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 #include "safe_macros.h"
55
56 #define PIPEWRTCNT 100 /* must be an even number */
57
58 char *TCID = "pipe09";
59 int TST_TOTAL = 1;
60
61 void setup(void);
62 void cleanup(void);
63
do_read(int fd,void * buf,size_t count)64 ssize_t do_read(int fd, void *buf, size_t count)
65 {
66 ssize_t n;
67
68 do {
69 n = read(fd, buf, count);
70 } while (n < 0 && errno == EINTR);
71
72 return n;
73 }
74
main(int ac,char ** av)75 int main(int ac, char **av)
76 {
77 int lc;
78
79 int i, red, wtstatus;
80 int pipefd[2]; /* fds for pipe read/write */
81 char rebuf[BUFSIZ];
82 int Acnt = 0, Bcnt = 0; /* count 'A' and 'B' */
83 int fork_1, fork_2; /* ret values in parent */
84
85 tst_parse_opts(ac, av, NULL, NULL);
86
87 setup();
88
89 for (lc = 0; TEST_LOOPING(lc); lc++) {
90
91 /* reset tst_count in case we are looping */
92 tst_count = 0;
93
94 TEST(pipe(pipefd));
95
96 if (TEST_RETURN == -1) {
97 tst_resm(TFAIL, "pipe() call failed");
98 continue;
99 }
100
101 if ((fork_1 = FORK_OR_VFORK()) == -1) {
102 tst_brkm(TBROK, cleanup, "fork() #1 failed");
103 }
104
105 if (fork_1 == 0) { /* 1st child */
106 if (close(pipefd[0]) != 0) {
107 tst_resm(TWARN, "pipefd[0] close failed, "
108 "errno = %d", errno);
109 exit(1);
110 }
111
112 for (i = 0; i < PIPEWRTCNT / 2; ++i) {
113 if (write(pipefd[1], "A", 1) != 1) {
114 tst_resm(TWARN, "write to pipe failed");
115 exit(1);
116 }
117 }
118 exit(0);
119 }
120
121 /* parent */
122
123 SAFE_WAITPID(cleanup, fork_1, &wtstatus, 0);
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 SAFE_WAITPID(cleanup, fork_2, &wtstatus, 0);
150 if (WEXITSTATUS(wtstatus) != 0) {
151 tst_brkm(TBROK, cleanup, "problem detected in child, "
152 "wait status %d, errno = %d", wtstatus, errno);
153 }
154
155 if (close(pipefd[1]) != 0) {
156 tst_brkm(TBROK | TERRNO, cleanup,
157 "pipefd[1] close failed");
158 }
159
160 while ((red = do_read(pipefd[0], rebuf, 100)) > 0) {
161 for (i = 0; i < red; i++) {
162 if (rebuf[i] == 'A') {
163 Acnt++;
164 continue;
165 }
166 if (rebuf[i] == 'B') {
167 Bcnt++;
168 continue;
169 }
170 tst_resm(TFAIL, "got bogus '%c' character",
171 rebuf[i]);
172 break;
173 }
174 }
175
176 if (red == -1) {
177 tst_brkm(TBROK | TERRNO, cleanup,
178 "reading pipefd pipe failed");
179 }
180
181 if (Bcnt == Acnt && Bcnt == (PIPEWRTCNT / 2)) {
182 tst_resm(TPASS, "functionality appears to be correct");
183 } else {
184 tst_resm(TFAIL, "functionality is not correct - Acnt "
185 "= %d, Bcnt = %d", Acnt, Bcnt);
186 }
187
188 /* clean up things in case we are looping */
189 Acnt = Bcnt = 0;
190 }
191 cleanup();
192
193 tst_exit();
194 }
195
196 /*
197 * setup() - performs all ONE TIME setup for this test.
198 */
setup(void)199 void setup(void)
200 {
201
202 tst_sig(FORK, DEF_HANDLER, cleanup);
203
204 TEST_PAUSE;
205 }
206
207 /*
208 * cleanup() - performs all ONE TIME cleanup for this test at
209 * completion or premature exit.
210 */
cleanup(void)211 void cleanup(void)
212 {
213 }
214