Getting Started with QNX Neutrino - QNX Software Systems

Clocks and timers
© 2009, QNX Software Systems GmbH & Co. KG.
Note that the sigev_coid could be a connection to any channel (usually, though not
necessarily, the channel associated with the process that’s initiating the event).
Signal notification
To send a signal, set the sigev_notify field to one of:
SIGEV_SIGNAL
Send a regular signal to the process.
SIGEV_SIGNAL_CODE
Send a signal containing an 8-bit code to the process.
SIGEV_SIGNAL_THREAD
Send a signal containing an 8-bit code to a specific thread.
For SIGEV_SIGNAL*, the additional fields you’ll have to fill are:
Field
sigev_signo
sigev_code
Value and meaning
Signal number to send (from , e.g., SIGALRM).
An 8-bit code (if using SIGEV_SIGNAL_CODE or
SIGEV_SIGNAL_THREAD).
Thread notification
To create a thread whenever the timer fires, set the sigev_notify field to
SIGEV_THREAD and fill these fields:
Field
sigev_notify_function
sigev_value
sigev_notify_attributes
Value and meaning
Address of void * function that accepts a void * to be
called when the event triggers.
Value passed as the parameter to the
sigev_notify_function() function.
Thread attributes structure (see the Processes and Threads
chapter, under “The thread attributes structure” for
details).
144 Chapter 3 • Clocks, Timers, and Getting a Kick Every So Often April 30, 2009