Re: [Libguestfs] [PATCH nbdkit 7/9] server: Add hand-written replacement for poll for Windows.

>+ * under an incompatible license. However Winsock has select so we >+ * can write a simple (but slow) emulation of poll using select. >+ */ >+int >+poll (struct pollfd *fds, int n, int timeout) >+{ >+ int i, nfds = 0, r; >+ fd_set readfds, writefds; >+ struct timeval tv, *tvp; >+ >+ FD_ZERO (&readfds); >+ FD_ZERO (&writefds); >+ >+ for (i = 0; i < n; ++i) { >+ if (fds[i].events & POLLIN) >+ FD_SET (fds[i].fd, &readfds); >+ if (fds[i].events & POLLOUT) >+ FD_SET (fds[i].fd, &writefds); >+ if (fds[i].fd > nfds) >+ nfds = fds[i].fd; >+ fds[i].revents = 0; >+ } >+ nfds++; Do we need to make sure that nfds does not exceed the limits of select? Calling FD_SET on a too-large fd causes memory corruption (twiddling bits outside of the fixed-length bitset is never good). Offhand, I didn't know the windows bitset length, but a quick google found: https://docs.microsoft.com/en-us/windows/win32/winsock/maximum-number-of-... where the default limit is 64 unless you set a compile-time macro prior to winsock2.h.