Wed Oct 28 15:48:46 2009

Asterisk developer's documentation


devicestate.c File Reference

Device state management. More...

#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "asterisk.h"
#include "asterisk/channel.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"
#include "asterisk/linkedlists.h"
#include "asterisk/logger.h"
#include "asterisk/devicestate.h"
#include "asterisk/pbx.h"
#include "asterisk/options.h"

Include dependency graph for devicestate.c:

Go to the source code of this file.

Data Structures

struct  devstate_cb
struct  state_change

Functions

static int __ast_device_state_changed_literal (char *buf)
int ast_device_state (const char *device)
 Asks a channel for device state.
int ast_device_state_changed (const char *fmt,...)
int ast_device_state_changed_literal (const char *dev)
 Tells Asterisk the State for Device is changed.
int ast_device_state_engine_init (void)
int ast_devstate_add (ast_devstate_cb_type callback, void *data)
 Registers a device state change callback.
void ast_devstate_del (ast_devstate_cb_type callback, void *data)
static AST_LIST_HEAD_STATIC (state_changes, state_change)
static AST_LIST_HEAD_STATIC (devstate_cbs, devstate_cb)
int ast_parse_device_state (const char *device)
 Search the Channels by Name.
const char * devstate2str (int devstate)
 Convert device state to text string for output.
static void * do_devstate_changes (void *data)
static void do_state_change (const char *device)

Variables

static ast_cond_t change_pending
static pthread_t change_thread = AST_PTHREADT_NULL
static const char * devstatestring []


Detailed Description

Device state management.

Definition in file devicestate.c.


Function Documentation

static int __ast_device_state_changed_literal ( char *  buf  )  [static]

Definition at line 197 of file devicestate.c.

References ast_cond_signal(), AST_LIST_FIRST, AST_LIST_INSERT_TAIL, AST_LIST_LOCK, AST_LIST_UNLOCK, AST_PTHREADT_NULL, calloc, change_pending, change_thread, do_state_change(), and list.

Referenced by ast_device_state_changed(), and ast_device_state_changed_literal().

00198 {
00199    char *device;
00200    struct state_change *change = NULL;
00201    char *tmp = NULL;
00202 
00203    device = buf;
00204 
00205    tmp = strrchr(device, '-');
00206    if (tmp)
00207       *tmp = '\0';
00208 
00209    if (change_thread != AST_PTHREADT_NULL)
00210       change = calloc(1, sizeof(*change) + strlen(device));
00211 
00212    if (!change) {
00213       /* we could not allocate a change struct, or */
00214       /* there is no background thread, so process the change now */
00215       do_state_change(device);
00216    } else {
00217       /* queue the change */
00218       strcpy(change->device, device);
00219       AST_LIST_LOCK(&state_changes);
00220       AST_LIST_INSERT_TAIL(&state_changes, change, list);
00221       if (AST_LIST_FIRST(&state_changes) == change)
00222          /* the list was empty, signal the thread */
00223          ast_cond_signal(&change_pending);
00224       AST_LIST_UNLOCK(&state_changes);
00225    }
00226 
00227    return 1;
00228 }

int ast_device_state ( const char *  device  ) 

Asks a channel for device state.

Parameters:
device like a dialstring Asks a channel for device state, data is normaly a number from dialstring used by the low level module Trys the channel devicestate callback if not supported search in the active channels list for the device. Returns an AST_DEVICE_??? state -1 on failure

Definition at line 104 of file devicestate.c.

References AST_DEVICE_INVALID, AST_DEVICE_NOT_INUSE, AST_DEVICE_UNKNOWN, ast_get_channel_tech(), ast_parse_device_state(), ast_strdupa, ast_channel_tech::devicestate, strsep(), and ast_channel::tech.

Referenced by ast_extension_state2(), chanavail_exec(), create_queue_member(), do_state_change(), reload_queues(), and transmit_state_notify().

