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

Deprecated. All threads now unconditionally save and restore floating-point state, so this flag has no effect.

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)