/* * libev epoll fd activity backend * * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de> * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include <sys/epoll.h> static void epoll_modify (EV_P_ int fd, int oev, int nev) { int mode = nev ? oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD : EPOLL_CTL_DEL; struct epoll_event ev; ev.data.u64 = fd; /* use u64 to fully initialise the struct, for nicer strace etc. */ ev.events = (nev & EV_READ ? EPOLLIN : 0) | (nev & EV_WRITE ? EPOLLOUT : 0); if (epoll_ctl (epoll_fd, mode, fd, &ev)) if (errno != ENOENT /* on ENOENT the fd went away, so try to do the right thing */ || (nev && epoll_ctl (epoll_fd, EPOLL_CTL_ADD, fd, &ev))) fd_kill (EV_A_ fd); } static void epoll_poll (EV_P_ ev_tstamp timeout) { int i; int eventcnt = epoll_wait (epoll_fd, epoll_events, epoll_eventmax, (int)ceil (timeout * 1000.)); if (eventcnt < 0) { if (errno != EINTR) syserr ("(libev) epoll_wait"); return; } for (i = 0; i < eventcnt; ++i) fd_event ( EV_A_ epoll_events [i].data.u64, (epoll_events [i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0) | (epoll_events [i].events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0) ); /* if the receive array was full, increase its size */ if (expect_false (eventcnt == epoll_eventmax)) { ev_free (epoll_events); epoll_eventmax = array_roundsize (epoll_events, epoll_eventmax << 1); epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); } } static int epoll_init (EV_P_ int flags) { epoll_fd = epoll_create (256); if (epoll_fd < 0) return 0; fcntl (epoll_fd, F_SETFD, FD_CLOEXEC); backend_fudge = 1e-3; /* needed to compensate for epoll returning early */ backend_modify = epoll_modify; backend_poll = epoll_poll; epoll_eventmax = 64; /* intiial number of events receivable per poll */ epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); return EVBACKEND_EPOLL; } static void epoll_destroy (EV_P) { close (epoll_fd); ev_free (epoll_events); } static void epoll_fork (EV_P) { close (epoll_fd); while ((epoll_fd = epoll_create (256)) < 0) syserr ("(libev) epoll_create"); fcntl (epoll_fd, F_SETFD, FD_CLOEXEC); fd_rearm_all (EV_A); }