autoservice.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2006, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  *
  21  * \brief Automatic channel service routines
  22  *
  23  * \author Mark Spencer <markster@digium.com>
  24  */
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/time.h>
  30 #include <signal.h>
  31 #include <errno.h>
  32 #include <unistd.h>
  33
  34 #include "asterisk.h"
  35
  36 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  37
  38 #include "asterisk/pbx.h"
  39 #include "asterisk/frame.h"
  40 #include "asterisk/sched.h"
  41 #include "asterisk/options.h"
  42 #include "asterisk/channel.h"
  43 #include "asterisk/logger.h"
  44 #include "asterisk/file.h"
  45 #include "asterisk/translate.h"
  46 #include "asterisk/manager.h"
  47 #include "asterisk/chanvars.h"
  48 #include "asterisk/linkedlists.h"
  49 #include "asterisk/indications.h"
  50 #include "asterisk/lock.h"
  51 #include "asterisk/utils.h"
  52
  53 #define MAX_AUTOMONS 256
  54
  55 struct asent {
  56         struct ast_channel *chan;
  57         AST_LIST_ENTRY(asent) list;
  58 };
  59
  60 static AST_LIST_HEAD_STATIC(aslist, asent);
  61
  62 static pthread_t asthread = AST_PTHREADT_NULL;
  63
  64 static void *autoservice_run(void *ign)
  65 {
  66
  67         for(;;) {
  68                 struct ast_channel *mons[MAX_AUTOMONS];
  69                 struct ast_channel *chan;
  70                 struct asent *as;
  71                 int x = 0, ms = 500;
  72
  73                 AST_LIST_LOCK(&aslist);
  74                 AST_LIST_TRAVERSE(&aslist, as, list) {
  75                         if (!as->chan->_softhangup) {
  76                                 if (x < MAX_AUTOMONS)
  77                                         mons[x++] = as->chan;
  78                                 else
  79                                         ast_log(LOG_WARNING, "Exceeded maximum number of automatic monitoring events.  Fix autoservice.c\n");
  80                         }
  81                 }
  82                 AST_LIST_UNLOCK(&aslist);
  83
  84                 chan = ast_waitfor_n(mons, x, &ms);
  85                 if (chan) {
  86                         /* Read and ignore anything that occurs */
  87                         struct ast_frame *f = ast_read(chan);
  88                         if (f)
  89                                 ast_frfree(f);
  90                 }
  91         }
  92         asthread = AST_PTHREADT_NULL;
  93         return NULL;
  94 }
  95
  96 int ast_autoservice_start(struct ast_channel *chan)
  97 {
  98         int res = -1;
  99         struct asent *as;
 100         AST_LIST_LOCK(&aslist);
 101
 102         /* Check if the channel already has autoservice */
 103         AST_LIST_TRAVERSE(&aslist, as, list) {
 104                 if (as->chan == chan)
 105                         break;
 106         }
 107         /* XXX if found, we return -1, why ??? */
 108
 109         /* If not, start autoservice on channel */
 110         if (!as && (as = ast_calloc(1, sizeof(*as)))) {
 111                 as->chan = chan;
 112                 AST_LIST_INSERT_HEAD(&aslist, as, list);
 113                 res = 0;
 114                 if (asthread == AST_PTHREADT_NULL) { /* need start the thread */
 115                         if (ast_pthread_create(&asthread, NULL, autoservice_run, NULL)) {
 116                                 ast_log(LOG_WARNING, "Unable to create autoservice thread :(\n");
 117                                 /* There will only be a single member in the list at this point,
 118                                    the one we just added. */
 119                                 AST_LIST_REMOVE(&aslist, as, list);
 120                                 free(as);
 121                                 res = -1;
 122                         } else
 123                                 pthread_kill(asthread, SIGURG);
 124                 }
 125         }
 126         AST_LIST_UNLOCK(&aslist);
 127         return res;
 128 }
 129
 130 int ast_autoservice_stop(struct ast_channel *chan)
 131 {
 132         int res = -1;
 133         struct asent *as;
 134
 135         AST_LIST_LOCK(&aslist);
 136         AST_LIST_TRAVERSE_SAFE_BEGIN(&aslist, as, list) {
 137                 if (as->chan == chan) {
 138                         AST_LIST_REMOVE_CURRENT(&aslist, list);
 139                         free(as);
 140                         if (!chan->_softhangup)
 141                                 res = 0;
 142                         break;
 143                 }
 144         }
 145         AST_LIST_TRAVERSE_SAFE_END
 146
 147         if (asthread != AST_PTHREADT_NULL)
 148                 pthread_kill(asthread, SIGURG);
 149         AST_LIST_UNLOCK(&aslist);
 150
 151         /* Wait for it to un-block */
 152         while(ast_test_flag(chan, AST_FLAG_BLOCKING))
 153                 usleep(1000);
 154         return res;
 155 }