uloop.c

   1 /*
   2  *   Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
   3  *   Copyright (C) 2010 John Crispin <blogic@openwrt.org>
   4  *   Copyright (C) 2010 Steven Barth <steven@midlink.org>
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  19  *
  20  */
  21
  22 #include <sys/time.h>
  23 #include <sys/types.h>
  24
  25 #include "uloop.h"
  26
  27 #ifdef USE_KQUEUE
  28 #include <sys/event.h>
  29 #endif
  30 #ifdef USE_EPOLL
  31 #include <sys/epoll.h>
  32 #endif
  33
  34 #include <unistd.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <errno.h>
  38 #include <poll.h>
  39 #include <string.h>
  40 #include <fcntl.h>
  41 #include <signal.h>
  42 #include <stdbool.h>
  43
  44 #ifndef ARRAY_SIZE
  45 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
  46 #endif
  47 #define ULOOP_MAX_EVENTS 10
  48
  49 struct uloop_timeout *first_timeout;
  50 static int poll_fd;
  51 static bool cancel;
  52
  53 #ifdef USE_KQUEUE
  54
  55 int uloop_init(void)
  56 {
  57         poll_fd = kqueue();
  58         if (poll_fd < 0)
  59                 return -1;
  60
  61         return 0;
  62 }
  63
  64
  65 static uint16_t get_flags(unsigned int flags, unsigned int mask)
  66 {
  67         uint16_t kflags = 0;
  68
  69         if (!(flags & mask))
  70                 return EV_DELETE;
  71
  72         kflags = EV_ADD;
  73         if (flags & ULOOP_EDGE_TRIGGER)
  74                 kflags |= EV_CLEAR;
  75
  76         return kflags;
  77 }
  78
  79 static int register_poll(struct uloop_fd *fd, unsigned int flags)
  80 {
  81         struct timespec timeout = { 0, 0 };
  82         struct kevent ev[2];
  83         unsigned int changed;
  84         int nev = 0;
  85
  86         changed = fd->kqflags ^ flags;
  87         if (changed & ULOOP_EDGE_TRIGGER)
  88                 changed |= flags;
  89
  90         if (changed & ULOOP_READ) {
  91                 uint16_t kflags = get_flags(flags, ULOOP_READ);
  92                 EV_SET(&ev[nev++], fd->fd, EVFILT_READ, kflags, 0, 0, fd);
  93         }
  94
  95         if (changed & ULOOP_WRITE) {
  96                 uint16_t kflags = get_flags(flags, ULOOP_WRITE);
  97                 EV_SET(&ev[nev++], fd->fd, EVFILT_READ, kflags, 0, 0, fd);
  98         }
  99
 100         if (nev && (kevent(poll_fd, ev, nev, NULL, 0, &timeout) == -1))
 101                 return -1;
 102
 103         fd->kqflags = flags;
 104         return 0;
 105 }
 106
 107 int uloop_fd_delete(struct uloop_fd *sock)
 108 {
 109         sock->registered = false;
 110         return register_poll(sock, 0);
 111 }
 112
 113 static void uloop_run_events(int timeout)
 114 {
 115         struct kevent events[ULOOP_MAX_EVENTS];
 116         struct timespec ts;
 117         int nfds, n;
 118
 119         if (timeout > 0) {
 120                 ts.tv_sec = timeout / 1000;
 121                 ts.tv_nsec = timeout * 1000000;
 122         }
 123
 124         nfds = kevent(poll_fd, NULL, 0, events, ARRAY_SIZE(events), timeout > 0 ? &ts : NULL);
 125         for(n = 0; n < nfds; ++n)
 126         {
 127                 struct uloop_fd *u = events[n].udata;
 128                 unsigned int ev = 0;
 129
 130                 if(events[n].flags & EV_ERROR) {
 131                         u->error = true;
 132                         uloop_fd_delete(u);
 133                 }
 134
 135                 if(events[n].filter == EVFILT_READ)
 136                         ev |= ULOOP_READ;
 137                 else if (events[n].filter == EVFILT_WRITE)
