ebc78d78a2
Since the fd update tables are per-thread, we need to have a bit per thread to indicate whether an update exists, otherwise this can lead to lost update events every time multiple threads want to update the same FD. In practice *for now*, it only happens at start time when listeners are enabled and ask for polling after facing their first EAGAIN. But since the pollers are still shared, a lost event is still recovered by a neighbor thread. This will not reliably work anymore with per-thread pollers, where it has been observed a few times on startup that a single-threaded listener would not always accept incoming connections upon startup. It's worth noting that during this code review it appeared that the "new" flag in the fdtab isn't used anymore. This fix should be backported to 1.8.