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- /*
- * libev poll fd activity backend
- *
- * Copyright (c) 2007,2008,2009,2010,2011,2016,2019 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.
- */
-
- #include <poll.h>
-
- inline_size
- void
- array_needsize_pollidx (int *base, int offset, int count)
- {
- /* using memset (.., -1, ...) is tempting, we we try
- * to be ultraportable
- */
- base += offset;
- while (count--)
- *base++ = -1;
- }
-
- static void
- poll_modify (EV_P_ int fd, int oev, int nev)
- {
- int idx;
-
- if (oev == nev)
- return;
-
- array_needsize (int, pollidxs, pollidxmax, fd + 1, array_needsize_pollidx);
-
- idx = pollidxs [fd];
-
- if (idx < 0) /* need to allocate a new pollfd */
- {
- pollidxs [fd] = idx = pollcnt++;
- array_needsize (struct pollfd, polls, pollmax, pollcnt, array_needsize_noinit);
- polls [idx].fd = fd;
- }
-
- assert (polls [idx].fd == fd);
-
- if (nev)
- polls [idx].events =
- (nev & EV_READ ? POLLIN : 0)
- | (nev & EV_WRITE ? POLLOUT : 0);
- else /* remove pollfd */
- {
- pollidxs [fd] = -1;
-
- if (ecb_expect_true (idx < --pollcnt))
- {
- polls [idx] = polls [pollcnt];
- pollidxs [polls [idx].fd] = idx;
- }
- }
- }
-
- static void
- poll_poll (EV_P_ ev_tstamp timeout)
- {
- struct pollfd *p;
- int res;
-
- EV_RELEASE_CB;
- res = poll (polls, pollcnt, EV_TS_TO_MSEC (timeout));
- EV_ACQUIRE_CB;
-
- if (ecb_expect_false (res < 0))
- {
- if (errno == EBADF)
- fd_ebadf (EV_A);
- else if (errno == ENOMEM && !syserr_cb)
- fd_enomem (EV_A);
- else if (errno != EINTR)
- ev_syserr ("(libev) poll");
- }
- else
- for (p = polls; res; ++p)
- {
- assert (("libev: poll returned illegal result, broken BSD kernel?", p < polls + pollcnt));
-
- if (ecb_expect_false (p->revents)) /* this expect is debatable */
- {
- --res;
-
- if (ecb_expect_false (p->revents & POLLNVAL))
- {
- assert (("libev: poll found invalid fd in poll set", 0));
- fd_kill (EV_A_ p->fd);
- }
- else
- fd_event (
- EV_A_
- p->fd,
- (p->revents & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
- | (p->revents & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
- );
- }
- }
- }
-
- inline_size
- int
- poll_init (EV_P_ int flags)
- {
- backend_mintime = EV_TS_CONST (1e-3);
- backend_modify = poll_modify;
- backend_poll = poll_poll;
-
- pollidxs = 0; pollidxmax = 0;
- polls = 0; pollmax = 0; pollcnt = 0;
-
- return EVBACKEND_POLL;
- }
-
- inline_size
- void
- poll_destroy (EV_P)
- {
- ev_free (pollidxs);
- ev_free (polls);
- }
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