fix `rb_thread_wait_for_single_fd` on non MN case

`rb_thread_wait_for_single_fd(fd)` waits until `fd` is ready. Without MN it shouldn't use `thread_io_wait_events()` for the retry checking (alwasy false if MN is not active). 

1 files changed, 33 insertions, 30 deletions

diff --git a/thread.c b/thread.c
index a402102435..070d1bbdfa 100644
--- a/thread.c
+++ b/thread.c
@@ -4342,7 +4342,11 @@ rb_thread_fd_select(int max, rb_fdset_t * read, rb_fdset_t * write, rb_fdset_t *
 int
 rb_thread_wait_for_single_fd(int fd, int events, struct timeval *timeout)
 {
- struct pollfd fds[1];
+ struct pollfd fds[1] = {{
+ .fd = fd,
+ .events = (short)events,
+ .revents = 0,
+ }};
 int result = 0;
 nfds_t nfds;
 struct waiting_fd wfd;
@@ -4354,37 +4358,36 @@ rb_thread_wait_for_single_fd(int fd, int events, struct timeval *timeout)

 thread_io_setup_wfd(th, fd, &wfd);

- EC_PUSH_TAG(wfd.th->ec);
- if ((state = EC_EXEC_TAG()) == TAG_NONE) {
- rb_hrtime_t *to, rel, end = 0;
- struct timeval tv;
-
- RUBY_VM_CHECK_INTS_BLOCKING(wfd.th->ec);
-
- timeout_prepare(&to, &rel, &end, timeout);
- fds[0].fd = fd;
- fds[0].events = (short)events;
- fds[0].revents = 0;
-
- do {
- nfds = 1;
-
- lerrno = 0;
- BLOCKING_REGION(wfd.th, {
- struct timespec ts;
-
- if (!RUBY_VM_INTERRUPTED(wfd.th->ec)) {
- result = ppoll(fds, nfds, rb_hrtime2timespec(&ts, to), 0);
- if (result < 0) lerrno = errno;
- }
- }, ubf_select, wfd.th, TRUE);
-
+ if (timeout == NULL && thread_io_wait_events(th, fd, events, NULL)) {
+ // fd is readable
+ state = 0;
+ fds[0].revents = events;
+ errno = 0;
+ }
+ else {
+ EC_PUSH_TAG(wfd.th->ec);
+ if ((state = EC_EXEC_TAG()) == TAG_NONE) {
+ rb_hrtime_t *to, rel, end = 0;
 RUBY_VM_CHECK_INTS_BLOCKING(wfd.th->ec);
- } while (wait_retryable(&result, lerrno, to, end) &&
- thread_io_wait_events(th, fd, events, rb_hrtime2timeval(&tv, to)) &&
- wait_retryable(&result, lerrno, to, end));
+ timeout_prepare(&to, &rel, &end, timeout);
+ do {
+ nfds = 1;
+
+ lerrno = 0;
+ BLOCKING_REGION(wfd.th, {
+ struct timespec ts;
+
+ if (!RUBY_VM_INTERRUPTED(wfd.th->ec)) {
+ result = ppoll(fds, nfds, rb_hrtime2timespec(&ts, to), 0);
+ if (result < 0) lerrno = errno;
+ }
+ }, ubf_select, wfd.th, TRUE);
+
+ RUBY_VM_CHECK_INTS_BLOCKING(wfd.th->ec);
+ } while (wait_retryable(&result, lerrno, to, end));
+ }
+ EC_POP_TAG();
 }
- EC_POP_TAG();

 thread_io_wake_pending_closer(&wfd);