opensolaris man page for ddi_periodic_delete

ddi_periodic_delete(9F) 				   Kernel Functions for Drivers 				   ddi_periodic_delete(9F)

NAME
       ddi_periodic_delete - cancel nanosecond periodic timeout requests

SYNOPSIS
       #include <sys/dditypes.h>
       #include <sys/sunddi.h>

       void ddi_periodic_delete(ddi_periodic_t req)

INTERFACE LEVEL
       Solaris DDI specific (Solaris DDI)

PARAMETERS
       req    ddi_periodic_t opaque value returned by ddi_periodic_add(9F).

DESCRIPTION
       The ddi_periodic_delete() function cancels the ddi_periodic_add(9F) request that was previously issued.

       As  with  untimeout(9F),  calling  ddi_periodic_delete()  against a periodic timeout request which is either running on another CPU, or has
       already been canceled causes no problems. Unlike untimeout(9F), there are no restrictions on the lock which might be held across  the  call
       to ddi_periodic_delete().

CONTEXT
       The ddi_periodic_delete() function may be called from user or kernel context.

EXAMPLES
       Example 1 Cancelling a timeout request

       In  the following example, the device driver cancels the timeout request by calling ddi_periodic_delete() against the request that was pre-
       viously issued.

	 /*
	 * Stop the periodic timer
	 */
	 static void
	 stop_periodic_timer(struct my_state *statep)
	 {
		  ddi_periodic_delete(statep->periodic_id);
		  mutex_destory(&statep->lock);
	 }

	 static void
	 start_periodic_timer(struct my_state *statep)
	 {
		  hrtime_t interval = CHECK_INTERVAL;

		  mutex_init(&statep->lock, NULL, MUTEX_DRIVER,
		      (void *)DDI_IPL_0);

		  /*
		   * Register my_callback which is invoked periodically
		   * in CHECK_INTERVAL in kernel context.
		   */
		  statep->periodic_id = ddi_periodic_add(my_periodic_func,
		      statep, interval, DDI_IPL_0);
	 }

	 static void
	 my_periodic_func(void *arg)
	 {
		    /*
		     * This handler is invoked periodically.
		     */
		    struct my_state *statep = (struct my_state *)arg;

		    mutex_enter(&statep->lock);
		    if (load_unbalanced(statep)) {
			balance_tasks(statep);
		    }
		    mutex_exit(&statep->lock);
	 }

SEE ALSO
       cv_timedwait(9F), ddi_intr_get_pri(9F),	ddi_periodic_add(9F),  delay(9F),  drv_usectohz(9F),  qtimeout(9F),  quntimeout(9F),  timeout(9F),
       untimeout(9F)

SunOS 5.11							    2 Oct 2007						   ddi_periodic_delete(9F)