 138                         ev |= ULOOP_WRITE;
 139
 140                 if(events[n].flags & EV_EOF)
 141                         u->eof = true;
 142                 else if (!ev)
 143                         continue;
 144
 145                 if(u->cb)
 146                         u->cb(u, ev);
 147         }
 148 }
 149
 150 #endif
 151
 152 #ifdef USE_EPOLL
 153
 154 /**
 155  * FIXME: uClibc < 0.9.30.3 does not define EPOLLRDHUP for Linux >= 2.6.17
 156  */
 157 #ifndef EPOLLRDHUP
 158 #define EPOLLRDHUP 0x2000
 159 #endif
 160
 161 int uloop_init(void)
 162 {
 163         poll_fd = epoll_create(32);
 164         if (poll_fd < 0)
 165                 return -1;
 166
 167         fcntl(poll_fd, F_SETFD, fcntl(poll_fd, F_GETFD) | FD_CLOEXEC);
 168         return 0;
 169 }
 170
 171 static int register_poll(struct uloop_fd *fd, unsigned int flags)
 172 {
 173         struct epoll_event ev;
 174         int op = fd->registered ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
 175
 176         memset(&ev, 0, sizeof(struct epoll_event));
 177
 178         if (flags & ULOOP_READ)
 179                 ev.events |= EPOLLIN | EPOLLRDHUP;
 180
 181         if (flags & ULOOP_WRITE)
 182                 ev.events |= EPOLLOUT;
 183
 184         if (flags & ULOOP_EDGE_TRIGGER)
 185                 ev.events |= EPOLLET;
 186
 187         ev.data.fd = fd->fd;
 188         ev.data.ptr = fd;
 189
 190         return epoll_ctl(poll_fd, op, fd->fd, &ev);
 191 }
 192
 193 int uloop_fd_delete(struct uloop_fd *sock)
 194 {
 195         sock->registered = false;
 196         return epoll_ctl(poll_fd, EPOLL_CTL_DEL, sock->fd, 0);
 197 }
 198
 199 static void uloop_run_events(int timeout)
 200 {
 201         struct epoll_event events[ULOOP_MAX_EVENTS];
 202         int nfds, n;
 203
 204         nfds = epoll_wait(poll_fd, events, ARRAY_SIZE(events), timeout);
 205         for(n = 0; n < nfds; ++n)
 206         {
 207                 struct uloop_fd *u = events[n].data.ptr;
 208                 unsigned int ev = 0;
 209
 210                 if(events[n].events & EPOLLERR) {
 211                         u->error = true;
 212                         uloop_fd_delete(u);
 213                 }
 214
 215                 if(!(events[n].events & (EPOLLRDHUP|EPOLLIN|EPOLLOUT|EPOLLERR)))
 216                         continue;
 217
 218                 if(events[n].events & EPOLLRDHUP)
 219                         u->eof = true;
 220
 221                 if(events[n].events & EPOLLIN)
 222                         ev |= ULOOP_READ;
 223
 224                 if(events[n].events & EPOLLOUT)
 225                         ev |= ULOOP_WRITE;
 226
 227                 if(u->cb)
 228                         u->cb(u, ev);
 229         }
 230 }
 231
 232 #endif
 233
 234 int uloop_fd_add(struct uloop_fd *sock, unsigned int flags)
 235 {
 236         unsigned int fl;
 237         int ret;
 238
 239         if (!sock->registered) {
 240                 fl = fcntl(sock->fd, F_GETFL, 0);
 241                 fl |= O_NONBLOCK;
 242                 fcntl(sock->fd, F_SETFL, fl);
 243         }
 244
 245         ret = register_poll(sock, flags);
 246         if (ret < 0)
 247                 goto out;
 248
 249         sock->registered = true;
 250         sock->eof = false;
 251
 252 out:
 253         return ret;
 254 }
 255
 256 static int tv_diff(struct timeval *t1, struct timeval *t2)
 257 {
 258         if (t1->tv_sec != t2->tv_sec)
 259                 return (t1->tv_sec - t2->tv_sec) * 1000;
