javax.realtime
Class RealtimeThread

java.lang.Object
  java.lang.Thread
      javax.realtime.RealtimeThread

All Implemented Interfaces:

java.lang.Runnable, Schedulable

Direct Known Subclasses:

ActivationLatency, BridgeReporter, Car, Car, CarArrivals, ChangeFlaps, ChangeLandingGear, CycleBurner, Job, NoHeapRealtimeThread, OneShotTimerThread, PeriodicTimerThread, Pilot, Terminator, TestAltitude

public abstract class RealtimeThread

extends java.lang.Thread

implements Schedulable

RealtimeThread extends java.lang.Thread and includes classes and methods to get and set parameter objects, manage the execution of those threads with a ReleaseParameters type of PeriodicParameters, and waiting.

A RealtimeThread object must be placed in a memory area such that thread logic may unexceptionally access instance variables and such that Java methods on java.lang.Thread (e.g., enumerate and join) complete normally except where such execution may cause access violations.

Parameters for constructors may be null. In such cases the default value will be the default value set for the particular type by the associated instance of Scheduler.

Author:

gary

Field Summary

boolean	activePhaseToDo True iff this RealtimeThread is executing an active phase, i.e., is the coroutine currently under execution in this DSS.
EventNotice	currentEventNotice Points to the unique EventNotice for this RealtimeThread.
int	currentPriority The current priority of this RealtimeThread, which may temporarily be greater than its base priority, due to priority inheritance.
static int	defaultPriority
protected AbsoluteTime	endTime
protected double	lastPriorityChangeNanos
protected AbsoluteTime	lastWaitStart
protected java.lang.Runnable	logic Not passed to superclass because we need to maintain two run() functions: the one in this RealtimeThread, and the one provided by constructor argument
protected MemoryArea	memoryArea This RealtimeThread's MemoryArea.
protected MemoryParameters	memoryParameters This RealtimeThread's MemoryParameters.
protected ProcessingGroupParameters	processingGroup This RealtimeThread's ProcessingGroupParameters.
protected ReleaseParameters	releaseParameters This RealtimeThread's ReleaseParameters.
java.util.Set	resourcesHeld The set of resources currently held by this RealtimeThread.
protected Scheduler	scheduler This RealtimeThread's Scheduler.
protected SchedulingParameters	scheduling This RealtimeThread's Scheduler.
protected long	startAbsoluteMillis The milliseconds of this RealtimeThread's start cost.
boolean	started True iff this RealtimeThread has started, i.e., begun its run() routine.
protected AbsoluteTime	startTime The time at which this RealtimeThread started running.
boolean	terminated
protected double	timeWeightedPriority
Resource	waitingForResource The resource, if any, that this RealtimeThread is currently waiting for.
protected RelativeTime	waitTime Accumulates time this RealtimeThread has spent waiting for a Resource.

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

protected	RealtimeThread() Default constructor
	RealtimeThread(SchedulingParameters scheduling) Constructor
	RealtimeThread(SchedulingParameters scheduling, ReleaseParameters releaseParameters) Constructor
	RealtimeThread(SchedulingParameters scheduling, ReleaseParameters releaseParameters, MemoryParameters memoryParameters, MemoryArea memoryArea, ProcessingGroupParameters processingGroup, java.lang.Runnable logic) Constructor
protected	RealtimeThread(java.lang.String name)
	RealtimeThread(java.lang.String name, SchedulingParameters scheduling) Constructor
	RealtimeThread(java.lang.String name, SchedulingParameters scheduling, ReleaseParameters releaseParameters) Constructor
	RealtimeThread(java.lang.String name, SchedulingParameters scheduling, ReleaseParameters releaseParameters, MemoryParameters memoryParameters, MemoryArea memoryArea, ProcessingGroupParameters processingGroup, java.lang.Runnable logic) Constructor

