ndet_s_itimer.c

操作系统SunOS 4.1.3版本的源码

#ifndef	lint
#ifdef sccs
static	char sccsid[] = "@(#)ndet_s_itimer.c 1.1 92/07/30 Copyr 1985 Sun Micro";
#endif
#endif

/*
 * Copyright (c) 1985 by Sun Microsystems, Inc.
 */

/*
 * Ndet_s_itimer.c - Implement the notify_set_itimer_func interface.
 */

#include <sunwindow/ntfy.h>
#include <sunwindow/ndet.h>
#include <sunwindow/ndis.h>
#include <sunwindow/nint.h>

extern Notify_func
notify_set_itimer_func(nclient, func, which, value, ovalue)
	Notify_client nclient;
	Notify_func func;
	int which;
	struct itimerval *value, *ovalue;
{
	Notify_func old_func = NOTIFY_FUNC_NULL;
	register NTFY_CLIENT *client;
	NTFY_CONDITION *condition;
	NTFY_TYPE type;

	NTFY_BEGIN_CRITICAL;
	/* Check arguments */
	if (ndet_check_which(which, &type))
		goto Done;
	/* Allow null value */
	if (value == NTFY_ITIMER_NULL)
		value = &NOTIFY_NO_ITIMER;
	else
		/* Pre-qualify so doesn't blow up in setitimer later */
		if (ndet_check_tv(&(value->it_value)) ||
		    ndet_check_tv(&(value->it_interval)))
			goto Done;
	/* Find/create client that corresponds to nclient */
	if ((client = ntfy_new_nclient(&ndet_clients, nclient,
            &ndet_client_latest)) == NTFY_CLIENT_NULL)
		goto Done;
	/* Find/create condition */
	if ((condition = ntfy_new_condition(&(client->conditions), type,
	    &(client->condition_latest), NTFY_DATA_NULL, NTFY_IGNORE_DATA)) ==
	    NTFY_CONDITION_NULL)
		goto Done;
	/* Set ovalue if not null */
	if (ovalue != NTFY_ITIMER_NULL) {
		/*
		 * Data will have zero value if first time client has
		 * specified itimer of this type
		 */
		if (condition->data.ntfy_itimer == (struct ntfy_itimer *)0)
			*ovalue = NOTIFY_NO_ITIMER;
		else
			(void) notify_itimer_value(nclient, which, ovalue);
	}
	/* Set condition data */
	if (condition->data.ntfy_itimer == (struct ntfy_itimer *)0)
		condition->data.ntfy_itimer = ntfy_alloc_ntfy_itimer();
	condition->data.ntfy_itimer->itimer = *value;
	ndet_reset_itimer_set_tv(condition);
	/* Exchange functions */
	old_func = nint_set_func(condition, func);
	/* Remove condition if func is null or value indicates no timer */
	if (func == NOTIFY_FUNC_NULL || !timerisset(&(value->it_value))) {
		ndis_flush_condition(nclient, type,
		    NTFY_DATA_NULL, NTFY_IGNORE_DATA);
		ntfy_unset_condition(&ndet_clients, client, condition,
		    &ndet_client_latest, NTFY_NDET);
	}
	/*
	 * Have notifier check for itimer changes next time around loop.
	 * Will notice and adjust signal handling at this time.
	 */
	ndet_flags |= (type == NTFY_REAL_ITIMER)? NDET_REAL_CHANGE:
	    NDET_VIRTUAL_CHANGE;
Done:
	NTFY_END_CRITICAL;
	return(old_func);
}