xref: /netbsd-src/tests/lib/librt/t_sem.c (revision 76c7fc5f6b13ed0b1508e6b313e88e59977ed78e)
1 /* $NetBSD: t_sem.c,v 1.4 2019/02/03 03:20:24 thorpej Exp $ */
2 
3 /*
4  * Copyright (c) 2008, 2010, 2019 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Copyright (C) 2000 Jason Evans <jasone@freebsd.org>.
31  * All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice(s), this list of conditions and the following disclaimer as
38  *    the first lines of this file unmodified other than the possible
39  *    addition of one or more copyright notices.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *    notice(s), this list of conditions and the following disclaimer in
42  *    the documentation and/or other materials provided with the
43  *    distribution.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
46  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
48  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
49  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
50  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
51  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
52  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
53  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
54  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
55  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56  */
57 
58 #include <sys/cdefs.h>
59 __COPYRIGHT("@(#) Copyright (c) 2008, 2010, 2019\
60  The NetBSD Foundation, inc. All rights reserved.");
61 __RCSID("$NetBSD: t_sem.c,v 1.4 2019/02/03 03:20:24 thorpej Exp $");
62 
63 #include <sys/mman.h>
64 #include <sys/wait.h>
65 
66 #include <errno.h>
67 #include <fcntl.h>
68 #include <semaphore.h>
69 #include <stdio.h>
70 #include <unistd.h>
71 
72 #include <atf-c.h>
73 
74 #define NCHILDREN 10
75 
76 ATF_TC_WITH_CLEANUP(basic);
77 ATF_TC_HEAD(basic, tc)
78 {
79 	atf_tc_set_md_var(tc, "descr", "Checks basic functionality of POSIX "
80 	    "semaphores");
81 }
82 ATF_TC_BODY(basic, tc)
83 {
84 	int val;
85 	sem_t *sem_b;
86 
87 	if (sysconf(_SC_SEMAPHORES) == -1)
88 		atf_tc_skip("POSIX semaphores not supported");
89 
90 	sem_b = sem_open("/sem_b", O_CREAT | O_EXCL, 0644, 0);
91 	ATF_REQUIRE(sem_b != SEM_FAILED);
92 
93 	ATF_REQUIRE_EQ(sem_getvalue(sem_b, &val), 0);
94 	ATF_REQUIRE_EQ(val, 0);
95 
96 	ATF_REQUIRE_EQ(sem_post(sem_b), 0);
97 	ATF_REQUIRE_EQ(sem_getvalue(sem_b, &val), 0);
98 	ATF_REQUIRE_EQ(val, 1);
99 
100 	ATF_REQUIRE_EQ(sem_wait(sem_b), 0);
101 	ATF_REQUIRE_EQ(sem_trywait(sem_b), -1);
102 	ATF_REQUIRE_EQ(errno, EAGAIN);
103 	ATF_REQUIRE_EQ(sem_post(sem_b), 0);
104 	ATF_REQUIRE_EQ(sem_trywait(sem_b), 0);
105 	ATF_REQUIRE_EQ(sem_post(sem_b), 0);
106 	ATF_REQUIRE_EQ(sem_wait(sem_b), 0);
107 	ATF_REQUIRE_EQ(sem_post(sem_b), 0);
108 
109 	ATF_REQUIRE_EQ(sem_close(sem_b), 0);
110 	ATF_REQUIRE_EQ(sem_unlink("/sem_b"), 0);
111 }
112 ATF_TC_CLEANUP(basic, tc)
113 {
114 	(void)sem_unlink("/sem_b");
115 }
116 
117 ATF_TC_WITH_CLEANUP(child);
118 ATF_TC_HEAD(child, tc)
119 {
120 	atf_tc_set_md_var(tc, "descr", "Checks using semaphores to synchronize "
121 	    "parent with multiple child processes");
