Machinekit

Machinekit

hal_export_funct

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
hal_add_funct_to_thread