android13/external/ltp/testcases/kernel/syscalls/select/select04.c

89 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2020 Linaro Limited. All rights reserved.
* Author: Viresh Kumar <viresh.kumar@linaro.org>
*/
/*\
* [Description]
*
* Test to check if fd set bits are cleared by select().
*
* [Algorithm]
* - Check that writefds flag is cleared on full pipe
* - Check that readfds flag is cleared on empty pipe
*/
#include <unistd.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/types.h>
#include <fcntl.h>
#include "select_var.h"
static fd_set readfds_pipe, writefds_pipe;
static int fd_empty[2], fd_full[2];
static struct tcases {
int *fd;
fd_set *readfds;
fd_set *writefds;
char *desc;
} tests[] = {
{&fd_empty[0], &readfds_pipe, NULL, "No data to read"},
{&fd_full[1], NULL, &writefds_pipe, "No space to write"},
};
static void run(unsigned int n)
{
struct tcases *tc = &tests[n];
struct timeval timeout = {.tv_sec = 0, .tv_usec = 1000};
FD_SET(fd_empty[0], &readfds_pipe);
FD_SET(fd_full[1], &writefds_pipe);
TEST(do_select(*tc->fd + 1, tc->readfds, tc->writefds, NULL, &timeout));
if (TST_RET) {
tst_res(TFAIL, "%s: select() should have timed out", tc->desc);
return;
}
if ((tc->readfds && FD_ISSET(*tc->fd, tc->readfds)) ||
(tc->writefds && FD_ISSET(*tc->fd, tc->writefds))) {
tst_res(TFAIL, "%s: select() didn't clear the fd set", tc->desc);
return;
}
tst_res(TPASS, "%s: select() cleared the fd set", tc->desc);
}
static void setup(void)
{
int buf = 0;
select_info();
SAFE_PIPE(fd_empty);
FD_ZERO(&readfds_pipe);
SAFE_PIPE2(fd_full, O_NONBLOCK);
FD_ZERO(&writefds_pipe);
/* Make the write buffer full for fd_full */
do {
TEST(write(fd_full[1], &buf, sizeof(buf)));
} while (TST_RET != -1);
if (TST_ERR != EAGAIN)
tst_res(TFAIL | TTERRNO, "write() failed with unexpected error");
}
static struct tst_test test = {
.test = run,
.tcnt = ARRAY_SIZE(tests),
.test_variants = TEST_VARIANTS,
.setup = setup,
.needs_tmpdir = 1,
};