Automatic channel service routines. More...

#include "asterisk.h"
#include <sys/time.h>
#include <signal.h>
#include "asterisk/_private.h"
#include "asterisk/pbx.h"
#include "asterisk/frame.h"
#include "asterisk/sched.h"
#include "asterisk/channel.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"
#include "asterisk/lock.h"
#include "asterisk/utils.h"

Include dependency graph for autoservice.c:

Go to the source code of this file.

Data Structures
struct	asent
struct	aslist
Defines
#define	MAX_AUTOMONS 1500
Functions
void	ast_autoservice_init (void)
int	ast_autoservice_start (struct ast_channel *chan)
	Automatically service a channel for us...
int	ast_autoservice_stop (struct ast_channel *chan)
	Stop servicing a channel for us...
static void *	autoservice_run (void *ign)
Variables
static int	as_chan_list_state
static ast_cond_t	as_cond
static struct aslist	aslist
static pthread_t	asthread = AST_PTHREADT_NULL

Detailed Description

Automatic channel service routines.

Author:: Mark Spencer <markster@digium.com>; Russell Bryant <russell@digium.com>

Definition in file autoservice.c.

Define Documentation

#define MAX_AUTOMONS 1500

Definition at line 50 of file autoservice.c.

Referenced by autoservice_run().

Function Documentation

void ast_autoservice_init ( void )

Provided by autoservice.c

Definition at line 318 of file autoservice.c.

References as_cond, and ast_cond_init().

Referenced by main().

{
   ast_cond_init(&as_cond, NULL);
}

int ast_autoservice_start ( struct ast_channel * chan )

Automatically service a channel for us...

Return values:

	0	success
	-1	failure, or the channel is already being autoserviced

Definition at line 192 of file autoservice.c.

References as_cond, ast_calloc, ast_channel_lock, ast_channel_unlock, ast_cond_signal(), AST_FLAG_END_DTMF_ONLY, AST_LIST_EMPTY, AST_LIST_INSERT_HEAD, AST_LIST_LOCK, AST_LIST_REMOVE, AST_LIST_TRAVERSE, AST_LIST_UNLOCK, ast_log(), ast_pthread_create_background, AST_PTHREADT_NULL, ast_set_flag, ast_test_flag, asthread, autoservice_run(), asent::chan, free, asent::list, LOG_WARNING, asent::orig_end_dtmf_flag, and asent::use_count.

Referenced by _macro_exec(), acf_curl_exec(), acf_odbc_read(), acf_odbc_write(), ast_dtmf_stream(), ast_get_enum(), ast_get_srv(), ast_get_txt(), bridge_playfile(), builtin_atxfer(), builtin_automixmonitor(), builtin_blindtransfer(), conf_play(), confbridge_exec(), dial_exec_full(), feature_exec_app(), function_realtime_read(), function_realtime_readdestroy(), function_realtime_store(), function_realtime_write(), leave_conference_bridge(), lock_read(), lua_autoservice_start(), lua_get_variable_value(), lua_pbx_exec(), lua_set_variable(), lua_set_variable_value(), originate_exec(), osplookup_exec(), pbx_find_extension(), play_message_in_bridged_call(), post_join_marked(), realtimefield_read(), shell_helper(), sla_station_exec(), smdi_msg_retrieve_read(), system_exec_helper(), try_calling(), and trylock_read().

{
   int res = 0;
   struct asent *as;

   AST_LIST_LOCK(&aslist);
   AST_LIST_TRAVERSE(&aslist, as, list) {
      if (as->chan == chan) {
         as->use_count++;
         break;
      }
   }
   AST_LIST_UNLOCK(&aslist);

   if (as) {
      /* Entry exists, autoservice is already handling this channel */
      return 0;
   }

   if (!(as = ast_calloc(1, sizeof(*as))))
      return -1;
   
   /* New entry created */
   as->chan = chan;
   as->use_count = 1;

   ast_channel_lock(chan);
   as->orig_end_dtmf_flag = ast_test_flag(chan, AST_FLAG_END_DTMF_ONLY) ? 1 : 0;
   if (!as->orig_end_dtmf_flag)
      ast_set_flag(chan, AST_FLAG_END_DTMF_ONLY);
   ast_channel_unlock(chan);

   AST_LIST_LOCK(&aslist);

   if (AST_LIST_EMPTY(&aslist) && asthread != AST_PTHREADT_NULL) {
      ast_cond_signal(&as_cond);
   }

   AST_LIST_INSERT_HEAD(&aslist, as, list);

   if (asthread == AST_PTHREADT_NULL) { /* need start the thread */
      if (ast_pthread_create_background(&asthread, NULL, autoservice_run, NULL)) {
         ast_log(LOG_WARNING, "Unable to create autoservice thread :(\n");
         /* There will only be a single member in the list at this point,
            the one we just added. */
         AST_LIST_REMOVE(&aslist, as, list);
         free(as);
         asthread = AST_PTHREADT_NULL;
         res = -1;
      } else {
         pthread_kill(asthread, SIGURG);
      }
   }

   AST_LIST_UNLOCK(&aslist);

   return res;
}

int ast_autoservice_stop ( struct ast_channel * chan )

Stop servicing a channel for us...

Note:: if chan is locked prior to calling ast_autoservice_stop, it is likely that there will be a deadlock between the thread that calls ast_autoservice_stop and the autoservice thread. It is important that chan is not locked prior to this call

Return values:

	0	success
	-1	error, or the channel has been hungup

Definition at line 251 of file autoservice.c.

References ast_channel::_softhangup, as_chan_list_state, ast_channel_lock, ast_channel_unlock, ast_clear_flag, AST_FLAG_END_DTMF_ONLY, ast_frfree, AST_LIST_LOCK, AST_LIST_REMOVE_CURRENT, AST_LIST_REMOVE_HEAD, AST_LIST_TRAVERSE_SAFE_BEGIN, AST_LIST_UNLOCK, AST_PTHREADT_NULL, ast_queue_frame_head(), asthread, asent::chan, asent::deferred_frames, f, free, asent::list, asent::orig_end_dtmf_flag, and asent::use_count.

Referenced by _macro_exec(), acf_curl_exec(), acf_odbc_read(), acf_odbc_write(), array(), ast_dtmf_stream(), ast_get_enum(), ast_get_srv(), ast_get_txt(), ast_hangup(), bridge_playfile(), builtin_atxfer(), builtin_automixmonitor(), conf_play(), confbridge_exec(), dial_exec_full(), feature_exec_app(), finishup(), function_realtime_read(), function_realtime_readdestroy(), function_realtime_store(), function_realtime_write(), leave_conference_bridge(), lock_read(), lua_autoservice_stop(), lua_get_variable_value(), lua_pbx_exec(), lua_set_variable(), lua_set_variable_value(), originate_exec(), osplookup_exec(), pbx_find_extension(), play_message_in_bridged_call(), post_join_marked(), realtimefield_read(), shell_helper(), sla_station_exec(), smdi_msg_retrieve_read(), system_exec_helper(), try_calling(), and trylock_read().

{
   int res = -1;
   struct asent *as, *removed = NULL;
   struct ast_frame *f;
   int chan_list_state;

   AST_LIST_LOCK(&aslist);

   /* Save the autoservice channel list state.  We _must_ verify that the channel
    * list has been rebuilt before we return.  Because, after we return, the channel
    * could get destroyed and we don't want our poor autoservice thread to step on
    * it after its gone! */
   chan_list_state = as_chan_list_state;

   /* Find the entry, but do not free it because it still can be in the
      autoservice thread array */
   AST_LIST_TRAVERSE_SAFE_BEGIN(&aslist, as, list) {  
      if (as->chan == chan) {
         as->use_count--;
         if (as->use_count < 1) {
            AST_LIST_REMOVE_CURRENT(list);
            removed = as;
         }
         break;
      }
   }
   AST_LIST_TRAVERSE_SAFE_END;

   if (removed && asthread != AST_PTHREADT_NULL) {
      pthread_kill(asthread, SIGURG);
   }

   AST_LIST_UNLOCK(&aslist);

   if (!removed) {
      return 0;
   }

   /* Wait while autoservice thread rebuilds its list. */
   while (chan_list_state == as_chan_list_state) {
      usleep(1000);
   }

   /* Now autoservice thread should have no references to our entry
      and we can safely destroy it */

   if (!chan->_softhangup) {
      res = 0;
   }

   if (!as->orig_end_dtmf_flag) {
      ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
   }

   ast_channel_lock(chan);
   while ((f = AST_LIST_REMOVE_HEAD(&as->deferred_frames, frame_list))) {
      ast_queue_frame_head(chan, f);
      ast_frfree(f);
   }
   ast_channel_unlock(chan);

   free(as);

   return res;
}

static void* autoservice_run ( void * ign ) [static]

Definition at line 73 of file autoservice.c.

References ast_check_hangup(), ast_cond_wait(), AST_FRAME_CNG, AST_FRAME_CONTROL, AST_FRAME_DTMF_BEGIN, AST_FRAME_DTMF_END, AST_FRAME_HTML, AST_FRAME_IAX, AST_FRAME_IMAGE, AST_FRAME_MODEM, AST_FRAME_NULL, AST_FRAME_TEXT, AST_FRAME_VIDEO, AST_FRAME_VOICE, ast_frdup(), ast_frfree, ast_frisolate(), AST_LIST_EMPTY, AST_LIST_INSERT_HEAD, AST_LIST_LOCK, AST_LIST_TRAVERSE, AST_LIST_UNLOCK, ast_log(), ast_read(), ast_waitfor_n(), asthread, asent::chan, f, ast_frame::frametype, LOG_WARNING, and MAX_AUTOMONS.

Referenced by ast_autoservice_start().

{
   struct ast_frame hangup_frame = {
      .frametype = AST_FRAME_CONTROL,
      .subclass = AST_CONTROL_HANGUP,
   };

   for (;;) {
      struct ast_channel *mons[MAX_AUTOMONS];
      struct asent *ents[MAX_AUTOMONS];
      struct ast_channel *chan;
      struct asent *as;
      int i, x = 0, ms = 50;
      struct ast_frame *f = NULL;
      struct ast_frame *defer_frame = NULL;

      AST_LIST_LOCK(&aslist);

      /* At this point, we know that no channels that have been removed are going
       * to get used again. */
      as_chan_list_state++;

      if (AST_LIST_EMPTY(&aslist)) {
         ast_cond_wait(&as_cond, &aslist.lock);
      }

      AST_LIST_TRAVERSE(&aslist, as, list) {
         if (!ast_check_hangup(as->chan)) {
            if (x < MAX_AUTOMONS) {
               ents[x] = as;
               mons[x++] = as->chan;
            } else {
               ast_log(LOG_WARNING, "Exceeded maximum number of automatic monitoring events.  Fix autoservice.c\n");
            }
         }
      }

      AST_LIST_UNLOCK(&aslist);

      if (!x) {
         continue;
      }

      chan = ast_waitfor_n(mons, x, &ms);
      if (!chan) {
         continue;
      }

      f = ast_read(chan);

      if (!f) {
         /* No frame means the channel has been hung up.
          * A hangup frame needs to be queued here as ast_waitfor() may
          * never return again for the condition to be detected outside
          * of autoservice.  So, we'll leave a HANGUP queued up so the
          * thread in charge of this channel will know. */

         defer_frame = &hangup_frame;
      } else {

         /* Do not add a default entry in this switch statement.  Each new
          * frame type should be addressed directly as to whether it should
          * be queued up or not. */

         switch (f->frametype) {
         /* Save these frames */
         case AST_FRAME_DTMF_END:
         case AST_FRAME_CONTROL:
         case AST_FRAME_TEXT:
         case AST_FRAME_IMAGE:
         case AST_FRAME_HTML:
            defer_frame = f;
            break;

         /* Throw these frames away */
         case AST_FRAME_DTMF_BEGIN:
         case AST_FRAME_VOICE:
         case AST_FRAME_VIDEO:
         case AST_FRAME_NULL:
         case AST_FRAME_IAX:
         case AST_FRAME_CNG:
         case AST_FRAME_MODEM:
            break;
         }
      }

      if (defer_frame) {
         for (i = 0; i < x; i++) {
            struct ast_frame *dup_f;
            
            if (mons[i] != chan) {
               continue;
            }
            
            if (defer_frame != f) {
               if ((dup_f = ast_frdup(defer_frame))) {
                  AST_LIST_INSERT_HEAD(&ents[i]->deferred_frames, dup_f, frame_list);
               }
            } else {
               if ((dup_f = ast_frisolate(defer_frame))) {
                  if (dup_f != defer_frame) {
                     ast_frfree(defer_frame);
                  }
                  AST_LIST_INSERT_HEAD(&ents[i]->deferred_frames, dup_f, frame_list);
               }
            }
            
            break;
         }
      } else if (f) {
         ast_frfree(f);
      }
   }

   asthread = AST_PTHREADT_NULL;

   return NULL;
}