uloop-kqueue.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 static int uloop_init_pollfd(void)
  19 {
  20         struct timespec timeout = { 0, 0 };
  21         struct kevent ev = {};
  22
  23         if (poll_fd >= 0)
  24                 return 0;
  25
  26         poll_fd = kqueue();
  27         if (poll_fd < 0)
  28                 return -1;
  29
  30         EV_SET(&ev, SIGCHLD, EVFILT_SIGNAL, EV_ADD, 0, 0, 0);
  31         kevent(poll_fd, &ev, 1, NULL, 0, &timeout);
  32
  33         return 0;
  34 }
  35
  36
  37 static uint16_t get_flags(unsigned int flags, unsigned int mask)
  38 {
  39         uint16_t kflags = 0;
  40
  41         if (!(flags & mask))
  42                 return EV_DELETE;
  43
  44         kflags = EV_ADD;
  45         if (flags & ULOOP_EDGE_TRIGGER)
  46                 kflags |= EV_CLEAR;
  47
  48         return kflags;
  49 }
  50
  51 static struct kevent events[ULOOP_MAX_EVENTS];
  52
  53 static int register_kevent(struct uloop_fd *fd, unsigned int flags)
  54 {
  55         struct timespec timeout = { 0, 0 };
  56         struct kevent ev[2];
  57         int nev = 0;
  58         unsigned int fl = 0;
  59         unsigned int changed;
  60         uint16_t kflags;
  61
  62         if (flags & ULOOP_EDGE_DEFER)
  63                 flags &= ~ULOOP_EDGE_TRIGGER;
  64
  65         changed = flags ^ fd->flags;
  66         if (changed & ULOOP_EDGE_TRIGGER)
  67                 changed |= flags;
  68
  69         if (!changed)
  70                 return 0;
  71
  72         if (changed & ULOOP_READ) {
  73                 kflags = get_flags(flags, ULOOP_READ);
  74                 EV_SET(&ev[nev++], fd->fd, EVFILT_READ, kflags, 0, 0, fd);
  75         }
  76
  77         if (changed & ULOOP_WRITE) {
  78                 kflags = get_flags(flags, ULOOP_WRITE);
  79                 EV_SET(&ev[nev++], fd->fd, EVFILT_WRITE, kflags, 0, 0, fd);
  80         }
  81
  82         if (!flags)
  83                 fl |= EV_DELETE;
  84
  85         if (kevent(poll_fd, ev, nev, NULL, fl, &timeout) == -1)
  86                 return -1;
  87
  88         return 0;
  89 }
  90
  91 static int register_poll(struct uloop_fd *fd, unsigned int flags)
  92 {
  93         if (flags & ULOOP_EDGE_TRIGGER)
  94                 flags |= ULOOP_EDGE_DEFER;
  95         else
  96                 flags &= ~ULOOP_EDGE_DEFER;
  97
  98         return register_kevent(fd, flags);
  99 }
 100
 101 static int __uloop_fd_delete(struct uloop_fd *fd)
 102 {
 103         return register_poll(fd, 0);
 104 }
 105
 106 static int uloop_fetch_events(int timeout)
 107 {
 108         struct timespec ts;
 109         int nfds, n;
 110
 111         if (timeout >= 0) {
 112                 ts.tv_sec = timeout / 1000;
 113                 ts.tv_nsec = (timeout % 1000) * 1000000;
 114         }
 115
 116         nfds = kevent(poll_fd, NULL, 0, events, ARRAY_SIZE(events), timeout >= 0 ? &ts : NULL);
 117         for (n = 0; n < nfds; n++) {
 118                 struct uloop_fd_event *cur = &cur_fds[n];
 119                 struct uloop_fd *u = events[n].udata;
 120                 unsigned int ev = 0;
 121
 122                 cur->fd = u;
 123                 if (!u)
 124                         continue;
 125
 126                 if (events[n].flags & EV_ERROR) {
 127                         u->error = true;
 128                         if (!(u->flags & ULOOP_ERROR_CB))
 129                                 uloop_fd_delete(u);
 130                 }
 131
 132                 if(events[n].filter == EVFILT_READ)
 133                         ev |= ULOOP_READ;
 134                 else if (events[n].filter == EVFILT_WRITE)
 135                         ev |= ULOOP_WRITE;
 136
 137                 if (events[n].flags & EV_EOF)
 138                         u->eof = true;
 139                 else if (!ev)
 140                         cur->fd = NULL;
 141
 142                 cur->events = ev;
 143                 if (u->flags & ULOOP_EDGE_DEFER) {
 144                         u->flags &= ~ULOOP_EDGE_DEFER;
 145                         u->flags |= ULOOP_EDGE_TRIGGER;
 146                         register_kevent(u, u->flags);
 147                 }
 148         }
 149         return nfds;
 150 }