An activity which is triggered by the availability of data on a set of file descriptors. More...

#include <rtt/extras/FileDescriptorActivity.hpp>

Inheritance diagram for RTT::extras::FileDescriptorActivity:

Public Types
typedef boost::shared_ptr < ActivityInterface >	shared_ptr
Public Member Functions
	FileDescriptorActivity (int priority, base::RunnableInterface *_r=0, const std::string &name="FileDescriptorActivity")
	Create a FileDescriptorActivity with a given priority and base::RunnableInterface instance.
	FileDescriptorActivity (int scheduler, int priority, base::RunnableInterface *_r=0, const std::string &name="FileDescriptorActivity")
	Create a FileDescriptorActivity with a given scheduler type, priority and base::RunnableInterface instance.
bool	isRunning () const
	Query if the activity is initialized and executing.
void	watch (int fd)
	Sets the file descriptor the activity should be listening to.
void	unwatch (int fd)
	Removes a file descriptor from the set of watched FDs.
void	clearAllWatches ()
	Remove all FDs that are currently being watched.
bool	isWatched (int fd) const
	True if this specific FD is being watched by the activity.
bool	isUpdated (int fd) const
	True if this specific FD has new data.
bool	hasTimeout () const
	True if the base::RunnableInterface has been triggered because of a timeout, instead of because of new data is available.
bool	hasError () const
	True if one of the file descriptors has a problem (for instance it has been closed)
void	setTimeout (int timeout)
	Sets the timeout, in milliseconds, for waiting on the IO.
int	getTimeout () const
	Get the timeout, in milliseconds, for waiting on the IO.
virtual bool	start ()
	Start the activity.
virtual void	loop ()
virtual bool	breakLoop ()
virtual bool	stop ()
	Stop the activity This will stop the activity by removing it from the 'run-queue' of a thread or call RunnableInterface::breakLoop().
virtual void	step ()
	Called by loop() when data is available on the file descriptor.
virtual bool	trigger ()
	Force calling step() even if no data is available on the file descriptor, and returns true if the signalling was successful.
virtual bool	execute ()
	Execute this activity such that it executes a step or loop of the RunnableInterface.
virtual bool	isActive () const
	Query if the activity is started.
virtual bool	isPeriodic () const
	Inspect if this activity is periodic.
virtual Seconds	getPeriod () const
	Get the periodicity of this activity in Seconds.
void	getPeriod (secs &s, nsecs &ns) const
	Get the periodicity of this thread (seconds, nanoseconds)
virtual bool	setPeriod (Seconds period)
	Set the periodicity of this activity in Seconds.
bool	setPeriod (secs s, nsecs ns)
	Set the periodicity of this thread (seconds, nanoseconds)
bool	setPeriod (TIME_SPEC p)
	Set the periodicity of this thread.
virtual unsigned	getCpuAffinity () const
	Get the cpu affinity of this activity.
virtual bool	setCpuAffinity (unsigned cpu)
	Set the cpu affinity of this activity.
virtual os::ThreadInterface *	thread ()
	Returns a pointer to the thread which will run this activity.
virtual bool	initialize ()
virtual void	finalize ()
virtual bool	run (RunnableInterface *r)
	Run exclusively this RunnableInterface.
virtual nsecs	getPeriodNS () const
	Get the periodicity in nanoseconds.
virtual const char *	getName () const
	Read the name of this task.
virtual RTOS_TASK *	getTask ()
	Get the RTOS_TASK pointer.
virtual const RTOS_TASK *	getTask () const
	const version of the above.
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 bool	setPriority (int priority)
	Set the priority of this Thread.
virtual int	getPriority () const
	The priority of this Thread.
virtual unsigned int	getPid () const
	Returns the Process or Thread ID of this thread, as assigned by the Operating System.
virtual void	yield ()
	Yields (put to the back of the scheduler queue) the calling thread.
virtual void	setMaxOverrun (int m)
virtual int	getMaxOverrun () const
virtual void	setWaitPeriodPolicy (int p)
	Set the wait policy of a periodic thread.
unsigned int	threadNumber () const
	The unique thread number (within the same process).
bool	isSelf () const
Static Public Member Functions
static void	setStackSize (unsigned int ssize)
	Sets the stack size of the threads to be created.
Protected Member Functions
void	disableRun (RunnableInterface *caller)
	This method is only meant for RunnableInterface (ie runner) in order to inform the ActivityInterface it should no longer be used.
void	terminate ()
	Exit and destroy the thread.
void	emergencyStop ()
Protected Attributes
RunnableInterface *	runner
int	threadnb
	Threads are given an unique number, which follows thread creation order.
Friends
class	RunnableInterface

