autoservice.c

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/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Automatic channel service routines
 * 
 * Copyright (C) 1999, Mark Spencer
 *
 * Mark Spencer <markster@linux-support.net>
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <string.h>
#include <sys/time.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <math.h>       /* For PI */
#include <asterisk/pbx.h>
#include <asterisk/frame.h>
#include <asterisk/sched.h>
#include <asterisk/options.h>
#include <asterisk/channel.h>
#include <asterisk/channel_pvt.h>
#include <asterisk/logger.h>
#include <asterisk/file.h>
#include <asterisk/translate.h>
#include <asterisk/manager.h>
#include <asterisk/chanvars.h>
#include <asterisk/linkedlists.h>
#include <asterisk/indications.h>

#define MAX_AUTOMONS 256

AST_MUTEX_DEFINE_STATIC(autolock);

struct asent {
   struct ast_channel *chan;
   struct asent *next;
};

static struct asent *aslist = NULL;
static pthread_t asthread = AST_PTHREADT_NULL;

static void *autoservice_run(void *ign)
{
   struct ast_channel *mons[MAX_AUTOMONS];
   int x;
   int ms;
   struct ast_channel *chan;
   struct asent *as;
   struct ast_frame *f;
   for(;;) {
      x = 0;
      ast_mutex_lock(&autolock);
      as = aslist;
      while(as) {
         if (!as->chan->_softhangup) {
            if (x < MAX_AUTOMONS)
               mons[x++] = as->chan;
            else
               ast_log(LOG_WARNING, "Exceeded maximum number of automatic monitoring events.  Fix autoservice.c\n");
         }
         as = as->next;
      }
      ast_mutex_unlock(&autolock);

/*       if (!aslist)
         break; */
      ms = 500;
      chan = ast_waitfor_n(mons, x, &ms);
      if (chan) {
         /* Read and ignore anything that occurs */
         f = ast_read(chan);
         if (f)
            ast_frfree(f);
      }
   }
   asthread = AST_PTHREADT_NULL;
   return NULL;
}

int ast_autoservice_start(struct ast_channel *chan)
{
   int res = -1;
   struct asent *as;
   int needstart;
   ast_mutex_lock(&autolock);
   needstart = (asthread == AST_PTHREADT_NULL) ? 1 : 0 /* aslist ? 0 : 1 */;
   as = aslist;
   while(as) {
      if (as->chan == chan)
         break;
      as = as->next;
   }
   if (!as) {
      as = malloc(sizeof(struct asent));
      if (as) {
         memset(as, 0, sizeof(struct asent));
         as->chan = chan;
         as->next = aslist;
         aslist = as;
         res = 0;
         if (needstart) {
            if (pthread_create(&asthread, NULL, autoservice_run, NULL)) {
               ast_log(LOG_WARNING, "Unable to create autoservice thread :(\n");
               free(aslist);
               aslist = NULL;
               res = -1;
            } else
               pthread_kill(asthread, SIGURG);
         }
      }
   }
   ast_mutex_unlock(&autolock);
   return res;
}

int ast_autoservice_stop(struct ast_channel *chan)
{
   int res = -1;
   struct asent *as, *prev;
   ast_mutex_lock(&autolock);
   as = aslist;
   prev = NULL;
   while(as) {
      if (as->chan == chan)
         break;
      prev = as;
      as = as->next;
   }
   if (as) {
      if (prev)
         prev->next = as->next;
      else
         aslist = as->next;
      free(as);
      if (!chan->_softhangup)
         res = 0;
   }
   if (asthread != AST_PTHREADT_NULL) 
      pthread_kill(asthread, SIGURG);
   ast_mutex_unlock(&autolock);
   /* Wait for it to un-block */
   while(chan->blocking)
      usleep(1000);
   return res;
}

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