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untimeout(9r) [osf1 man page]

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)

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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
untimeout() 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
untimeout() returns -1 if the id is not found. Otherwise, it returns an integer value greater than or equal to 0. CONTEXT
untimeout() can be called from user or interrupt 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 5.10 18 Feb 1998 untimeout(9F)
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