Wed Aug 18 22:33:51 2010

Asterisk developer's documentation


devicestate.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2008, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@digium.com>
00007  * Russell Bryant <russell@digium.com>
00008  *
00009  * See http://www.asterisk.org for more information about
00010  * the Asterisk project. Please do not directly contact
00011  * any of the maintainers of this project for assistance;
00012  * the project provides a web site, mailing lists and IRC
00013  * channels for your use.
00014  *
00015  * This program is free software, distributed under the terms of
00016  * the GNU General Public License Version 2. See the LICENSE file
00017  * at the top of the source tree.
00018  */
00019 
00020 /*! \file
00021  *
00022  * \brief Device state management
00023  *
00024  * \author Mark Spencer <markster@digium.com> 
00025  * \author Russell Bryant <russell@digium.com>
00026  *
00027  * \arg \ref AstExtState
00028  */
00029 
00030 /*! \page AstExtState Extension and device states in Asterisk
00031  *
00032  * (Note that these descriptions of device states and extension
00033  * states have not been updated to the way things work
00034  * in Asterisk 1.6.)
00035  *
00036  * Asterisk has an internal system that reports states
00037  * for an extension. By using the dialplan priority -1,
00038  * also called a \b hint, a connection can be made from an
00039  * extension to one or many devices. The state of the extension
00040  * now depends on the combined state of the devices.
00041  *
00042  * The device state is basically based on the current calls.
00043  * If the devicestate engine can find a call from or to the
00044  * device, it's in use.
00045  * 
00046  * Some channel drivers implement a callback function for 
00047  * a better level of reporting device states. The SIP channel
00048  * has a complicated system for this, which is improved 
00049  * by adding call limits to the configuration.
00050  * 
00051  * Functions that want to check the status of an extension
00052  * register themself as a \b watcher.
00053  * Watchers in this system can subscribe either to all extensions
00054  * or just a specific extensions.
00055  *
00056  * For non-device related states, there's an API called
00057  * devicestate providers. This is an extendible system for
00058  * delivering state information from outside sources or
00059  * functions within Asterisk. Currently we have providers
00060  * for app_meetme.c - the conference bridge - and call
00061  * parking (metermaids).
00062  *
00063  * There are manly three subscribers to extension states 
00064  * within Asterisk:
00065  * - AMI, the manager interface
00066  * - app_queue.c - the Queue dialplan application
00067  * - SIP subscriptions, a.k.a. "blinking lamps" or 
00068  *   "buddy lists"
00069  *
00070  * The CLI command "show hints" show last known state
00071  *
00072  * \note None of these handle user states, like an IM presence
00073  * system. res_jabber.c can subscribe and watch such states
00074  * in jabber/xmpp based systems.
00075  *
00076  * \section AstDevStateArch Architecture for devicestates
00077  *
00078  * When a channel driver or asterisk app changes state for 
00079  * a watched object, it alerts the core. The core queues
00080  * a change. When the change is processed, there's a query
00081  * sent to the channel driver/provider if there's a function
00082  * to handle that, otherwise a channel walk is issued to find
00083  * a channel that involves the object.
00084  * 
00085  * The changes are queued and processed by a separate thread.
00086  * This thread calls the watchers subscribing to status 
00087  * changes for the object. For manager, this results 
00088  * in events. For SIP, NOTIFY requests.
00089  *
00090  * - Device states
00091  *    \arg \ref devicestate.c 
00092  *    \arg \ref devicestate.h 
00093  *
00094  * \section AstExtStateArch Architecture for extension states
00095  * 
00096  * Hints are connected to extension. If an extension changes state
00097  * it checks the hint devices. If there is a hint, the callbacks into
00098  * device states are checked. The aggregated state is set for the hint
00099  * and reported back.
00100  *
00101  * - Extension states
00102  *    \arg \ref AstENUM ast_extension_states
00103  *    \arg \ref pbx.c 
00104  *    \arg \ref pbx.h 
00105  * - Structures
00106  *    - \ref ast_state_cb struct.  Callbacks for watchers
00107  *    - Callback ast_state_cb_type
00108  *    - \ref ast_hint struct.
