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libev/ev_epoll.c

108 lines
3.2 KiB
C

/*
* 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);
epoll_ctl (epoll_fd, mode, fd, &ev);
}
static void
epoll_postfork_child (EV_P)
{
int fd;
epoll_fd = epoll_create (256);
fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);
/* re-register interest in fds */
for (fd = 0; fd < anfdmax; ++fd)
if (anfds [fd].events)//D
epoll_modify (EV_A_ fd, EV_NONE, anfds [fd].events);
}
static void
epoll_poll (EV_P_ ev_tstamp timeout)
{
int eventcnt = epoll_wait (epoll_fd, events, eventmax, ceil (timeout * 1000.));
int i;
if (eventcnt < 0)
return;
for (i = 0; i < eventcnt; ++i)
fd_event (
EV_A_
events [i].data.u64,
(events [i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0)
| (events [i].events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0)
);
/* if the receive array was full, increase its size */
if (expect_false (eventcnt == eventmax))
{
free (events);
eventmax = array_roundsize (events, eventmax << 1);
events = malloc (sizeof (struct epoll_event) * 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);
method_fudge = 1e-3; /* needed to compensate for epoll returning early */
method_modify = epoll_modify;
method_poll = epoll_poll;
eventmax = 64; /* intiial number of events receivable per poll */
events = malloc (sizeof (struct epoll_event) * eventmax);
return EVMETHOD_EPOLL;
}