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/*
* libev poll 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.
*/
#include <poll.h>
inline_size
void
pollidx_init (int *base, int count)
{
/* consider using memset (.., -1, ...), which is practically guaranteed
* to work on all systems implementing poll */
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, pollidx_init);
idx = pollidxs [fd];
if (idx < 0) /* need to allocate a new pollfd */
{
pollidxs [fd] = idx = pollcnt++;
array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
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 (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, timeout * 1e3);
EV_ACQUIRE_CB;
if (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 (expect_false (p->revents)) /* this expect is debatable */
{
--res;
if (expect_false (p->revents & POLLNVAL))
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 = 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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