uloop-epoll.c

   1 /*
   2  * uloop - event loop implementation
   3  *
   4  * Copyright (C) 2010-2016 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 /**
  20  * FIXME: uClibc < 0.9.30.3 does not define EPOLLRDHUP for Linux >= 2.6.17
  21  */
  22 #ifndef EPOLLRDHUP
  23 #define EPOLLRDHUP 0x2000
  24 #endif
  25
  26 static int uloop_init_pollfd(void)
  27 {
  28         if (poll_fd >= 0)
  29                 return 0;
  30
  31         poll_fd = epoll_create(32);
  32         if (poll_fd < 0)
  33                 return -1;
  34
  35         fcntl(poll_fd, F_SETFD, fcntl(poll_fd, F_GETFD) | FD_CLOEXEC);
  36         return 0;
  37 }
  38
  39 static int register_poll(struct uloop_fd *fd, unsigned int flags)
  40 {
  41         struct epoll_event ev;
  42         int op = fd->registered ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
  43
  44         memset(&ev, 0, sizeof(struct epoll_event));
  45
  46         if (flags & ULOOP_READ)
  47                 ev.events |= EPOLLIN | EPOLLRDHUP;
  48
  49         if (flags & ULOOP_WRITE)
  50                 ev.events |= EPOLLOUT;
  51
  52         if (flags & ULOOP_EDGE_TRIGGER)
  53                 ev.events |= EPOLLET;
  54
  55         ev.data.ptr = fd;
  56         fd->flags = flags;
  57
  58         return epoll_ctl(poll_fd, op, fd->fd, &ev);
  59 }
  60
  61 static struct epoll_event events[ULOOP_MAX_EVENTS];
  62
  63 static int __uloop_fd_delete(struct uloop_fd *sock)
  64 {
  65         sock->flags = 0;
  66         return epoll_ctl(poll_fd, EPOLL_CTL_DEL, sock->fd, 0);
  67 }
  68
  69 static int uloop_fetch_events(int timeout)
  70 {
  71         int n, nfds;
  72
  73         nfds = epoll_wait(poll_fd, events, ARRAY_SIZE(events), timeout);
  74         for (n = 0; n < nfds; ++n) {
  75                 struct uloop_fd_event *cur = &cur_fds[n];
  76                 struct uloop_fd *u = events[n].data.ptr;
  77                 unsigned int ev = 0;
  78
  79                 cur->fd = u;
  80                 if (!u)
  81                         continue;
  82
  83                 if (events[n].events & (EPOLLERR|EPOLLHUP)) {
  84                         u->error = true;
  85                         if (!(u->flags & ULOOP_ERROR_CB))
  86                                 uloop_fd_delete(u);
  87                 }
  88
  89                 if(!(events[n].events & (EPOLLRDHUP|EPOLLIN|EPOLLOUT|EPOLLERR|EPOLLHUP))) {
  90                         cur->fd = NULL;
  91                         continue;
  92                 }
  93
  94                 if(events[n].events & EPOLLRDHUP)
  95                         u->eof = true;
  96
  97                 if(events[n].events & EPOLLIN)
  98                         ev |= ULOOP_READ;
  99
 100                 if(events[n].events & EPOLLOUT)
 101                         ev |= ULOOP_WRITE;
 102
 103                 cur->events = ev;
 104         }
 105
 106         return nfds;
 107 }