Method Summary

boolean	addToFeasibility() Add this thread to the current scheduler's feasibility set
void	addToWaitTime(RelativeTime time)
double	averagePriority()
abstract void	body() Where all the application work gets done.
int	dynamicPriority() Compute dynamic priority of this .
void	exit() Exit a run method.
int	getBasePriority()
AbsoluteTime	getLastWaitStart()
MemoryParameters	getMemoryParameters() Set this thread's memory parameters
ProcessingGroupParameters	getProcessingGroupParameters() Get this thread's processing group parameters
ReleaseParameters	getReleaseParameters() Get this thread's release parameters
Scheduler	getScheduler() Get this thread's scheduler
SchedulingParameters	getSchedulingParameters() Get this thread's scheduling parameters
void	initialize() Start this thread, and wait until it has actually started.
boolean	isActive() Tests whether this RealtimeThread is running or scheduled to run later.
void	notifyPriorityChange(int oldPriority, int newPriority)
static void	printAllStatistics()
void	printResourcesHeld()
void	printStatistics()
void	printTimes()
boolean	removeFromFeasibility() Remove this thread from its scheduler's feasibility set
void	run() The run() method of this thread.
void	setLastWaitStart()
void	setMemoryParameters(MemoryParameters memoryParameters) Set this thread's memory parameters
boolean	setMemoryParametersIfFeasible(MemoryParameters memoryParameters) Set this thread's memory parameters if it would still be feasible given that change
void	setProcessingGroupParameters(ProcessingGroupParameters processingGroup) Set this thread's processing group parameters
boolean	setProcessingGroupParametersIfFeasible(ProcessingGroupParameters groupParameters) Set this thread's processing group parameters if it would still be feasible given that change
void	setReleaseParameters(ReleaseParameters releaseParameters) Set this thread's release parameters
boolean	setReleaseParametersIfFeasible(ReleaseParameters releaseParameters) Set this thread's release parameters if it would still be feasible given that change
void	setScheduler(Scheduler scheduler) Set this thread's scheduler
void	setScheduler(Scheduler scheduler, SchedulingParameters scheduling, ReleaseParameters releaseParameters, MemoryParameters memoryParameters, ProcessingGroupParameters processingGroup) Set all the following parameters of this thread:
void	setSchedulingParameters(SchedulingParameters scheduling) Set this RealtimeThread's scheduling parameters
boolean	setSchedulingParametersIfFeasible(SchedulingParameters scheduling) Set this thread's scheduling parameters if it would still be feasible given that change
java.lang.String	toString() Construct a string representation of this thread.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, yield

Methods inherited from class java.lang.Object

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

Field Detail

currentPriority

public int currentPriority

The current priority of this RealtimeThread, which may temporarily be greater than its base priority, due to priority inheritance.

resourcesHeld

public java.util.Set resourcesHeld

The set of resources currently held by this RealtimeThread. Used in priority inheritance calculation.

waitingForResource

public Resource waitingForResource

The resource, if any, that this RealtimeThread is currently waiting for.

started

public boolean started

True iff this RealtimeThread has started, i.e., begun its run() routine.

terminated

public boolean terminated

activePhaseToDo

public boolean activePhaseToDo

True iff this RealtimeThread is executing an active phase, i.e., is the coroutine currently under execution in this DSS.

currentEventNotice

public EventNotice currentEventNotice

Points to the unique EventNotice for this RealtimeThread. Must be null if this RealtimeThread is unscheduled, i.e., passivated or terminated.

scheduler

protected Scheduler scheduler

This RealtimeThread's Scheduler.

scheduling

protected SchedulingParameters scheduling

This RealtimeThread's Scheduler.

releaseParameters

protected ReleaseParameters releaseParameters

This RealtimeThread's ReleaseParameters.

memoryParameters

protected MemoryParameters memoryParameters

This RealtimeThread's MemoryParameters.

memoryArea

protected MemoryArea memoryArea

This RealtimeThread's MemoryArea.

processingGroup

protected ProcessingGroupParameters processingGroup

This RealtimeThread's ProcessingGroupParameters.

defaultPriority

public static final int defaultPriority

See Also:

Constant Field Values

startTime

protected AbsoluteTime startTime

The time at which this RealtimeThread started running.

endTime

protected AbsoluteTime endTime

startAbsoluteMillis

protected long startAbsoluteMillis

The milliseconds of this RealtimeThread's start cost.

waitTime

protected RelativeTime waitTime

Accumulates time this RealtimeThread has spent waiting for a Resource.

lastPriorityChangeNanos

protected double lastPriorityChangeNanos

timeWeightedPriority

protected double timeWeightedPriority

lastWaitStart

protected AbsoluteTime lastWaitStart

logic

protected java.lang.Runnable logic

Not passed to superclass because we need to maintain two run() functions: the one in this RealtimeThread, and the one provided by constructor argument