00105 {
00106    char *buf;
00107    char *tech;
00108    char *number;
00109    const struct ast_channel_tech *chan_tech;
00110    int res = 0;
00111    
00112    buf = ast_strdupa(device);
00113    tech = strsep(&buf, "/");
00114    number = buf;
00115    if (!number)
00116       return AST_DEVICE_INVALID;
00117       
00118    chan_tech = ast_get_channel_tech(tech);
00119    if (!chan_tech)
00120       return AST_DEVICE_INVALID;
00121 
00122    if (!chan_tech->devicestate)  /* Does the channel driver support device state notification? */
00123       return ast_parse_device_state(device); /* No, try the generic function */
00124    else {
00125       res = chan_tech->devicestate(number);  /* Ask the channel driver for device state */
00126       if (res == AST_DEVICE_UNKNOWN) {
00127          res = ast_parse_device_state(device);
00128          /* at this point we know the device exists, but the channel driver
00129             could not give us a state; if there is no channel state available,
00130             it must be 'not in use'
00131          */
00132          if (res == AST_DEVICE_UNKNOWN)
00133             res = AST_DEVICE_NOT_INUSE;
00134          return res;
00135       } else
00136          return res;
00137    }
00138 }

int ast_device_state_changed ( const char *  fmt,
  ... 
)

int ast_device_state_changed_literal ( const char *  device  ) 

Tells Asterisk the State for Device is changed.

Parameters:
device devicename like a dialstrin Asterisk polls the new extensionstates and calls the registered callbacks for the changed extensions Returns 0 on success, -1 on failure

Definition at line 230 of file devicestate.c.

References __ast_device_state_changed_literal(), and ast_strdupa.

Referenced by ast_channel_free(), and ast_setstate().

00231 {
00232    char *buf;
00233    buf = ast_strdupa(dev);
00234    return __ast_device_state_changed_literal(buf);
00235 }

int ast_device_state_engine_init ( void   ) 

Definition at line 275 of file devicestate.c.

References ast_cond_init(), ast_log(), ast_pthread_create, change_pending, change_thread, do_devstate_changes(), and LOG_ERROR.

Referenced by main().

00276 {
00277    ast_cond_init(&change_pending, NULL);
00278    if (ast_pthread_create(&change_thread, NULL, do_devstate_changes, NULL) < 0) {
00279       ast_log(LOG_ERROR, "Unable to start device state change thread.\n");
00280       return -1;
00281    }
00282 
00283    return 0;
00284 }

int ast_devstate_add ( ast_devstate_cb_type  callback,
void *  data 
)

Registers a device state change callback.

Parameters:
callback Callback
data to pass to callback The callback is called if the state for extension is changed Return -1 on failure, ID on success

Definition at line 141 of file devicestate.c.

References AST_LIST_INSERT_HEAD, AST_LIST_LOCK, AST_LIST_UNLOCK, devstate_cb::callback, calloc, devstate_cb::data, and list.

Referenced by load_module().

00142 {
00143    struct devstate_cb *devcb;
00144 
00145    if (!callback)
00146       return -1;
00147 
00148    devcb = calloc(1, sizeof(*devcb));
00149    if (!devcb)
00150       return -1;
00151 
00152    devcb->data = data;
00153    devcb->callback = callback;
00154 
00155    AST_LIST_LOCK(&devstate_cbs);
00156    AST_LIST_INSERT_HEAD(&devstate_cbs, devcb, list);
00157    AST_LIST_UNLOCK(&devstate_cbs);
00158 
00159    return 0;
00160 }

void ast_devstate_del ( ast_devstate_cb_type  callback,
void *  data 
)

Definition at line 163 of file devicestate.c.

References AST_LIST_LOCK, AST_LIST_REMOVE_CURRENT, AST_LIST_TRAVERSE_SAFE_BEGIN, AST_LIST_TRAVERSE_SAFE_END, AST_LIST_UNLOCK, devstate_cb::callback, devstate_cb::data, free, and list.

Referenced by unload_module().

00164 {
00165    struct devstate_cb *devcb;
00166 
00167    AST_LIST_LOCK(&devstate_cbs);
00168    AST_LIST_TRAVERSE_SAFE_BEGIN(&devstate_cbs, devcb, list) {
00169       if ((devcb->callback == callback) && (devcb->data == data)) {
00170          AST_LIST_REMOVE_CURRENT(&devstate_cbs, list);
00171          free(devcb);
00172          break;
00173       }
00174    }
00175    AST_LIST_TRAVERSE_SAFE_END;
00176    AST_LIST_UNLOCK(&devstate_cbs);
00177 }

static AST_LIST_HEAD_STATIC ( state_changes  ,
state_change   
) [static]

static AST_LIST_HEAD_STATIC ( devstate_cbs  ,
devstate_cb   
) [static]

int ast_parse_device_state ( const char *  device  ) 

Search the Channels by Name.

