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 (!(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         struct fd_event *fde;
 222         struct timeval now;
 223
 224         GetTimeOfDay(&now);
 225
 226         if ((event_ctx->timed_events != NULL)
 227             && (timeval_compare(&now, &event_ctx->timed_events->when) >= 0)) {
 228
 229                 DEBUG(10, ("Running event \"%s\" %lx\n",
 230                            event_ctx->timed_events->event_name,
 231                            (unsigned long)event_ctx->timed_events));
 232
 233                 event_ctx->timed_events->handler(
 234                         event_ctx,
 235                         event_ctx->timed_events, now,
 236                         event_ctx->timed_events->private_data);
 237
 238                 return true;
 239         }
 240
 241         if (selrtn == 0) {
 242                 /*
 243                  * No fd ready
 244                  */
 245                 return false;
 246         }
 247
 248         for (fde = event_ctx->fd_events; fde; fde = fde->next) {
 249                 uint16 flags = 0;
 250
 251                 if (FD_ISSET(fde->fd, read_fds)) flags |= EVENT_FD_READ;
 252                 if (FD_ISSET(fde->fd, write_fds)) flags |= EVENT_FD_WRITE;
 253
 254                 if (flags & fde->flags) {
 255                         fde->handler(event_ctx, fde, flags, fde->private_data);
 256                         return true;
 257                 }
 258         }
 259
 260         return false;
 261 }
 262
 263
 264 struct timeval *get_timed_events_timeout(struct event_context *event_ctx,
 265                                          struct timeval *to_ret)
 266 {
 267         struct timeval now;
 268
 269         if (event_ctx->timed_events == NULL) {
 270                 return NULL;
 271         }
 272
 273         now = timeval_current();
 274         *to_ret = timeval_until(&now, &event_ctx->timed_events->when);
 275
 276         DEBUG(10, ("timed_events_timeout: %d/%d\n", (int)to_ret->tv_sec,
 277                 (int)to_ret->tv_usec));
 278
 279         return to_ret;
 280 }
 281
 282 int event_loop_once(struct event_context *ev)
 283 {
 284         struct timeval now, to;
 285         fd_set r_fds, w_fds;
 286         int maxfd = 0;
 287         int ret;
 288
 289         FD_ZERO(&r_fds);
 290         FD_ZERO(&w_fds);
 291
 292         to.tv_sec = 9999;       /* Max timeout */
 293         to.tv_usec = 0;
 294
 295         GetTimeOfDay(&now);
 296
 297         if (!event_add_to_select_args(ev, &now, &r_fds, &w_fds, &to, &maxfd)) {
 298                 return -1;
 299         }
 300
 301         if (timeval_is_zero(&to)) {
 302                 run_events(ev, 0, NULL, NULL);
 303                 return 0;
 304         }
 305
 306         ret = sys_select(maxfd+1, &r_fds, &w_fds, NULL, &to);
 307
 308         if (ret == -1 && errno != EINTR) {
 309                 return -1;
 310         }
 311
 312         run_events(ev, ret, &r_fds, &w_fds);
 313         return 0;
 314 }
 315
 316 static int event_context_destructor(struct event_context *ev)
 317 {
 318         while (ev->fd_events != NULL) {
 319                 ev->fd_events->event_ctx = NULL;
 320                 DLIST_REMOVE(ev->fd_events, ev->fd_events);
 321         }
 322         while (ev->timed_events != NULL) {
 323                 ev->timed_events->event_ctx = NULL;
 324                 DLIST_REMOVE(ev->timed_events, ev->timed_events);
 325         }
 326         return 0;
 327 }
 328
 329 void event_context_reinit(struct event_context *ev)
 330 {
 331         event_context_destructor(ev);
 332         return;
 333 }
 334
 335 struct event_context *event_context_init(TALLOC_CTX *mem_ctx)
 336 {
 337         struct event_context *result;
 338
 339         result = TALLOC_ZERO_P(mem_ctx, struct event_context);
 340         if (result == NULL) {
 341                 return NULL;
 342         }
 343
 344         talloc_set_destructor(result, event_context_destructor);
 345         return result;
 346 }
 347
 348 void dump_event_list(struct event_context *event_ctx)
 349 {
 350         struct timed_event *te;
 351         struct fd_event *fe;
 352         struct timeval evt, now;
 353
 354         if (!event_ctx) {
 355                 return;
 356         }
 357
 358         now = timeval_current();
 359
 360         DEBUG(10,("dump_event_list:\n"));
 361
 362         for (te = event_ctx->timed_events; te; te = te->next) {
 363
 364                 evt = timeval_until(&now, &te->when);
 365
 366                 DEBUGADD(10,("Timed Event \"%s\" %lx handled in %d seconds (at %s)\n",
 367                            te->event_name,
 368                            (unsigned long)te,
 369                            (int)evt.tv_sec,
 370                            http_timestring(te->when.tv_sec)));
 371         }
 372
 373         for (fe = event_ctx->fd_events; fe; fe = fe->next) {
 374
 375                 DEBUGADD(10,("FD Event %d %lx, flags: 0x%04x\n",
 376                            fe->fd,
 377                            (unsigned long)fe,
 378                            fe->flags));
 379         }
 380 }