luo980/libuv
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

zos: fix early exit of epoll_wait() (#3653)

Browse Source 
This fixes an early exit bug in z/OS implementation of epoll_wait(),
resulting in some file events not being correctly captured.

The problem is that reventcount should only be incremented by 1, because
_NFDS counts as 1 even for fds with multiple revents set.

Also makes a few minor improvements to remove redundant checks.

Co-authored-by: Igor Todorovski <itodorov@ca.ibm.com>
This commit is contained in:
Wayne Zhang 2022-06-28 23:42:11 -04:00 committed by GitHub
parent e3aaff185f
commit 27eec099d6
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 19 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
src/unix/os390-syscalls.c
View File

@ -284,6 +284,8 @@ int epoll_wait(uv__os390_epoll* lst, struct epoll_event* events,
nmsgsfds_t size;
struct pollfd* pfds;
int pollret;
int pollfdret;
int pollmsgret;
int reventcount;
int nevents;
struct pollfd msg_fd;
@ -304,24 +306,24 @@ int epoll_wait(uv__os390_epoll* lst, struct epoll_event* events,
return -1;
}
if (lst->size > 0)
_SET_FDS_MSGS(size, 1, lst->size - 1);
else
_SET_FDS_MSGS(size, 0, 0);
assert(lst->size > 0);
_SET_FDS_MSGS(size, 1, lst->size - 1);
pfds = lst->items;
pollret = poll(pfds, size, timeout);
if (pollret <= 0)
return pollret;
assert(lst->size > 0);
pollret = _NFDS(pollret) + _NMSGS(pollret);
pollfdret = _NFDS(pollret);
pollmsgret = _NMSGS(pollret);
reventcount = 0;
nevents = 0;
msg_fd = pfds[lst->size - 1];
msg_fd = pfds[lst->size - 1]; /* message queue is always last entry */
maxevents = maxevents - pollmsgret; /* allow spot for message queue */
for (i = 0;
i < lst->size && i < maxevents && reventcount < pollret; ++i) {
i < lst->size - 1 &&
nevents < maxevents &&
reventcount < pollfdret; ++i) {
struct epoll_event ev;
struct pollfd* pfd;
@ -332,18 +334,18 @@ int epoll_wait(uv__os390_epoll* lst, struct epoll_event* events,
ev.fd = pfd->fd;
ev.events = pfd->revents;
ev.is_msg = 0;
if (pfd->revents & POLLIN && pfd->revents & POLLOUT)
reventcount += 2;
else if (pfd->revents & (POLLIN | POLLOUT))
++reventcount;
pfd->revents = 0;
reventcount++;
events[nevents++] = ev;
}
if (msg_fd.revents != 0 && msg_fd.fd != -1)
if (i == lst->size)
events[nevents - 1].is_msg = 1;
if (pollmsgret > 0 && msg_fd.revents != 0 && msg_fd.fd != -1) {
struct epoll_event ev;
ev.fd = msg_fd.fd;
ev.events = msg_fd.revents;
ev.is_msg = 1;
events[nevents++] = ev;
}
return nevents;
}

1
src/unix/os390.c
View File

@ -1030,6 +1030,5 @@ int uv__io_fork(uv_loop_t* loop) {
*/
loop->ep = NULL;
uv__platform_loop_delete(loop);
return uv__platform_loop_init(loop);
}