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 = 0;
 121                 ts.tv_nsec = 0;
 122         } else {
 123                 ts.tv_sec = timeout / 1000;
 124                 ts.tv_nsec = timeout * 1000000;
 125         }
 126
 127         nfds = kevent(poll_fd, NULL, 0, events, ARRAY_SIZE(events), &ts);
 128         for(n = 0; n < nfds; ++n)
 129         {
 130                 struct uloop_fd *u = events[n].udata;
 131                 unsigned int ev = 0;
 132
 133                 if(events[n].flags & EV_ERROR) {
 134                         u->error = true;
 135                         uloop_fd_delete(u);
 136                 }
 137
 138                 if(events[n].filter == EVFILT_READ)
 139                         ev |= ULOOP_READ;
 140                 else if (events[n].filter == EVFILT_WRITE)
 141                         ev |= ULOOP_WRITE;
 142
 143                 if(events[n].flags & EV_EOF)
 144                         u->eof = true;
 145                 else if (!ev)
 146                         continue;
 147
 148                 if(u->cb)
 149                         u->cb(u, ev);
 150         }
 151 }
 152
 153 #endif
 154
 155 #ifdef USE_EPOLL
 156
 157 /**
 158  * FIXME: uClibc < 0.9.30.3 does not define EPOLLRDHUP for Linux >= 2.6.17
 159  */
 160 #ifndef EPOLLRDHUP
 161 #define EPOLLRDHUP 0x2000
 162 #endif
 163
 164 int uloop_init(void)
 165 {
 166         poll_fd = epoll_create(32);
 167         if (poll_fd < 0)
 168                 return -1;
 169
 170         fcntl(poll_fd, F_SETFD, fcntl(poll_fd, F_GETFD) | FD_CLOEXEC);
 171         return 0;
 172 }
 173
 174 static int register_poll(struct uloop_fd *fd, unsigned int flags)
 175 {
 176         struct epoll_event ev;
 177         int op = fd->registered ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
 178
 179         memset(&ev, 0, sizeof(struct epoll_event));
 180
 181         if (flags & ULOOP_READ)
 182                 ev.events |= EPOLLIN | EPOLLRDHUP;
 183
 184         if (flags & ULOOP_WRITE)
 185                 ev.events |= EPOLLOUT;
 186
 187         if (flags & ULOOP_EDGE_TRIGGER)
 188                 ev.events |= EPOLLET;
 189
 190         ev.data.fd = fd->fd;
 191         ev.data.ptr = fd;
 192
 193         return epoll_ctl(poll_fd, op, fd->fd, &ev);
 194 }
 195
 196 int uloop_fd_delete(struct uloop_fd *sock)
 197 {
 198         sock->registered = false;
 199         return epoll_ctl(poll_fd, EPOLL_CTL_DEL, sock->fd, 0);
 200 }
 201
 202 static void uloop_run_events(int timeout)
 203 {
 204         struct epoll_event events[ULOOP_MAX_EVENTS];
 205         int nfds, n;
 206
 207         nfds = epoll_wait(poll_fd, events, ARRAY_SIZE(events), timeout);
 208         for(n = 0; n < nfds; ++n)
 209         {
 210                 struct uloop_fd *u = events[n].data.ptr;
 211                 unsigned int ev = 0;
 212
 213                 if(events[n].events & EPOLLERR) {
 214                         u->error = true;
 215                         uloop_fd_delete(u);
 216                 }
 217
 218                 if(!(events[n].events & (EPOLLRDHUP|EPOLLIN|EPOLLOUT|EPOLLERR)))
 219                         continue;
 220
 221                 if(events[n].events & EPOLLRDHUP)
 222                         u->eof = true;
 223
 224                 if(events[n].events & EPOLLIN)
 225                         ev |= ULOOP_READ;
 226
 227                 if(events[n].events & EPOLLOUT)
 228                         ev |= ULOOP_WRITE;
 229
 230                 if(u->cb)
 231                         u->cb(u, ev);
 232         }
 233 }
 234
 235 #endif
 236
 237 int uloop_fd_add(struct uloop_fd *sock, unsigned int flags)
 238 {
 239         unsigned int fl;
 240         int ret;
 241
 242         if (!sock->registered) {
 243                 fl = fcntl(sock->fd, F_GETFL, 0);
 244                 fl |= O_NONBLOCK;
 245                 fcntl(sock->fd, F_SETFL, fl);
 246         }
 247
