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 static struct uloop_timeout *first_timeout;
  50 static int poll_fd = -1;
  51 bool uloop_cancelled = false;
  52
  53 #ifdef USE_KQUEUE
  54
  55 int uloop_init(void)
  56 {
  57         if (poll_fd >= 0)
  58                 return 0;
  59
  60         poll_fd = kqueue();
  61         if (poll_fd < 0)
  62                 return -1;
  63
  64         return 0;
  65 }
  66
  67
  68 static uint16_t get_flags(unsigned int flags, unsigned int mask)
  69 {
  70         uint16_t kflags = 0;
  71
  72         if (!(flags & mask))
  73                 return EV_DELETE;
  74
  75         kflags = EV_ADD;
  76         if (flags & ULOOP_EDGE_TRIGGER)
  77                 kflags |= EV_CLEAR;
  78
  79         return kflags;
  80 }
  81
  82 static int register_poll(struct uloop_fd *fd, unsigned int flags)
  83 {
  84         struct timespec timeout = { 0, 0 };
  85         struct kevent ev[2];
  86         unsigned int changed;
  87         int nev = 0;
  88
  89         changed = fd->kqflags ^ flags;
  90         if (changed & ULOOP_EDGE_TRIGGER)
  91                 changed |= flags;
  92
  93         if (changed & ULOOP_READ) {
  94                 uint16_t kflags = get_flags(flags, ULOOP_READ);
  95                 EV_SET(&ev[nev++], fd->fd, EVFILT_READ, kflags, 0, 0, fd);
  96         }
  97
  98         if (changed & ULOOP_WRITE) {
  99                 uint16_t kflags = get_flags(flags, ULOOP_WRITE);
 100                 EV_SET(&ev[nev++], fd->fd, EVFILT_WRITE, kflags, 0, 0, fd);
 101         }
 102
 103         if (nev && (kevent(poll_fd, ev, nev, NULL, 0, &timeout) == -1))
 104                 return -1;
 105
 106         fd->kqflags = flags;
 107         return 0;
 108 }
 109
 110 int uloop_fd_delete(struct uloop_fd *sock)
 111 {
 112         sock->registered = false;
 113         return register_poll(sock, 0);
 114 }
 115
 116 static void uloop_run_events(int timeout)
 117 {
 118         struct kevent events[ULOOP_MAX_EVENTS];
 119         struct timespec ts;
 120         int nfds, n;
 121
 122         if (timeout > 0) {
 123                 ts.tv_sec = timeout / 1000;
 124                 ts.tv_nsec = (timeout % 1000) * 1000000;
 125         }
 126
 127         nfds = kevent(poll_fd, NULL, 0, events, ARRAY_SIZE(events), timeout > 0 ? &ts : NULL);
 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         if (poll_fd >= 0)
 167                 return 0;
 168
 169         poll_fd = epoll_create(32);
 170         if (poll_fd < 0)
 171                 return -1;
 172
 173         fcntl(poll_fd, F_SETFD, fcntl(poll_fd, F_GETFD) | FD_CLOEXEC);
 174         return 0;
 175 }
 176
 177 static int register_poll(struct uloop_fd *fd, unsigned int flags)
 178 {
 179         struct epoll_event ev;
 180         int op = fd->registered ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
 181
 182         memset(&ev, 0, sizeof(struct epoll_event));
 183
 184         if (flags & ULOOP_READ)
 185                 ev.events |= EPOLLIN | EPOLLRDHUP;
 186
 187         if (flags & ULOOP_WRITE)
 188                 ev.events |= EPOLLOUT;
 189
 190         if (flags & ULOOP_EDGE_TRIGGER)
 191                 ev.events |= EPOLLET;
 192
 193         ev.data.fd = fd->fd;
 194         ev.data.ptr = fd;
 195
 196         return epoll_ctl(poll_fd, op, fd->fd, &ev);
 197 }
 198
 199 int uloop_fd_delete(struct uloop_fd *sock)
 200 {
 201         sock->registered = false;
 202         return epoll_ctl(poll_fd, EPOLL_CTL_DEL, sock->fd, 0);
 203 }
 204
 205 static void uloop_run_events(int timeout)
 206 {
 207         struct epoll_event events[ULOOP_MAX_EVENTS];
 208         int nfds, n;
 209
 210         nfds = epoll_wait(poll_fd, events, ARRAY_SIZE(events), timeout);
 211         for(n = 0; n < nfds; ++n)
 212         {
 213                 struct uloop_fd *u = events[n].data.ptr;
 214                 unsigned int ev = 0;
 215
 216                 if(events[n].events & EPOLLERR) {
 217                         u->error = true;
 218                         uloop_fd_delete(u);
 219                 }
 220
 221                 if(!(events[n].events & (EPOLLRDHUP|EPOLLIN|EPOLLOUT|EPOLLERR)))
 222                         continue;
 223
 224                 if(events[n].events & EPOLLRDHUP)
 225                         u->eof = true;
 226
 227                 if(events[n].events & EPOLLIN)
 228                         ev |= ULOOP_READ;
 229
 230                 if(events[n].events & EPOLLOUT)
 231                         ev |= ULOOP_WRITE;
