Public Member Functions | Protected Member Functions

JoystickAcquisitionThread Class Reference

Joystick acqusition thread for Linux joystick API. More...

#include "acquisition_thread.h"

Inheritance diagram for JoystickAcquisitionThread:
Inheritance graph
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List of all members.

Public Member Functions

 JoystickAcquisitionThread ()
 Constructor.
 JoystickAcquisitionThread (const char *device_file, JoystickBlackBoardHandler *handler, fawkes::Logger *logger)
 Alternative constructor.
virtual void init ()
 Initialize the thread.
virtual void finalize ()
 Finalize the thread.
virtual void loop ()
 Code to execute in the thread.
bool lock_if_new_data ()
 Lock data if fresh.
void unlock ()
 Unlock data.
char num_axes () const
 Get number of axes.
char num_buttons () const
 Get number of buttons.
const char * joystick_name () const
 Get joystick name.
unsigned int pressed_buttons () const
 Pressed buttons.
float * axis_x_values ()
 Get values for X axes.
float * axis_y_values ()
 Get values for Y axes.

Protected Member Functions

virtual void run ()
 Stub to see name in backtrace for easier debugging.

Detailed Description

Joystick acqusition thread for Linux joystick API.

See also:
Linux Kernel Documentation (joystick-api.txt)
Author:
Tim Niemueller

Definition at line 49 of file acquisition_thread.h.


Constructor & Destructor Documentation

JoystickAcquisitionThread::JoystickAcquisitionThread (  ) 

Constructor.

Definition at line 74 of file acquisition_thread.cpp.

References fawkes::Thread::set_prepfin_conc_loop().

JoystickAcquisitionThread::JoystickAcquisitionThread ( const char *  device_file,
JoystickBlackBoardHandler handler,
fawkes::Logger logger 
)

Alternative constructor.

This constructor is meant to be used to create an instance that is used outside of Fawkes.

Parameters:
device_file joystick device file
handler BlackBoard handler that will post data to the BlackBoard
logger logging instance

Definition at line 91 of file acquisition_thread.cpp.

References init().


Member Function Documentation

float * JoystickAcquisitionThread::axis_x_values (  ) 

Get values for X axes.

Returns:
array of X axis values.

Definition at line 326 of file acquisition_thread.cpp.

Referenced by JoystickSensorThread::loop().

float * JoystickAcquisitionThread::axis_y_values (  ) 

Get values for Y axes.

Returns:
array of Y axis values.

Definition at line 336 of file acquisition_thread.cpp.

Referenced by JoystickSensorThread::loop().

void JoystickAcquisitionThread::finalize (  )  [virtual]

Finalize the thread.

This method is executed just before the thread is canceled and destroyed. It is always preceeded by a call to prepare_finalize(). If this is not the case this is a failure. The condition can be checked with the boolean variable finalize_prepared.

This method is meant to be used in conjunction with aspects and to cover thread inter-dependencies. This routine MUST bring the thread into a safe state such that it may be canceled and destroyed afterwards. If there is any reason that this cannot happen make your prepare_finalize() reports so.

This method is called by the thread manager just before the thread is being cancelled. Here you can do whatever steps are necessary just before the thread is cancelled. Note that you thread is still running and might be in the middle of a loop, so it is not a good place to give up on all resources used. Mind segmentation faults that could happen. Protect the area with a mutex that you lock at the beginning of your loop and free in the end, and that you lock at the beginning of finalize and then never unlock. Also not that the finalization may be canceled afterwards. The next thing that happens is that either the thread is canceled and destroyed or that the finalization is canceled and the thread has to run again.

Finalize is called on a thread just before it is deleted. It is guaranteed to be called on a fully initialized thread (if no exception is thrown in init()) (this guarantee holds in the Fawkes framework).

The default implementation does nothing besides throwing an exception if prepare_finalize() has not been called.

Exceptions:
Exception thrown if prepare_finalize() has not been called.
See also:
prepare_finalize()
cancel_finalize()

Reimplemented from fawkes::Thread.

Definition at line 180 of file acquisition_thread.cpp.

void JoystickAcquisitionThread::init (  )  [virtual]

Initialize the thread.

This method is meant to be used in conjunction with aspects. Some parts of the initialization may only happen after some aspect of the thread has been initialized. Implement the init method with these actions. It is guaranteed to be called just after all aspects have been initialized and only once in the lifetime of the thread. Throw an exception if any problem occurs and the thread should not run.

Just because your init() routine suceeds and everything looks fine for this thread does not automatically imply that it will run. If it belongs to a group of threads in a ThreadList and any of the other threads fail to initialize then no thread from this group is run and thus this thread will never run. In that situation finalize() is called for this very instance, prepare_finalize() however is not called.

See also:
Fawkes Thread Aspects

Reimplemented from fawkes::Thread.

Definition at line 106 of file acquisition_thread.cpp.

References fawkes::Exception::append(), fawkes::ConfigurableAspect::config, fawkes::Configuration::get_string(), and fawkes::Thread::name().

Referenced by JoystickAcquisitionThread().

const char * JoystickAcquisitionThread::joystick_name (  )  const

Get joystick name.

Returns:
joystick name

Definition at line 306 of file acquisition_thread.cpp.

bool JoystickAcquisitionThread::lock_if_new_data (  ) 

Lock data if fresh.

If new data has been received since get_distance_data() or get_echo_data() was called last the data is locked, no new data can arrive until you call unlock(), otherwise the lock is immediately released after checking.

Returns:
true if the lock was acquired and there is new data, false otherwise

Definition at line 261 of file acquisition_thread.cpp.

References fawkes::Mutex::lock(), and fawkes::Mutex::unlock().

Referenced by JoystickSensorThread::loop().

void JoystickAcquisitionThread::loop (  )  [virtual]

Code to execute in the thread.

Implement this method to hold the code you want to be executed continously. If you do not implement this method, the default is that the thread will exit. This is useful if you choose to only implement once().

Reimplemented from fawkes::Thread.

Definition at line 190 of file acquisition_thread.cpp.

References JoystickBlackBoardHandler::joystick_changed(), JoystickBlackBoardHandler::joystick_unplugged(), fawkes::Mutex::lock(), fawkes::Logger::log_warn(), fawkes::LoggingAspect::logger, fawkes::Thread::name(), and fawkes::Mutex::unlock().

char JoystickAcquisitionThread::num_axes (  )  const

Get number of axes.

Returns:
number of axes.

Definition at line 286 of file acquisition_thread.cpp.

Referenced by JoystickSensorThread::loop().

char JoystickAcquisitionThread::num_buttons (  )  const

Get number of buttons.

Returns:
number of buttons.

Definition at line 296 of file acquisition_thread.cpp.

Referenced by JoystickSensorThread::loop().

unsigned int JoystickAcquisitionThread::pressed_buttons (  )  const

Pressed buttons.

Returns:
bit field where each set bit represents a pressed button.

Definition at line 316 of file acquisition_thread.cpp.

Referenced by JoystickSensorThread::loop().

virtual void JoystickAcquisitionThread::run (  )  [inline, protected, virtual]

Stub to see name in backtrace for easier debugging.

See also:
Thread::run()

Reimplemented from fawkes::Thread.

Definition at line 75 of file acquisition_thread.h.

void JoystickAcquisitionThread::unlock (  ) 

Unlock data.

Definition at line 275 of file acquisition_thread.cpp.

References fawkes::Mutex::unlock().

Referenced by JoystickSensorThread::loop().


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