1 /*
2  * Copyright (c) 2008 Bret S. Lambert <blambert@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "local.h"
18 
19 void
20 fwrite_thread(void *v)
21 {
22 	FILE *file = v;
23 	int i;
24 
25 	for (i = 0; i < 4096; i++) {
26 		if (fwrite(TEXT, sizeof(char), strlen(TEXT), file) == 0) {
27 
28 			if (feof(file))
29 				break;
30 
31 			printf("OMG!!!\n");
32 			fflush(stdout);
33 			break;
34 		}
35 	}
36 }
37 
38 int
39 main(void)
40 {
41 	char sfn[24];
42 	char buf[sizeof(TEXT)];
43 	FILE *sfp;
44 	int fd;
45 
46 	strlcpy(sfn, "/tmp/barnacles.XXXXXXXX", sizeof(sfn));
47 	if ((fd = mkstemp(sfn)) == -1 ||
48 	    (sfp = fdopen(fd, "w+")) == NULL) {
49 		int saved_errno = errno;
50 		if (fd != -1) {
51 			unlink(sfn);
52 			close(fd);
53 		}
54 		errc(1, saved_errno, "could not open temporary file");
55 	}
56 
57 	run_threads(fwrite_thread, sfp);
58 
59 	while (fread(buf, sizeof(char), strlen(TEXT), sfp))	/* verify */
60 		if (strncmp(buf, TEXT, sizeof(TEXT)))
61 			err(1, "Thread writes were not atomic!!!");
62 
63 	unlink(sfn);
64 	close(fd);
65 
66 	exit(0);
67 }
68