 232
 233                 if(u->cb)
 234                         u->cb(u, ev);
 235         }
 236 }
 237
 238 #endif
 239
 240 int uloop_fd_add(struct uloop_fd *sock, unsigned int flags)
 241 {
 242         unsigned int fl;
 243         int ret;
 244
 245         if (!sock->registered && !(flags & ULOOP_BLOCKING)) {
 246                 fl = fcntl(sock->fd, F_GETFL, 0);
 247                 fl |= O_NONBLOCK;
 248                 fcntl(sock->fd, F_SETFL, fl);
 249         }
 250
 251         ret = register_poll(sock, flags);
 252         if (ret < 0)
 253                 goto out;
 254
 255         sock->registered = true;
 256         sock->eof = false;
 257
 258 out:
 259         return ret;
 260 }
 261
 262 static int tv_diff(struct timeval *t1, struct timeval *t2)
 263 {
 264         if (t1->tv_sec != t2->tv_sec)
 265                 return (t1->tv_sec - t2->tv_sec) * 1000;
 266         else
 267                 return (t1->tv_usec - t2->tv_usec) / 1000;
 268 }
 269
 270 int uloop_timeout_add(struct uloop_timeout *timeout)
 271 {
 272         struct uloop_timeout **head = &first_timeout;
 273         struct uloop_timeout *prev = NULL;
 274
 275         if (timeout->pending)
 276                 return -1;
 277
 278         while (*head) {
 279                 if (tv_diff(&(*head)->time, &timeout->time) > 0)
 280                         break;
 281
 282                 prev = *head;
 283                 head = &(*head)->next;
 284         }
 285
 286         timeout->prev = prev;
 287         timeout->next = *head;
 288         if (timeout->next)
 289                 timeout->next->prev = timeout;
 290         *head = timeout;
 291         timeout->pending = true;
 292
 293         return 0;
 294 }
 295
 296 int uloop_timeout_set(struct uloop_timeout *timeout, int msecs)
 297 {
 298         struct timeval *time = &timeout->time;
 299
 300         if (timeout->pending)
 301                 uloop_timeout_cancel(timeout);
 302
 303         gettimeofday(&timeout->time, NULL);
 304
 305         time->tv_sec += msecs / 1000;
 306         time->tv_usec += msecs % 1000;
 307
 308         if (time->tv_usec > 1000000) {
 309                 time->tv_sec++;
 310                 time->tv_usec %= 100000;
 311         }
 312
 313         return uloop_timeout_add(timeout);
 314 }
 315
 316 int uloop_timeout_cancel(struct uloop_timeout *timeout)
 317 {
 318         if (!timeout->pending)
 319                 return -1;
 320
 321         if (timeout->prev)
 322                 timeout->prev->next = timeout->next;
 323         else
 324                 first_timeout = timeout->next;
 325
 326         if (timeout->next)
 327                 timeout->next->prev = timeout->prev;
 328
 329         timeout->pending = false;
 330
 331         return 0;
 332 }
 333
 334 static void uloop_handle_sigint(int signo)
 335 {
 336         uloop_cancelled = true;
 337 }
 338
 339 static void uloop_setup_signals(void)
 340 {
 341         struct sigaction s;
 342         memset(&s, 0, sizeof(struct sigaction));
 343         s.sa_handler = uloop_handle_sigint;
 344         s.sa_flags = 0;
 345         sigaction(SIGINT, &s, NULL);
 346 }
 347
 348 static int uloop_get_next_timeout(struct timeval *tv)
 349 {
 350         int diff;
 351
 352         if (!first_timeout)
 353                 return -1;
 354
 355         diff = tv_diff(&first_timeout->time, tv);
 356         if (diff < 0)
 357                 return 0;
 358
 359         return diff;
 360 }
 361
 362 static void uloop_process_timeouts(struct timeval *tv)
 363 {
 364         struct uloop_timeout *timeout;
 365
 366         while (first_timeout) {
 367                 if (tv_diff(&first_timeout->time, tv) > 0)
 368                         break;
 369
 370                 timeout = first_timeout;
 371                 uloop_timeout_cancel(timeout);
 372                 if (timeout->cb)
 373                         timeout->cb(timeout);
 374         }
 375 }
 376
 377 void uloop_run(void)
 378 {
 379         struct timeval tv;
 380
 381         uloop_setup_signals();
 382         while(!uloop_cancelled)
 383         {
 384                 gettimeofday(&tv, NULL);
 385                 uloop_process_timeouts(&tv);
 386                 if (uloop_cancelled)
 387                         break;
 388                 uloop_run_events(uloop_get_next_timeout(&tv));
 389         }
 390 }
 391
 392 void uloop_done(void)
 393 {
 394         if (poll_fd < 0)
 395                 return;
 396
 397         close(poll_fd);
 398         poll_fd = -1;
 399 }