122 }
123 ATF_TC_BODY(child, tc)
124 {
125 	pid_t children[NCHILDREN];
126 	unsigned i, j;
127 	sem_t *sem_a;
128 	int status;
129 
130 	pid_t pid;
131 
132 	if (sysconf(_SC_SEMAPHORES) == -1)
133 		atf_tc_skip("POSIX semaphores not supported");
134 
135 	sem_a = sem_open("/sem_a", O_CREAT | O_EXCL, 0644, 0);
136 	ATF_REQUIRE(sem_a != SEM_FAILED);
137 
138 	for (j = 1; j <= 2; j++) {
139 		for (i = 0; i < NCHILDREN; i++) {
140 			switch ((pid = fork())) {
141 			case -1:
142 				atf_tc_fail("fork() returned -1");
143 			case 0:
144 				printf("PID %d waiting for semaphore...\n",
145 				    getpid());
146 				ATF_REQUIRE_MSG(sem_wait(sem_a) == 0,
147 				    "sem_wait failed; iteration %d", j);
148 				printf("PID %d got semaphore\n", getpid());
149 				_exit(0);
150 			default:
151 				children[i] = pid;
152 				break;
153 			}
154 		}
155 
156 		for (i = 0; i < NCHILDREN; i++) {
157 			sleep(1);
158 			printf("main loop %d: posting...\n", j);
159 			ATF_REQUIRE_EQ(sem_post(sem_a), 0);
160 		}
161 
162 		for (i = 0; i < NCHILDREN; i++) {
163 			ATF_REQUIRE_EQ(waitpid(children[i], &status, 0), children[i]);
164 			ATF_REQUIRE(WIFEXITED(status));
165 			ATF_REQUIRE_EQ(WEXITSTATUS(status), 0);
166 		}
167 	}
168 
169 	ATF_REQUIRE_EQ(sem_close(sem_a), 0);
170 	ATF_REQUIRE_EQ(sem_unlink("/sem_a"), 0);
171 }
172 ATF_TC_CLEANUP(child, tc)
173 {
174 	(void)sem_unlink("/sem_a");
175 }
176 
177 ATF_TC_WITH_CLEANUP(pshared);
178 ATF_TC_HEAD(pshared, tc)
179 {
180 	atf_tc_set_md_var(tc, "descr", "Checks using pshared unnamed "
181 	    "semaphores to synchronize a master with multiple slave processes");
182 }
183 
184 struct shared_region {
185 	sem_t	the_sem;
186 };
187 
188 static struct shared_region *
189 get_shared_region(int o_flags)
190 {
191 
192 	int fd = shm_open("/shm_semtest_a", o_flags, 0644);
193 	ATF_REQUIRE(fd != -1);
194 
195 	ATF_REQUIRE_EQ(ftruncate(fd, sizeof(struct shared_region)), 0);
196 
197 	void *rv = mmap(NULL, sizeof(struct shared_region),
198 	    PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
199 	ATF_REQUIRE(rv != MAP_FAILED);
200 
201 	(void)close(fd);
202 
203 	return rv;
204 }
205 
206 static void
207 put_shared_region(struct shared_region *r)
208 {
209 	ATF_REQUIRE_EQ(munmap(r, sizeof(struct shared_region)), 0);
210 }
211 
212 ATF_TC_BODY(pshared, tc)
213 {
214 	struct shared_region *master_region, *slave_region;;
215 
216 	if (sysconf(_SC_SEMAPHORES) == -1)
217 		atf_tc_skip("POSIX semaphores not supported");
218 
219 	/*
220 	 * Create a shared memory region to contain the pshared
221 	 * semaphore, create the semaphore there, and then detach
222 	 * from the shared memory region to ensure that our child
223 	 * processes will be getting at it from scratch.
224 	 */
225 	master_region = get_shared_region(O_RDWR | O_CREAT | O_EXCL);
226 	ATF_REQUIRE(sem_init(&master_region->the_sem, 1, 0) == 0);
227 	put_shared_region(master_region);
228 
229 	/*
230 	 * Now execute a test that's essentially equivalent to the
231 	 * "child" test above, but using the pshared semaphore in the
232 	 * shared memory region.