Parameters:
device like a dialstring Search the Device in active channels by compare the channelname against the devicename. Compared are only the first chars to the first '-' char. Returns an AST_DEVICE_UNKNOWN if no channel found or AST_DEVICE_INUSE if a channel is found

Definition at line 80 of file devicestate.c.

References ast_channel::_state, AST_CHANNEL_NAME, AST_DEVICE_INUSE, AST_DEVICE_RINGING, AST_DEVICE_UNKNOWN, ast_get_channel_by_name_prefix_locked(), ast_mutex_unlock(), AST_STATE_RINGING, ast_channel::lock, and match().

Referenced by ast_device_state().

00081 {
00082    struct ast_channel *chan;
00083    char match[AST_CHANNEL_NAME];
00084    int res;
00085 
00086    ast_copy_string(match, device, sizeof(match)-1);
00087    strcat(match, "-");
00088    chan = ast_get_channel_by_name_prefix_locked(match, strlen(match));
00089 
00090    if (!chan)
00091       return AST_DEVICE_UNKNOWN;
00092 
00093    if (chan->_state == AST_STATE_RINGING)
00094       res = AST_DEVICE_RINGING;
00095    else
00096       res = AST_DEVICE_INUSE;
00097    
00098    ast_mutex_unlock(&chan->lock);
00099 
00100    return res;
00101 }

const char* devstate2str ( int  devstate  ) 

Convert device state to text string for output.

Parameters:
devstate Current device state

Definition at line 74 of file devicestate.c.

Referenced by __queues_show(), changethread(), and do_state_change().

00075 {
00076    return devstatestring[devstate];
00077 }

static void* do_devstate_changes ( void *  data  )  [static]

Definition at line 250 of file devicestate.c.

References ast_cond_wait(), AST_LIST_LOCK, AST_LIST_REMOVE_HEAD, AST_LIST_UNLOCK, change_pending, do_state_change(), free, and list.

Referenced by ast_device_state_engine_init().

00251 {
00252    struct state_change *cur;
00253 
00254    AST_LIST_LOCK(&state_changes);
00255    for(;;) {
00256       /* the list lock will _always_ be held at this point in the loop */
00257       cur = AST_LIST_REMOVE_HEAD(&state_changes, list);
00258       if (cur) {
00259          /* we got an entry, so unlock the list while we process it */
00260          AST_LIST_UNLOCK(&state_changes);
00261          do_state_change(cur->device);
00262          free(cur);
00263          AST_LIST_LOCK(&state_changes);
00264       } else {
00265          /* there was no entry, so atomically unlock the list and wait for
00266             the condition to be signalled (returns with the lock held) */
00267          ast_cond_wait(&change_pending, &state_changes.lock);
00268       }
00269    }
00270 
00271    return NULL;
00272 }

static void do_state_change ( const char *  device  )  [static]

Definition at line 180 of file devicestate.c.

References ast_device_state(), ast_hint_state_changed(), AST_LIST_LOCK, AST_LIST_TRAVERSE, AST_LIST_UNLOCK, ast_log(), devstate_cb::callback, devstate_cb::data, devstate2str(), list, LOG_DEBUG, and option_debug.

Referenced by __ast_device_state_changed_literal(), and do_devstate_changes().

00181 {
00182    int state;
00183    struct devstate_cb *devcb;
00184 
00185    state = ast_device_state(device);
00186    if (option_debug > 2)
00187       ast_log(LOG_DEBUG, "Changing state for %s - state %d (%s)\n", device, state, devstate2str(state));
00188 
00189    AST_LIST_LOCK(&devstate_cbs);
00190    AST_LIST_TRAVERSE(&devstate_cbs, devcb, list)
00191       devcb->callback(device, state, devcb->data);
00192    AST_LIST_UNLOCK(&devstate_cbs);
00193 
00194    ast_hint_state_changed(device);
00195 }


Variable Documentation

pthread_t change_thread = AST_PTHREADT_NULL [static]

const char* devstatestring[] [static]

Definition at line 44 of file devicestate.c.


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