00109  *    - Functions
00110  *    - ast_extension_state_add()
00111  *    - ast_extension_state_del()
00112  *    - ast_get_hint()
00113  * 
00114  */
00115 
00116 #include "asterisk.h"
00117 
00118 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 205414 $")
00119 
00120 #include "asterisk/_private.h"
00121 #include "asterisk/channel.h"
00122 #include "asterisk/utils.h"
00123 #include "asterisk/lock.h"
00124 #include "asterisk/linkedlists.h"
00125 #include "asterisk/devicestate.h"
00126 #include "asterisk/pbx.h"
00127 #include "asterisk/app.h"
00128 #include "asterisk/event.h"
00129 
00130 /*! \brief Device state strings for printing */
00131 static const char *devstatestring[] = {
00132    /* 0 AST_DEVICE_UNKNOWN */ "Unknown",  /*!< Valid, but unknown state */
00133    /* 1 AST_DEVICE_NOT_INUSE */  "Not in use",  /*!< Not used */
00134    /* 2 AST_DEVICE IN USE */  "In use",   /*!< In use */
00135    /* 3 AST_DEVICE_BUSY */    "Busy",     /*!< Busy */
00136    /* 4 AST_DEVICE_INVALID */ "Invalid",  /*!< Invalid - not known to Asterisk */
00137    /* 5 AST_DEVICE_UNAVAILABLE */   "Unavailable", /*!< Unavailable (not registred) */
00138    /* 6 AST_DEVICE_RINGING */ "Ringing",  /*!< Ring, ring, ring */
00139    /* 7 AST_DEVICE_RINGINUSE */  "Ring+Inuse",  /*!< Ring and in use */
00140    /* 8 AST_DEVICE_ONHOLD */  "On Hold"   /*!< On Hold */
00141 };
00142 
00143 /*!\brief Mapping for channel states to device states */
00144 static const struct chan2dev {
00145    enum ast_channel_state chan;
00146    enum ast_device_state dev;
00147 } chan2dev[] = {
00148    { AST_STATE_DOWN,            AST_DEVICE_NOT_INUSE },
00149    { AST_STATE_RESERVED,        AST_DEVICE_INUSE },
00150    { AST_STATE_OFFHOOK,         AST_DEVICE_INUSE },
00151    { AST_STATE_DIALING,         AST_DEVICE_INUSE },
00152    { AST_STATE_RING,            AST_DEVICE_INUSE },
00153    { AST_STATE_RINGING,         AST_DEVICE_RINGING },
00154    { AST_STATE_UP,              AST_DEVICE_INUSE },
00155    { AST_STATE_BUSY,            AST_DEVICE_BUSY },
00156    { AST_STATE_DIALING_OFFHOOK, AST_DEVICE_INUSE },
00157    { AST_STATE_PRERING,         AST_DEVICE_RINGING },
00158    { -100,                      -100 },
00159 };
00160 
00161 /*! \brief  A device state provider (not a channel) */
00162 struct devstate_prov {
00163    char label[40];
00164    ast_devstate_prov_cb_type callback;
00165    AST_RWLIST_ENTRY(devstate_prov) list;
00166 };
00167 
00168 /*! \brief A list of providers */
00169 static AST_RWLIST_HEAD_STATIC(devstate_provs, devstate_prov);
00170 
00171 struct state_change {
00172    AST_LIST_ENTRY(state_change) list;
00173    char device[1];
00174 };
00175 
00176 /*! \brief The state change queue. State changes are queued
00177    for processing by a separate thread */
00178 static AST_LIST_HEAD_STATIC(state_changes, state_change);
00179 
00180 /*! \brief The device state change notification thread */
00181 static pthread_t change_thread = AST_PTHREADT_NULL;
00182 
00183 /*! \brief Flag for the queue */
00184 static ast_cond_t change_pending;
00185 
00186 struct devstate_change {
00187    AST_LIST_ENTRY(devstate_change) entry;
00188    uint32_t state;
00189    struct ast_eid eid;
00190    char device[1];
00191 };
00192 
00193 struct {
00194    pthread_t thread;
00195    struct ast_event_sub *event_sub;
00196    ast_cond_t cond;
00197    ast_mutex_t lock;
00198    AST_LIST_HEAD_NOLOCK(, devstate_change) devstate_change_q;
00199    unsigned int enabled:1;
00200 } devstate_collector = {
00201    .thread = AST_PTHREADT_NULL,
00202    .enabled = 0,
00203 };
00204 
00205 /* Forward declarations */
00206 static int getproviderstate(const char *provider, const char *address);
00207 
00208 /*! \brief Find devicestate as text message for output */
