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

#include <rtt/extras/FileDescriptorActivityInterface.hpp>

Inheritance diagram for RTT::extras::FileDescriptorActivityInterface:

Public Member Functions
virtual	~FileDescriptorActivityInterface ()

virtual void	watch (int fd)=0
	Sets the file descriptor the activity should be listening to. More...

virtual void	unwatch (int fd)=0
	Removes a file descriptor from the set of watched FDs. More...

virtual void	clearAllWatches ()=0
	Remove all FDs that are currently being watched. More...

virtual bool	isWatched (int fd) const =0
	True if this specific FD is being watched by the activity. More...

virtual bool	isUpdated (int fd) const =0
	True if this specific FD has new data. More...

virtual bool	hasTimeout () const =0
	True if the base::RunnableInterface has been triggered because of a timeout, instead of because of new data is available. More...

virtual bool	hasError () const =0
	True if one of the file descriptors has a problem (for instance it has been closed) More...

virtual void	setTimeout (int timeout)=0
	Sets the timeout, in milliseconds, for waiting on the IO. More...

virtual void	setTimeout_us (int timeout_us)=0
	Sets the timeout, in microseconds, for waiting on the IO. More...

virtual int	getTimeout () const =0
	Get the timeout, in milliseconds, for waiting on the IO. More...

virtual int	getTimeout_us () const =0
	Get the timeout, in microseconds, for waiting on the IO. More...

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); // or in microseconds fd_activity->setTimeout_us(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 95 of file FileDescriptorActivityInterface.hpp.

Constructor & Destructor Documentation

virtual RTT::extras::FileDescriptorActivityInterface::~FileDescriptorActivityInterface ( )

inlinevirtual

Definition at line 98 of file FileDescriptorActivityInterface.hpp.

Member Function Documentation

virtual void RTT::extras::FileDescriptorActivityInterface::clearAllWatches ( )

pure virtual

Remove all FDs that are currently being watched.

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual int RTT::extras::FileDescriptorActivityInterface::getTimeout ( ) const

pure virtual

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

Set to 0 for blocking behaviour (no timeout).

Returns: The timeout (milliseconds)

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual int RTT::extras::FileDescriptorActivityInterface::getTimeout_us ( ) const

pure virtual

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

Set to 0 for blocking behaviour (no timeout).

Returns: The timeout (microseconds)

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual bool RTT::extras::FileDescriptorActivityInterface::hasError ( ) const

pure virtual

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().

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual bool RTT::extras::FileDescriptorActivityInterface::hasTimeout ( ) const

pure virtual

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().

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual bool RTT::extras::FileDescriptorActivityInterface::isUpdated ( int fd ) const

pure virtual

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().

Parameters

fd	the file descriptor

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual bool RTT::extras::FileDescriptorActivityInterface::isWatched ( int fd ) const

pure virtual

True if this specific FD is being watched by the activity.

Parameters

fd	the file descriptor

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual void RTT::extras::FileDescriptorActivityInterface::setTimeout ( int timeout )

pure virtual

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

Set to 0 for blocking behaviour (no timeout).

Precondition: 0 <= timeout (otherwise an error is logged and timeout is ignored)

Parameters

timeout The timeout (milliseconds)

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual void RTT::extras::FileDescriptorActivityInterface::setTimeout_us ( int timeout_us )

pure virtual

Sets the timeout, in microseconds, for waiting on the IO.

Set to 0 for blocking behaviour (no timeout).

Precondition: 0 <= timeout (otherwise an error is logged and timeout_us is ignored)

Parameters

timeout The timeout (microseconds)

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual void RTT::extras::FileDescriptorActivityInterface::unwatch ( int fd )

pure virtual

Removes a file descriptor from the set of watched FDs.

This method is thread-safe, i.e. it can be called from any thread

Parameters

fd	the file descriptor

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

virtual void RTT::extras::FileDescriptorActivityInterface::watch ( int fd )

pure virtual

Sets the file descriptor the activity should be listening to.

This method is thread-safe, i.e. it can be called from any thread

Parameters

fd	the file descriptor

Implemented in RTT::extras::FileDescriptorActivity, and RTT::extras::FileDescriptorSimulationActivity.

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

rtt/extras/FileDescriptorActivityInterface.hpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation