source3/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(struct timed_event *te)
  27 {
  28         DEBUG(10, ("Destroying timed event %lx \"%s\"\n", (unsigned long)te,
  29                 te->event_name));
  30         DLIST_REMOVE(timed_events, te);
  31         return 0;
  32 }
  33
  34 /****************************************************************************
  35  Schedule a function for future calling, cancel with TALLOC_FREE().
  36  It's the responsibility of the handler to call TALLOC_FREE() on the event
  37  handed to it.
  38 ****************************************************************************/
  39
  40 struct timed_event *add_timed_event(TALLOC_CTX *mem_ctx,
  41                                 struct timeval when,
  42                                 const char *event_name,
  43                                 void (*handler)(struct timed_event *te,
  44                                                 const struct timeval *now,
  45                                                 void *private_data),
  46                                 void *private_data)
  47 {
  48         struct timed_event *te, *last_te, *cur_te;
  49
  50         te = TALLOC_P(mem_ctx, struct timed_event);
  51         if (te == NULL) {
  52                 DEBUG(0, ("talloc failed\n"));
  53                 return NULL;
  54         }
  55
  56         te->when = when;
  57         te->event_name = event_name;
  58         te->handler = handler;
  59         te->private_data = private_data;
  60
  61         /* keep the list ordered - this is NOT guarenteed as event times
  62            may be changed after insertion */
  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         /* Run all events that are pending, not just one (as we
  84            did previously. */
  85
  86         while (timed_events) {
  87                 struct timeval now;
  88                 GetTimeOfDay(&now);
  89
  90                 if (timeval_compare(&now, &timed_events->when) < 0) {
  91                         /* Nothing to do yet */
  92                         DEBUG(11, ("run_events: Nothing to do\n"));
  93                         return;
  94                 }
  95
  96                 DEBUG(10, ("Running event \"%s\" %lx\n", timed_events->event_name,
  97                         (unsigned long)timed_events));
  98
  99                 timed_events->handler(timed_events, &now, timed_events->private_data);
 100         }
 101 }
 102
 103 struct timeval *get_timed_events_timeout(struct timeval *to_ret)
 104 {
 105         struct timeval now;
 106
 107         if (timed_events == NULL) {
 108                 return NULL;
 109         }
 110
 111         now = timeval_current();
 112         *to_ret = timeval_until(&now, &timed_events->when);
 113
 114         DEBUG(10, ("timed_events_timeout: %d/%d\n", (int)to_ret->tv_sec,
 115                 (int)to_ret->tv_usec));
 116
 117         return to_ret;
 118 }
 119
 120 int set_event_dispatch_time(const char *event_name, struct timeval when)
 121 {
 122         int num_events = 0;
 123         struct timed_event *te;
 124
 125         for (te = timed_events; te; te = te->next) {
 126                 if (strcmp(event_name, te->event_name) == 0) {
 127                         te->when = when;
 128                         num_events++;
 129                 }
 130         }
 131         return num_events;
 132 }
 133
 134 /* Returns 1 if event was found and cancelled, 0 otherwise. */
 135
 136 int cancel_named_event(const char *event_name)
 137 {
 138         struct timed_event *te;
 139
 140         for (te = timed_events; te; te = te->next) {
 141                 if (strcmp(event_name, te->event_name) == 0) {
 142                         TALLOC_FREE(te);
 143                         return 1;
 144                 }
 145         }
 146         return 0;
 147 }