00209 const char *devstate2str(enum ast_device_state devstate) 
00210 {
00211    return devstatestring[devstate];
00212 }
00213 
00214 enum ast_device_state ast_state_chan2dev(enum ast_channel_state chanstate)
00215 {
00216    int i;
00217    chanstate &= 0xFFFF;
00218    for (i = 0; chan2dev[i].chan != -100; i++) {
00219       if (chan2dev[i].chan == chanstate) {
00220          return chan2dev[i].dev;
00221       }
00222    }
00223    return AST_DEVICE_UNKNOWN;
00224 }
00225 
00226 const char *ast_devstate_str(enum ast_device_state state)
00227 {
00228    const char *res = "UNKNOWN";
00229 
00230    switch (state) {
00231    case AST_DEVICE_UNKNOWN:
00232       break;
00233    case AST_DEVICE_NOT_INUSE:
00234       res = "NOT_INUSE";
00235       break;
00236    case AST_DEVICE_INUSE:
00237       res = "INUSE";
00238       break;
00239    case AST_DEVICE_BUSY:
00240       res = "BUSY";
00241       break;
00242    case AST_DEVICE_INVALID:
00243       res = "INVALID";
00244       break;
00245    case AST_DEVICE_UNAVAILABLE:
00246       res = "UNAVAILABLE";
00247       break;
00248    case AST_DEVICE_RINGING:
00249       res = "RINGING";
00250       break;
00251    case AST_DEVICE_RINGINUSE:
00252       res = "RINGINUSE";
00253       break;
00254    case AST_DEVICE_ONHOLD:
00255       res = "ONHOLD";
00256       break;
00257    case AST_DEVICE_TOTAL:
00258       break;
00259    }
00260 
00261    return res;
00262 }
00263 
00264 enum ast_device_state ast_devstate_val(const char *val)
00265 {
00266    if (!strcasecmp(val, "NOT_INUSE"))
00267       return AST_DEVICE_NOT_INUSE;
00268    else if (!strcasecmp(val, "INUSE"))
00269       return AST_DEVICE_INUSE;
00270    else if (!strcasecmp(val, "BUSY"))
00271       return AST_DEVICE_BUSY;
00272    else if (!strcasecmp(val, "INVALID"))
00273       return AST_DEVICE_INVALID;
00274    else if (!strcasecmp(val, "UNAVAILABLE"))
00275       return AST_DEVICE_UNAVAILABLE;
00276    else if (!strcasecmp(val, "RINGING"))
00277       return AST_DEVICE_RINGING;
00278    else if (!strcasecmp(val, "RINGINUSE"))
00279       return AST_DEVICE_RINGINUSE;
00280    else if (!strcasecmp(val, "ONHOLD"))
00281       return AST_DEVICE_ONHOLD;
00282 
00283    return AST_DEVICE_UNKNOWN;
00284 }
00285 
00286 /*! \brief Find out if device is active in a call or not 
00287    \note find channels with the device's name in it
00288    This function is only used for channels that does not implement 
00289    devicestate natively
00290 */
00291 enum ast_device_state ast_parse_device_state(const char *device)
00292 {
00293    struct ast_channel *chan;
00294    char match[AST_CHANNEL_NAME];
00295    enum ast_device_state res;
00296 
00297    ast_copy_string(match, device, sizeof(match)-1);
00298    strcat(match, "-");
00299    chan = ast_get_channel_by_name_prefix_locked(match, strlen(match));
00300 
00301    if (!chan)
00302       return AST_DEVICE_UNKNOWN;
00303 
00304    if (chan->_state == AST_STATE_RINGING)
00305       res = AST_DEVICE_RINGING;
00306    else
00307       res = AST_DEVICE_INUSE;
00308    
00309    ast_channel_unlock(chan);
00310 
00311    return res;
00312 }
00313 
00314 static enum ast_device_state devstate_cached(const char *device)
00315 {
00316    enum ast_device_state res = AST_DEVICE_UNKNOWN;
00317    struct ast_event *event;
00318 
00319    event = ast_event_get_cached(AST_EVENT_DEVICE_STATE,
00320       AST_EVENT_IE_DEVICE, AST_EVENT_IE_PLTYPE_STR, device,
00321       AST_EVENT_IE_END);
00322 
00323    if (!event)
00324       return res;
00325 
00326    res = ast_event_get_ie_uint(event, AST_EVENT_IE_STATE);
00327 
00328    ast_event_destroy(event);
00329 
00330    return res;
00331 }
00332 
00333 /*! \brief Check device state through channel specific function or generic function */
