1 /*
2 *
3 * Copyright (c) International Business Machines Corp., 2001
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20 /*
21 * NAME
22 * pipe09.c
23 *
24 * DESCRIPTION
25 * Check that two processes can use the same pipe at the same time.
26 *
27 * ALGORITHM
28 * 1. Open a pipe
29 * 2. Fork a child which writes to the pipe
30 * 3. Fork another child which writes a different character to the pipe
31 * 4. Have the parent read from the pipe
32 * 5. It should get the characters from both children.
33 *
34 * USAGE: <for command-line>
35 * pipe09 [-c n] [-f] [-i n] [-I x] [-P x] [-t]
36 * where, -c n : Run n copies concurrently.
37 * -f : Turn off functionality Testing.
38 * -i n : Execute test n times.
39 * -I x : Execute test for x seconds.
40 * -P x : Pause for x seconds between iterations.
41 * -t : Turn on syscall timing.
42 *
43 * HISTORY
44 * 07/2001 Ported by Wayne Boyer
45 *
46 * RESTRICTIONS
47 * None
48 */
49 #include <unistd.h>
50 #include <signal.h>
51 #include <sys/wait.h>
52 #include <errno.h>
53 #include "test.h"
54
55 #define PIPEWRTCNT 100 /* must be an even number */
56
57 char *TCID = "pipe09";
58 int TST_TOTAL = 1;
59
60 void setup(void);
61 void cleanup(void);
62
do_read(int fd,void * buf,size_t count)63 ssize_t do_read(int fd, void *buf, size_t count)
64 {
65 ssize_t n;
66
67 do {
68 n = read(fd, buf, count);
69 } while (n < 0 && errno == EINTR);
70
71 return n;
72 }
73
main(int ac,char ** av)74 int main(int ac, char **av)
75 {
76 int lc;
77
78 int i, red, wtstatus;
79 int pipefd[2]; /* fds for pipe read/write */
80 char rebuf[BUFSIZ];
81 int Acnt = 0, Bcnt = 0; /* count 'A' and 'B' */
82 int fork_1, fork_2; /* ret values in parent */
83
84 tst_parse_opts(ac, av, NULL, NULL);
85
86 setup();
87
88 for (lc = 0; TEST_LOOPING(lc); lc++) {
89
90 /* reset tst_count in case we are looping */
91 tst_count = 0;
92
93 TEST(pipe(pipefd));
94
95 if (TEST_RETURN == -1) {
96 tst_resm(TFAIL, "pipe() call failed");
97 continue;
98 }
99
100 if ((fork_1 = FORK_OR_VFORK()) == -1) {
101 tst_brkm(TBROK, cleanup, "fork() #1 failed");
102 }
103
104 if (fork_1 == 0) { /* 1st child */
105 if (close(pipefd[0]) != 0) {
106 tst_resm(TWARN, "pipefd[0] close failed, "
107 "errno = %d", errno);
108 exit(1);
109 }
110
111 for (i = 0; i < PIPEWRTCNT / 2; ++i) {
112 if (write(pipefd[1], "A", 1) != 1) {
113 tst_resm(TWARN, "write to pipe failed");
114 exit(1);
115 }
116 }
117 exit(0);
118 }
119
120 /* parent */
121
122 if (waitpid(fork_1, &wtstatus, 0) == -1)
123 tst_brkm(TBROK, cleanup, "waitpid failed");
124 if (WIFEXITED(wtstatus) && WEXITSTATUS(wtstatus) != 0) {
125 tst_brkm(TBROK, cleanup, "child exited abnormally");
126 }
127
128 if ((fork_2 = FORK_OR_VFORK()) == -1) {
129 tst_brkm(TBROK, cleanup, "fork() #2 failed");
130 }
131
132 if (fork_2 == 0) { /* 2nd child */
133 if (close(pipefd[0]) != 0) {
134 perror("pipefd[0] close failed");
135 exit(1);
136 }
137
138 for (i = 0; i < PIPEWRTCNT / 2; ++i) {
139 if (write(pipefd[1], "B", 1) != 1) {
140 perror("write to pipe failed");
141 exit(1);
142 }
143 }
144 exit(0);
145 }
146
147 /* parent */
148
149 if (waitpid(fork_2, &wtstatus, 0) == -1)
150 tst_brkm(TBROK, cleanup, "waitpid failed");
151 if (WEXITSTATUS(wtstatus) != 0) {
152 tst_brkm(TBROK, cleanup, "problem detected in child, "
153 "wait status %d, errno = %d", wtstatus, errno);
154 }
155
156 if (close(pipefd[1]) != 0) {
157 tst_brkm(TBROK | TERRNO, cleanup,
158 "pipefd[1] close failed");
159 }
160
161 while ((red = do_read(pipefd[0], rebuf, 100)) > 0) {
162 for (i = 0; i < red; i++) {
163 if (rebuf[i] == 'A') {
164 Acnt++;
165 continue;
166 }
167 if (rebuf[i] == 'B') {
168 Bcnt++;
169 continue;
170 }
171 tst_resm(TFAIL, "got bogus '%c' character",
172 rebuf[i]);
173 break;
174 }
175 }
176
177 if (red == -1) {
178 tst_brkm(TBROK | TERRNO, cleanup,
179 "reading pipefd pipe failed");
180 }
181
182 if (Bcnt == Acnt && Bcnt == (PIPEWRTCNT / 2)) {
183 tst_resm(TPASS, "functionality appears to be correct");
184 } else {
185 tst_resm(TFAIL, "functionality is not correct - Acnt "
186 "= %d, Bcnt = %d", Acnt, Bcnt);
187 }
188
189 /* clean up things in case we are looping */
190 Acnt = Bcnt = 0;
191 }
192 cleanup();
193
194 tst_exit();
195 }
196
197 /*
198 * setup() - performs all ONE TIME setup for this test.
199 */
setup(void)200 void setup(void)
201 {
202
203 tst_sig(FORK, DEF_HANDLER, cleanup);
204
205 TEST_PAUSE;
206 }
207
208 /*
209 * cleanup() - performs all ONE TIME cleanup for this test at
210 * completion or premature exit.
211 */
cleanup(void)212 void cleanup(void)
213 {
214 }
215