SuperClock() Create a SuperClock with accel 1.0, DEFAULT_ACCUMULATE_SLEEP and DEFAULT_SLEEP_TO_DEADLINE.
SuperClock(double accel) Create a SuperClock with DEFAULT_ACCUMULATE_SLEEP and DEFAULT_SLEEP_TO_DEADLINE.
SuperClock(double accel, boolean accumulateSleep, boolean sleepToDeadline) Create a SuperClock.

Method Summary

Methods

Modifier and Type	Method and Description
double	getAccel() Get the time acceleration factor.
double	getCurrentTime() Get the acceltime in accelseconds relative to an arbitrary epoch.
protected double	getWallTime() Get the wall-clock time in seconds relative to an arbitrary epoch.
boolean	isAccumulateSleep() Check whether we're accumulating sleep.
boolean	isPaused() Check if this clock is currently paused.
boolean	isSleepToDeadline() Check whether we're sleeping to deadline.
void	pause() Pause.
protected void	periodicThreadEnding(PeriodicThread periodicThread) Hook called just before a PeriodicThread ends.
protected void	periodicThreadStarting(PeriodicThread periodicThread) Hook called just after a PeriodicThread starts.
void	setAccel(double accel) Set the time acceleration factor.
void	setAccumulateSleep(boolean accumulateSleep) Set whether to accumulate sleep.
void	setSleepToDeadline(boolean sleepToDeadline) Set whether to sleep to deadline.
void	sleep(double seconds) Sleep the current thread for the requested number of accelseconds.
void	unPause() Un-pause().

Methods inherited from class java.lang.Object

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

Field Detail

cvsid

private static final java.lang.String cvsid

CVS id.

See Also:

Constant Field Values

SLEEP_GRANULARITY

public static final double SLEEP_GRANULARITY

Real-world sleep granularity, see CompatTime.getSleepGranularity().

MIN_SLEEP

public static final double MIN_SLEEP

Minimum accumulated sleep.

DEFAULT_ACCUMULATE_SLEEP

public static final boolean DEFAULT_ACCUMULATE_SLEEP

Whether to accumulate sleep by default.

See Also:

Constant Field Values

DEFAULT_SLEEP_TO_DEADLINE

public static final boolean DEFAULT_SLEEP_TO_DEADLINE

Whether to sleep to deadline by default.

See Also:

Constant Field Values

accel

protected float accel

The time acceleration factor.

32 bits so we don't have to synchronize to read and write it.

lastWallTime

protected double lastWallTime

The last wall time.

time

protected double time

The current (accel) time.

periodicThreads

protected java.util.Vector<PeriodicThread> periodicThreads

All current active PeriodicThreads, lazily consed.

paused

protected boolean paused

Whethere we've been pause()d.

pausedAt

protected double pausedAt

The wall time at which we were paused in seconds if paused.

accumulateSleep

protected boolean accumulateSleep

Whether to accumulate sleep, default DEFAULT_ACCUMULATE_SLEEP.

sleepToDeadline

protected boolean sleepToDeadline

Whether we're sleeping to deadline, default DEFAULT_SLEEP_TO_DEADLINE.

sleepState

protected static java.lang.ThreadLocal sleepState

Holds thread-specific SuperClock.SleepState.

Constructor Detail

SuperClock

public SuperClock(double accel,
          boolean accumulateSleep,
          boolean sleepToDeadline)

Create a SuperClock.

Parameters:

accel - the time acceleration factor

accumulateSleep - whether to accumulate sleep time (see sleep(double))

sleepToDeadline - whether to sleep to deadline only (see sleep(double))

SuperClock

public SuperClock(double accel)

Create a SuperClock with DEFAULT_ACCUMULATE_SLEEP and DEFAULT_SLEEP_TO_DEADLINE.

Parameters:

accel - the time acceleration factor

SuperClock

public SuperClock()

Create a SuperClock with accel 1.0, DEFAULT_ACCUMULATE_SLEEP and DEFAULT_SLEEP_TO_DEADLINE.

Method Detail

setAccel

public void setAccel(double accel)

Set the time acceleration factor.

A factor of 2.0 means time runs twice as fast as it would in reality.

Parameters:

accel - the time acceleration factor

getAccel

public double getAccel()

Get the time acceleration factor.

Returns:

the time acceleration factor

pause

public void pause()

Pause.

Has no effect if already paused.

Subsequent calls to getCurrentTime() will appear as if time was frozen when pause()d. Calls to sleep(double) will block until unPause()d, and any PeriodicThreads will also stop iterating until unPause()d.

unPause

public void unPause()

Un-pause().

isPaused

public boolean isPaused()

Check if this clock is currently paused.

Returns:

true iff this clock is currently paused

getCurrentTime

public double getCurrentTime()

Get the acceltime in accelseconds relative to an arbitrary epoch.

Overrides:

getCurrentTime in class Clock

Returns:

the acceltime in accelseconds relative to an arbitrary epoch

getWallTime

protected double getWallTime()

Get the wall-clock time in seconds relative to an arbitrary epoch.

Returns:

the wall-clock time in seconds relative to an arbitrary epoch

sleep

public void sleep(double seconds)
           throws java.lang.InterruptedException

Sleep the current thread for the requested number of accelseconds.

If we are pause()d before the sleep then we won't start sleeping until after we're unPause()d, and we'll wait for that in (real-world time) increments of SLEEP_GRANULARITY seconds.

If sleep accumulation (see setAccumulateSleep(boolean)) is turned on, then an actual sleep will only occur after enough sleep accelseconds have accumulated to require a real-world sleep of at least MIN_SLEEP seconds. Separate accumulators are maintained for all calling threads.

If sleep to deadline (see setSleepToDeadline(boolean)) is turned on then the we'll try to sleep only until the actual deadline, where the deadline is the acceltime at call (or since the beginning of the current sleep accumulation for the calling thread, if accumulating) plus the accel seconds according to the current accel.

Overrides:

sleep in class Clock

Parameters:

seconds - how long to sleep in accelseconds, non-negative

Throws:

java.lang.InterruptedException

setAccumulateSleep

public void setAccumulateSleep(boolean accumulateSleep)

Set whether to accumulate sleep.

See sleep(double).

Has no effect if the current mode is as requested.

Parameters:

accumulateSleep - whether to accumulate sleep

isAccumulateSleep

public boolean isAccumulateSleep()

Check whether we're accumulating sleep.

See sleep(double).

Returns:

whether we're accumulating sleep

setSleepToDeadline

public void setSleepToDeadline(boolean sleepToDeadline)

Set whether to sleep to deadline.

See sleep(double).

Has no effect if the current mode is as requested.

Parameters:

sleepToDeadline - whether to sleep to deadline

isSleepToDeadline

public boolean isSleepToDeadline()

Check whether we're sleeping to deadline.

See sleep(double).

Returns:

whether we're sleeping to deadline

periodicThreadStarting

protected void periodicThreadStarting(PeriodicThread periodicThread)

Hook called just after a PeriodicThread starts.

This impl adds periodicThread to periodicThreads.

Overrides:

periodicThreadStarting in class Clock

Parameters:

periodicThread - the periodic thread

periodicThreadEnding

protected void periodicThreadEnding(PeriodicThread periodicThread)

Hook called just before a PeriodicThread ends.

This impl removes periodicThread from periodicThreads.

Overrides:

periodicThreadEnding in class Clock

Parameters:

periodicThread - the periodic thread