[LTP] [PATCH 1/2] syscalls/epoll_*: allow for epoll_wait returning a subset of events
Cyril Hrubis
chrubis@suse.cz
Thu Jul 27 17:20:49 CEST 2017
Hi!
> static void check_epoll_ctl(int opt, int exp_num)
> {
> int res;
> -
> + unsigned int events;
> char write_buf[] = "test";
> char read_buf[sizeof(write_buf)];
>
> @@ -94,32 +94,59 @@ static void check_epoll_ctl(int opt, int exp_num)
> {.events = 0, .data.fd = 0}
> };
>
> + events = EPOLLIN;
> + if (exp_num == 2)
> + events |= EPOLLOUT;
> +
> SAFE_WRITE(1, fd[1], write_buf, sizeof(write_buf));
>
> - res = epoll_wait(epfd, res_evs, 2, -1);
> - if (res == -1)
> - tst_brk(TBROK | TERRNO, "epoll_wait() fails");
> + while (events) {
> + int events_returned = 0;
>
> - if (res != exp_num) {
> - tst_res(TFAIL, "epoll_wait() returns %i, expected %i",
> - res, exp_num);
> - goto end;
> - }
> + bzero(res_evs, sizeof(res_evs));
We should remove the initialization of the res_evs array since we are
clearing it here.
> + res = epoll_wait(epfd, res_evs, 2, -1);
> + if (res == -1)
> + tst_brk(TBROK | TERRNO, "epoll_wait() fails");
>
> - if (exp_num == 1) {
> - if (!has_event(res_evs, 2, fd[0], EPOLLIN) ||
> - !has_event(res_evs, 2, 0, 0)) {
> - tst_res(TFAIL, "epoll_wait() fails to "
> - "get expected fd and event");
> + if (res == 0) {
> + tst_res(TFAIL, "epoll_wait() returns 0, expected %s",
> + events == (EPOLLIN|EPOLLOUT) ? "1 or 2" : "1");
> goto end;
> }
> - }
>
> - if (exp_num == 2) {
> - if (!has_event(res_evs, 2, fd[0], EPOLLIN) ||
> - !has_event(res_evs, 2, fd[1], EPOLLOUT)) {
> - tst_res(TFAIL, "epoll_wait() fails to "
> - "get expected fd and event");
> + if (res == 1 && (res_evs[1].data.fd || res_evs[1].events)) {
> + tst_res(TFAIL,
> + "epoll_wait() returns 1 with 2 events");
> + goto end;
> + }
> +
> + if (has_event(res_evs, 2, fd[0], EPOLLIN)) {
> + if (events & EPOLLIN) {
> + events &= ~EPOLLIN;
> + events_returned++;
> + } else {
> + tst_res(TFAIL, "epoll_wait() returned %d "
> + "and EPOLLIN %x twice", fd[0],
> + EPOLLIN);
> + goto end;
> + }
> + }
> +
> + if (has_event(res_evs, 2, fd[1], EPOLLOUT)) {
> + if (events & EPOLLOUT) {
> + events &= ~EPOLLOUT;
> + events_returned++;
> + } else {
> + tst_res(TFAIL, "epoll_wait() returned %d "
> + "and EPOLLOUT %x twice", fd[1],
> + EPOLLOUT);
> + goto end;
> + }
> + }
> +
> + if (res != events_returned) {
> + tst_res(TFAIL, "epoll_wait() returned %d, expected %d",
> + res, events_returned);
I find this part a bit confusing. The res is actually number of events
returned from the epoll_wait() while the events_returned is a counter
for events that were matched correctly.
So what abou simplifying the logic a bit and doing:
while (events) {
int events_matched = 0;
res = epoll_wait(...);
if (res <= 0) {
tst_res(TFAIL | TERRNO, "epoll_wait() returned %i", res);
goto end;
}
if ((events & EPOLLIN) && has_event(res_evs, 2, fd[0], EPOLLIN)) {
events_matched++;
events &= ~EPOLLIN;
}
//the same for EPOLLOUT
if (res != events_matched) {
tst_res(TFAIL, "Got unexpected events");
//And possibly dump the res_evs here
goto end;
}
}
> goto end;
> }
> }
> diff --git a/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c b/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c
> index c8c55720f..1ea1ca2ec 100644
> --- a/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c
> +++ b/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c
> @@ -200,34 +200,59 @@ static void verify_epollio(void)
> {
> char write_buf[] = "Testing";
> char read_buf[sizeof(write_buf)];
> + uint32_t events = EPOLLIN | EPOLLOUT;
>
> SAFE_WRITE(cleanup, 1, fds[1], write_buf, sizeof(write_buf));
>
> - TEST(epoll_wait(epfd, epevs, 3, -1));
> -
> - if (TEST_RETURN == -1) {
> - tst_resm(TFAIL | TTERRNO, "epoll_wait() epollio failed");
> - goto end;
> - }
> -
> - if (TEST_RETURN != 2) {
> - tst_resm(TFAIL, "epoll_wait() returned %li, expected 2",
> - TEST_RETURN);
> - goto end;
> - }
> -
> - if (!has_event(epevs, 2, fds[0], EPOLLIN)) {
> - dump_epevs(epevs, 2);
> - tst_resm(TFAIL, "epoll_wait() expected %d and EPOLLIN %x",
> - fds[0], EPOLLIN);
> - goto end;
> - }
> -
> - if (!has_event(epevs, 2, fds[1], EPOLLOUT)) {
> - dump_epevs(epevs, 2);
> - tst_resm(TFAIL, "epoll_wait() expected %d and EPOLLOUT %x",
> - fds[1], EPOLLOUT);
> - goto end;
> + while (events) {
> + int events_returned = 0;
> +
> + TEST(epoll_wait(epfd, epevs, 3, -1));
> +
> + if (TEST_RETURN == -1) {
> + tst_resm(TFAIL | TTERRNO, "epoll_wait() epollio failed");
> + goto end;
> + }
> +
> + if (TEST_RETURN == 0) {
> + tst_resm(TFAIL, "epoll_wait() returned 0, expected %s",
> + events == (EPOLLIN|EPOLLOUT) ? "1 or 2" : "1");
> + goto end;
> + }
> +
> + if (has_event(epevs, 2, fds[0], EPOLLIN)) {
> + if (events & EPOLLIN) {
> + events &= ~EPOLLIN;
> + events_returned++;
> + } else {
> + dump_epevs(epevs, 2);
> + tst_resm(TFAIL, "epoll_wait() returned %d "
> + "and EPOLLIN %x twice", fds[0],
> + EPOLLIN);
> + goto end;
> + }
> + }
> +
> + if (has_event(epevs, 2, fds[1], EPOLLOUT)) {
> + if (events & EPOLLOUT) {
> + events &= ~EPOLLOUT;
> + events_returned++;
> + } else {
> + dump_epevs(epevs, 2);
> + tst_resm(TFAIL, "epoll_wait() returned %d "
> + "and EPOLLOUT %x twice", fds[1],
> + EPOLLOUT);
> + goto end;
> + }
> + }
> +
> + if (TEST_RETURN != events_returned) {
> + dump_epevs(epevs, 2);
> + tst_resm(TFAIL,
> + "epoll_wait() returned %li, expected %d",
> + TEST_RETURN, events_returned);
> + goto end;
> + }
> }
Here as well.
--
Cyril Hrubis
chrubis@suse.cz
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