Detailed Description

An activity which is triggered by the availability of data on a set of file descriptors.

step() (and hence the base::RunnableInterface's step() method) is called when data is available or when an error is encountered on the file descriptor.

To use it, one must add the file descriptors to watch in the task's configureHook()

FileDescriptorActivity* fd_activity = dynamic_cast<FileDescriptorActivity*>(getActivity().get()); if (fd_activity) { fd_activity->watch(device_fd); // optional, set a timeout in milliseconds fd_activity->setTimeout(1000); }

Then, updateHook() and -- when in ERROR state -- errorHook() will be called when one of these three events happen:

new data is available on one of the watched FDs
an error happens on one of the watched FDs
the timeout is reached

The different cases can be tested in updateHook() as follows:

FileDescriptorActivity* fd_activity = dynamic_cast<FileDescriptorActivity*>(getActivity().get()); if (fd_activity) { if (fd_activity->hasError()) { } else if (fd_activity->hasTimeout()) { } else { // If there is more than one FD, discriminate. Otherwise, // we don't need to use isUpdated if (fd_activity->isUpdated(device_fd)) { } else if (fd_activity->isUpdated(another_fd)) { } } }

Definition at line 101 of file FileDescriptorActivity.hpp.

Constructor & Destructor Documentation

FileDescriptorActivity::FileDescriptorActivity	(	int	priority,
		base::RunnableInterface *	_r = `0`,
		const std::string &	name = `"FileDescriptorActivity"`
	)

Create a FileDescriptorActivity with a given priority and base::RunnableInterface instance.

Create a FileDescriptorActivity with a given priority and RunnableInterface instance.

The default scheduler for NonPeriodicActivity objects is ORO_SCHED_RT.

Parameters:

priority	The priority of the underlying thread.
_r	The optional runner, if none, this->loop() is called.
name	The name of the underlying thread.

The default scheduler for NonPeriodicActivity objects is ORO_SCHED_RT.

Parameters:

priority	The priority of the underlying thread.
_r	The optional runner, if none, this->loop() is called.

Definition at line 79 of file FileDescriptorActivity.cpp.

FileDescriptorActivity::FileDescriptorActivity	(	int	scheduler,
		int	priority,
		base::RunnableInterface *	_r = `0`,
		const std::string &	name = `"FileDescriptorActivity"`
	)

Create a FileDescriptorActivity with a given scheduler type, priority and base::RunnableInterface instance.

Create a FileDescriptorActivity with a given scheduler type, priority and RunnableInterface instance.

Parameters:

scheduler	The scheduler in which the activitie's thread must run. Use ORO_SCHED_OTHER or ORO_SCHED_RT.
priority	The priority of the underlying thread.
_r	The optional runner, if none, this->loop() is called.
name	The name of the underlying thread.
scheduler	The scheduler in which the activitie's thread must run. Use ORO_SCHED_OTHER or ORO_SCHED_RT.
priority	The priority of the underlying thread.
_r	The optional runner, if none, this->loop() is called.

Definition at line 97 of file FileDescriptorActivity.cpp.

Member Function Documentation

bool FileDescriptorActivity::breakLoop ( ) [virtual]

See also:: base::RunnableInterface::breakLoop()

Reimplemented from RTT::Activity.

Definition at line 285 of file FileDescriptorActivity.cpp.

void RTT::base::ActivityInterface::disableRun ( RunnableInterface * caller ) [inline, protected, inherited]

This method is only meant for RunnableInterface (ie runner) in order to inform the ActivityInterface it should no longer be used.

run(0) can not be used in this case because it would recurse.