Constructor Detail

RealtimeThread

protected RealtimeThread()

Default constructor

RealtimeThread

protected RealtimeThread(java.lang.String name)

RealtimeThread

public RealtimeThread(SchedulingParameters scheduling)

Constructor

Parameters:

scheduling - the SchedulingParameters for this object

RealtimeThread

public RealtimeThread(SchedulingParameters scheduling,
                      ReleaseParameters releaseParameters)

Constructor

Parameters:

scheduling - the SchedulingParameters for this object

releaseParameters - the ReleaseParameters for this object

RealtimeThread

public RealtimeThread(SchedulingParameters scheduling,
                      ReleaseParameters releaseParameters,
                      MemoryParameters memoryParameters,
                      MemoryArea memoryArea,
                      ProcessingGroupParameters processingGroup,
                      java.lang.Runnable logic)

Constructor

Parameters:

scheduling - the SchedulingParameters for this object

releaseParameters - the ReleaseParameters for this object

memoryParameters - the MemoryParameters for this object

memoryArea - the MemoryArea for this object

processingGroup - the ProcessingGroupParameters for this object

logic - the Runnable code for this object

RealtimeThread

public RealtimeThread(java.lang.String name,
                      SchedulingParameters scheduling)

Constructor

Parameters:

name - the String name of this object

scheduling - the SchedulingParameters for this object

RealtimeThread

public RealtimeThread(java.lang.String name,
                      SchedulingParameters scheduling,
                      ReleaseParameters releaseParameters)

Constructor

Parameters:

name - the String name of this object

scheduling - the SchedulingParameters for this object

releaseParameters - the ReleaseParameters for this object

RealtimeThread

public RealtimeThread(java.lang.String name,
                      SchedulingParameters scheduling,
                      ReleaseParameters releaseParameters,
                      MemoryParameters memoryParameters,
                      MemoryArea memoryArea,
                      ProcessingGroupParameters processingGroup,
                      java.lang.Runnable logic)

Constructor

Parameters:

name - the String name of this object

scheduling - the SchedulingParameters for this object

releaseParameters - the ReleaseParameters for this object

memoryParameters - the MemoryParameters for this object

memoryArea - the MemoryArea for this object

processingGroup - the ProcessingGroupParameters for this object

logic - the Runnable code for this object

Method Detail

body

public abstract void body()
                   throws java.lang.InterruptedException,
                          ThreadTerminatedException

Where all the application work gets done. Analogous to Thread.run(), but that method is used as a wrapper RealtimeThread to initialize, passivate and clean up this RealtimeThread. Must be overridden in subclass.

Throws:

java.lang.InterruptedException - thrown if a wait() is interrupted

ThreadTerminatedException - thrown if a simulation shutdown occurs while this thread has not yet terminated

run

public void run()

The run() method of this thread.

Specified by:

run in interface java.lang.Runnable

dynamicPriority

public int dynamicPriority()

Compute dynamic priority of this . All resources held must be examined, since they can induce temporary priority elevation, in the cases of priority inheritance and priority ceiling.

Returns:

the dynamic priority

initialize

public void initialize()

Start this thread, and wait until it has actually started.

toString

public java.lang.String toString()

Construct a string representation of this thread.

Returns:

the string representation

exit

public void exit()

Exit a run method.

addToFeasibility

public boolean addToFeasibility()

Add this thread to the current scheduler's feasibility set

Specified by:

addToFeasibility in interface Schedulable

Returns:

true if the resulting system is feasible

Not currently implemented

getMemoryParameters

public MemoryParameters getMemoryParameters()

Set this thread's memory parameters

Specified by:

getMemoryParameters in interface Schedulable

Returns:

the MemoryParameters of this object.

getProcessingGroupParameters

public ProcessingGroupParameters getProcessingGroupParameters()

Get this thread's processing group parameters

Specified by:

getProcessingGroupParameters in interface Schedulable

Returns:

the ProcessingGroupParameters of this object.

getReleaseParameters

public ReleaseParameters getReleaseParameters()

Get this thread's release parameters

Specified by:

getReleaseParameters in interface Schedulable

Returns:

the ReleaseParameters of this object.

getScheduler

public Scheduler getScheduler()

Get this thread's scheduler

Specified by:

getScheduler in interface Schedulable

Returns:

the current scheduler

getSchedulingParameters

public SchedulingParameters getSchedulingParameters()

