diff options
Diffstat (limited to 'framework/src/audit/src/libev/ev_epoll.c')
| -rw-r--r-- | framework/src/audit/src/libev/ev_epoll.c | 279 |
1 files changed, 0 insertions, 279 deletions
diff --git a/framework/src/audit/src/libev/ev_epoll.c b/framework/src/audit/src/libev/ev_epoll.c deleted file mode 100644 index 8a9b20f6..00000000 --- a/framework/src/audit/src/libev/ev_epoll.c +++ /dev/null @@ -1,279 +0,0 @@ -/* - * libev epoll fd activity backend - * - * Copyright (c) 2007,2008,2009,2010,2011 Marc Alexander Lehmann <libev@schmorp.de> - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without modifica- - * tion, are permitted provided that the following conditions are met: - * - * 1. Redistributions of source code must retain the above copyright notice, - * this list of conditions and the following disclaimer. - * - * 2. 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED - * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- - * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO - * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- - * CIAL, 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 OTH- - * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED - * OF THE POSSIBILITY OF SUCH DAMAGE. - * - * Alternatively, the contents of this file may be used under the terms of - * the GNU General Public License ("GPL") version 2 or any later version, - * in which case the provisions of the GPL are applicable instead of - * the above. If you wish to allow the use of your version of this file - * only under the terms of the GPL and not to allow others to use your - * version of this file under the BSD license, indicate your decision - * by deleting the provisions above and replace them with the notice - * and other provisions required by the GPL. If you do not delete the - * provisions above, a recipient may use your version of this file under - * either the BSD or the GPL. - */ - -/* - * general notes about epoll: - * - * a) epoll silently removes fds from the fd set. as nothing tells us - * that an fd has been removed otherwise, we have to continually - * "rearm" fds that we suspect *might* have changed (same - * problem with kqueue, but much less costly there). - * b) the fact that ADD != MOD creates a lot of extra syscalls due to a) - * and seems not to have any advantage. - * c) the inability to handle fork or file descriptors (think dup) - * limits the applicability over poll, so this is not a generic - * poll replacement. - * d) epoll doesn't work the same as select with many file descriptors - * (such as files). while not critical, no other advanced interface - * seems to share this (rather non-unixy) limitation. - * e) epoll claims to be embeddable, but in practise you never get - * a ready event for the epoll fd (broken: <=2.6.26, working: >=2.6.32). - * f) epoll_ctl returning EPERM means the fd is always ready. - * - * lots of "weird code" and complication handling in this file is due - * to these design problems with epoll, as we try very hard to avoid - * epoll_ctl syscalls for common usage patterns and handle the breakage - * ensuing from receiving events for closed and otherwise long gone - * file descriptors. - */ - -#include <sys/epoll.h> - -#define EV_EMASK_EPERM 0x80 - -static void -epoll_modify (EV_P_ int fd, int oev, int nev) -{ - struct epoll_event ev; - unsigned char oldmask; - - /* - * we handle EPOLL_CTL_DEL by ignoring it here - * on the assumption that the fd is gone anyways - * if that is wrong, we have to handle the spurious - * event in epoll_poll. - * if the fd is added again, we try to ADD it, and, if that - * fails, we assume it still has the same eventmask. - */ - if (!nev) - return; - - oldmask = anfds [fd].emask; - anfds [fd].emask = nev; - - /* store the generation counter in the upper 32 bits, the fd in the lower 32 bits */ - ev.data.u64 = (uint64_t)(uint32_t)fd - | ((uint64_t)(uint32_t)++anfds [fd].egen << 32); - ev.events = (nev & EV_READ ? EPOLLIN : 0) - | (nev & EV_WRITE ? EPOLLOUT : 0); - - if (expect_true (!epoll_ctl (backend_fd, oev && oldmask != nev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &ev))) - return; - - if (expect_true (errno == ENOENT)) - { - /* if ENOENT then the fd went away, so try to do the right thing */ - if (!epoll_ctl (backend_fd, EPOLL_CTL_ADD, fd, &ev)) - return; - } - else if (expect_true (errno == EEXIST)) - { - /* EEXIST means we ignored a previous DEL, but the fd is still active */ - /* if the kernel mask is the same as the new mask, we assume it hasn't changed */ - if (oldmask == nev) - goto dec_egen; - - if (!epoll_ctl (backend_fd, EPOLL_CTL_MOD, fd, &ev)) - return; - } - else if (expect_true (errno == EPERM)) - { - /* EPERM means the fd is always ready, but epoll is too snobbish */ - /* to handle it, unlike select or poll. */ - anfds [fd].emask = EV_EMASK_EPERM; - - /* add fd to epoll_eperms, if not already inside */ - if (!