Definition at line 73 of file ActivityInterface.hpp.

Referenced by RTT::base::RunnableInterface::setActivity(), and RTT::base::RunnableInterface::~RunnableInterface().

bool RTT::Activity::execute ( ) [virtual, inherited]

Execute this activity such that it executes a step or loop of the RunnableInterface.

When you invoke execute() you intend to call the step() or loop() methods. Some activity implementations allow a user controlled execute, others ignore it, in which case execute() returns false.

Semantics: If execute() returns true, the activity has been executed exactly once during execute().

Return values:

true	When this->isActive() and the implementation allows external executes.
false	When !this->isActive() or the implementation does not allow external updating.

See also:: trigger() for use in callbacks which want execute() to be executed.

Implements RTT::base::ActivityInterface.

Definition at line 131 of file Activity.cpp.

void RTT::Activity::finalize ( ) [virtual, inherited]

See also:: base::RunnableInterface::finalize()

Reimplemented from RTT::os::Thread.

Reimplemented in RTT::corba::OrbRunner.

Definition at line 113 of file Activity.cpp.

References RTT::base::RunnableInterface::finalize().

unsigned RTT::Activity::getCpuAffinity ( ) const [virtual, inherited]

Get the cpu affinity of this activity.

Returns:: The cpu affinity of this activity.

Implements RTT::base::ActivityInterface.

Definition at line 158 of file Activity.cpp.

Seconds RTT::Activity::getPeriod ( ) const [virtual, inherited]

Get the periodicity of this activity in Seconds.

Returns:: The execution period of this activity (zero if !this->isPeriodic() ).

Implements RTT::base::ActivityInterface.

Definition at line 143 of file Activity.cpp.

nsecs RTT::os::Thread::getPeriodNS ( ) const [virtual, inherited]

Get the periodicity in nanoseconds.

Return zero if non periodic.

Implements RTT::os::ThreadInterface.

Definition at line 583 of file Thread.cpp.

unsigned int RTT::os::Thread::getPid ( ) const [virtual, inherited]

Returns the Process or Thread ID of this thread, as assigned by the Operating System.

This function tries to return the Thread ID, if the OS supports it, otherwise it returns the process ID. If that is not available either, zero is returned. On Linux systems for example, the Thread ID of the main thread is equal to the Process ID. The Thread ID of every newly created thread is different from the Process ID (and unique).

Implements RTT::os::ThreadInterface.

Definition at line 598 of file Thread.cpp.

References RTT::os::rtos_task_get_pid().

int RTT::os::Thread::getPriority ( ) const [virtual, inherited]

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 RTT::os::ThreadInterface.

Definition at line 573 of file Thread.cpp.

References RTT::os::rtos_task_get_priority().

Referenced by RTT::extras::SimulationThread::SimulationThread().

int RTT::os::Thread::getScheduler ( ) const [virtual, inherited]

Get the scheduler policy in which this thread runs.

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

See also:: setScheduler

Implements RTT::os::ThreadInterface.

Definition at line 475 of file Thread.cpp.

References RTT::os::rtos_task_get_scheduler().

Referenced by RTT::os::Thread::setScheduler().

virtual RTOS_TASK* RTT::os::Thread::getTask ( ) [inline, virtual, inherited]

Get the RTOS_TASK pointer.

Note:: Using this function leads to non-portable code. It is here for users which wish to tweak OS specific thread settings.

Implements RTT::os::ThreadInterface.

Definition at line 174 of file Thread.hpp.

Referenced by RTT::os::thread_function().

int FileDescriptorActivity::getTimeout ( ) const

Get the timeout, in milliseconds, for waiting on the IO.

Set to 0 for blocking behaviour (no timeout).

Definition at line 113 of file FileDescriptorActivity.cpp.

bool FileDescriptorActivity::hasError ( ) const

True if one of the file descriptors has a problem (for instance it has been closed)

This should only be used from within the base::RunnableInterface this activity is driving, i.e. in TaskContext::updateHook() or TaskContext::errorHook().

