SingleThread Class Reference

#include </home/sspr/src/www/orocos-1.0/export/build/orocos-rtt-1.2.2/build/rtt/os/SingleThread.hpp>

Inheritance diagram for SingleThread:

List of all members.

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Detailed Description

This Thread abstraction class represents a single-shot thread which can be started many times.

The first invocation of start() invokes the initialize() function and runs the loop() method in the thread. When loop() returns the thread waits for another start() to execute loop() again. When stop() is called when the thread is still executing loop() and breakLoop() returns true (not the default), the stop() function succeeds and the finalize() method is called by stop(). A next invocation of start() will again call initialize() before loop() is executed and so on. The user must provide an implementation of breakLoop() returning true to make stop() work while loop() is being executed. stop() will not execute finalize() if the thread executes loop() and breakLoop() is not reimplemented to return true. If the thread was not executing loop(), stop will always call finalize() and return success.

When a RunnableInterface object is given, the above methods initialize(), loop(), breakLoop() and finalize() are called on that object instead of on the SingleThread's virtual functions.

See also:

RunnableInterface

Public Types
typedef double	Seconds
typedef long	secs
typedef long	msecs
typedef long long	nsecs
Public Member Functions
	SingleThread (int priority, const std::string &name, OS::RunnableInterface *r=0)
	Create a single-shot Thread with priority priority, a name and optionally, an object to execute.
	SingleThread (int scheduler, int priority, const std::string &name, OS::RunnableInterface *r=0)
	Create a single-shot Thread with priority priority, a name and optionally, an object to execute.
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.
virtual bool	isRunning () const
	Returns whether the thread is running.
virtual bool	isActive () const
	Returns whether the thread is active.
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.
virtual Seconds	getPeriod () const
	Get the periodicity in Seconds.
virtual nsecs	getPeriodNS () const
	Get the periodicity in nanoseconds.
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.
unsigned int	threadNumber () const
	The unique thread number.
Protected Member Functions
virtual bool	breakLoop ()
virtual void	loop ()
virtual bool	initialize ()
virtual void	finalize ()
Protected Attributes
int	threadnb
	Threads are given an unique number, which follows thread creation order.
Friends
void *	singleThread_f (void *t)

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Constructor & Destructor Documentation

SingleThread	(	int	priority,
		const std::string &	name,
		OS::RunnableInterface *	r = 0
	)

Create a single-shot Thread with priority priority, a name and optionally, an object to execute.

Parameters:

	priority	The priority of the thread, in the ORO_SCHED_RT domain.
	name	The name of the Thread.
	r	The optional RunnableInterface instance to run. If not present, the thread's own virtual functions are executed.

SingleThread	(	int	scheduler,
		int	priority,
		const std::string &	name,
		OS::RunnableInterface *	r = 0
	)

Create a single-shot Thread with priority priority, a name and optionally, an object to execute.

Parameters:

	scheduler	The scheduler, one of ORO_SCHED_RT or ORO_SCHED_OTHER.
	priority	The priority of the thread, in the scheduler domain.
	name	The name of the Thread.
	r	The optional RunnableInterface instance to run. If not present, the thread's own virtual functions are executed.

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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:

r

The object to run or zero to clear.

Returns:

true if accepted, false if the thread is running.

Implements ThreadInterface.

virtual bool start

(

)

[virtual]

Start the thread.

Postcondition:

if !this->isRunning(), then execute initialize() and execute loop() in the thread.

if this->isRunning(), then schedule a start of loop() in the thread.

this->isRunning is true

Returns:

true if successfull.

Implements ThreadInterface.

Reimplemented in NonPeriodicActivity.

virtual bool stop

(

)

[virtual]

Stop the thread.

The return value of stop, is the same as the return value of RunnableInterface::breakLoop().

Precondition:

this->isRunning()

Postcondition:

if breakLoop() returns true, then execute finalize() and this->isRunning() == false

if breakLoop() returns false (the default), then do nothing.

Returns:

true if successfull.

Implements ThreadInterface.

Reimplemented in NonPeriodicActivity.

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 Seconds getPeriod

(

)

const [inline, virtual]

Get the periodicity in Seconds.

Return zero if non periodic.

Implements ThreadInterface.

Reimplemented in NonPeriodicActivity.

virtual nsecs getPeriodNS

(

)

const [inline, virtual]

Get the periodicity in nanoseconds.

Return zero if non periodic.

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.

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Member Data Documentation

int threadnb [protected, inherited]

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

See also:

OS::threads

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The documentation for this class was generated from the following file:

• rtt/os/SingleThread.hpp

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