Wed Oct 28 11:45:50 2009

Asterisk developer's documentation


autoservice.c File Reference

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 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().

00319 {
00320    ast_cond_init(&as_cond, NULL);
00321 }

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_automonitor(), builtin_blindtransfer(), conf_play(), dial_exec_full(), feature_exec_app(), function_realtime_read(), function_realtime_readdestroy(), function_realtime_store(), function_realtime_write(), lock_read(), lua_autoservice_start(), lua_get_variable_value(), lua_pbx_exec(), lua_set_variable(), lua_set_variable_value(), osplookup_exec(), pbx_find_extension(), shell_helper(), sla_station_exec(), smdi_msg_retrieve_read(), system_exec_helper(), try_calling(), and trylock_read().

00193 {
00194    int res = 0;
00195    struct asent *as;
00196 
00197    AST_LIST_LOCK(&aslist);
00198    AST_LIST_TRAVERSE(&aslist, as, list) {
00199       if (as->chan == chan) {
00200          as->use_count++;
00201          break;
00202       }
00203    }
00204    AST_LIST_UNLOCK(&aslist);
00205 
00206    if (as) {
00207       /* Entry exists, autoservice is already handling this channel */
00208       return 0;
00209    }
00210 
00211    if (!(as = ast_calloc(1, sizeof(*as))))
00212       return -1;
00213    
00214    /* New entry created */
00215    as->chan = chan;
00216    as->use_count = 1;
00217 
00218    ast_channel_lock(chan);
00219    as->orig_end_dtmf_flag = ast_test_flag(chan, AST_FLAG_END_DTMF_ONLY) ? 1 : 0;
00220    if (!as->orig_end_dtmf_flag)
00221       ast_set_flag(chan, AST_FLAG_END_DTMF_ONLY);
00222    ast_channel_unlock(chan);
00223 
00224    AST_LIST_LOCK(&aslist);
00225 
00226    if (AST_LIST_EMPTY(&aslist) && asthread != AST_PTHREADT_NULL) {
00227       ast_cond_signal(&as_cond);
00228    }
00229 
00230    AST_LIST_INSERT_HEAD(&aslist, as, list);
00231 
00232    if (asthread == AST_PTHREADT_NULL) { /* need start the thread */
00233       if (ast_pthread_create_background(&asthread, NULL, autoservice_run, NULL)) {
00234          ast_log(LOG_WARNING, "Unable to create autoservice thread :(\n");
00235          /* There will only be a single member in the list at this point,
00236             the one we just added. */
00237          AST_LIST_REMOVE(&aslist, as, list);
00238          free(as);
00239          asthread = AST_PTHREADT_NULL;
00240          res = -1;
00241       } else {
00242          pthread_kill(asthread, SIGURG);
00243       }
00244    }
00245 
00246    AST_LIST_UNLOCK(&aslist);
00247 
00248    return res;
00249 }

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_TRAVERSE_SAFE_END, AST_LIST_UNLOCK, AST_PTHREADT_NULL, ast_queue_frame_head(), asthread, asent::chan, asent::deferred_frames, f, ast_frame::frame_list, 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(), builtin_automonitor(), conf_play(), dial_exec_full(), feature_exec_app(), finishup(), function_realtime_read(), function_realtime_readdestroy(), function_realtime_store(), function_realtime_write(), lock_read(), lua_autoservice_stop(), lua_get_variable_value(), lua_pbx_exec(), lua_set_variable(), lua_set_variable_value(), osplookup_exec(), pbx_find_extension(), shell_helper(), sla_station_exec(), smdi_msg_retrieve_read(), system_exec_helper(), try_calling(), and trylock_read().

00252 {
00253    int res = -1;
00254    struct asent *as, *removed = NULL;
00255    struct ast_frame *f;
00256    int chan_list_state;
00257 
00258    AST_LIST_LOCK(&aslist);
00259 
00260    /* Save the autoservice channel list state.  We _must_ verify that the channel
00261     * list has been rebuilt before we return.  Because, after we return, the channel
00262     * could get destroyed and we don't want our poor autoservice thread to step on
00263     * it after its gone! */
00264    chan_list_state = as_chan_list_state;
00265 
00266    /* Find the entry, but do not free it because it still can be in the
00267       autoservice thread array */
00268    AST_LIST_TRAVERSE_SAFE_BEGIN(&aslist, as, list) {  
00269       if (as->chan == chan) {
00270          as->use_count--;
00271          if (as->use_count < 1) {
00272             AST_LIST_REMOVE_CURRENT(list);
00273             removed = as;
00274          }
00275          break;
00276       }
00277    }
00278    AST_LIST_TRAVERSE_SAFE_END;
00279 
00280    if (removed && asthread != AST_PTHREADT_NULL) {
00281       pthread_kill(asthread, SIGURG);
00282    }
00283 
00284    AST_LIST_UNLOCK(&aslist);
00285 
00286    if (!removed) {
00287       return 0;
00288    }
00289 
00290    /* Wait while autoservice thread rebuilds its list. */
00291    while (chan_list_state == as_chan_list_state) {
00292       usleep(1000);
00293    }
00294 
00295    /* Now autoservice thread should have no references to our entry
00296       and we can safely destroy it */
00297 
00298    if (!chan->_softhangup) {
00299       res = 0;
00300    }
00301 
00302    if (!as->orig_end_dtmf_flag) {
00303       ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
00304    }
00305 
00306    ast_channel_lock(chan);
00307    while ((f = AST_LIST_REMOVE_HEAD(&as->deferred_frames, frame_list))) {
00308       ast_queue_frame_head(chan, f);
00309       ast_frfree(f);
00310    }
00311    ast_channel_unlock(chan);
00312 
00313    free(as);
00314 
00315    return res;
00316 }

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

Definition at line 73 of file autoservice.c.

