src/signal.c

   1 /* Generic signalling/notification infrastructure */
   2 /* (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org>
   3  * All Rights Reserved
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  */
  20
  21 #include <osmocom/core/signal.h>
  22 #include <osmocom/core/talloc.h>
  23 #include <osmocom/core/linuxlist.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <errno.h>
  27
  28 void *tall_sigh_ctx;
  29 static LLIST_HEAD(signal_handler_list);
  30
  31 struct signal_handler {
  32         struct llist_head entry;
  33         unsigned int subsys;
  34         signal_cbfn *cbfn;
  35         void *data;
  36 };
  37
  38
  39 int register_signal_handler(unsigned int subsys, signal_cbfn *cbfn, void *data)
  40 {
  41         struct signal_handler *sig_data;
  42
  43         sig_data = talloc(tall_sigh_ctx, struct signal_handler);
  44         if (!sig_data)
  45                 return -ENOMEM;
  46
  47         memset(sig_data, 0, sizeof(*sig_data));
  48
  49         sig_data->subsys = subsys;
  50         sig_data->data = data;
  51         sig_data->cbfn = cbfn;
  52
  53         /* FIXME: check if we already have a handler for this subsys/cbfn/data */
  54
  55         llist_add_tail(&sig_data->entry, &signal_handler_list);
  56
  57         return 0;
  58 }
  59
  60 void unregister_signal_handler(unsigned int subsys, signal_cbfn *cbfn, void *data)
  61 {
  62         struct signal_handler *handler;
  63
  64         llist_for_each_entry(handler, &signal_handler_list, entry) {
  65                 if (handler->cbfn == cbfn && handler->data == data
  66                     && subsys == handler->subsys) {
  67                         llist_del(&handler->entry);
  68                         talloc_free(handler);
  69                         break;
  70                 }
  71         }
  72 }
  73
  74
  75 void dispatch_signal(unsigned int subsys, unsigned int signal, void *signal_data)
  76 {
  77         struct signal_handler *handler;
  78
  79         llist_for_each_entry(handler, &signal_handler_list, entry) {
  80                 if (handler->subsys != subsys)
  81                         continue;
  82                 (*handler->cbfn)(subsys, signal, handler->data, signal_data);
  83         }
  84 }