lightweight X11 utility to dim the screen and/or keyboard backlight when idle
use a pipe to force an exit
Since the exit handler can't brighten on its own, just write into
the pipe and return. The poll() call is now checking on the pipe
and if it detects a write, brighten back up and exit cleanly.
+36
-20
+36
-20
xdimmer.c
+36
-20
xdimmer.c
···
91
91
void als_fetch(void);
92
92
void usage(void);
93
93
int XPeekEventOrTimeout(Display *, XEvent *, unsigned int);
94
+
int exitmsg[2];
94
95
95
96
extern char *__progname;
96
97
···
216
217
signal(SIGINT, bail);
217
218
signal(SIGTERM, bail);
218
219
220
+
/* setup a pipe to wait for an exit message from bail() */
221
+
pipe(exitmsg);
222
+
219
223
xloop();
220
224
221
225
return 0;
···
258
262
XEvent e;
259
263
XSyncAlarmNotifyEvent *alarm_e;
260
264
261
-
if (exiting)
262
-
break;
263
-
264
265
DPRINTF(("waiting for next event\n"));
265
266
266
267
/* if we're checking an als, only wait 1 second for x event */
···
269
270
als_fetch();
270
271
continue;
271
272
}
273
+
274
+
if (exiting)
275
+
break;
272
276
273
277
XNextEvent(dpy, &e);
274
278
···
684
688
if (exiting)
685
689
exit(0);
686
690
691
+
/*
692
+
* Doing X ops inside a signal handler causes an infinite loop in
693
+
* _XReply/xcb, so we can't properly brighten and exit ourselves.
694
+
* write to the pipe setup earlier so our event loop will see it upon
695
+
* polling.
696
+
*/
687
697
DPRINTF(("got signal %d, trying to exit\n", sig));
688
-
689
-
/* XXX: doing X ops inside a signal handler causes an infinite loop in
690
-
* _XReply/xcb, so we can't properly brighten() and exit, so we just
691
-
* set a flag and wait for the next time our idle counter stuff happens
692
-
* so we can exit there */
693
-
if (dimmed)
694
-
exiting = 1;
695
-
else
696
-
exit(0);
698
+
write(exitmsg[1], &exitmsg, 1);
699
+
exiting = 1;
697
700
}
698
701
699
702
int
700
703
XPeekEventOrTimeout(Display *dpy, XEvent *e, unsigned int msecs)
701
704
{
702
-
struct pollfd pfd[1];
705
+
struct pollfd pfd[2];
703
706
704
-
if (!XPending(dpy)) {
707
+
while (!XPending(dpy)) {
705
708
memset(&pfd, 0, sizeof(pfd));
706
709
pfd[0].fd = ConnectionNumber(dpy);
707
710
pfd[0].events = POLLIN;
711
+
pfd[1].fd = exitmsg[0];
712
+
pfd[1].events = POLLIN;
708
713
709
-
if (poll(pfd, 1, msecs == 0 ? INFTIM : msecs) == 0)
714
+
switch (poll(pfd, 2, msecs == 0 ? INFTIM : msecs)) {
715
+
case -1:
716
+
/* signal, maybe exit handler, we'll loop again */
717
+
DPRINTF(("poll returned -1 for errno %d\n", errno));
718
+
break;
719
+
case 0:
720
+
/* timed out */
710
721
return 0;
711
-
712
-
if (pfd[0].revents) {
713
-
DPRINTF(("%s: got X event\n", __func__));
714
-
XPeekEvent(dpy, e);
715
-
return 1;
722
+
default:
723
+
if (pfd[1].revents) {
724
+
DPRINTF(("%s: got exit message\n", __func__));
725
+
exiting = 1;
726
+
return 1;
727
+
} else if (pfd[0].revents) {
728
+
DPRINTF(("%s: got X event\n", __func__));
729
+
XPeekEvent(dpy, e);
730
+
return 1;
731
+
}
716
732
}
717
733
}
718
734