klibc/tests/select.c

/*
 * Simple test of select()
 */

#include <sys/select.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>

int main(int argc, char *argv[])
{
	int fdn, fdz, pfd[2], rv;
	fd_set readset;
	struct timeval timeout;
	int err = 0;

	/* We can always read from /dev/zero; open a pipe that is never
	   ready for a "never readable" file descriptor */
	fdz = open("/dev/zero", O_RDONLY);
	pipe(pfd);
	fdn = pfd[0];

	FD_ZERO(&readset);
	FD_SET(fdn, &readset);

	timeout.tv_sec = 0;
	timeout.tv_usec = 100000;

	rv = select(FD_SETSIZE, &readset, NULL, NULL, &timeout);

	if (rv != 0) {
		fprintf(stderr,
			"select with timeout failed (rv = %d, errno = %s)\n",
			rv, strerror(errno));
		err++;
	}

	FD_ZERO(&readset);
	FD_SET(fdn, &readset);
	FD_SET(fdz, &readset);

	rv = select(FD_SETSIZE, &readset, NULL, NULL, &timeout);

	if (rv != 1 || !FD_ISSET(fdz, &readset) ||
	    FD_ISSET(fdn, &readset)) {
		fprintf(stderr,
			"select with /dev/zero failed (rv = %d, errno = %s)\n",
			rv, strerror(errno));
		err++;
	}

	return err;
}
1	/*
2	* Simple test of select()
3	*/
4
5	#include <sys/select.h>
6	#include <fcntl.h>
7	#include <stdio.h>
8	#include <string.h>
9	#include <errno.h>
10	#include <unistd.h>
11
12	int main(int argc, char *argv[])
13	{
14	int fdn, fdz, pfd[2], rv;
15	fd_set readset;
16	struct timeval timeout;
17	int err = 0;
18
19	/* We can always read from /dev/zero; open a pipe that is never
20	ready for a "never readable" file descriptor */
21	fdz = open("/dev/zero", O_RDONLY);
22	pipe(pfd);
23	fdn = pfd[0];
24
25	FD_ZERO(&readset);
26	FD_SET(fdn, &readset);
27
28	timeout.tv_sec = 0;
29	timeout.tv_usec = 100000;
30
31	rv = select(FD_SETSIZE, &readset, NULL, NULL, &timeout);
32
33	if (rv != 0) {
34	fprintf(stderr,
35	"select with timeout failed (rv = %d, errno = %s)\n",
36	rv, strerror(errno));
37	err++;
38	}
39
40	FD_ZERO(&readset);
41	FD_SET(fdn, &readset);
42	FD_SET(fdz, &readset);
43
44	rv = select(FD_SETSIZE, &readset, NULL, NULL, &timeout);
45
46	if (rv != 1 \|\| !FD_ISSET(fdz, &readset) \|\|
47	FD_ISSET(fdn, &readset)) {
48	fprintf(stderr,
49	"select with /dev/zero failed (rv = %d, errno = %s)\n",
50	rv, strerror(errno));
51	err++;
52	}
53
54	return err;
55	}