git.meshlink.io Git - meshlink/blob - src/event.c

   1 /*
   2     event.c -- I/O and timeout event handling
   3     Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License along
  16     with this program; if not, write to the Free Software Foundation, Inc.,
  17     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "system.h"
  21
  22 #include "dropin.h"
  23 #include "event.h"
  24 #include "net.h"
  25 #include "splay_tree.h"
  26 #include "utils.h"
  27 #include "xalloc.h"
  28
  29 static int io_compare(const io_t *a, const io_t *b) {
  30         return a->fd - b->fd;
  31 }
  32
  33 static int timeout_compare(const timeout_t *a, const timeout_t *b) {
  34         struct timeval diff;
  35         timersub(&a->tv, &b->tv, &diff);
  36         if(diff.tv_sec < 0)
  37                 return -1;
  38         if(diff.tv_sec > 0)
  39                 return 1;
  40         if(diff.tv_usec < 0)
  41                 return -1;
  42         if(diff.tv_usec > 0)
  43                 return 1;
  44         if(a < b)
  45                 return -1;
  46         if(a > b)
  47                 return 1;
  48         return 0;
  49 }
  50
  51 void io_add(event_loop_t *loop, io_t *io, io_cb_t cb, void *data, int fd, int flags) {
  52         if(io->cb)
  53                 return;
  54
  55         io->fd = fd;
  56         io->cb = cb;
  57         io->data = data;
  58         io->node.data = io;
  59
  60         io_set(loop, io, flags);
  61
  62         if(!splay_insert_node(&loop->ios, &io->node))
  63                 abort();
  64 }
  65
  66 void io_set(event_loop_t *loop, io_t *io, int flags) {
  67         io->flags = flags;
  68
  69         if(flags & IO_READ)
  70                 FD_SET(io->fd, &loop->readfds);
  71         else
  72                 FD_CLR(io->fd, &loop->readfds);
  73
  74         if(flags & IO_WRITE)
  75                 FD_SET(io->fd, &loop->writefds);
  76         else
  77                 FD_CLR(io->fd, &loop->writefds);
  78 }
  79
  80 void io_del(event_loop_t *loop, io_t *io) {
  81         if(!io->cb)
  82                 return;
  83
  84         io_set(loop, io, 0);
  85
  86         splay_unlink_node(&loop->ios, &io->node);
  87         io->cb = NULL;
  88 }
  89
  90 void timeout_add(event_loop_t *loop, timeout_t *timeout, timeout_cb_t cb, void *data, struct timeval *tv) {
  91         timeout->cb = cb;
  92         timeout->data = data;
  93         timeout->node.data = timeout;
  94
  95         timeout_set(loop, timeout, tv);
  96 }
  97
  98 void timeout_set(event_loop_t *loop, timeout_t *timeout, struct timeval *tv) {
  99         if(timerisset(&timeout->tv))
 100                 splay_unlink_node(&loop->timeouts, &timeout->node);
 101
 102         if(!loop->now.tv_sec)
 103                 gettimeofday(&loop->now, NULL);
 104
 105         timeradd(&loop->now, tv, &timeout->tv);
 106
 107         if(!splay_insert_node(&loop->timeouts, &timeout->node))
 108                 abort();
 109 }
 110
 111 void timeout_del(event_loop_t *loop, timeout_t *timeout) {
 112         if(!timeout->cb)
 113                 return;
 114
 115         splay_unlink_node(&loop->timeouts, &timeout->node);
 116         timeout->cb = 0;
 117         timeout->tv = (struct timeval){0, 0};
 118 }
 119
 120 bool event_loop_run(event_loop_t *loop) {
 121         loop->running = true;
 122
 123         fd_set readable;
 124         fd_set writable;
 125
 126         while(loop->running) {
 127                 gettimeofday(&loop->now, NULL);
 128                 struct timeval diff, *tv = NULL;
 129
 130                 while(loop->timeouts.head) {
 131                         timeout_t *timeout = loop->timeouts.head->data;
 132                         timersub(&timeout->tv, &loop->now, &diff);
 133
 134                         if(diff.tv_sec < 0) {
 135                                 timeout->cb(loop, timeout->data);
 136                                 if(timercmp(&timeout->tv, &loop->now, <))
 137                                         timeout_del(loop, timeout);
 138                         } else {
 139                                 tv = &diff;
 140                                 break;
 141                         }
 142                 }
 143
 144                 memcpy(&readable, &loop->readfds, sizeof readable);
 145                 memcpy(&writable, &loop->writefds, sizeof writable);
 146
 147                 int fds = 0;
 148
 149                 if(loop->ios.tail) {
 150                         io_t *last = loop->ios.tail->data;
 151                         fds = last->fd + 1;
 152                 }
 153
 154                 int n = select(fds, &readable, &writable, NULL, tv);
 155
 156                 if(n < 0) {
 157                         if(sockwouldblock(errno))
 158                                 continue;
 159                         else
 160                                 return false;
 161                 }
 162
 163                 if(!n)
 164                         continue;
 165
 166                 for splay_each(io_t, io, &loop->ios) {
 167                         if(FD_ISSET(io->fd, &writable))
 168                                 io->cb(loop, io->data, IO_WRITE);
 169                         else if(FD_ISSET(io->fd, &readable))
 170                                 io->cb(loop, io->data, IO_READ);
 171                 }
 172         }
 173
 174         return true;
 175 }
 176
 177 void event_flush_output(event_loop_t *loop) {
 178         for splay_each(io_t, io, &loop->ios)
 179                 if(FD_ISSET(io->fd, &loop->writefds))
 180                         io->cb(loop, io->data, IO_WRITE);
 181 }
 182
 183 void event_loop_stop(event_loop_t *loop) {
 184         loop->running = false;
 185 }
 186
 187 void event_loop_init(event_loop_t *loop) {
 188         loop->ios.compare = (splay_compare_t)io_compare;
 189         loop->timeouts.compare = (splay_compare_t)timeout_compare;
 190         gettimeofday(&loop->now, NULL);
 191 }
 192
 193 void event_loop_exit(event_loop_t *loop) {
 194         for splay_each(io_t, io, &loop->ios)
 195                 splay_free_node(&loop->ios, node);
 196         for splay_each(timeout_t, timeout, &loop->timeouts)
 197                 splay_free_node(&loop->timeouts, node);
 198 }