00334 static enum ast_device_state _ast_device_state(const char *device, int check_cache)
00335 {
00336    char *buf;
00337    char *number;
00338    const struct ast_channel_tech *chan_tech;
00339    enum ast_device_state res;
00340    /*! \brief Channel driver that provides device state */
00341    char *tech;
00342    /*! \brief Another provider of device state */
00343    char *provider = NULL;
00344 
00345    /* If the last known state is cached, just return that */
00346    if (check_cache) {
00347       res = devstate_cached(device);
00348       if (res != AST_DEVICE_UNKNOWN) {
00349          return res;
00350       }
00351    }
00352 
00353    buf = ast_strdupa(device);
00354    tech = strsep(&buf, "/");
00355    if (!(number = buf)) {
00356       if (!(provider = strsep(&tech, ":")))
00357          return AST_DEVICE_INVALID;
00358       /* We have a provider */
00359       number = tech;
00360       tech = NULL;
00361    }
00362 
00363    if (provider)  {
00364       ast_debug(3, "Checking if I can find provider for \"%s\" - number: %s\n", provider, number);
00365       return getproviderstate(provider, number);
00366    }
00367 
00368    ast_debug(4, "No provider found, checking channel drivers for %s - %s\n", tech, number);
00369 
00370    if (!(chan_tech = ast_get_channel_tech(tech)))
00371       return AST_DEVICE_INVALID;
00372 
00373    if (!(chan_tech->devicestate)) /* Does the channel driver support device state notification? */
00374       return ast_parse_device_state(device); /* No, try the generic function */
00375 
00376    res = chan_tech->devicestate(number);
00377 
00378    if (res != AST_DEVICE_UNKNOWN)
00379       return res;
00380 
00381    res = ast_parse_device_state(device);
00382 
00383    return res;
00384 }
00385 
00386 enum ast_device_state ast_device_state(const char *device)
00387 {
00388    /* This function is called from elsewhere in the code to find out the
00389     * current state of a device.  Check the cache, first. */
00390 
00391    return _ast_device_state(device, 1);
00392 }
00393 
00394 /*! \brief Add device state provider */
00395 int ast_devstate_prov_add(const char *label, ast_devstate_prov_cb_type callback)
00396 {
00397    struct devstate_prov *devprov;
00398 
00399    if (!callback || !(devprov = ast_calloc(1, sizeof(*devprov))))
00400       return -1;
00401 
00402    devprov->callback = callback;
00403    ast_copy_string(devprov->label, label, sizeof(devprov->label));
00404 
00405    AST_RWLIST_WRLOCK(&devstate_provs);
00406    AST_RWLIST_INSERT_HEAD(&devstate_provs, devprov, list);
00407    AST_RWLIST_UNLOCK(&devstate_provs);
00408 
00409    return 0;
00410 }
00411 
00412 /*! \brief Remove device state provider */
00413 int ast_devstate_prov_del(const char *label)
00414 {
00415    struct devstate_prov *devcb;
00416    int res = -1;
00417 
00418    AST_RWLIST_WRLOCK(&devstate_provs);
00419    AST_RWLIST_TRAVERSE_SAFE_BEGIN(&devstate_provs, devcb, list) {
00420       if (!strcasecmp(devcb->label, label)) {
00421          AST_RWLIST_REMOVE_CURRENT(list);
00422          ast_free(devcb);
00423          res = 0;
00424          break;
00425       }
00426    }
00427    AST_RWLIST_TRAVERSE_SAFE_END;
00428    AST_RWLIST_UNLOCK(&devstate_provs);
00429 
00430    return res;
00431 }
00432 
00433 /*! \brief Get provider device state */
00434 static int getproviderstate(const char *provider, const char *address)
00435 {
00436    struct devstate_prov *devprov;
00437    int res = AST_DEVICE_INVALID;
00438 
00439    AST_RWLIST_RDLOCK(&devstate_provs);
00440    AST_RWLIST_TRAVERSE(&devstate_provs, devprov, list) {
00441       ast_debug(5, "Checking provider %s with %s\n", devprov->label, provider);
00442 
00443       if (!strcasecmp(devprov->label, provider)) {
00444          res = devprov->callback(address);
