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 2 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, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24 struct timed_event {
  25         struct timed_event *next, *prev;
  26         struct event_context *event_ctx;
  27         struct timeval when;
  28         const char *event_name;
  29         void (*handler)(struct event_context *event_ctx,
  30                         struct timed_event *te,
  31                         const struct timeval *now,
  32                         void *private_data);
  33         void *private_data;
  34 };
  35
  36 struct fd_event {
  37         struct fd_event *prev, *next;
  38         struct event_context *event_ctx;
  39         int fd;
  40         uint16_t flags; /* see EVENT_FD_* flags */
  41         void (*handler)(struct event_context *event_ctx,
  42                         struct fd_event *event,
  43                         uint16 flags,
  44                         void *private_data);
  45         void *private_data;
  46 };
  47
  48 #define EVENT_FD_WRITEABLE(fde) \
  49         event_set_fd_flags(fde, event_get_fd_flags(fde) | EVENT_FD_WRITE)
  50 #define EVENT_FD_READABLE(fde) \
  51         event_set_fd_flags(fde, event_get_fd_flags(fde) | EVENT_FD_READ)
  52
  53 #define EVENT_FD_NOT_WRITEABLE(fde) \
  54         event_set_fd_flags(fde, event_get_fd_flags(fde) & ~EVENT_FD_WRITE)
  55 #define EVENT_FD_NOT_READABLE(fde) \
  56         event_set_fd_flags(fde, event_get_fd_flags(fde) & ~EVENT_FD_READ)
  57
  58 struct event_context {
  59         struct timed_event *timed_events;
  60         struct fd_event *fd_events;
  61 };
  62
  63 static int timed_event_destructor(struct timed_event *te)
  64 {
  65         DEBUG(10, ("Destroying timed event %lx \"%s\"\n", (unsigned long)te,
  66                 te->event_name));
  67         DLIST_REMOVE(te->event_ctx->timed_events, te);
  68         return 0;
  69 }
  70
  71 /****************************************************************************
  72  Add te by time.
  73 ****************************************************************************/
  74
  75 static void add_event_by_time(struct timed_event *te)
  76 {
  77         struct event_context *ctx = te->event_ctx;
  78         struct timed_event *last_te, *cur_te;
  79
  80         /* Keep the list ordered by time. We must preserve this. */
  81         last_te = NULL;
  82         for (cur_te = ctx->timed_events; cur_te; cur_te = cur_te->next) {
  83                 /* if the new event comes before the current one break */
  84                 if (!timeval_is_zero(&cur_te->when) &&
  85                                 timeval_compare(&te->when, &cur_te->when) < 0) {
  86                         break;
  87                 }
  88                 last_te = cur_te;
  89         }
  90
  91         DLIST_ADD_AFTER(ctx->timed_events, te, last_te);
  92 }
  93
  94 /****************************************************************************
  95  Schedule a function for future calling, cancel with TALLOC_FREE().
  96  It's the responsibility of the handler to call TALLOC_FREE() on the event
  97  handed to it.
