On Fri, Apr 21, 2023 at 06:11:29PM +0100, Andre Przywara wrote: > > + read(epoll->stop_fd, &stop, sizeof(stop)); > > + write(epoll->stop_fd, &stop, sizeof(stop)); > > read(2) and write(2) (sys)calls without checking the return value upsets > Ubuntu's compiler: > > epoll.c: In function ‘epoll__thread’: > epoll.c:27:2: error: ignoring return value of ‘read’, declared with attribute warn_unused_result [-Werror=unused-result] > 27 | read(epoll->stop_fd, &stop, sizeof(stop)); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > (same for the write in the line after) > Since we use -Werror, this is fatal. > > I fixed it for now with: > if (read(epoll->stop_fd, &stop, sizeof(stop)) < 0) > return NULL; > > Not sure if there is a more meaningful way to bail out at this point. Ah right, previous code did `tmp = write(fd, &tmp, sizeof(tmp))` which seemed too silly to keep, and my compilers didn't complain. I'll add pr_warnings here. Thanks, Jean