References ast_check_hangup(), ast_cond_wait(), AST_CONTROL_HANGUP, 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::frame_list, ast_frame::frametype, LOG_WARNING, and MAX_AUTOMONS.

Referenced by ast_autoservice_start().

00074 {
00075    struct ast_frame hangup_frame = {
00076       .frametype = AST_FRAME_CONTROL,
00077       .subclass = AST_CONTROL_HANGUP,
00078    };
00079 
00080    for (;;) {
00081       struct ast_channel *mons[MAX_AUTOMONS];
00082       struct asent *ents[MAX_AUTOMONS];
00083       struct ast_channel *chan;
00084       struct asent *as;
00085       int i, x = 0, ms = 50;
00086       struct ast_frame *f = NULL;
00087       struct ast_frame *defer_frame = NULL;
00088 
00089       AST_LIST_LOCK(&aslist);
00090 
00091       /* At this point, we know that no channels that have been removed are going
00092        * to get used again. */
00093       as_chan_list_state++;
00094 
00095       if (AST_LIST_EMPTY(&aslist)) {
00096          ast_cond_wait(&as_cond, &aslist.lock);
00097       }
00098 
00099       AST_LIST_TRAVERSE(&aslist, as, list) {
00100          if (!ast_check_hangup(as->chan)) {
00101             if (x < MAX_AUTOMONS) {
00102                ents[x] = as;
00103                mons[x++] = as->chan;
00104             } else {
00105                ast_log(LOG_WARNING, "Exceeded maximum number of automatic monitoring events.  Fix autoservice.c\n");
00106             }
00107          }
00108       }
00109 
00110       AST_LIST_UNLOCK(&aslist);
00111 
00112       if (!x) {
00113          continue;
00114       }
00115 
00116       chan = ast_waitfor_n(mons, x, &ms);
00117       if (!chan) {
00118          continue;
00119       }
00120 
00121       f = ast_read(chan);
00122 
00123       if (!f) {
00124          /* No frame means the channel has been hung up.
00125           * A hangup frame needs to be queued here as ast_waitfor() may
00126           * never return again for the condition to be detected outside
00127           * of autoservice.  So, we'll leave a HANGUP queued up so the
00128           * thread in charge of this channel will know. */
00129 
00130          defer_frame = &hangup_frame;
00131       } else {
00132 
00133          /* Do not add a default entry in this switch statement.  Each new
00134           * frame type should be addressed directly as to whether it should
00135           * be queued up or not. */
00136 
00137          switch (f->frametype) {
00138          /* Save these frames */
00139          case AST_FRAME_DTMF_END:
00140          case AST_FRAME_CONTROL:
00141          case AST_FRAME_TEXT:
00142          case AST_FRAME_IMAGE:
00143          case AST_FRAME_HTML:
00144             defer_frame = f;
00145             break;
00146 
00147          /* Throw these frames away */
00148          case AST_FRAME_DTMF_BEGIN:
00149          case AST_FRAME_VOICE:
00150          case AST_FRAME_VIDEO:
00151          case AST_FRAME_NULL:
00152          case AST_FRAME_IAX:
00153          case AST_FRAME_CNG:
00154          case AST_FRAME_MODEM:
00155             break;
00156          }
00157       }
00158 
00159       if (defer_frame) {
00160          for (i = 0; i < x; i++) {
00161             struct ast_frame *dup_f;
00162             
00163             if (mons[i] != chan) {
00164                continue;
00165             }
00166             
00167             if (defer_frame != f) {
00168                if ((dup_f = ast_frdup(defer_frame))) {
00169                   AST_LIST_INSERT_HEAD(&ents[i]->deferred_frames, dup_f, frame_list);
00170                }
00171             } else {
00172                if ((dup_f = ast_frisolate(defer_frame))) {
00173                   if (dup_f != defer_frame) {
00174                      ast_frfree(defer_frame);
00175                   }
00176                   AST_LIST_INSERT_HEAD(&ents[i]->deferred_frames, dup_f, frame_list);
00177                }
00178             }
00179             
00180             break;
00181          }
00182       } else if (f) {
00183          ast_frfree(f);
00184       }
00185    }
00186 
00187    asthread = AST_PTHREADT_NULL;
00188 
00189    return NULL;
00190 }


Variable Documentation

int as_chan_list_state [static]

Definition at line 71 of file autoservice.c.

Referenced by ast_autoservice_stop().

ast_cond_t as_cond [static]

Definition at line 67 of file autoservice.c.

Referenced by ast_autoservice_init(), and ast_autoservice_start().

pthread_t asthread = AST_PTHREADT_NULL [static]

Definition at line 69 of file autoservice.c.

Referenced by ast_autoservice_start(), ast_autoservice_stop(), and autoservice_run().


Generated on Wed Oct 28 11:45:51 2009 for Asterisk - the Open Source PBX by  doxygen 1.5.6