00445          break;
00446       }
00447    }
00448    AST_RWLIST_UNLOCK(&devstate_provs);
00449 
00450    return res;
00451 }
00452 
00453 static void devstate_event(const char *device, enum ast_device_state state)
00454 {
00455    struct ast_event *event;
00456    enum ast_event_type event_type;
00457 
00458    if (devstate_collector.enabled) {
00459       /* Distributed device state is enabled, so this state change is a change
00460        * for a single server, not the real state. */
00461       event_type = AST_EVENT_DEVICE_STATE_CHANGE;
00462    } else {
00463       event_type = AST_EVENT_DEVICE_STATE;
00464    }
00465 
00466    ast_debug(3, "device '%s' state '%d'\n", device, state);
00467 
00468    if (!(event = ast_event_new(event_type,
00469          AST_EVENT_IE_DEVICE, AST_EVENT_IE_PLTYPE_STR, device,
00470          AST_EVENT_IE_STATE, AST_EVENT_IE_PLTYPE_UINT, state,
00471          AST_EVENT_IE_END))) {
00472       return;
00473    }
00474 
00475    ast_event_queue_and_cache(event);
00476 }
00477 
00478 /*! Called by the state change thread to find out what the state is, and then
00479  *  to queue up the state change event */
00480 static void do_state_change(const char *device)
00481 {
00482    enum ast_device_state state;
00483 
00484    state = _ast_device_state(device, 0);
00485 
00486    ast_debug(3, "Changing state for %s - state %d (%s)\n", device, state, devstate2str(state));
00487 
00488    devstate_event(device, state);
00489 }
00490 
00491 int ast_devstate_changed_literal(enum ast_device_state state, const char *device)
00492 {
00493    struct state_change *change;
00494 
00495    /* 
00496     * If we know the state change (how nice of the caller of this function!)
00497     * then we can just generate a device state event. 
00498     *
00499     * Otherwise, we do the following:
00500     *   - Queue an event up to another thread that the state has changed
00501     *   - In the processing thread, it calls the callback provided by the
00502     *     device state provider (which may or may not be a channel driver)
00503     *     to determine the state.
00504     *   - If the device state provider does not know the state, or this is
00505     *     for a channel and the channel driver does not implement a device
00506     *     state callback, then we will look through the channel list to
00507     *     see if we can determine a state based on active calls.
00508     *   - Once a state has been determined, a device state event is generated.
00509     */
00510 
00511    if (state != AST_DEVICE_UNKNOWN) {
00512       devstate_event(device, state);
00513    } else if (change_thread == AST_PTHREADT_NULL || !(change = ast_calloc(1, sizeof(*change) + strlen(device)))) {
00514       /* we could not allocate a change struct, or */
00515       /* there is no background thread, so process the change now */
00516       do_state_change(device);
00517    } else {
00518       /* queue the change */
00519       strcpy(change->device, device);
00520       AST_LIST_LOCK(&state_changes);
00521       AST_LIST_INSERT_TAIL(&state_changes, change, list);
00522       ast_cond_signal(&change_pending);
00523       AST_LIST_UNLOCK(&state_changes);
00524    }
00525 
00526    return 1;
00527 }
00528 
00529 int ast_device_state_changed_literal(const char *dev)
00530 {
00531    return ast_devstate_changed_literal(AST_DEVICE_UNKNOWN, dev);
00532 }
00533 
00534 int ast_devstate_changed(enum ast_device_state state, const char *fmt, ...) 
00535 {
00536    char buf[AST_MAX_EXTENSION];
00537    va_list ap;
00538 
00539    va_start(ap, fmt);
00540    vsnprintf(buf, sizeof(buf), fmt, ap);
00541    va_end(ap);
00542 
00543    return ast_devstate_changed_literal(state, buf);
00544 }
00545 
00546 int ast_device_state_changed(const char *fmt, ...) 
