1#include <stdio.h>
2#include <fcntl.h>
3#include <unistd.h>
4#include <errno.h>
5#include <string.h>
6#include <sys/wait.h>
7#include "test.h"
8
9#define TEST(c, ...) ((c) ? 1 : (t_error(#c" failed: " __VA_ARGS__),0))
10#define TESTE(c) (errno=0, TEST(c, "errno = %s\n", strerror(errno)))
11
12int main(void)
13{
14	struct flock fl = {0};
15	FILE *f;
16	int fd;
17	pid_t pid;
18	int status;
19
20	if (!TESTE(f=tmpfile())) return t_status;
21	fd = fileno(f);
22
23	fl.l_type = F_WRLCK;
24	fl.l_whence = SEEK_SET;
25	fl.l_start = 0;
26	fl.l_len = 0;
27	TESTE(fcntl(fd, F_SETLK, &fl)==0);
28
29	pid = fork();
30	if (!pid) {
31		fl.l_type = F_RDLCK;
32		_exit(fcntl(fd, F_SETLK, &fl)==0 ||
33			(errno!=EAGAIN && errno!=EACCES));
34	}
35	while (waitpid(pid, &status, 0)<0 && errno==EINTR);
36	TEST(status==0, "lock failed to work\n");
37
38	pid = fork();
39	if (!pid) {
40		fl.l_type = F_WRLCK;
41		_exit(fcntl(fd, F_GETLK, &fl) || fl.l_pid != getppid());
42	}
43	while (waitpid(pid, &status, 0)<0 && errno==EINTR);
44	TEST(status==0, "child failed to detect lock held by parent\n");
45
46	fclose(f);
47
48	return t_status;
49}
50