HAL_SIGNAL_NEW(3)

NAME
hal_signal_new, hal_signal_delete, hal_link, hal_unlink - Manipulate HAL signals

SYNTAX

int hal_signal_new(const char* signal_name, hal_type_t type)

int hal_signal_delete(const char* signal_name)

int hal_link(const char* pin_name, const char* signal_name)

int hal_unlink(const char* pin_name)

ARGUMENTS

signal_name
    The name of the signal.

pin_name
    The name of the pin.

type
    The type of the signal, as specified in hal_type_t(3).

DESCRIPTION

hal_signal_new creates a new signal object. Once a signal has been created, pins can be linked to it with hal_link. The signal object contains the actual storage for the signal data. Pin objects linked to the signal have pointers that point to the data. name is the name of the new signal. It may be no longer than HAL_NAME_LEN characters. If there is already a signal with the same name the call will fail.

hal_link links a pin to a signal. If the pin is already linked to the desired signal, the command succeeds. If the pin is already linked to some other signal, it is an error. In either case, the existing connection is not modified. (Use hal_unlink to break an existing connection.) If the signal already has other pins linked to it, they are unaffected - one signal can be linked to many pins, but a pin can be linked to only one signal.

hal_unlink unlinks any signal from the specified pin.

hal_signal_delete deletes a signal object. Any pins linked to the object are unlinked.

RETURN VALUE

Returns a HAL status code.

SEE ALSO

hal_type_t(3)