NAME

SYNOPSIS

void
watchdog_fn(void *private, u_int cmd, int *error);

EVENTHANDLER_REGISTER(watchdog_list, watchdog_fn, private, 0);

EVENTHANDLER_DEREGISTER(watchdog_list, eventhandler_tag);

DESCRIPTION

The function must examine the cmd argument and act on it as follows:

If cmd is zero, the watchdog must be disabled and the error argument left untouched. If the watchdog cannot be disabled, the error argument must be set to EOPNOTSUPP.

Else the watchdog should be reset and configured to a timeout of (1 << (cmd & WD_INTERVAL)) nanoseconds or larger and the error argument be set to zero to signal arming of a watchdog.

If the watchdog cannot be configured to the proposed timeout, it must be disabled and the error argument left as is (to avoid hiding the arming of another watchdog).

There is no specification of what the watchdog should do when it times out, but a hardware reset or similar “drastic but certain” behaviour is recommended.

SEE ALSO

AUTHORS