11ab64890Smrg/*
21ab64890Smrg
31ab64890SmrgCopyright 1986, 1998  The Open Group
41ab64890Smrg
51ab64890SmrgPermission to use, copy, modify, distribute, and sell this software and its
61ab64890Smrgdocumentation for any purpose is hereby granted without fee, provided that
71ab64890Smrgthe above copyright notice appear in all copies and that both that
81ab64890Smrgcopyright notice and this permission notice appear in supporting
91ab64890Smrgdocumentation.
101ab64890Smrg
111ab64890SmrgThe above copyright notice and this permission notice shall be included in
121ab64890Smrgall copies or substantial portions of the Software.
131ab64890Smrg
141ab64890SmrgTHE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
151ab64890SmrgIMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
161ab64890SmrgFITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
171ab64890SmrgOPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
181ab64890SmrgAN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
191ab64890SmrgCONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
201ab64890Smrg
211ab64890SmrgExcept as contained in this notice, the name of The Open Group shall not be
221ab64890Smrgused in advertising or otherwise to promote the sale, use or other dealings
231ab64890Smrgin this Software without prior written authorization from The Open Group.
241ab64890Smrg
251ab64890Smrg*/
261ab64890Smrg
271ab64890Smrg#ifdef HAVE_CONFIG_H
281ab64890Smrg#include <config.h>
291ab64890Smrg#endif
301ab64890Smrg#include "Xlibint.h"
311ab64890Smrg
3261b2299dSmrg/*
331ab64890Smrg * Flush output and (wait for and) return the next event matching the
341ab64890Smrg * predicate in the queue.
351ab64890Smrg */
361ab64890Smrg
371ab64890Smrgint
381ab64890SmrgXIfEvent (
391ab64890Smrg	register Display *dpy,
401ab64890Smrg	register XEvent *event,
411ab64890Smrg	Bool (*predicate)(
421ab64890Smrg			  Display*			/* display */,
431ab64890Smrg			  XEvent*			/* event */,
441ab64890Smrg			  char*				/* arg */
451ab64890Smrg			  ),		/* function to call */
461ab64890Smrg	char *arg)
471ab64890Smrg{
481ab64890Smrg	register _XQEvent *qelt, *prev;
491ab64890Smrg	unsigned long qe_serial = 0;
5061b2299dSmrg
510efe039aSmartin	LockDisplay(dpy);
52876003caSmrg#ifdef XTHREADS
53876003caSmrg	dpy->ifevent_thread = xthread_self();
54876003caSmrg#endif
55876003caSmrg	dpy->in_ifevent++;
561ab64890Smrg	prev = NULL;
571ab64890Smrg	while (1) {
581ab64890Smrg	    for (qelt = prev ? prev->next : dpy->head;
591ab64890Smrg		 qelt;
601ab64890Smrg		 prev = qelt, qelt = qelt->next) {
611ab64890Smrg		if(qelt->qserial_num > qe_serial
621ab64890Smrg		   && (*predicate)(dpy, &qelt->event, arg)) {
631ab64890Smrg		    *event = qelt->event;
641ab64890Smrg		    _XDeq(dpy, prev, qelt);
65b4ee4795Smrg		    _XStoreEventCookie(dpy, event);
660efe039aSmartin		    dpy->in_ifevent--;
671ab64890Smrg		    UnlockDisplay(dpy);
681ab64890Smrg		    return 0;
691ab64890Smrg		}
701ab64890Smrg	    }
711ab64890Smrg	    if (prev)
721ab64890Smrg		qe_serial = prev->qserial_num;
731ab64890Smrg	    _XReadEvents(dpy);
741ab64890Smrg	    if (prev && prev->qserial_num != qe_serial)
751ab64890Smrg		/* another thread has snatched this event */
761ab64890Smrg		prev = NULL;
771ab64890Smrg	}
781ab64890Smrg}
79