#include <FileDescriptorActivity.hpp>

Inheritance diagram for RTT::extras::FileDescriptorActivity:

Public Member Functions
virtual bool	breakLoop ()
void	clearAllWatches ()
	FileDescriptorActivity (int priority, base::RunnableInterface *_r=0, const std::string &name="FileDescriptorActivity")
	FileDescriptorActivity (int scheduler, int priority, base::RunnableInterface *_r=0, const std::string &name="FileDescriptorActivity")
int	getTimeout () const
bool	hasError () const
bool	hasTimeout () const
bool	isRunning () const
bool	isUpdated (int fd) const
bool	isWatched (int fd) const
virtual void	loop ()
void	setTimeout (int timeout)
virtual bool	start ()
virtual void	step ()
virtual bool	stop ()
virtual bool	trigger ()
void	unwatch (int fd)
void	watch (int fd)
virtual	~FileDescriptorActivity ()
Private Member Functions
void	triggerUpdateSets ()
Private Attributes
fd_set	m_fd_set
fd_set	m_fd_work
bool	m_has_error
bool	m_has_timeout
int	m_interrupt_pipe [2]
RTT::os::Mutex	m_lock
bool	m_running
int	m_timeout
std::set< int >	m_watched_fds
Static Private Attributes
static const char	CMD_BREAK_LOOP = 0
static const char	CMD_TRIGGER = 1
static const char	CMD_UPDATE_SETS = 2

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. 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.

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.

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.

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.

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.

Definition at line 97 of file FileDescriptorActivity.cpp.

FileDescriptorActivity::~FileDescriptorActivity ( ) [virtual]

Definition at line 106 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 FileDescriptorActivity::clearAllWatches ( )

Remove all FDs that are currently being watched

Definition at line 135 of file FileDescriptorActivity.cpp.

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 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.

bool FileDescriptorActivity::isWatched ( int fd ) const

True if this specific FD is being watched by the activity

Definition at line 153 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.

void FileDescriptorActivity::setTimeout ( int timeout )

Sets the timeout, in milliseconds, for waiting on the IO. Set to 0 for blocking behaviour (no timeout).

Definition at line 115 of file FileDescriptorActivity.cpp.

bool FileDescriptorActivity::start ( ) [virtual]

Start the activity. This will call RunnableInterface::initialize() and upon success, effectively start the activity, by running the RunnableInterface::step() or RunnableInterface::loop() in a thread.

See also:: isPeriodic()

Returns:: true if the activity is started, false otherwise

Reimplemented from RTT::Activity.

Definition at line 157 of file FileDescriptorActivity.cpp.

void FileDescriptorActivity::step ( ) [virtual]

Called by loop() when data is available on the file descriptor. By default, it calls step() on the associated runner interface (if any)

Reimplemented from RTT::Activity.

Definition at line 296 of file FileDescriptorActivity.cpp.

bool FileDescriptorActivity::stop ( ) [virtual]

Stop the activity This will stop the activity by removing it from the 'run-queue' of a thread or call RunnableInterface::breakLoop(). If no errors occured, RunnableInterface::finalize() is called.