 260         else
 261                 return (t1->tv_usec - t2->tv_usec) / 1000;
 262 }
 263
 264 int uloop_timeout_add(struct uloop_timeout *timeout)
 265 {
 266         struct uloop_timeout **head = &first_timeout;
 267         struct uloop_timeout *prev = NULL;
 268
 269         if (timeout->pending)
 270                 return -1;
 271
 272         while (*head) {
 273                 if (tv_diff(&(*head)->time, &timeout->time) > 0)
 274                         break;
 275
 276                 prev = *head;
 277                 head = &(*head)->next;
 278         }
 279
 280         timeout->prev = prev;
 281         timeout->next = *head;
 282         if (timeout->next)
 283                 timeout->next->prev = timeout;
 284         *head = timeout;
 285         timeout->pending = true;
 286
 287         return 0;
 288 }
 289
 290 int uloop_timeout_set(struct uloop_timeout *timeout, int msecs)
 291 {
 292         struct timeval *time = &timeout->time;
 293
 294         if (timeout->pending)
 295                 uloop_timeout_cancel(timeout);
 296
 297         gettimeofday(&timeout->time, NULL);
 298
 299         time->tv_sec += msecs / 1000;
 300         time->tv_usec += msecs % 1000;
 301
 302         if (time->tv_usec > 1000000) {
 303                 time->tv_sec++;
 304                 time->tv_usec %= 100000;
 305         }
 306
 307         return uloop_timeout_add(timeout);
 308 }
 309
 310 int uloop_timeout_cancel(struct uloop_timeout *timeout)
 311 {
 312         if (!timeout->pending)
 313                 return -1;
 314
 315         if (timeout->prev)
 316                 timeout->prev->next = timeout->next;
 317         else
 318                 first_timeout = timeout->next;
 319
 320         if (timeout->next)
 321                 timeout->next->prev = timeout->prev;
 322
 323         timeout->pending = false;
 324
 325         return 0;
 326 }
 327
 328 static void uloop_handle_sigint(int signo)
 329 {
 330         cancel = true;
 331 }
 332
 333 static void uloop_setup_signals(void)
 334 {
 335         struct sigaction s;
 336         memset(&s, 0, sizeof(struct sigaction));
 337         s.sa_handler = uloop_handle_sigint;
 338         s.sa_flags = 0;
 339         sigaction(SIGINT, &s, NULL);
 340 }
 341
 342 static int uloop_get_next_timeout(struct timeval *tv)
 343 {
 344         int diff;
 345
 346         if (!first_timeout)
 347                 return -1;
 348
 349         diff = tv_diff(&first_timeout->time, tv);
 350         if (diff < 0)
 351                 return 0;
 352
 353         return diff;
 354 }
 355
 356 static void uloop_process_timeouts(struct timeval *tv)
 357 {
 358         struct uloop_timeout *timeout;
 359
 360         while (first_timeout) {
 361                 if (tv_diff(&first_timeout->time, tv) > 0)
 362                         break;
 363
 364                 timeout = first_timeout;
 365                 uloop_timeout_cancel(timeout);
 366                 if (timeout->cb)
 367                         timeout->cb(timeout);
 368         }
 369 }
 370
 371 void uloop_end(void)
 372 {
 373         cancel = true;
 374 }
 375
 376 void uloop_run(void)
 377 {
 378         struct timeval tv;
 379
 380         uloop_setup_signals();
 381         while(!cancel)
 382         {
 383                 gettimeofday(&tv, NULL);
 384                 uloop_process_timeouts(&tv);
 385                 uloop_run_events(uloop_get_next_timeout(&tv));
 386         }
 387 }
 388
 389 void uloop_done(void)
 390 {
 391         close(poll_fd);
 392 }