source/lib/events.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Timed event library.
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Volker Lendecke 2005
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22
  23 struct timed_event {
  24         struct timed_event *next, *prev;
  25         struct event_context *event_ctx;
  26         struct timeval when;
  27         const char *event_name;
  28         void (*handler)(struct event_context *event_ctx,
  29                         struct timed_event *te,
  30                         struct timeval now,
  31                         void *private_data);
  32         void *private_data;
  33 };
  34
  35 struct fd_event {
  36         struct fd_event *prev, *next;
  37         struct event_context *event_ctx;
  38         int fd;
  39         uint16_t flags; /* see EVENT_FD_* flags */
  40         void (*handler)(struct event_context *event_ctx,
  41                         struct fd_event *event,
  42                         uint16 flags,
  43                         void *private_data);
  44         void *private_data;
  45 };
  46
  47 struct event_context {
  48         struct timed_event *timed_events;
  49         struct fd_event *fd_events;
  50 };
  51
  52 static int timed_event_destructor(struct timed_event *te)
  53 {
  54         DEBUG(10, ("Destroying timed event %lx \"%s\"\n", (unsigned long)te,
  55                 te->event_name));
  56         if (te->event_ctx != NULL) {
  57                 DLIST_REMOVE(te->event_ctx->timed_events, te);
  58         }
  59         return 0;
  60 }
  61
  62 /****************************************************************************
  63  Add te by time.
  64 ****************************************************************************/
  65
  66 static void add_event_by_time(struct timed_event *te)
  67 {
  68         struct event_context *ctx = te->event_ctx;
  69         struct timed_event *last_te, *cur_te;
  70
  71         /* Keep the list ordered by time. We must preserve this. */
  72         last_te = NULL;
  73         for (cur_te = ctx->timed_events; cur_te; cur_te = cur_te->next) {
  74                 /* if the new event comes before the current one break */
  75                 if (!timeval_is_zero(&cur_te->when) &&
  76                                 timeval_compare(&te->when, &cur_te->when) < 0) {
  77                         break;
  78                 }
  79                 last_te = cur_te;
  80         }
  81
  82         DLIST_ADD_AFTER(ctx->timed_events, te, last_te);
  83 }
  84
  85 /****************************************************************************
  86  Schedule a function for future calling, cancel with TALLOC_FREE().
  87  It's the responsibility of the handler to call TALLOC_FREE() on the event
  88  handed to it.
  89 ****************************************************************************/
  90
  91 struct timed_event *_event_add_timed(struct event_context *event_ctx,
  92                                 TALLOC_CTX *mem_ctx,
  93                                 struct timeval when,
  94                                 const char *event_name,
  95                                 void (*handler)(struct event_context *event_ctx,
  96                                                 struct timed_event *te,
  97                                                 struct timeval now,
  98                                                 void *private_data),
  99                                 void *private_data)
 100 {
 101         struct timed_event *te;
 102
 103         te = TALLOC_P(mem_ctx, struct timed_event);
 104         if (te == NULL) {
 105                 DEBUG(0, ("talloc failed\n"));
 106                 return NULL;
 107         }
 108
 109         te->event_ctx = event_ctx;
 110         te->when = when;
 111         te->event_name = event_name;
 112         te->handler = handler;
 113         te->private_data = private_data;
 114
 115         add_event_by_time(te);
 116
 117         talloc_set_destructor(te, timed_event_destructor);
 118
 119         DEBUG(10, ("Added timed event \"%s\": %lx\n", event_name,
 120                         (unsigned long)te));
 121         return te;
 122 }
 123
 124 static int fd_event_destructor(struct fd_event *fde)
 125 {
 126         if (fde->event_ctx != NULL) {
 127                 DLIST_REMOVE(fde->event_ctx->fd_events, fde);
 128         }
 129         return 0;
 130 }
 131
 132 struct fd_event *event_add_fd(struct event_context *event_ctx,
 133                               TALLOC_CTX *mem_ctx,
 134                               int fd, uint16_t flags,
 135                               void (*handler)(struct event_context *event_ctx,
 136                                               struct fd_event *event,
 137                                               uint16 flags,
 138                                               void *private_data),
 139                               void *private_data)
 140 {
 141         struct fd_event *fde;
 142
 143         if (fd < 0 || fd >= FD_SETSIZE) {
 144                 errno = EBADF;
 145                 return NULL;
 146         }
 147
 148         if (!(fde = TALLOC_P(mem_ctx, struct fd_event))) {
 149                 return NULL;
 150         }
 151
 152         fde->event_ctx = event_ctx;
 153         fde->fd = fd;
 154         fde->flags = flags;
 155         fde->handler = handler;
 156         fde->private_data = private_data;
 157
 158         DLIST_ADD(event_ctx->fd_events, fde);
 159
 160         talloc_set_destructor(fde, fd_event_destructor);
 161         return fde;
 162 }
 163
 164 void event_fd_set_writeable(struct fd_event *fde)
 165 {
 166         fde->flags |= EVENT_FD_WRITE;
 167 }
 168
 169 void event_fd_set_not_writeable(struct fd_event *fde)
 170 {
 171         fde->flags &= ~EVENT_FD_WRITE;
 172 }
 173
 174 void event_fd_set_readable(struct fd_event *fde)
 175 {
 176         fde->flags |= EVENT_FD_READ;
 177 }
 178
 179 void event_fd_set_not_readable(struct fd_event *fde)
 180 {
 181         fde->flags &= ~EVENT_FD_READ;
 182 }
 183
 184 /*
 185  * Return if there's something in the queue
 186  */
 187
 188 bool event_add_to_select_args(struct event_context *event_ctx,
 189                               const struct timeval *now,
 190                               fd_set *read_fds, fd_set *write_fds,
 191                               struct timeval *timeout, int *maxfd)
 192 {
 193         struct fd_event *fde;
 194         struct timeval diff;
 195         bool ret = False;
 196
 197         for (fde = event_ctx->fd_events; fde; fde = fde->next) {
 198                 if (fde->fd < 0 || fde->fd >= FD_SETSIZE) {
 199                         /* We ignore here, as it shouldn't be
 200                            possible to add an invalid fde->fd
 201                            but we don't want FD_SET to see an
 202                            invalid fd. */
 203                         continue;
 204                 }
 205
 206                 if (fde->flags & EVENT_FD_READ) {
 207                         FD_SET(fde->fd, read_fds);
 208                         ret = True;
 209                 }
 210                 if (fde->flags & EVENT_FD_WRITE) {
 211                         FD_SET(fde->fd, write_fds);
 212                         ret = True;
 213                 }
 214
 215                 if ((fde->flags & (EVENT_FD_READ|EVENT_FD_WRITE))
 216                     && (fde->fd > *maxfd)) {
 217                         *maxfd = fde->fd;
 218                 }
 219         }
 220
 221         if (event_ctx->timed_events == NULL) {
 222                 return ret;
 223         }
 224
 225         diff = timeval_until(now, &event_ctx->timed_events->when);
 226         *timeout = timeval_min(timeout, &diff);
 227
 228         return True;
 229 }
 230
 231 bool run_events(struct event_context *event_ctx,
 232                 int selrtn, fd_set *read_fds, fd_set *write_fds)
 233 {
 234         struct fd_event *fde;
 235         struct timeval now;
 236
 237         GetTimeOfDay(&now);
 238
 239         if ((event_ctx->timed_events != NULL)
 240             && (timeval_compare(&now, &event_ctx->timed_events->when) >= 0)) {
 241
 242                 DEBUG(10, ("Running event \"%s\" %lx\n",
 243                            event_ctx->timed_events->event_name,
 244                            (unsigned long)event_ctx->timed_events));
 245
 246                 event_ctx->timed_events->handler(
 247                         event_ctx,
 248                         event_ctx->timed_events, now,
 249                         event_ctx->timed_events->private_data);
 250
 251                 return true;
 252         }
 253
 254         if (selrtn == 0) {
 255                 /*
 256                  * No fd ready
 257                  */
 258                 return false;
 259         }
 260
 261         for (fde = event_ctx->fd_events; fde; fde = fde->next) {
 262                 uint16 flags = 0;
 263
 264                 if (FD_ISSET(fde->fd, read_fds)) flags |= EVENT_FD_READ;
 265                 if (FD_ISSET(fde->fd, write_fds)) flags |= EVENT_FD_WRITE;
 266
 267                 if (flags & fde->flags) {
 268                         fde->handler(event_ctx, fde, flags, fde->private_data);
 269                         return true;
 270                 }
 271         }
 272
 273         return false;
 274 }
 275
 276
 277 struct timeval *get_timed_events_timeout(struct event_context *event_ctx,
 278                                          struct timeval *to_ret)
 279 {
 280         struct timeval now;
 281
 282         if (event_ctx->timed_events == NULL) {
 283                 return NULL;
 284         }
 285
 286         now = timeval_current();
 287         *to_ret = timeval_until(&now, &event_ctx->timed_events->when);
 288
 289         DEBUG(10, ("timed_events_timeout: %d/%d\n", (int)to_ret->tv_sec,
 290                 (int)to_ret->tv_usec));
 291
 292         return to_ret;
 293 }
 294
 295 int event_loop_once(struct event_context *ev)
 296 {
 297         struct timeval now, to;
 298         fd_set r_fds, w_fds;
 299         int maxfd = 0;
 300         int ret;
 301
 302         FD_ZERO(&r_fds);
 303         FD_ZERO(&w_fds);
 304
 305         to.tv_sec = 9999;       /* Max timeout */
 306         to.tv_usec = 0;
 307
 308         GetTimeOfDay(&now);
 309
 310         if (!event_add_to_select_args(ev, &now, &r_fds, &w_fds, &to, &maxfd)) {
 311                 return -1;
 312         }
 313
 314         if (timeval_is_zero(&to)) {
 315                 run_events(ev, 0, NULL, NULL);
 316                 return 0;
 317         }
 318
 319         ret = sys_select(maxfd+1, &r_fds, &w_fds, NULL, &to);
 320
 321         if (ret == -1 && errno != EINTR) {
 322                 return -1;
 323         }
 324
 325         run_events(ev, ret, &r_fds, &w_fds);
 326         return 0;
 327 }
 328
 329 static int event_context_destructor(struct event_context *ev)
 330 {
 331         while (ev->fd_events != NULL) {
 332                 ev->fd_events->event_ctx = NULL;
 333                 DLIST_REMOVE(ev->fd_events, ev->fd_events);
 334         }
 335         while (ev->timed_events != NULL) {
 336                 ev->timed_events->event_ctx = NULL;
 337                 DLIST_REMOVE(ev->timed_events, ev->timed_events);
 338         }
 339         return 0;
 340 }
 341
 342 void event_context_reinit(struct event_context *ev)
 343 {
 344         event_context_destructor(ev);
 345         return;
 346 }
 347
 348 struct event_context *event_context_init(TALLOC_CTX *mem_ctx)
 349 {
 350         struct event_context *result;
 351
 352         result = TALLOC_ZERO_P(mem_ctx, struct event_context);
 353         if (result == NULL) {
 354                 return NULL;
 355         }
 356
 357         talloc_set_destructor(result, event_context_destructor);
 358         return result;
 359 }
 360
 361 void dump_event_list(struct event_context *event_ctx)
 362 {
 363         struct timed_event *te;
 364         struct fd_event *fe;
 365         struct timeval evt, now;
 366
 367         if (!event_ctx) {
 368                 return;
 369         }
 370
 371         now = timeval_current();
 372
 373         DEBUG(10,("dump_event_list:\n"));
 374
 375         for (te = event_ctx->timed_events; te; te = te->next) {
 376
 377                 evt = timeval_until(&now, &te->when);
 378
 379                 DEBUGADD(10,("Timed Event \"%s\" %lx handled in %d seconds (at %s)\n",
 380                            te->event_name,
 381                            (unsigned long)te,
 382                            (int)evt.tv_sec,
 383                            http_timestring(te->when.tv_sec)));
 384         }
 385
 386         for (fe = event_ctx->fd_events; fe; fe = fe->next) {
 387
 388                 DEBUGADD(10,("FD Event %d %lx, flags: 0x%04x\n",
 389                            fe->fd,
 390                            (unsigned long)fe,
 391                            fe->flags));
 392         }
 393 }