1 /*	$OpenBSD: kqueue-signal.c,v 1.1 2011/07/07 02:00:51 guenther Exp $	*/
2 /*
3  *	Written by Philip Guenther <guenther@openbsd.org> 2011 Public Domain
4  */
5 
6 #include <sys/types.h>
7 #include <sys/event.h>
8 #include <sys/socket.h>
9 #include <sys/un.h>
10 #include <sys/wait.h>
11 
12 #include <stdlib.h>
13 #include <stdio.h>
14 #include <string.h>
15 #include <err.h>
16 #include <errno.h>
17 #include <unistd.h>
18 #include <signal.h>
19 
20 #define ASS(cond, mess) do { if (!(cond)) { mess; return 1; } } while (0)
21 
22 #define ASSX(cond) ASS(cond, warnx("assertion " #cond " failed on line %d", __LINE__))
23 
24 volatile sig_atomic_t saw_usr1 = 0;
25 volatile sig_atomic_t result = 0;
26 int kq;
27 
28 int
29 sigtest(int signum, int catch)
30 {
31 	struct kevent ke;
32 	struct timespec ts;
33 
34 	ts.tv_sec = 10;
35 	ts.tv_nsec = 0;
36 
37 	ASS(kevent(kq, NULL, 0, &ke, 1, &ts) == 1,
38 	    warn("can't fetch event on kqueue"));
39 	ASSX(ke.filter == EVFILT_SIGNAL);
40 	ASSX(ke.ident == signum);
41 	ASSX(ke.data == catch);
42 	return (0);
43 }
44 
45 void
46 usr1handler(int signum)
47 {
48 	saw_usr1 = 1;
49 	result = sigtest(SIGUSR1, 1);
50 }
51 
52 
53 int do_signal(void);
54 
55 int
56 do_signal(void)
57 {
58 	struct kevent ke;
59 	pid_t pid = getpid();
60 	sigset_t mask;
61 
62 	ASS((kq = kqueue()) >= 0, warn("kqueue"));
63 
64 	signal(SIGUSR1, usr1handler);
65 	signal(SIGUSR2, SIG_IGN);
66 
67 	EV_SET(&ke, SIGUSR1, EVFILT_SIGNAL, EV_ADD|EV_ENABLE, 0, 0, NULL);
68 	ASS(kevent(kq, &ke, 1, NULL, 0, NULL) == 0,
69 	    warn("can't register events on kqueue"));
70 	EV_SET(&ke, SIGUSR2, EVFILT_SIGNAL, EV_ADD|EV_ENABLE, 0, 0, NULL);
71 	ASS(kevent(kq, &ke, 1, NULL, 0, NULL) == 0,
72 	    warn("can't register events on kqueue"));
73 
74 	ASSX(saw_usr1 == 0);
75 	kill(pid, SIGUSR1);
76 	ASSX(saw_usr1 == 1);
77 
78 	kill(pid, SIGUSR2);
79 	if (sigtest(SIGUSR2, 1))
80 		return (1);
81 	kill(pid, SIGUSR2);
82 	kill(pid, SIGUSR2);
83 	if (sigtest(SIGUSR2, 2))
84 		return (1);
85 
86 	sigemptyset(&mask);
87 	sigaddset(&mask, SIGUSR1);
88 	sigaddset(&mask, SIGUSR2);
89 	sigprocmask(SIG_BLOCK, &mask, NULL);
90 
91 	signal(SIGUSR1, SIG_DFL);
92 	kill(pid, SIGUSR1);
93 	kill(pid, SIGUSR2);
94 
95 	close(kq);
96 
97 	return (0);
98 }
99 
100