1 /*
2 Copyright (C) 2004 Michael J. Silbersack. All rights reserved.
3
4 Redistribution and use in source and binary forms, with or without
5 modification, are permitted provided that the following conditions
6 are met:
7 1. Redistributions of source code must retain the above copyright
8 notice, this list of conditions and the following disclaimer.
9 2. Redistributions in binary form must reproduce the above copyright
10 notice, this list of conditions and the following disclaimer in the
11 documentation and/or other materials provided with the distribution.
12
13 THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 SUCH DAMAGE.
24 */
25
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #include <sys/wait.h>
29 #include <sys/event.h>
30 #include <assert.h>
31 #include <err.h>
32 #include <errno.h>
33 #include <inttypes.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <unistd.h>
37
38 /*
39 * The goal of this program is to see if fstat reports the correct
40 * data count for a pipe. Prior to revision 1.172 of sys_pipe.c,
41 * 0 would be returned once the pipe entered direct write mode.
42 *
43 * Linux (2.6) always returns zero, so it's not a valuable platform
44 * for comparison.
45 */
46
47 int
main(void)48 main(void)
49 {
50 char buffer[32768], buffer2[32768], go[] = "go", go2[] = "go2";
51 int desc[2], ipc_coord[2];
52 struct kevent event, ke;
53 ssize_t error;
54 int successes = 0;
55 struct stat status;
56 pid_t new_pid;
57 int kq;
58
59 error = pipe(desc);
60 if (error == -1)
61 err(1, "Couldn't allocate data pipe");
62
63 error = pipe(ipc_coord);
64 if (error == -1)
65 err(1, "Couldn't allocate IPC coordination pipe");
66
67 new_pid = fork();
68 assert(new_pid != -1);
69
70 close(new_pid == 0 ? desc[0] : desc[1]);
71
72 #define SYNC_R(i, _buf) do { \
73 int _error = errno; \
74 warnx("%d: waiting for synchronization", __LINE__); \
75 if (read(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \
76 err(1, "failed to synchronize (%s)", (i == 0 ? "parent" : "child")); \
77 errno = _error; \
78 } while(0)
79
80 #define SYNC_W(i, _buf) do { \
81 int _error = errno; \
82 warnx("%d: sending synchronization", __LINE__); \
83 if (write(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \
84 err(1, "failed to synchronize (%s)", (i == 0 ? "child" : "parent")); \
85 errno = _error; \
86 } while(0)
87
88 #define WRITE(s) do { \
89 ssize_t _size; \
90 if ((_size = write(desc[1], &buffer, s)) != s) \
91 warn("short write; wrote %zd, expected %d", _size, s); \
92 } while(0)
93
94 if (new_pid == 0) {
95
96 SYNC_R(0, go);
97 WRITE(145);
98 SYNC_W(0, go2);
99
100 SYNC_R(0, go);
101 WRITE(2048);
102 SYNC_W(0, go2);
103
104 SYNC_R(0, go);
105 WRITE(4096);
106 SYNC_W(0, go2);
107
108 SYNC_R(0, go);
109 WRITE(8191);
110 SYNC_W(0, go2);
111
112 SYNC_R(0, go);
113 SYNC_W(0, go2); /* XXX: why is this required? */
114 WRITE(8192);
115 SYNC_W(0, go2);
116
117 close(ipc_coord[0]);
118 close(ipc_coord[1]);
119
120 _exit(0);
121 }
122
123 kq = kqueue();
124 if (kq == -1)
125 _exit(1);
126
127 EV_SET(&ke, desc[0], EVFILT_READ, EV_ADD, 0, 0, NULL);
128
129 /* Attach event to the kqueue. */
130 if (kevent(kq, &ke, 1, NULL, 0, NULL) != 0)
131 _exit(2);
132
133 while (successes < 5) {
134 SYNC_W(1, go);
135 SYNC_R(1, go2);
136
137 /* Ensure data is available to read */
138 if (kevent(kq, NULL, 0, &event, 1, NULL) != 1)
139 _exit(3);
140
141 fstat(desc[0], &status);
142 error = read(desc[0], &buffer2, sizeof(buffer2));
143
144 if (status.st_size != error)
145 err(1, "FAILURE: stat size %jd read size %zd",
146 (intmax_t)status.st_size, error);
147 if (error > 0) {
148 printf("SUCCESS at stat size %jd read size %zd\n",
149 (intmax_t)status.st_size, error);
150 successes++;
151 }
152 }
153
154 exit(0);
155 }
156