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 #define EVENT_FD_WRITEABLE(fde) \
  48         event_set_fd_flags(fde, event_get_fd_flags(fde) | EVENT_FD_WRITE)
  49 #define EVENT_FD_READABLE(fde) \
  50         event_set_fd_flags(fde, event_get_fd_flags(fde) | EVENT_FD_READ)
  51
  52 #define EVENT_FD_NOT_WRITEABLE(fde) \
  53         event_set_fd_flags(fde, event_get_fd_flags(fde) & ~EVENT_FD_WRITE)
  54 #define EVENT_FD_NOT_READABLE(fde) \
  55         event_set_fd_flags(fde, event_get_fd_flags(fde) & ~EVENT_FD_READ)
  56
  57 struct event_context {
  58         struct timed_event *timed_events;
  59         struct fd_event *fd_events;
  60 };
  61
  62 static int timed_event_destructor(struct timed_event *te)
  63 {
  64         DEBUG(10, ("Destroying timed event %lx \"%s\"\n", (unsigned long)te,
  65                 te->event_name));
  66         if (te->event_ctx) {
  67                 DLIST_REMOVE(te->event_ctx->timed_events, te);
  68         }
  69         return 0;
  70 }
  71
  72 /****************************************************************************
  73  Add te by time.
  74 ****************************************************************************/
  75
  76 static void add_event_by_time(struct timed_event *te)
  77 {
  78         struct event_context *ctx = te->event_ctx;
  79         struct timed_event *last_te, *cur_te;
  80
  81         /* Keep the list ordered by time. We must preserve this. */
  82         last_te = NULL;
  83         for (cur_te = ctx->timed_events; cur_te; cur_te = cur_te->next) {
  84                 /* if the new event comes before the current one break */
  85                 if (!timeval_is_zero(&cur_te->when) &&
  86                                 timeval_compare(&te->when, &cur_te->when) < 0) {
  87                         break;
  88                 }
  89                 last_te = cur_te;
  90         }
  91
  92         DLIST_ADD_AFTER(ctx->timed_events, te, last_te);
  93 }
  94
  95 /****************************************************************************
  96  Schedule a function for future calling, cancel with TALLOC_FREE().
  97  It's the responsibility of the handler to call TALLOC_FREE() on the event
  98  handed to it.
  99 ****************************************************************************/
 100
 101 struct timed_event *event_add_timed(struct event_context *event_ctx,
 102                                 TALLOC_CTX *mem_ctx,
 103                                 struct timeval when,
 104                                 const char *event_name,
 105                                 void (*handler)(struct event_context *event_ctx,
 106                                                 struct timed_event *te,
 107                                                 const struct timeval *now,
 108                                                 void *private_data),
 109                                 void *private_data)
 110 {
 111         struct timed_event *te;
 112
 113         te = TALLOC_P(mem_ctx, struct timed_event);
 114         if (te == NULL) {
 115                 DEBUG(0, ("talloc failed\n"));
 116                 return NULL;
 117         }
 118
 119         te->event_ctx = event_ctx;
 120         te->when = when;
 121         te->event_name = event_name;
 122         te->handler = handler;
 123         te->private_data = private_data;
 124
 125         add_event_by_time(te);
 126
 127         talloc_set_destructor(te, timed_event_destructor);
 128
 129         DEBUG(10, ("Added timed event \"%s\": %lx\n", event_name,
 130                         (unsigned long)te));
 131         return te;
 132 }
 133
 134 static int fd_event_destructor(struct fd_event *fde)
 135 {
 136         struct event_context *event_ctx = fde->event_ctx;
 137
 138         if (event_ctx) {
 139                 DLIST_REMOVE(event_ctx->fd_events, fde);
 140         }
 141         return 0;
 142 }
 143
 144 struct fd_event *event_add_fd(struct event_context *event_ctx,
 145                               TALLOC_CTX *mem_ctx,
 146                               int fd, uint16_t flags,
 147                               void (*handler)(struct event_context *event_ctx,
