untimeout(9r)untimeout(9r)NAME
untimeout - General: Removes the scheduled routine from the callout queues
SYNOPSIS
boolean_t untimeout(
int (*function) (),
caddr_t argument );
ARGUMENTS
Specifies a pointer to the routine to be removed from the callout queues. Specifies a single argument to be passed to the called routine.
DESCRIPTION
The untimeout routine removes the scheduled routine from the callout queue. The specified routine was placed on the callout queue in a pre-
vious call to the timeout routine. The argument formal parameter must match the argument parameter you specified in the previous call to
timeout.
If the specified routine is not in the callout queue, untimeout returns without removing any scheduled routines.
RETURN VALUES
The untimeout routine returns the value TRUE on success and the value FALSE on failure.
SEE ALSO
Routines: timeout(9r)untimeout(9r)
Check Out this Related Man Page
untimeout(9F) Kernel Functions for Drivers untimeout(9F)NAME
untimeout - cancel previous timeout function call
SYNOPSIS
#include <sys/types.h>
#include <sys/conf.h>
clock_t untimeout(timeout_id_t id);
INTERFACE LEVEL
Architecture independent level 1 (DDI/DKI).
PARAMETERS
id Opaque timeout ID from a previous timeout(9F) call.
DESCRIPTION
The untimeout() function cancels a pending timeout(9F) request. untimeout() will not return until the pending callback is cancelled or has
run. Because of this, locks acquired by the callback routine should not be held across the call to untimeout() or a deadlock may result.
Since no mutex should be held across the call to untimeout(), there is a race condition between the occurrence of an expected event and the
execution of the timeout handler. In particular, it should be noted that no problems will result from calling untimeout() for a timeout
which is either running on another CPU, or has already completed. Drivers should be structured with the understanding that the arrival of
both an interrupt and a timeout for that interrupt can occasionally occur, in either order.
RETURN VALUES
The untimeout() function returns -1 if the id is not found. Otherwise, it returns an integer value greater than or equal to 0.
CONTEXT
The untimeout() function can be called from user, interrupt, or kernel context.
EXAMPLES
In the following example, the device driver has issued an IO request and is waiting for the device to respond. If the device does not
respond within 5 seconds, the device driver will print out an error message to the console.
static void
xxtimeout_handler(void *arg)
{
struct xxstate *xsp = (struct xxstate *)arg;
mutex_enter(&xsp->lock);
cv_signal(&xsp->cv);
xsp->flags |= TIMED_OUT;
mutex_exit(&xsp->lock);
xsp->timeout_id = 0;
}
static uint_t
xxintr(caddr_t arg)
{
struct xxstate *xsp = (struct xxstate *)arg;
.
.
.
mutex_enter(&xsp->lock);
/* Service interrupt */
cv_signal(&xsp->cv);
mutex_exit(&xsp->lock);
if (xsp->timeout_id != 0) {
(void) untimeout(xsp->timeout_id);
xsp->timeout_id = 0;
}
return(DDI_INTR_CLAIMED);
}
static void
xxcheckcond(struct xxstate *xsp)
{
.
.
.
xsp->timeout_id = timeout(xxtimeout_handler,
xsp, (5 * drv_usectohz(1000000)));
mutex_enter(&xsp->lock);
while (/* Waiting for interrupt or timeout*/)
cv_wait(&xsp->cv, &xsp->lock);
if (xsp->flags & TIMED_OUT)
cmn_err(CE_WARN, "Device not responding");
.
.
.
mutex_exit(&xsp->lock);
.
.
.
}
SEE ALSO open(9E), cv_signal(9F), cv_wait_sig(9F), delay(9F), timeout(9F)
Writing Device Drivers
SunOS 5.11 16 Jan 2006 untimeout(9F)