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 int64_t get_timestamp_us(void)
 107 {
 108 #ifdef CLOCK_MONOTONIC
 109         struct timespec ts = { 0, 0 };
 110
 111         clock_gettime(CLOCK_MONOTONIC, &ts);
 112
 113         return ts.tv_sec * 1000000 + ts.tv_nsec / 1000;
 114 #else
 115         struct timeval tv = { 0, 0 };
 116
 117         gettimeofday(&tv, NULL);
 118
 119         return tv.tv_sec * 1000000 + tv.tv_usec;
 120 #endif
 121 }
 122
 123 static int uloop_fetch_events(int timeout)
 124 {
 125         struct timespec ts;
 126         int nfds, n;
 127
 128         if (timeout >= 0) {
 129                 ts.tv_sec = timeout / 1000;
 130                 ts.tv_nsec = (timeout % 1000) * 1000000;
 131         }
 132
 133         nfds = kevent(poll_fd, NULL, 0, events, ARRAY_SIZE(events), timeout >= 0 ? &ts : NULL);
 134         for (n = 0; n < nfds; n++) {
 135                 if (events[n].filter == EVFILT_TIMER) {
 136                         struct uloop_interval *tm = events[n].udata;
 137
 138                         tm->priv.time.fired = get_timestamp_us();
 139                         tm->expirations += events[n].data;
 140                         tm->cb(tm);
 141
 142                         continue;
 143                 }
 144
 145                 struct uloop_fd_event *cur = &cur_fds[n];
 146                 struct uloop_fd *u = events[n].udata;
 147                 unsigned int ev = 0;
 148
 149                 cur->fd = u;
 150                 if (!u)
 151                         continue;
 152
 153                 if (events[n].flags & EV_ERROR) {
 154                         u->error = true;
 155                         if (!(u->flags & ULOOP_ERROR_CB))
 156                                 uloop_fd_delete(u);
 157                 }
 158
 159                 if(events[n].filter == EVFILT_READ)
 160                         ev |= ULOOP_READ;
 161                 else if (events[n].filter == EVFILT_WRITE)
 162                         ev |= ULOOP_WRITE;
 163
 164                 if (events[n].flags & EV_EOF)
 165                         u->eof = true;
 166                 else if (!ev)
 167                         cur->fd = NULL;
 168
 169                 cur->events = ev;
 170                 if (u->flags & ULOOP_EDGE_DEFER) {
 171                         u->flags &= ~ULOOP_EDGE_DEFER;
 172                         u->flags |= ULOOP_EDGE_TRIGGER;
 173                         register_kevent(u, u->flags);
 174                 }
 175         }
 176         return nfds;
 177 }
 178
 179 static int timer_register(struct uloop_interval *tm, unsigned int msecs)
 180 {
 181         struct kevent ev;
 182
 183         tm->priv.time.msecs = msecs;
 184         tm->priv.time.fired = get_timestamp_us();
 185
 186         EV_SET(&ev, (uintptr_t)tm, EVFILT_TIMER, EV_ADD, NOTE_USECONDS, msecs * 1000, tm);
 187
 188         return kevent(poll_fd, &ev, 1, NULL, 0, NULL);
 189 }
 190
 191 static int timer_remove(struct uloop_interval *tm)
 192 {
 193         struct kevent ev;
 194
 195         EV_SET(&ev, (uintptr_t)tm, EVFILT_TIMER, EV_DELETE, 0, 0, NULL);
 196
 197         return kevent(poll_fd, &ev, 1, NULL, 0, NULL);
 198 }
 199
 200 static int64_t timer_next(struct uloop_interval *tm)
 201 {
 202         int64_t t1 = tm->priv.time.fired;
 203         int64_t t2 = get_timestamp_us();
 204
 205         while (t1 < t2)
 206                 t1 += tm->priv.time.msecs * 1000;
 207
 208         return (t1 - t2) / 1000;
 209 }