00547 {
00548    char buf[AST_MAX_EXTENSION];
00549    va_list ap;
00550 
00551    va_start(ap, fmt);
00552    vsnprintf(buf, sizeof(buf), fmt, ap);
00553    va_end(ap);
00554 
00555    return ast_devstate_changed_literal(AST_DEVICE_UNKNOWN, buf);
00556 }
00557 
00558 /*! \brief Go through the dev state change queue and update changes in the dev state thread */
00559 static void *do_devstate_changes(void *data)
00560 {
00561    struct state_change *next, *current;
00562 
00563    for (;;) {
00564       /* This basically pops off any state change entries, resets the list back to NULL, unlocks, and processes each state change */
00565       AST_LIST_LOCK(&state_changes);
00566       if (AST_LIST_EMPTY(&state_changes))
00567          ast_cond_wait(&change_pending, &state_changes.lock);
00568       next = AST_LIST_FIRST(&state_changes);
00569       AST_LIST_HEAD_INIT_NOLOCK(&state_changes);
00570       AST_LIST_UNLOCK(&state_changes);
00571 
00572       /* Process each state change */
00573       while ((current = next)) {
00574          next = AST_LIST_NEXT(current, list);
00575          do_state_change(current->device);
00576          ast_free(current);
00577       }
00578    }
00579 
00580    return NULL;
00581 }
00582 
00583 static void destroy_devstate_change(struct devstate_change *sc)
00584 {
00585    ast_free(sc);
00586 }
00587 
00588 #define MAX_SERVERS 64
00589 struct change_collection {
00590    struct devstate_change states[MAX_SERVERS];
00591    size_t num_states;
00592 };
00593 
00594 static void devstate_cache_cb(const struct ast_event *event, void *data)
00595 {
00596    struct change_collection *collection = data;
00597    int i;
00598    const struct ast_eid *eid;
00599 
00600    if (collection->num_states == ARRAY_LEN(collection->states)) {
00601       ast_log(LOG_ERROR, "More per-server state values than we have room for (MAX_SERVERS is %d)\n",
00602          MAX_SERVERS);
00603       return;
00604    }
00605 
00606    if (!(eid = ast_event_get_ie_raw(event, AST_EVENT_IE_EID))) {
00607       ast_log(LOG_ERROR, "Device state change event with no EID\n");
00608       return;
00609    }
00610 
00611    i = collection->num_states;
00612 
00613    collection->states[i].state = ast_event_get_ie_uint(event, AST_EVENT_IE_STATE);
00614    collection->states[i].eid = *eid;
00615 
00616    collection->num_states++;
00617 }
00618 
00619 static void process_collection(const char *device, struct change_collection *collection)
00620 {
00621    int i;
00622    struct ast_devstate_aggregate agg;
00623    enum ast_device_state state;
00624    struct ast_event *event;
00625 
00626    ast_devstate_aggregate_init(&agg);
00627 
00628    for (i = 0; i < collection->num_states; i++) {
00629       ast_debug(1, "Adding per-server state of '%s' for '%s'\n", 
00630          devstate2str(collection->states[i].state), device);
00631       ast_devstate_aggregate_add(&agg, collection->states[i].state);
00632    }
00633 
00634    state = ast_devstate_aggregate_result(&agg);
00635 
00636    ast_debug(1, "Aggregate devstate result is %d\n", state);
00637 
00638    event = ast_event_get_cached(AST_EVENT_DEVICE_STATE,
00639       AST_EVENT_IE_DEVICE, AST_EVENT_IE_PLTYPE_STR, device,
00640       AST_EVENT_IE_END);
00641    
00642    if (event) {
00643       enum ast_device_state old_state;
00644 
00645       old_state = ast_event_get_ie_uint(event, AST_EVENT_IE_STATE);
00646       
00647       ast_event_destroy(event);
00648 
00649       if (state == old_state) {
00650          /* No change since last reported device state */
00651          ast_debug(1, "Aggregate state for device '%s' has not changed from '%s'\n",
