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 static struct timed_event *timed_events;
  25
  26 static int timed_event_destructor(void *p)
  27 {
  28         struct timed_event *te = talloc_get_type_abort(p, struct timed_event);
  29         DEBUG(10, ("Destroying timed event %lx \"%s\"\n", (unsigned long)te,
  30                 te->event_name));
  31         DLIST_REMOVE(timed_events, te);
  32         return 0;
  33 }
  34
  35 /****************************************************************************
  36  Schedule a function for future calling, cancel with TALLOC_FREE().
  37  It's the responsibility of the handler to call TALLOC_FREE() on the event
  38  handed to it.
  39 ****************************************************************************/
  40
  41 struct timed_event *add_timed_event(TALLOC_CTX *mem_ctx,
  42                                 struct timeval when,
  43                                 const char *event_name,
  44                                 void (*handler)(struct timed_event *te,
  45                                                 const struct timeval *now,
  46                                                 void *private_data),
  47                                 void *private_data)
  48 {
  49         struct timed_event *te, *last_te, *cur_te;
  50
  51         te = TALLOC_P(mem_ctx, struct timed_event);
  52         if (te == NULL) {
  53                 DEBUG(0, ("talloc failed\n"));
  54                 return NULL;
  55         }
  56
  57         te->when = when;
  58         te->event_name = event_name;
  59         te->handler = handler;
  60         te->private_data = private_data;
  61
  62         /* keep the list ordered */
  63         last_te = NULL;
  64         for (cur_te = timed_events; cur_te; cur_te = cur_te->next) {
  65                 /* if the new event comes before the current one break */
  66                 if (!timeval_is_zero(&cur_te->when) &&
  67                                 timeval_compare(&te->when, &cur_te->when) < 0) {
  68                         break;
  69                 }
  70                 last_te = cur_te;
  71         }
  72
  73         DLIST_ADD_AFTER(timed_events, te, last_te);
  74         talloc_set_destructor(te, timed_event_destructor);
  75
  76         DEBUG(10, ("Added timed event \"%s\": %lx\n", event_name,
  77                         (unsigned long)te));
  78         return te;
  79 }
  80
  81 void run_events(void)
  82 {
  83         struct timeval now;
  84
  85         if (timed_events == NULL) {
  86                 /* No syscall if there are no events */
  87                 DEBUG(11, ("run_events: No events\n"));
  88                 return;
  89         }
  90
  91         GetTimeOfDay(&now);
  92
  93         if (timeval_compare(&now, &timed_events->when) < 0) {
  94                 /* Nothing to do yet */
  95                 DEBUG(11, ("run_events: Nothing to do\n"));
  96                 return;
  97         }
  98
  99         DEBUG(10, ("Running event \"%s\" %lx\n", timed_events->event_name,
 100                 (unsigned long)timed_events));
 101
 102         timed_events->handler(timed_events, &now, timed_events->private_data);
 103         return;
 104 }
 105
 106 struct timeval *get_timed_events_timeout(struct timeval *to_ret, time_t default_to)
 107 {
 108         struct timeval now;
 109
 110         if (timed_events == NULL) {
 111                 if (default_to == (time_t)-1) {
 112                         return NULL;
 113                 }
 114                 *to_ret = timeval_set(default_to, 0);
 115                 return to_ret;
 116         }
 117
 118         now = timeval_current();
 119         *to_ret = timeval_until(&now, &timed_events->when);
 120
 121         DEBUG(10, ("timed_events_timeout: %d/%d\n", (int)to_ret->tv_sec,
 122                 (int)to_ret->tv_usec));
 123
 124         return to_ret;
 125 }