/* * libev kqueue 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/types.h> #include <sys/time.h> #include <sys/queue.h> #include <sys/event.h> #include <string.h> #include <errno.h> static void kqueue_change (EV_P_ int fd, int filter, int flags, int fflags) { struct kevent *ke; ++kqueue_changecnt; array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2); EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0); } #ifndef NOTE_EOF # define NOTE_EOF 0 #endif static void kqueue_modify (EV_P_ int fd, int oev, int nev) { if (oev != nev) { if (oev & EV_READ) kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0); if (oev & EV_WRITE) kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0); } /* to detect close/reopen reliably, we have to re-add */ /* event requests even when oev == nev */ if (nev & EV_READ) kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD, NOTE_EOF); if (nev & EV_WRITE) kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD, NOTE_EOF); } static void kqueue_poll (EV_P_ ev_tstamp timeout) { int res, i; struct timespec ts; /* need to resize so there is enough space for errors */ if (kqueue_changecnt > kqueue_eventmax) { ev_free (kqueue_events); kqueue_eventmax = array_roundsize (struct kevent, kqueue_changecnt); kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax); } ts.tv_sec = (time_t)timeout; ts.tv_nsec = (long)((timeout - (ev_tstamp)ts.tv_sec) * 1e9); res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts); kqueue_changecnt = 0; if (res < 0) { if (errno != EINTR) syserr ("(libev) kevent"); return; } for (i = 0; i < res; ++i) { int fd = kqueue_events [i].ident; if (expect_false (kqueue_events [i].flags & EV_ERROR)) { int err = kqueue_events [i].data; /* we are only interested in errors for fds that we are interested in :) */ if (anfds [fd].events) { if (err == ENOENT) /* resubmit changes on ENOENT */ kqueue_modify (EV_A_ fd, 0, anfds [fd].events); else if (err == EBADF) /* on EBADF, we re-check the fd */ { if (fd_valid (fd)) kqueue_modify (EV_A_ fd, 0, anfds [fd].events); else fd_kill (EV_A_ fd); } else /* on all other errors, we error out on the fd */ fd_kill (EV_A_ fd); } } else fd_event ( EV_A_ fd, kqueue_events [i].filter == EVFILT_READ ? EV_READ : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE : 0 ); } if (expect_false (res == kqueue_eventmax)) { ev_free (kqueue_events); kqueue_eventmax = array_roundsize (struct kevent, kqueue_eventmax << 1); kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax); } } static int kqueue_init (EV_P_ int flags) { struct kevent ch, ev; /* Initalize the kernel queue */ if ((backend_fd = kqueue ()) < 0) return 0; fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */ /* fudge *might* be zero from the documentation, but bsd docs are notoriously wrong */ backend_fudge = 1e-3; /* needed to compensate for kevent returning early */ backend_modify = kqueue_modify; backend_poll = kqueue_poll; kqueue_eventmax = 64; /* initial number of events receivable per poll */ kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax); kqueue_changes = 0; kqueue_changemax = 0; kqueue_changecnt = 0; return EVBACKEND_KQUEUE; } static void kqueue_destroy (EV_P) { close (backend_fd); ev_free (kqueue_events); ev_free (kqueue_changes); } static void kqueue_fork (EV_P) { close (backend_fd); while ((backend_fd = kqueue ()) < 0) syserr ("(libev) kqueue"); fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* re-register interest in fds */ fd_rearm_all (EV_A); }