Orocos: PeriodicThread Class Reference

It has a fixed priority, a name and a (changable) periodicity. The common methods to use are start() and stop().

Step() Overruns are detected and the threshold to 'emergency stop' the thread can be set by setMaxOverrun(). Overruns must be accumulated 'on average' to trigger this behavior: one not overrunning step() compensates for one overrunning step().


Public Types
typedef double	Seconds
typedef long	secs
typedef long	msecs
typedef long long	nsecs
Public Member Functions
	PeriodicThread (int priority, const std::string &name, double period, OS::RunnableInterface *r=0)
	Create a Thread with a given priority and a name.
	PeriodicThread (int scheduler, int priority, const std::string &name, double period, OS::RunnableInterface *r=0)
	Create a Thread with a given scheduler type, priority and a name.
virtual bool	run (OS::RunnableInterface *r)
	Run the functionality of one RunnableInterface object.
virtual bool	start ()
	Start the thread.
virtual bool	stop ()
	Stop the thread.
bool	setPeriod (Seconds s)
	Set the periodicity of this thread in seconds.
bool	setPeriod (secs s, nsecs ns)
	Set the periodicity of this thread (seconds, nanoseconds).
void	getPeriod (secs &s, nsecs &ns) const
	Get the periodicity of this thread (seconds, nanoseconds).
virtual Seconds	getPeriod () const
	Get the periodicity of this thread in seconds.
virtual nsecs	getPeriodNS () const
	Get the periodicity of this thread in nano-seconds.
virtual bool	isRunning () const
	Returns whether the thread is running.
virtual const char *	getName () const
	Read the name of this task.
virtual RTOS_TASK *	getTask ()
	Get the RTOS_TASK pointer FIXME should this be a const?
virtual bool	setScheduler (int sched_type)
	Change the scheduler policy in which this thread runs.
virtual int	getScheduler () const
	Get the scheduler policy in which this thread runs.
bool	setPeriod (TIME_SPEC p)
	Set the periodicity of this thread.
virtual bool	setPriority (int priority)
	Set the priority of this Thread.
virtual int	getPriority () const
	The priority of this Thread.
virtual void	yield ()
	Yields (but to the back of the scheduler queue) the calling thread.
void	setMaxOverrun (int m)
int	getMaxOverrun () const
void	terminate ()
	Exit and destroy the thread.
void	emergencyStop ()
unsigned int	threadNumber () const
	The unique thread number.
Protected Member Functions
virtual void	continuousStepping (bool yes_no)
virtual bool	setToStop ()
	Use this from within step() to stop this thread.
virtual void	step ()
virtual bool	initialize ()
virtual void	finalize ()
Protected Attributes
int	threadnb
	Threads are given an unique number, which follows thread creation order.
Friends
void *	periodicThread (void *t)

Constructor & Destructor Documentation

PeriodicThread	(	int	priority,
		const std::string &	name,
		double	period,
		OS::RunnableInterface *	r = `0`
	)

Create a Thread with a given priority and a name.

Parameters:

	priority	The priority of the thread, with zero being the highest, 99 being the lowest.
	name	The name of the Thread.
	period	The period in seconds (eg 0.001) of the thread.
	r	The optional RunnableInterface instance to run. If not present, the thread's own virtual functions are executed.

PeriodicThread	(	int	scheduler,
		int	priority,
		const std::string &	name,
		double	period,
		OS::RunnableInterface *	r = `0`
	)

Create a Thread with a given scheduler type, priority and a name.

Parameters:

	scheduler	The scheduler, one of ORO_SCHED_RT or ORO_SCHED_OTHER.
	priority	The priority of the thread, with zero being the highest, 99 being the lowest.
	name	The name of the Thread.
	period	The period in seconds (eg 0.001) of the thread.
	r	The optional RunnableInterface instance to run. If not present, the thread's own virtual functions are executed.

Member Function Documentation

virtual bool run ( OS::RunnableInterface * r ) [virtual]

Run the functionality of one RunnableInterface object.

Only one RunnableInterface object can be run, the old one is disconnected.

Parameters:

The object to run or zero to clear.

Returns:: true if accepted, false if the thread is running.

Implements ThreadInterface.

virtual bool setScheduler ( int sched_type ) [virtual]

Change the scheduler policy in which this thread runs.

Parameters:

sched_type

An OS-specific value which selects a scheduler. Orocos requires that these two values are available:

ORO_SCHED_RT: Hint the OS that this thread should be scheduled as a priority or real-time process.
ORO_SCHED_OTHER: Hint the OS that this thread should not be scheduled as a priority or real-time process.

Your OS can in addition provide other sched_type's which map more naturally to the schedulers present. If your OS does not make a distinction between real-time and other, both values may map to the same scheduler type.

Returns:: true if the change could be made.

Implements ThreadInterface.

virtual int getScheduler ( ) const [virtual]

Get the scheduler policy in which this thread runs.

Returns:: An OS-specific value which represents the used scheduler.

See also:: setScheduler

Implements ThreadInterface.

virtual bool setPriority ( int priority ) [virtual]

Set the priority of this Thread.

Parameters:

priority

The priority given upon construction of this thread. It has to be interpreted in the current OS scheduler.

See also:: setScheduler

Implements ThreadInterface.

virtual int getPriority ( ) const [virtual]

The priority of this Thread.

Returns:: The priority given upon construction of this thread or set with setPriority. The returned number has to be interpreted in the current OS scheduler.

See also:: setScheduler

Implements ThreadInterface.

void terminate ( )

Exit and destroy the thread.

Precondition:: this is only called from within the destructor.

Postcondition:: the thread does no longer exist.

virtual bool setToStop ( ) [protected, virtual]

Use this from within step() to stop this thread.

This function will call finalize() as well, thus it is advised to call this function as the last statement in your step().

Member Data Documentation

int threadnb [protected, inherited]

Threads are given an unique number, which follows thread creation order.

See also:: OS::threads

PeriodicThread Class Reference

Detailed Description

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation