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                         const 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                                                 const 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 (!(fde = TALLOC_P(mem_ctx, struct fd_event))) {
 144                 return NULL;
 145         }
 146
 147         fde->event_ctx = event_ctx;
 148         fde->fd = fd;
 149         fde->flags = flags;
 150         fde->handler = handler;
 151         fde->private_data = private_data;
 152
 153         DLIST_ADD(event_ctx->fd_events, fde);
 154
 155         talloc_set_destructor(fde, fd_event_destructor);
 156         return fde;
 157 }
 158
 159 void event_fd_set_writeable(struct fd_event *fde)
 160 {
 161         fde->flags |= EVENT_FD_WRITE;
 162 }
 163
 164 void event_fd_set_not_writeable(struct fd_event *fde)
 165 {
 166         fde->flags &= ~EVENT_FD_WRITE;
 167 }
 168
 169 void event_fd_set_readable(struct fd_event *fde)
 170 {
 171         fde->flags |= EVENT_FD_READ;
 172 }
 173
 174 void event_fd_set_not_readable(struct fd_event *fde)
 175 {
 176         fde->flags &= ~EVENT_FD_READ;
 177 }
 178
 179 /*
 180  * Return if there's something in the queue
 181  */
 182
 183 bool event_add_to_select_args(struct event_context *event_ctx,
 184                               const struct timeval *now,
 185                               fd_set *read_fds, fd_set *write_fds,
 186                               struct timeval *timeout, int *maxfd)
 187 {
 188         struct fd_event *fde;
 189         struct timeval diff;
 190         bool ret = False;
 191
 192         for (fde = event_ctx->fd_events; fde; fde = fde->next) {
 193                 if (fde->flags & EVENT_FD_READ) {
 194                         FD_SET(fde->fd, read_fds);
 195                         ret = True;
 196                 }
 197                 if (fde->flags & EVENT_FD_WRITE) {
 198                         FD_SET(fde->fd, write_fds);
 199                         ret = True;
 200                 }
 201
 202                 if ((fde->flags & (EVENT_FD_READ|EVENT_FD_WRITE))
 203                     && (fde->fd > *maxfd)) {
 204                         *maxfd = fde->fd;
 205                 }
 206         }
 207
 208         if (event_ctx->timed_events == NULL) {
 209                 return ret;
 210         }
 211
 212         diff = timeval_until(now, &event_ctx->timed_events->when);
 213         *timeout = timeval_min(timeout, &diff);
 214
 215         return True;
 216 }
 217
 218 bool run_events(struct event_context *event_ctx,
 219                 int selrtn, fd_set *read_fds, fd_set *write_fds)
 220 {
 221         bool fired = False;
 222         struct fd_event *fde, *next;
 223
 224         /* Run all events that are pending, not just one (as we
 225            did previously. */
 226
 227         while (event_ctx->timed_events) {
 228                 struct timeval now;
 229                 GetTimeOfDay(&now);
 230
 231                 if (timeval_compare(
 232                             &now, &event_ctx->timed_events->when) < 0) {
 233                         /* Nothing to do yet */
 234                         DEBUG(11, ("run_events: Nothing to do\n"));
 235                         break;
 236                 }
 237
 238                 DEBUG(10, ("Running event \"%s\" %lx\n",
 239                            event_ctx->timed_events->event_name,
 240                            (unsigned long)event_ctx->timed_events));
 241
 242                 event_ctx->timed_events->handler(
 243                         event_ctx,
 244                         event_ctx->timed_events, &now,
 245                         event_ctx->timed_events->private_data);
 246
 247                 fired = True;
 248         }
 249
 250         if (fired) {
 251                 /*
 252                  * We might have changed the socket status during the timed
 253                  * events, return to run select again.
 254                  */
 255                 return True;
 256         }
 257
 258         if (selrtn == 0) {
 259                 /*
 260                  * No fd ready
 261                  */
 262                 return fired;
 263         }
 264
 265         for (fde = event_ctx->fd_events; fde; fde = next) {
 266                 uint16 flags = 0;
 267
 268                 next = fde->next;
 269                 if (FD_ISSET(fde->fd, read_fds)) flags |= EVENT_FD_READ;
 270                 if (FD_ISSET(fde->fd, write_fds)) flags |= EVENT_FD_WRITE;
 271
 272                 if (flags & fde->flags) {
 273                         fde->handler(event_ctx, fde, flags, fde->private_data);
 274                         fired = True;
 275                 }
 276         }
 277
 278         return fired;
 279 }
 280
 281
 282 struct timeval *get_timed_events_timeout(struct event_context *event_ctx,
 283                                          struct timeval *to_ret)
 284 {
 285         struct timeval now;
 286
 287         if (event_ctx->timed_events == NULL) {
 288                 return NULL;
 289         }
 290
 291         now = timeval_current();
 292         *to_ret = timeval_until(&now, &event_ctx->timed_events->when);
 293
 294         DEBUG(10, ("timed_events_timeout: %d/%d\n", (int)to_ret->tv_sec,
 295                 (int)to_ret->tv_usec));
 296
 297         return to_ret;
 298 }
 299
 300 int event_loop_once(struct event_context *ev)
 301 {
 302         struct timeval now, to;
 303         fd_set r_fds, w_fds;
 304         int maxfd = 0;
 305         int ret;
 306
 307         FD_ZERO(&r_fds);
 308         FD_ZERO(&w_fds);
 309
 310         to.tv_sec = 9999;       /* Max timeout */
 311         to.tv_usec = 0;
 312
 313         GetTimeOfDay(&now);
 314
 315         if (!event_add_to_select_args(ev, &now, &r_fds, &w_fds, &to, &maxfd)) {
 316                 return -1;
 317         }
 318
 319         if (timeval_is_zero(&to)) {
 320                 run_events(ev, 0, NULL, NULL);
 321                 return 0;
 322         }
 323
 324         ret = sys_select(maxfd+1, &r_fds, &w_fds, NULL, &to);
 325
 326         if (ret == -1 && errno != EINTR) {
 327                 return -1;
 328         }
 329
 330         run_events(ev, ret, &r_fds, &w_fds);
 331         return 0;
 332 }
 333
 334 static int event_context_destructor(struct event_context *ev)
 335 {
 336         while (ev->fd_events != NULL) {
 337                 ev->fd_events->event_ctx = NULL;
 338                 DLIST_REMOVE(ev->fd_events, ev->fd_events);
 339         }
 340         while (ev->timed_events != NULL) {
 341                 ev->timed_events->event_ctx = NULL;
 342                 DLIST_REMOVE(ev->timed_events, ev->timed_events);
 343         }
 344         return 0;
 345 }
 346
 347 void event_context_reinit(struct event_context *ev)
 348 {
 349         event_context_destructor(ev);
 350         return;
 351 }
 352
 353 struct event_context *event_context_init(TALLOC_CTX *mem_ctx)
 354 {
 355         struct event_context *result;
 356
 357         result = TALLOC_ZERO_P(mem_ctx, struct event_context);
 358         if (result == NULL) {
 359                 return NULL;
 360         }
 361
 362         talloc_set_destructor(result, event_context_destructor);
 363         return result;
 364 }
 365
 366 void dump_event_list(struct event_context *event_ctx)
 367 {
 368         struct timed_event *te;
 369         struct fd_event *fe;
 370         struct timeval evt, now;
 371
 372         if (!event_ctx) {
 373                 return;
 374         }
 375
 376         now = timeval_current();
 377
 378         DEBUG(10,("dump_event_list:\n"));
 379
 380         for (te = event_ctx->timed_events; te; te = te->next) {
 381
 382                 evt = timeval_until(&now, &te->when);
 383
 384                 DEBUGADD(10,("Timed Event \"%s\" %lx handled in %d seconds (at %s)\n",
 385                            te->event_name,
 386                            (unsigned long)te,
 387                            (int)evt.tv_sec,
 388                            http_timestring(te->when.tv_sec)));
 389         }
 390
 391         for (fe = event_ctx->fd_events; fe; fe = fe->next) {
 392
 393                 DEBUGADD(10,("FD Event %d %lx, flags: 0x%04x\n",
 394                            fe->fd,
 395                            (unsigned long)fe,
 396                            fe->flags));
 397         }
 398 }