 148                                               struct fd_event *event,
 149                                               uint16 flags,
 150                                               void *private_data),
 151                               void *private_data)
 152 {
 153         struct fd_event *fde;
 154
 155         if (!(fde = TALLOC_P(mem_ctx, struct fd_event))) {
 156                 return NULL;
 157         }
 158
 159         fde->event_ctx = event_ctx;
 160         fde->fd = fd;
 161         fde->flags = flags;
 162         fde->handler = handler;
 163         fde->private_data = private_data;
 164
 165         DLIST_ADD(event_ctx->fd_events, fde);
 166
 167         talloc_set_destructor(fde, fd_event_destructor);
 168         return fde;
 169 }
 170
 171 void event_fd_set_writeable(struct fd_event *fde)
 172 {
 173         fde->flags |= EVENT_FD_WRITE;
 174 }
 175
 176 void event_fd_set_not_writeable(struct fd_event *fde)
 177 {
 178         fde->flags &= ~EVENT_FD_WRITE;
 179 }
 180
 181 void event_fd_set_readable(struct fd_event *fde)
 182 {
 183         fde->flags |= EVENT_FD_READ;
 184 }
 185
 186 void event_fd_set_not_readable(struct fd_event *fde)
 187 {
 188         fde->flags &= ~EVENT_FD_READ;
 189 }
 190
 191 /*
 192  * Return if there's something in the queue
 193  */
 194
 195 bool event_add_to_select_args(struct event_context *event_ctx,
 196                               const struct timeval *now,
 197                               fd_set *read_fds, fd_set *write_fds,
 198                               struct timeval *timeout, int *maxfd)
 199 {
 200         struct fd_event *fde;
 201         struct timeval diff;
 202         bool ret = False;
 203
 204         for (fde = event_ctx->fd_events; fde; fde = fde->next) {
 205                 if (fde->flags & EVENT_FD_READ) {
 206                         FD_SET(fde->fd, read_fds);
 207                         ret = True;
 208                 }
 209                 if (fde->flags & EVENT_FD_WRITE) {
 210                         FD_SET(fde->fd, write_fds);
 211                         ret = True;
 212                 }
 213
 214                 if ((fde->flags & (EVENT_FD_READ|EVENT_FD_WRITE))
 215                     && (fde->fd > *maxfd)) {
 216                         *maxfd = fde->fd;
 217                 }
 218         }
 219
 220         if (event_ctx->timed_events == NULL) {
 221                 return ret;
 222         }
 223
 224         diff = timeval_until(now, &event_ctx->timed_events->when);
 225         *timeout = timeval_min(timeout, &diff);
 226
 227         return True;
 228 }
 229
 230 bool events_pending(struct event_context *event_ctx)
 231 {
 232         struct fd_event *fde;
 233
 234         if (event_ctx->timed_events != NULL) {
 235                 return True;
 236         }
 237         for (fde = event_ctx->fd_events; fde; fde = fde->next) {
 238                 if (fde->flags & (EVENT_FD_READ|EVENT_FD_WRITE)) {
 239                         return True;
 240                 }
 241         }
 242         return False;
 243 }
 244
 245 bool run_events(struct event_context *event_ctx,
 246                 int selrtn, fd_set *read_fds, fd_set *write_fds)
 247 {
 248         struct fd_event *fde;
 249         struct timeval now;
 250
 251         GetTimeOfDay(&now);
 252
 253         if ((event_ctx->timed_events != NULL)
 254             && (timeval_compare(&now, &event_ctx->timed_events->when) >= 0)) {
 255
 256                 DEBUG(10, ("Running event \"%s\" %lx\n",
 257                            event_ctx->timed_events->event_name,
 258                            (unsigned long)event_ctx->timed_events));
 259
 260                 event_ctx->timed_events->handler(
 261                         event_ctx,
 262                         event_ctx->timed_events, &now,
 263                         event_ctx->timed_events->private_data);
 264
 265                 return true;
 266         }
 267
 268         if (selrtn == 0) {
 269                 /*
 270                  * No fd ready
 271                  */
 272                 return false;
 273         }