Get this thread's scheduling parameters

Specified by:

getSchedulingParameters in interface Schedulable

Returns:

the current scheduling parameters

getBasePriority

public int getBasePriority()

removeFromFeasibility

public boolean removeFromFeasibility()

Remove this thread from its scheduler's feasibility set

Specified by:

removeFromFeasibility in interface Schedulable

Returns:

true if the resulting system is feasible

Not currently implemented

setMemoryParameters

public void setMemoryParameters(MemoryParameters memoryParameters)

Set this thread's memory parameters

Specified by:

setMemoryParameters in interface Schedulable

Parameters:

memoryParameters -

setMemoryParametersIfFeasible

public boolean setMemoryParametersIfFeasible(MemoryParameters memoryParameters)

Set this thread's memory parameters if it would still be feasible given that change

Specified by:

setMemoryParametersIfFeasible in interface Schedulable

Parameters:

memoryParameters -

Not currently implemented

Returns:

true if the resulting system is feasible.

setProcessingGroupParameters

public void setProcessingGroupParameters(ProcessingGroupParameters processingGroup)

Set this thread's processing group parameters

Specified by:

setProcessingGroupParameters in interface Schedulable

Parameters:

processingGroup -

setProcessingGroupParametersIfFeasible

public boolean setProcessingGroupParametersIfFeasible(ProcessingGroupParameters groupParameters)

Set this thread's processing group parameters if it would still be feasible given that change

Specified by:

setProcessingGroupParametersIfFeasible in interface Schedulable

Parameters:

groupParameters -

Returns:

true if the resulting system is feasible

Not currently implemented

setReleaseParameters

public void setReleaseParameters(ReleaseParameters releaseParameters)

Set this thread's release parameters

Specified by:

setReleaseParameters in interface Schedulable

Parameters:

releaseParameters -

setReleaseParametersIfFeasible

public boolean setReleaseParametersIfFeasible(ReleaseParameters releaseParameters)

Set this thread's release parameters if it would still be feasible given that change

Specified by:

setReleaseParametersIfFeasible in interface Schedulable

Parameters:

releaseParameters -

Returns:

true if the resulting system is feasible

Not currently implemented

setScheduler

public void setScheduler(Scheduler scheduler)
                  throws java.lang.IllegalThreadStateException

Set this thread's scheduler

Specified by:

setScheduler in interface Schedulable

Parameters:

scheduler -

Throws:

java.lang.IllegalStateException

java.lang.IllegalThreadStateException

setScheduler

public void setScheduler(Scheduler scheduler,
                         SchedulingParameters scheduling,
                         ReleaseParameters releaseParameters,
                         MemoryParameters memoryParameters,
                         ProcessingGroupParameters processingGroup)
                  throws java.lang.IllegalThreadStateException

Set all the following parameters of this thread:

Specified by:

setScheduler in interface Schedulable

Parameters:

scheduler -

scheduling -

releaseParameters -

memoryParameters -

processingGroup -

Throws:

IllegalThreadstateException

java.lang.IllegalThreadStateException

setSchedulingParameters

public void setSchedulingParameters(SchedulingParameters scheduling)

Set this RealtimeThread's scheduling parameters

Specified by:

setSchedulingParameters in interface Schedulable

Parameters:

scheduling - The new scheduling parameters

setSchedulingParametersIfFeasible

public boolean setSchedulingParametersIfFeasible(SchedulingParameters scheduling)

Set this thread's scheduling parameters if it would still be feasible given that change

Specified by:

setSchedulingParametersIfFeasible in interface Schedulable

Parameters:

scheduling -

Returns:

true if the resulting system is feasible

Not currently implemented

isActive

public boolean isActive()

Tests whether this RealtimeThread is running or scheduled to run later.

Returns:

true iff this RealtimeThread is active

printResourcesHeld

public void printResourcesHeld()

printAllStatistics

public static void printAllStatistics()

notifyPriorityChange

public void notifyPriorityChange(int oldPriority,
                                 int newPriority)

averagePriority

public double averagePriority()

printStatistics

public void printStatistics()

getLastWaitStart

public AbsoluteTime getLastWaitStart()

printTimes

public void printTimes()

setLastWaitStart

public void setLastWaitStart()

addToWaitTime

public void addToWaitTime(RelativeTime time)