  98 ****************************************************************************/
  99
 100 struct timed_event *event_add_timed(struct event_context *event_ctx,
 101                                 TALLOC_CTX *mem_ctx,
 102                                 struct timeval when,
 103                                 const char *event_name,
 104                                 void (*handler)(struct event_context *event_ctx,
 105                                                 struct timed_event *te,
 106                                                 const struct timeval *now,
 107                                                 void *private_data),
 108                                 void *private_data)
 109 {
 110         struct timed_event *te;
 111
 112         te = TALLOC_P(mem_ctx, struct timed_event);
 113         if (te == NULL) {
 114                 DEBUG(0, ("talloc failed\n"));
 115                 return NULL;
 116         }
 117
 118         te->event_ctx = event_ctx;
 119         te->when = when;
 120         te->event_name = event_name;
 121         te->handler = handler;
 122         te->private_data = private_data;
 123
 124         add_event_by_time(te);
 125
 126         talloc_set_destructor(te, timed_event_destructor);
 127
 128         DEBUG(10, ("Added timed event \"%s\": %lx\n", event_name,
 129                         (unsigned long)te));
 130         return te;
 131 }
 132
 133 static int fd_event_destructor(struct fd_event *fde)
 134 {
 135         struct event_context *event_ctx = fde->event_ctx;
 136
 137         DLIST_REMOVE(event_ctx->fd_events, fde);
 138         return 0;
 139 }
 140
 141 struct fd_event *event_add_fd(struct event_context *event_ctx,
 142                               TALLOC_CTX *mem_ctx,
 143                               int fd, uint16_t flags,
 144                               void (*handler)(struct event_context *event_ctx,
 145                                               struct fd_event *event,
 146                                               uint16 flags,
 147                                               void *private_data),
 148                               void *private_data)
 149 {
 150         struct fd_event *fde;
 151
 152         if (!(fde = TALLOC_P(mem_ctx, struct fd_event))) {
 153                 return NULL;
 154         }
 155
 156         fde->event_ctx = event_ctx;
 157         fde->fd = fd;
 158         fde->flags = flags;
 159         fde->handler = handler;
 160         fde->private_data = private_data;
 161
 162         DLIST_ADD(event_ctx->fd_events, fde);
 163
 164         talloc_set_destructor(fde, fd_event_destructor);
 165         return fde;
 166 }
 167
 168 void event_fd_set_writeable(struct fd_event *fde)
 169 {
 170         fde->flags |= EVENT_FD_WRITE;
 171 }
 172
 173 void event_fd_set_not_writeable(struct fd_event *fde)
 174 {
 175         fde->flags &= ~EVENT_FD_WRITE;
 176 }
 177
 178 void event_fd_set_readable(struct fd_event *fde)
 179 {
 180         fde->flags |= EVENT_FD_READ;
 181 }
 182
 183 void event_fd_set_not_readable(struct fd_event *fde)
 184 {
 185         fde->flags &= ~EVENT_FD_READ;
 186 }
 187
 188 void 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
 196         for (fde = event_ctx->fd_events; fde; fde = fde->next) {
 197                 if (fde->flags & EVENT_FD_READ) {
 198                         FD_SET(fde->fd, read_fds);
 199                 }
 200                 if (fde->flags & EVENT_FD_WRITE) {
 201                         FD_SET(fde->fd, write_fds);
 202                 }
 203
 204                 if ((fde->flags & (EVENT_FD_READ|EVENT_FD_WRITE))
 205                     && (fde->fd > *maxfd)) {
 206                         *maxfd = fde->fd;
 207                 }
 208         }
 209
 210         if (event_ctx->timed_events == NULL) {
 211                 return;
 212         }
 213
 214         diff = timeval_until(now, &event_ctx->timed_events->when);
 215         *timeout = timeval_min(timeout, &diff);
 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) {
 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 struct event_context *event_context_init(TALLOC_CTX *mem_ctx)
 301 {
 302         return TALLOC_ZERO_P(NULL, struct event_context);
 303 }
 304
 305 int set_event_dispatch_time(struct event_context *event_ctx,
 306                             const char *event_name, struct timeval when)
 307 {
 308         struct timed_event *te;
 309
 310         for (te = event_ctx->timed_events; te; te = te->next) {
 311                 if (strcmp(event_name, te->event_name) == 0) {
 312                         DLIST_REMOVE(event_ctx->timed_events, te);
 313                         te->when = when;
 314                         add_event_by_time(te);
 315                         return 1;
 316                 }
 317         }
 318         return 0;
 319 }
 320
 321 /* Returns 1 if event was found and cancelled, 0 otherwise. */
 322
 323 int cancel_named_event(struct event_context *event_ctx,
 324                        const char *event_name)
 325 {
 326         struct timed_event *te;
 327
 328         for (te = event_ctx->timed_events; te; te = te->next) {
 329                 if (strcmp(event_name, te->event_name) == 0) {
 330                         TALLOC_FREE(te);
 331                         return 1;
 332                 }
 333         }
 334         return 0;
 335 }