w_start Kernel Service
Purpose
Starts a watchdog timer.
Syntax
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/watchdog.h>
void w_start ( w)
struct watchdog *w;Parameter
| Item | Description |
|---|---|
| w | Specifies the watchdog timer structure. |
Description
The watchdog timers, including the w_start kernel
service, are typically used to verify that an I/O operation completes in a reasonable time. The
w_start and w_stop kernel services are designed to allow the
timer to be started and stopped efficiently. The kernel decrements the
w->count watchdog count every second. The kernel calls the
w->func watchdog timer function when the
w->count watchdog count reaches 0. A watchdog timer is
ignored when the w->count watchdog count is less than or
equal to 0.
The w_start kernel
service sets the w->count watchdog count to a value
of w->restart.
Attention: The watchdog structure must be pinned when the w_start kernel service
is called. It must remain pinned until after the call to the
w_clear kernel service. During this time, the watchdog structure must not be altered
except by the watchdog services.Execution Environment
The w_start kernel service can be called from the process and interrupt environments.
Return Values
The w_start kernel service has no return values.