00652             device, devstate2str(state));
00653          return;
00654       }
00655    }
00656 
00657    ast_debug(1, "Aggregate state for device '%s' has changed to '%s'\n",
00658       device, devstate2str(state));
00659 
00660    event = ast_event_new(AST_EVENT_DEVICE_STATE,
00661       AST_EVENT_IE_DEVICE, AST_EVENT_IE_PLTYPE_STR, device,
00662       AST_EVENT_IE_STATE, AST_EVENT_IE_PLTYPE_UINT, state,
00663       AST_EVENT_IE_END);
00664 
00665    if (!event) {
00666       return;
00667    }
00668 
00669    ast_event_queue_and_cache(event);
00670 }
00671 
00672 static void handle_devstate_change(struct devstate_change *sc)
00673 {
00674    struct ast_event_sub *tmp_sub;
00675    struct change_collection collection = {
00676       .num_states = 0,
00677    };
00678 
00679    ast_debug(1, "Processing device state change for '%s'\n", sc->device);
00680 
00681    if (!(tmp_sub = ast_event_subscribe_new(AST_EVENT_DEVICE_STATE_CHANGE, devstate_cache_cb, &collection))) {
00682       ast_log(LOG_ERROR, "Failed to create subscription\n");
00683       return;
00684    }
00685 
00686    if (ast_event_sub_append_ie_str(tmp_sub, AST_EVENT_IE_DEVICE, sc->device)) {
00687       ast_log(LOG_ERROR, "Failed to append device IE\n");
00688       ast_event_sub_destroy(tmp_sub);
00689       return;
00690    }
00691 
00692    /* Populate the collection of device states from the cache */
00693    ast_event_dump_cache(tmp_sub);
00694 
00695    process_collection(sc->device, &collection);
00696 
00697    ast_event_sub_destroy(tmp_sub);
00698 }
00699 
00700 static void *run_devstate_collector(void *data)
00701 {
00702    for (;;) {
00703       struct devstate_change *sc;
00704 
00705       ast_mutex_lock(&devstate_collector.lock);
00706       while (!(sc = AST_LIST_REMOVE_HEAD(&devstate_collector.devstate_change_q, entry)))
00707          ast_cond_wait(&devstate_collector.cond, &devstate_collector.lock);
00708       ast_mutex_unlock(&devstate_collector.lock);
00709 
00710       handle_devstate_change(sc);
00711 
00712       destroy_devstate_change(sc);
00713    }
00714 
00715    return NULL;
00716 }
00717 
00718 static void devstate_change_collector_cb(const struct ast_event *event, void *data)
00719 {
00720    struct devstate_change *sc;
00721    const char *device;
00722    const struct ast_eid *eid;
00723    uint32_t state;
00724 
00725    device = ast_event_get_ie_str(event, AST_EVENT_IE_DEVICE);
00726    eid = ast_event_get_ie_raw(event, AST_EVENT_IE_EID);
00727    state = ast_event_get_ie_uint(event, AST_EVENT_IE_STATE);
00728 
00729    if (ast_strlen_zero(device) || !eid) {
00730       ast_log(LOG_ERROR, "Invalid device state change event received\n");
00731       return;
00732    }
00733 
00734    if (!(sc = ast_calloc(1, sizeof(*sc) + strlen(device))))
00735       return;
00736 
00737    strcpy(sc->device, device);
00738    sc->eid = *eid;
00739    sc->state = state;
00740 
00741    ast_mutex_lock(&devstate_collector.lock);
00742    AST_LIST_INSERT_TAIL(&devstate_collector.devstate_change_q, sc, entry);
00743    ast_cond_signal(&devstate_collector.cond);
00744    ast_mutex_unlock(&devstate_collector.lock);
00745 }
00746 
00747 /*! \brief Initialize the device state engine in separate thread */
00748 int ast_device_state_engine_init(void)
00749 {
00750    ast_cond_init(&change_pending, NULL);
00751    if (ast_pthread_create_background(&change_thread, NULL, do_devstate_changes, NULL) < 0) {
00752       ast_log(LOG_ERROR, "Unable to start device state change thread.\n");
00753       return -1;
00754    }
00755 
00756    return 0;
00757 }
00758 
00759 void ast_devstate_aggregate_init(struct ast_devstate_aggregate *agg)
