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
  57         return epoll_ctl(poll_fd, op, fd->fd, &ev);
  58 }
  59
  60 static struct epoll_event events[ULOOP_MAX_EVENTS];
  61
  62 static int __uloop_fd_delete(struct uloop_fd *sock)
  63 {
  64         sock->flags = 0;
  65         return epoll_ctl(poll_fd, EPOLL_CTL_DEL, sock->fd, 0);
  66 }
  67
  68 static int uloop_fetch_events(int timeout)
  69 {
  70         int n, nfds;
  71
  72         nfds = epoll_wait(poll_fd, events, ARRAY_SIZE(events), timeout);
  73         for (n = 0; n < nfds; ++n) {
  74                 struct uloop_fd_event *cur = &cur_fds[n];
  75                 struct uloop_fd *u = events[n].data.ptr;
  76                 unsigned int ev = 0;
  77
  78                 cur->fd = u;
  79                 if (!u)
  80                         continue;
  81
  82                 if (events[n].events & (EPOLLERR|EPOLLHUP)) {
  83                         u->error = true;
  84                         if (!(u->flags & ULOOP_ERROR_CB))
  85                                 uloop_fd_delete(u);
  86                 }
  87
  88                 if(!(events[n].events & (EPOLLRDHUP|EPOLLIN|EPOLLOUT|EPOLLERR|EPOLLHUP))) {
  89                         cur->fd = NULL;
  90                         continue;
  91                 }
  92
  93                 if(events[n].events & EPOLLRDHUP)
  94                         u->eof = true;
  95
  96                 if(events[n].events & EPOLLIN)
  97                         ev |= ULOOP_READ;
  98
  99                 if(events[n].events & EPOLLOUT)
 100                         ev |= ULOOP_WRITE;
 101
 102                 cur->events = ev;
 103         }
 104
 105         return nfds;
 106 }
 107
 108 static void dispatch_timer(struct uloop_fd *u, unsigned int events)
 109 {
 110         if (!(events & ULOOP_READ))
 111                 return;
 112
 113         uint64_t fired;
 114
 115         if (read(u->fd, &fired, sizeof(fired)) != sizeof(fired))
 116                 return;
 117
 118         struct uloop_interval *tm = container_of(u, struct uloop_interval, priv.ufd);
 119
 120         tm->expirations += fired;
 121         tm->cb(tm);
 122 }
 123
 124 static int timer_register(struct uloop_interval *tm, unsigned int msecs)
 125 {
 126         if (!tm->priv.ufd.registered) {
 127                 int fd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC|TFD_NONBLOCK);
 128
 129                 if (fd == -1)
 130                         return -1;
 131
 132                 tm->priv.ufd.fd = fd;
 133                 tm->priv.ufd.cb = dispatch_timer;
 134         }
 135
 136         struct itimerspec spec = {
 137                 .it_value = {
 138                         .tv_sec = msecs / 1000,
 139                         .tv_nsec = (msecs % 1000) * 1000000
 140                 },
 141                 .it_interval = {
 142                         .tv_sec = msecs / 1000,
 143                         .tv_nsec = (msecs % 1000) * 1000000
 144                 }
 145         };
 146
 147         if (timerfd_settime(tm->priv.ufd.fd, 0, &spec, NULL) == -1)
 148                 goto err;
 149
 150         if (uloop_fd_add(&tm->priv.ufd, ULOOP_READ) == -1)
 151                 goto err;
 152
 153         return 0;
 154
 155 err:
 156         uloop_fd_delete(&tm->priv.ufd);
 157         close(tm->priv.ufd.fd);
 158         memset(&tm->priv.ufd, 0, sizeof(tm->priv.ufd));
 159
 160         return -1;
 161 }
 162
 163 static int timer_remove(struct uloop_interval *tm)
 164 {
 165         int ret = __uloop_fd_delete(&tm->priv.ufd);
 166
 167         if (ret == 0) {
 168                 close(tm->priv.ufd.fd);
 169                 memset(&tm->priv.ufd, 0, sizeof(tm->priv.ufd));
 170         }
 171
 172         return ret;
 173 }
 174
 175 static int64_t timer_next(struct uloop_interval *tm)
 176 {
 177         struct itimerspec spec;
 178
 179         if (!tm->priv.ufd.registered)
 180                 return -1;
 181
 182         if (timerfd_gettime(tm->priv.ufd.fd, &spec) == -1)
 183                 return -1;
 184
 185         return spec.it_value.tv_sec * 1000 + spec.it_value.tv_nsec / 1000000;
 186 }