NAME

       hal_export_funct - create a realtime function callable from a thread

SYNTAX

       typedef void(*hal_funct_t)(void * arg, long period)

       int  hal_export_funct(const  char  *name,  hal_funct_t  funct, void *arg, int uses_fp, int reentrant, int
              comp_id)

ARGUMENTS

       name   The name of the function.

       funct  The pointer to the function

       arg    The argument to be passed as the first parameter of funct

       uses_fp
              Nonzero if the function uses floating-point operations, including  assignment  of  floating  point
              values with "=".

       reentrant
              If  reentrant  is  non-zero,  the function may be preempted and called again before the first call
              completes.  Otherwise, it may only be added to one thread.

       comp_id
              A HAL component identifier returned by an earlier call to hal_init.

DESCRIPTION

       hal_export_funct makes a realtime function provided by a component available to the system.  A subsequent
       call to hal_add_funct_to_thread can be used to schedule the execution of the function as  needed  by  the
       system.

       When  this  function  is  placed on a HAL thread, and HAL threads are started, funct is called repeatedly
       with two arguments: void *arg is the same value that was given to hal_export_funct, and  long  period  is
       the interval between calls in nanoseconds.

       Each call to the function should do a small amount of work and return.

RETURN VALUE

       Returns a HAL status code.

SEE ALSO

       hal_create_thread(3hal), hal_add_funct_to_thread(3hal)

LinuxCNC Documentation                             2006-10-12                             hal_export_funct(3hal)