 274
 275         for (fde = event_ctx->fd_events; fde; fde = fde->next) {
 276                 uint16 flags = 0;
 277
 278                 if (FD_ISSET(fde->fd, read_fds)) flags |= EVENT_FD_READ;
 279                 if (FD_ISSET(fde->fd, write_fds)) flags |= EVENT_FD_WRITE;
 280
 281                 if (flags) {
 282                         fde->handler(event_ctx, fde, flags, fde->private_data);
 283                         return true;
 284                 }
 285         }
 286
 287         return false;
 288 }
 289
 290
 291 struct timeval *get_timed_events_timeout(struct event_context *event_ctx,
 292                                          struct timeval *to_ret)
 293 {
 294         struct timeval now;
 295
 296         if (event_ctx->timed_events == NULL) {
 297                 return NULL;
 298         }
 299
 300         now = timeval_current();
 301         *to_ret = timeval_until(&now, &event_ctx->timed_events->when);
 302
 303         DEBUG(10, ("timed_events_timeout: %d/%d\n", (int)to_ret->tv_sec,
 304                 (int)to_ret->tv_usec));
 305
 306         return to_ret;
 307 }
 308
 309 int event_loop_once(struct event_context *ev)
 310 {
 311         struct timeval now, to;
 312         fd_set r_fds, w_fds;
 313         int maxfd = 0;
 314         int ret;
 315
 316         FD_ZERO(&r_fds);
 317         FD_ZERO(&w_fds);
 318
 319         to.tv_sec = 9999;       /* Max timeout */
 320         to.tv_usec = 0;
 321
 322         GetTimeOfDay(&now);
 323
 324         if (!event_add_to_select_args(ev, &now, &r_fds, &w_fds, &to, &maxfd)) {
 325                 return -1;
 326         }
 327
 328         if (timeval_is_zero(&to)) {
 329                 run_events(ev, 0, NULL, NULL);
 330                 return 0;
 331         }
 332
 333         ret = sys_select(maxfd+1, &r_fds, &w_fds, NULL, &to);
 334
 335         if (ret == -1 && errno != EINTR) {
 336                 return -1;
 337         }
 338
 339         run_events(ev, ret, &r_fds, &w_fds);
 340         return 0;
 341 }
 342
 343 static int event_context_destructor(struct event_context *ev)
 344 {
 345         while (ev->fd_events != NULL) {
 346                 ev->fd_events->event_ctx = NULL;
 347                 DLIST_REMOVE(ev->fd_events, ev->fd_events);
 348         }
 349         while (ev->timed_events != NULL) {
 350                 ev->timed_events->event_ctx = NULL;
 351                 DLIST_REMOVE(ev->timed_events, ev->timed_events);
 352         }
 353         return 0;
 354 }
 355
 356 void event_context_reinit(struct event_context *ev)
 357 {
 358         event_context_destructor(ev);
 359         return;
 360 }
 361
 362 struct event_context *event_context_init(TALLOC_CTX *mem_ctx)
 363 {
 364         struct event_context *result;
 365
 366         result = TALLOC_ZERO_P(mem_ctx, struct event_context);
 367         if (result == NULL) {
 368                 return NULL;
 369         }
 370
 371         talloc_set_destructor(result, event_context_destructor);
 372         return result;
 373 }
 374
 375 void dump_event_list(struct event_context *event_ctx)
 376 {
 377         struct timed_event *te;
 378         struct fd_event *fe;
 379         struct timeval evt, now;
 380
 381         if (!event_ctx) {
 382                 return;
 383         }
 384
 385         now = timeval_current();
 386
 387         DEBUG(10,("dump_event_list:\n"));
 388
 389         for (te = event_ctx->timed_events; te; te = te->next) {
 390
 391                 evt = timeval_until(&now, &te->when);
 392
 393                 DEBUGADD(10,("Timed Event \"%s\" %lx handled in %d seconds (at %s)\n",
 394                            te->event_name,
 395                            (unsigned long)te,
 396                            (int)evt.tv_sec,
 397                            http_timestring(te->when.tv_sec)));
 398         }
 399
 400         for (fe = event_ctx->fd_events; fe; fe = fe->next) {
 401
 402                 DEBUGADD(10,("FD Event %d %lx, flags: 0x%04x\n",
 403                            fe->fd,
 404                            (unsigned long)fe,
 405                            fe->flags));
 406         }
 407 }