Definition at line 149 of file FileDescriptorActivity.cpp.

bool FileDescriptorActivity::hasTimeout ( ) const

True if the base::RunnableInterface has been triggered because of a timeout, instead of because of new data is available.

This should only be used from within the base::RunnableInterface this activity is driving, i.e. in TaskContext::updateHook() or TaskContext::errorHook().

Definition at line 151 of file FileDescriptorActivity.cpp.

bool RTT::Activity::initialize ( ) [virtual, inherited]

See also:: base::RunnableInterface::initialize()

Reimplemented from RTT::os::Thread.

Reimplemented in RTT::corba::CorbaDispatcher, and RTT::mqueue::Dispatcher.

Definition at line 89 of file Activity.cpp.

References RTT::base::RunnableInterface::initialize().

bool RTT::Activity::isActive ( ) const [virtual, inherited]

Query if the activity is started.

This is less strict than isRunning(), it is true during initialize(), step() or loop() and finalize(). Use this method to check if an activity was start()ed.

Returns:: true if it is active, false otherwise

Implements RTT::base::ActivityInterface.

Definition at line 139 of file Activity.cpp.

Referenced by RTT::Activity::trigger().

bool RTT::Activity::isPeriodic ( ) const [virtual, inherited]

Inspect if this activity is periodic.

If so, it will call RunnableInterface::step(). If the activity is not periodic, it will call RunnableInterface::loop().

Returns:: true if periodic.

Implements RTT::base::ActivityInterface.

Definition at line 154 of file Activity.cpp.

bool FileDescriptorActivity::isRunning ( ) const [virtual]

Query if the activity is initialized and executing.

This is more strict than isActive(), it is only true after initialize() is executed and before finalize() is executed. More-over, an Activity may decide to be temporarily not running (not executing code), waiting for a signal to proceed. If this->isActive() and !this->isRunning() then the Activity is in a waiting state.

Returns:: true if it is running, false otherwise

Reimplemented from RTT::Activity.

Definition at line 111 of file FileDescriptorActivity.cpp.

bool FileDescriptorActivity::isUpdated ( int fd ) const

True if this specific FD has new data.

This should only be used from within the base::RunnableInterface this activity is driving, i.e. in TaskContext::updateHook() or TaskContext::errorHook().

Definition at line 147 of file FileDescriptorActivity.cpp.

void FileDescriptorActivity::loop ( ) [virtual]

See also:: base::RunnableInterface::loop()

Reimplemented from RTT::Activity.

Definition at line 188 of file FileDescriptorActivity.cpp.

References step().

bool ActivityInterface::run ( RunnableInterface * r ) [virtual, inherited]

Run exclusively this RunnableInterface.

Precondition:: this->isRunning() == false

Parameters:

r	The RunnableInterface to run exclusively.

Returns:: true if succeeded, false otherwise

Definition at line 57 of file ActivityInterface.cpp.

References RTT::base::ActivityInterface::isActive(), and RTT::base::RunnableInterface::setActivity().

Referenced by RTT::TaskContext::setActivity().

bool RTT::Activity::setCpuAffinity ( unsigned cpu ) [virtual, inherited]

Set the cpu affinity of this activity.

Returns:: true if it could be updated, false otherwise.

Implements RTT::base::ActivityInterface.

Definition at line 163 of file Activity.cpp.

bool RTT::Activity::setPeriod ( Seconds s ) [virtual, inherited]

Set the periodicity of this activity in Seconds.

Note that not all activity implementation support periods. A period of s == 0 indicates non periodic. A non supported setting returns false.

Returns:: true if it could be updated, false otherwise.

Implements RTT::base::ActivityInterface.

Definition at line 148 of file Activity.cpp.

bool RTT::os::Thread::setPriority ( int priority ) [virtual, inherited]

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 RTT::os::ThreadInterface.

Definition at line 563 of file Thread.cpp.

References RTT::os::rtos_task_set_priority().

bool RTT::os::Thread::setScheduler ( int sched_type ) [virtual, inherited]

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.