233 	 */
234 
235 	pid_t pid, children[NCHILDREN];
236 	unsigned i, j;
237 	int status;
238 
239 	for (j = 1; j <= 2; j++) {
240 		for (i = 0; i < NCHILDREN; i++) {
241 			switch ((pid = fork())) {
242 			case -1:
243 				atf_tc_fail("fork() returned -1");
244 			case 0:
245 				slave_region = get_shared_region(O_RDWR);
246 				printf("PID %d waiting for semaphore...\n",
247 				    getpid());
248 				ATF_REQUIRE_MSG(sem_wait(&slave_region->the_sem)
249 				    == 0,
250 				    "sem_wait failed; iteration %d", j);
251 				printf("PID %d got semaphore\n", getpid());
252 				_exit(0);
253 			default:
254 				children[i] = pid;
255 				break;
256 			}
257 		}
258 
259 		master_region = get_shared_region(O_RDWR);
260 
261 		for (i = 0; i < NCHILDREN; i++) {
262 			sleep(1);
263 			printf("main loop %d: posting...\n", j);
264 			ATF_REQUIRE_EQ(sem_post(&master_region->the_sem), 0);
265 		}
266 
267 		put_shared_region(master_region);
268 
269 		for (i = 0; i < NCHILDREN; i++) {
270 			ATF_REQUIRE_EQ(waitpid(children[i], &status, 0), children[i]);
271 			ATF_REQUIRE(WIFEXITED(status));
272 			ATF_REQUIRE_EQ(WEXITSTATUS(status), 0);
273 		}
274 	}
275 
276 	master_region = get_shared_region(O_RDWR);
277 	ATF_REQUIRE_EQ(sem_destroy(&master_region->the_sem), 0);
278 	put_shared_region(master_region);
279 
280 	ATF_REQUIRE_EQ(shm_unlink("/shm_semtest_a"), 0);
281 }
282 ATF_TC_CLEANUP(pshared, tc)
283 {
284 	/*
285 	 * The kernel will g/c the pshared semaphore when the process that
286 	 * created it exits, so no need to include that in the cleanup here.
287 	 */
288 	(void)shm_unlink("/shm_semtest_a");
289 }
290 
291 ATF_TC_WITH_CLEANUP(invalid_ops);
292 ATF_TC_HEAD(invalid_ops, tc)
293 {
294 	atf_tc_set_md_var(tc, "descr", "Validates behavior when calling "
295 	    "bad operations for the semaphore type");
296 }
297 ATF_TC_BODY(invalid_ops, tc)
298 {
299 	sem_t *sem;
300 	sem_t the_sem;
301 
302 	sem = sem_open("/sem_c", O_CREAT | O_EXCL, 0644, 0);
303 	ATF_REQUIRE(sem != SEM_FAILED);
304 	ATF_REQUIRE(sem_destroy(sem) == -1 && errno == EINVAL);
305 	ATF_REQUIRE_EQ(sem_close(sem), 0);
306 
307 	ATF_REQUIRE_EQ(sem_init(&the_sem, 0, 0), 0);
308 	ATF_REQUIRE(sem_close(&the_sem) == -1 && errno == EINVAL);
309 	ATF_REQUIRE_EQ(sem_destroy(&the_sem), 0);
310 }
311 ATF_TC_CLEANUP(invalid_ops, tc)
312 {
313 	(void)sem_unlink("/sem_c");
314 }
315 
316 ATF_TP_ADD_TCS(tp)
317 {
318 
319 	ATF_TP_ADD_TC(tp, basic);
320 	ATF_TP_ADD_TC(tp, child);
321 	ATF_TP_ADD_TC(tp, pshared);
322 	ATF_TP_ADD_TC(tp, invalid_ops);
323 
324 	return atf_no_error();
325 }
326