00760 {
00761    memset(agg, 0, sizeof(*agg));
00762 
00763    agg->all_unknown = 1;
00764    agg->all_unavail = 1;
00765    agg->all_busy = 1;
00766    agg->all_free = 1;
00767 }
00768 
00769 void ast_devstate_aggregate_add(struct ast_devstate_aggregate *agg, enum ast_device_state state)
00770 {
00771    switch (state) {
00772    case AST_DEVICE_NOT_INUSE:
00773       agg->all_unknown = 0;
00774       agg->all_unavail = 0;
00775       agg->all_busy = 0;
00776       break;
00777    case AST_DEVICE_INUSE:
00778       agg->in_use = 1;
00779       agg->all_unavail = 0;
00780       agg->all_free = 0;
00781       agg->all_unknown = 0;
00782       break;
00783    case AST_DEVICE_RINGING:
00784       agg->ring = 1;
00785       agg->all_unavail = 0;
00786       agg->all_free = 0;
00787       agg->all_unknown = 0;
00788       break;
00789    case AST_DEVICE_RINGINUSE:
00790       agg->in_use = 1;
00791       agg->ring = 1;
00792       agg->all_unavail = 0;
00793       agg->all_free = 0;
00794       agg->all_unknown = 0;
00795       break;
00796    case AST_DEVICE_ONHOLD:
00797       agg->all_unknown = 0;
00798       agg->all_unavail = 0;
00799       agg->all_free = 0;
00800       agg->on_hold = 1;
00801       break;
00802    case AST_DEVICE_BUSY:
00803       agg->all_unknown = 0;
00804       agg->all_unavail = 0;
00805       agg->all_free = 0;
00806       agg->busy = 1;
00807       agg->in_use = 1;
00808       break;
00809    case AST_DEVICE_UNAVAILABLE:
00810       agg->all_unknown = 0;
00811    case AST_DEVICE_INVALID:
00812       agg->all_busy = 0;
00813       agg->all_free = 0;
00814       break;
00815    case AST_DEVICE_UNKNOWN:
00816       agg->all_busy = 0;
00817       agg->all_free = 0;
00818       break;
00819    case AST_DEVICE_TOTAL: /* not a device state, included for completeness. */
00820       break;
00821    }
00822 }
00823 
00824 
00825 enum ast_device_state ast_devstate_aggregate_result(struct ast_devstate_aggregate *agg)
00826 {
00827    if (agg->all_free)
00828       return AST_DEVICE_NOT_INUSE;
00829    if ((agg->in_use || agg->on_hold) && agg->ring)
00830       return AST_DEVICE_RINGINUSE;
00831    if (agg->ring)
00832       return AST_DEVICE_RINGING;
00833    if (agg->busy)
00834       return AST_DEVICE_BUSY;
00835    if (agg->in_use)
00836       return AST_DEVICE_INUSE;
00837    if (agg->on_hold)
00838       return AST_DEVICE_ONHOLD;
00839    if (agg->all_busy)
00840       return AST_DEVICE_BUSY;
00841    if (agg->all_unknown)
00842       return AST_DEVICE_UNKNOWN;
00843    if (agg->all_unavail)
00844       return AST_DEVICE_UNAVAILABLE;
00845 
00846    return AST_DEVICE_NOT_INUSE;
00847 }
00848 
00849 int ast_enable_distributed_devstate(void)
00850 {
00851    if (devstate_collector.enabled) {
00852       return 0;
00853    }
00854 
00855    devstate_collector.event_sub = ast_event_subscribe(AST_EVENT_DEVICE_STATE_CHANGE,
00856       devstate_change_collector_cb, NULL, AST_EVENT_IE_END);
00857 
00858    if (!devstate_collector.event_sub) {
00859       ast_log(LOG_ERROR, "Failed to create subscription for the device state change collector\n");
00860       return -1;
00861    }
00862 
00863    ast_mutex_init(&devstate_collector.lock);
00864    ast_cond_init(&devstate_collector.cond, NULL);
00865    if (ast_pthread_create_background(&devstate_collector.thread, NULL, run_devstate_collector, NULL) < 0) {
00866       ast_log(LOG_ERROR, "Unable to start device state collector thread.\n");
00867       return -1;
00868    }
00869 
00870    devstate_collector.enabled = 1;
00871 
00872    return 0;
00873 }

Generated on Wed Aug 18 22:33:51 2010 for Asterisk - the Open Source PBX by  doxygen 1.4.7