[LTP] [PATCH v2] epoll_pwait/epoll_pwait01.c: add new testcase

[Cyril Hrubis]

Hi!
> +/*
> + * Description:
> + *  Basic test for epoll_pwait(2).
> + *  1) epoll_pwait(2) with sigmask argument allows the caller to
> + *     safely wait until either a file descriptor becomes ready
> + *     or the timeout expires.
> + *  2) epoll_pwait(2) with NULL sigmask argument fails if
> + *     interrupted by a signal handler, epoll_pwait(2) should
> + *     return -1 and set errno to EINTR.
> + */
> +
> +#include <sys/epoll.h>
> +#include <sys/types.h>
> +#include <unistd.h>
> +#include <string.h>
> +#include <errno.h>
> +
> +#include "test.h"
> +#include "epoll_pwait.h"
> +#include "safe_macros.h"
> +
> +char *TCID = "epoll_pwait01";
> +int TST_TOTAL = 2;
> +
> +static int epfd, fds[2];
> +static const char buf[] = "Testing";
> +static sigset_t sigset;
> +static struct epoll_event epevs;
> +static struct sigaction sa;
> +
> +static void setup(void);
> +static void sighandler(int sig LTP_ATTRIBUTE_UNUSED);
> +static void do_test(sigset_t *);
> +static void do_child(void);
> +static void cleanup(void);
> +
> +int main(int ac, char **av)
> +{
> +	int lc;
> +
> +	tst_parse_opts(ac, av, NULL, NULL);
> +
> +	setup();
> +
> +	for (lc = 0; TEST_LOOPING(lc); lc++) {
> +		tst_count = 0;
> +
> +		do_test(&sigset);
> +		do_test(NULL);
> +	}
> +
> +	cleanup();
> +	tst_exit();
> +}
> +
> +static void setup(void)
> +{
> +	if ((tst_kvercmp(2, 6, 19)) < 0) {
> +		tst_brkm(TCONF, NULL, "This test can only run on kernels "
> +			 "that are 2.6.19 or higher");
> +	}
> +
> +	tst_sig(FORK, DEF_HANDLER, cleanup);
> +
> +	TEST_PAUSE;
> +
> +	if (sigemptyset(&sigset) == -1)
> +		tst_brkm(TFAIL | TERRNO, NULL, "sigemptyset() failed");
> +
> +	if (sigaddset(&sigset, SIGUSR1) == -1)
> +		tst_brkm(TFAIL | TERRNO, NULL, "sigaddset() failed");
> +
> +	sa.sa_flags = 0;
> +	sa.sa_handler = sighandler;
> +	if (sigemptyset(&sa.sa_mask) == -1)
> +		tst_brkm(TFAIL | TERRNO, NULL, "sigemptyset() failed");
> +
> +	if (sigaction(SIGUSR1, &sa, NULL) == -1)
> +		tst_brkm(TFAIL | TERRNO, NULL, "sigaction() failed");
> +
> +	SAFE_PIPE(NULL, fds);
> +
> +	epfd = epoll_create(1);
> +	if (epfd == -1) {
> +		tst_brkm(TBROK | TERRNO, cleanup,
> +			 "failed to create epoll instance");
> +	}
> +
> +	epevs.events = EPOLLIN;
> +	epevs.data.fd = fds[0];
> +
> +	if (epoll_ctl(epfd, EPOLL_CTL_ADD, fds[0], &epevs) == -1) {
> +		tst_brkm(TBROK | TERRNO, cleanup,
> +			 "failed to register epoll target");
> +	}
> +}
> +
> +static void sighandler(int sig LTP_ATTRIBUTE_UNUSED)
> +{
> +
> +}
> +
> +static void do_test(sigset_t *sigmask)
> +{
> +	char read_buf[sizeof(buf)];
> +	pid_t cpid;
> +
> +	cpid = tst_fork();
> +	if (cpid < 0)
> +		tst_brkm(TBROK | TERRNO, cleanup, "fork() failed");
> +
> +	if (cpid == 0)
> +		do_child();
> +
> +	TEST(epoll_pwait(epfd, &epevs, 1, -1, sigmask));
> +
> +	if (sigmask != NULL) {
> +		if (TEST_RETURN == -1) {
> +			tst_resm(TFAIL | TTERRNO, "epoll_pwait() failed");
> +		} else if (TEST_RETURN != 1) {
> +			tst_resm(TFAIL, "epoll_pwait() returned %li, "
> +				 "expected 1", TEST_RETURN);
> +		} else {
> +			tst_resm(TPASS, "epoll_pwait(sigmask) blocked signal");
> +		}
> +	} else {
> +		if (TEST_RETURN != -1) {
> +			tst_resm(TFAIL, "epoll_wait() succeeded unexpectedly");
> +		} else {
> +			if (TEST_ERRNO == EINTR) {
> +				tst_resm(TPASS | TTERRNO,
> +					 "epoll_wait() failed as expected");
> +			} else {
> +				tst_resm(TFAIL | TTERRNO,
> +					 "epoll_wait() failed unexpectedly, "
> +					 "expected errno is EINTR");
> +			}
> +		}
> +	}


Can we put the checks in a separate functions and call them from here?

> +	tst_record_childstatus(cleanup, cpid);
> +
> +	SAFE_READ(cleanup, 1, fds[0], read_buf, sizeof(buf));
> +}
> +
> +static void do_child(void)
> +{
> +	if (tst_process_state_wait2(getppid(), 'S') != 0) {
> +		tst_brkm(TBROK | TERRNO, cleanup,
> +			 "failed to wait for parent process's state");
> +	}
> +
> +	SAFE_KILL(cleanup, getppid(), SIGUSR1);
> +
> +	sleep(1);

One second is too much, 0.1 second should be more than enough for the
test.

> +	SAFE_WRITE(cleanup, 1, fds[1], buf, sizeof(buf));

Technically we don't have to write anything here (and we could exit the
child without sleeping as well) if we passed a timeout to the
epoll_pwait() instead in the parent (we would have to check for timeout
instead of success but that shouldn't matter in this test).

> +	cleanup();
> +	tst_exit();
> +}

Otherwise it looks good.

-- 
Cyril Hrubis
chrubis@suse.cz