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| author | Takashi Yano <takashi.yano@nifty.ne.jp> | 2022-06-27 10:03:04 +0900 |
|---|---|---|
| committer | Takashi Yano <takashi.yano@nifty.ne.jp> | 2022-06-27 10:21:07 +0900 |
| commit | 5603daa90003aba39454b0e9b53d3ab79a9e041d (patch) | |
| tree | 5b8ba1abb726464b5bd94989804480e5735599f5 /winsup | |
| parent | 4d23f837dc9da544a202d555a9c8e9534668e14f (diff) | |
| download | newlib-5603daa90003aba39454b0e9b53d3ab79a9e041d.zip newlib-5603daa90003aba39454b0e9b53d3ab79a9e041d.tar.gz newlib-5603daa90003aba39454b0e9b53d3ab79a9e041d.tar.bz2 | |
Cygwin: poll: Fix a bug on inquiring same fd with different events.
- poll() has a bug that it returns event which is not inquired if
events are inquired in multiple pollfd entries on the same fd at
the same time. This patch fixes the issue.
Addresses: https://cygwin.com/pipermail/cygwin/2022-June/251732.html
Diffstat (limited to 'winsup')
| -rw-r--r-- | winsup/cygwin/poll.cc | 8 | ||||
| -rw-r--r-- | winsup/cygwin/release/3.3.6 | 5 |
2 files changed, 10 insertions, 3 deletions
diff --git a/winsup/cygwin/poll.cc b/winsup/cygwin/poll.cc index 4404134..a67507b 100644 --- a/winsup/cygwin/poll.cc +++ b/winsup/cygwin/poll.cc @@ -104,7 +104,7 @@ poll (struct pollfd *fds, nfds_t nfds, int timeout) fds[i].revents = POLLHUP; else { - if (FD_ISSET(fds[i].fd, read_fds)) + if ((fds[i].events & POLLIN) && FD_ISSET(fds[i].fd, read_fds)) /* This should be sufficient for sockets, too. Using MSG_PEEK, as before, can be considered dangerous at best. Quote from W. Richard Stevens: "The presence @@ -122,9 +122,11 @@ poll (struct pollfd *fds, nfds_t nfds, int timeout) fds[i].revents |= (POLLIN | POLLERR); else { - if (FD_ISSET(fds[i].fd, write_fds)) + if ((fds[i].events & POLLOUT) + && FD_ISSET(fds[i].fd, write_fds)) fds[i].revents |= POLLOUT; - if (FD_ISSET(fds[i].fd, except_fds)) + if ((fds[i].events & POLLPRI) + && FD_ISSET(fds[i].fd, except_fds)) fds[i].revents |= POLLPRI; } } diff --git a/winsup/cygwin/release/3.3.6 b/winsup/cygwin/release/3.3.6 index 49ac58b..f1a4b78 100644 --- a/winsup/cygwin/release/3.3.6 +++ b/winsup/cygwin/release/3.3.6 @@ -17,3 +17,8 @@ Bug Fixes - Handle setting very long window title correctly in console. Addresses: https://cygwin.com/pipermail/cygwin/2022-June/251662.html + +- Fix a bug of poll() that it returns event which is not inquired + if events are inquired in multiple pollfd entries on the same fd + at the same time. + Addresses: https://cygwin.com/pipermail/cygwin/2022-June/251732.html |