Re: [Libguestfs] [PATCH libnbd] lib/poll.c: Retry poll after EINTR

Sorry for a late reply... On Sat, Oct 23, 2021 at 11:10:08AM +0100, Richard W.M. Jones wrote: > > Fixing this in nbd_unlock_poll() avoids this issue in the entire > > library, when we wait for command completion. This seems more useful > > that fixing it in all libnbd clients. > > > > +++ b/lib/poll.c > > @@ -57,8 +57,11 @@ nbd_unlocked_poll (struct nbd_handle *h, int timeout) > > * would allow other threads to close file descriptors which we have > > * passed to poll. > > */ > > - r = poll (fds, 1, timeout); > > - debug (h, "poll end: r=%d revents=%x", r, fds[0].revents); > > + do { > > + r = poll (fds, 1, timeout); > > + debug (h, "poll end: r=%d revents=%x", r, fds[0].revents); > > + } while (r == -1 && errno == EINTR); > > + > > if (r == -1) { > > set_error (errno, "poll"); > > return -1; > > I think this is a perfectly reasonable solution, and better than > modifying the language bindings. I guess Eric should have the final > word here, but from my point of view ACK. As a library, libnbd has no idea if the overall program has installed signal handlers that may trigger EINTR, so being robust by retrying seems the sanest approach. ACK from me as well.