 248         ret = register_poll(sock, flags);
 249         if (ret < 0)
 250                 goto out;
 251
 252         sock->registered = true;
 253         sock->eof = false;
 254
 255 out:
 256         return ret;
 257 }
 258
 259 static int tv_diff(struct timeval *t1, struct timeval *t2)
 260 {
 261         if (t1->tv_sec != t2->tv_sec)
 262                 return (t1->tv_sec - t2->tv_sec) * 1000;
 263         else
 264                 return (t1->tv_usec - t2->tv_usec) / 1000;
 265 }
 266
 267 int uloop_timeout_add(struct uloop_timeout *timeout)
 268 {
 269         struct uloop_timeout **head = &first_timeout;
 270         struct uloop_timeout *prev = NULL;
 271
 272         if (timeout->pending)
 273                 return -1;
 274
 275         while (*head) {
 276                 if (tv_diff(&(*head)->time, &timeout->time) > 0)
 277                         break;
 278
 279                 prev = *head;
 280                 head = &(*head)->next;
 281         }
 282
 283         timeout->prev = prev;
 284         timeout->next = *head;
 285         if (timeout->next)
 286                 timeout->next->prev = timeout;
 287         *head = timeout;
 288         timeout->pending = true;
 289
 290         return 0;
 291 }
 292
 293 int uloop_timeout_set(struct uloop_timeout *timeout, int msecs)
 294 {
 295         struct timeval *time = &timeout->time;
 296
 297         if (timeout->pending)
 298                 uloop_timeout_cancel(timeout);
 299
 300         gettimeofday(&timeout->time, NULL);
 301
 302         time->tv_sec += msecs / 1000;
 303         time->tv_usec += msecs % 1000;
 304
 305         if (time->tv_usec > 1000000) {
 306                 time->tv_sec++;
 307                 time->tv_usec %= 100000;
 308         }
 309
 310         return uloop_timeout_add(timeout);
 311 }
 312
 313 int uloop_timeout_cancel(struct uloop_timeout *timeout)
 314 {
 315         if (!timeout->pending)
 316                 return -1;
 317
 318         if (timeout->prev)
 319                 timeout->prev->next = timeout->next;
 320         else
 321                 first_timeout = timeout->next;
 322
 323         if (timeout->next)
 324                 timeout->next->prev = timeout->prev;
 325
 326         timeout->pending = false;
 327
 328         return 0;
 329 }
 330
 331 static void uloop_handle_sigint(int signo)
 332 {
 333         cancel = true;
 334 }
 335
 336 static void uloop_setup_signals(void)
 337 {
 338         struct sigaction s;
 339         memset(&s, 0, sizeof(struct sigaction));
 340         s.sa_handler = uloop_handle_sigint;
 341         s.sa_flags = 0;
 342         sigaction(SIGINT, &s, NULL);
 343 }
 344
 345 static int uloop_get_next_timeout(struct timeval *tv)
 346 {
 347         int diff;
 348
 349         if (!first_timeout)
 350                 return -1;
 351
 352         diff = tv_diff(&first_timeout->time, tv);
 353         if (diff < 0)
 354                 return 0;
 355
 356         return diff;
 357 }
 358
 359 static void uloop_process_timeouts(struct timeval *tv)
 360 {
 361         struct uloop_timeout *timeout;
 362
 363         while (first_timeout) {
 364                 if (tv_diff(&first_timeout->time, tv) > 0)
 365                         break;
 366
 367                 timeout = first_timeout;
 368                 uloop_timeout_cancel(timeout);
 369                 if (timeout->cb)
 370                         timeout->cb(timeout);
 371         }
 372 }
 373
 374 void uloop_end(void)
 375 {
 376         cancel = true;
 377 }
 378
 379 void uloop_run(void)
 380 {
 381         struct timeval tv;
 382
 383         uloop_setup_signals();
 384         while(!cancel)
 385         {
 386                 gettimeofday(&tv, NULL);
 387                 uloop_process_timeouts(&tv);
 388                 uloop_run_events(uloop_get_next_timeout(&tv));
 389         }
 390 }
 391
 392 void uloop_done(void)
 393 {
 394         close(poll_fd);
 395 }