(oldmask & EV_EMASK_EPERM)) - { - array_needsize (int, epoll_eperms, epoll_epermmax, epoll_epermcnt + 1, EMPTY2); - epoll_eperms [epoll_epermcnt++] = fd; - } - - return; - } - - fd_kill (EV_A_ fd); - -dec_egen: - /* we didn't successfully call epoll_ctl, so decrement the generation counter again */ - --anfds [fd].egen; -} - -static void -epoll_poll (EV_P_ ev_tstamp timeout) -{ - int i; - int eventcnt; - - if (expect_false (epoll_epermcnt)) - timeout = 0.; - - /* epoll wait times cannot be larger than (LONG_MAX - 999UL) / HZ msecs, which is below */ - /* the default libev max wait time, however. */ - EV_RELEASE_CB; - eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, timeout * 1e3); - EV_ACQUIRE_CB; - - if (expect_false (eventcnt < 0)) - { - if (errno != EINTR) - ev_syserr ("(libev) epoll_wait"); - - return; - } - - for (i = 0; i < eventcnt; ++i) - { - struct epoll_event *ev = epoll_events + i; - - int fd = (uint32_t)ev->data.u64; /* mask out the lower 32 bits */ - int want = anfds [fd].events; - int got = (ev->events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0) - | (ev->events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0); - - /* - * check for spurious notification. - * this only finds spurious notifications on egen updates - * other spurious notifications will be found by epoll_ctl, below - * we assume that fd is always in range, as we never shrink the anfds array - */ - if (expect_false ((uint32_t)anfds [fd].egen != (uint32_t)(ev->data.u64 >> 32))) - { - /* recreate kernel state */ - postfork = 1; - continue; - } - - if (expect_false (got & ~want)) - { - anfds [fd].emask = want; - - /* - * we received an event but are not interested in it, try mod or del - * this often happens because we optimistically do not unregister fds - * when we are no longer interested in them, but also when we get spurious - * notifications for fds from another process. this is partially handled - * above with the gencounter check (== our fd is not the event fd), and - * partially here, when epoll_ctl returns an error (== a child has the fd - * but we closed it). - */ - ev->events = (want & EV_READ ? EPOLLIN : 0) - | (want & EV_WRITE ? EPOLLOUT : 0); - - /* pre-2.6.9 kernels require a non-null pointer with EPOLL_CTL_DEL, */ - /* which is fortunately easy to do for us. */ - if (epoll_ctl (backend_fd, want ? EPOLL_CTL_MOD : EPOLL_CTL_DEL, fd, ev)) - { - postfork = 1; /* an error occurred, recreate kernel state */ - continue; - } - } - - fd_event (EV_A_ fd, got); - } - - /* if the receive array was full, increase its size */ - if (expect_false (eventcnt == epoll_eventmax)) - { - ev_free (epoll_events); - epoll_eventmax = array_nextsize (sizeof (struct epoll_event), epoll_eventmax, epoll_eventmax + 1); - epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); - } - - /* now synthesize events for all fds where epoll fails, while select works... */ - for (i = epoll_epermcnt; i--; ) - { - int fd = epoll_eperms [i]; - unsigned char events = anfds [fd].events & (EV_READ | EV_WRITE); - - if (anfds [fd].emask & EV_EMASK_EPERM && events) - fd_event (EV_A_ fd, events); - else - { - epoll_eperms [i] = epoll_eperms [--epoll_epermcnt]; - anfds [fd].emask = 0; - } - } -} - -int inline_size -epoll_init (EV_P_ int flags) -{ -#ifdef EPOLL_CLOEXEC - backend_fd = epoll_create1 (EPOLL_CLOEXEC); - - if (backend_fd < 0 && (errno == EINVAL || errno == ENOSYS)) -#endif - backend_fd = epoll_create (256); - - if (backend_fd < 0) - return 0; - - fcntl (backend_fd, F_SETFD, FD_CLOEXEC); - - backend_mintime = 1e-3; /* epoll does sometimes return early, this is just to avoid the worst */ - backend_modify = epoll_modify; - backend_poll = epoll_poll; - - epoll_eventmax = 64; /* initial number of events receivable per poll */ - epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); - - return EVBACKEND_EPOLL; -} - -void inline_size -epoll_destroy (EV_P) -{ - ev_free (epoll_events); - array_free (epoll_eperm, EMPTY); -} - -void inline_size -epoll_fork (EV_P) -{ - close (backend_fd); - - while ((backend_fd = epoll_create (256)) < 0) - ev_syserr ("(libev) epoll_create"); - - fcntl (backend_fd, F_SETFD, FD_CLOEXEC); - - fd_rearm_all (EV_A); -} - |