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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: 184342 $")
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    }
00258 
00259    return res;
00260 }
00261 
00262 enum ast_device_state ast_devstate_val(const char *val)
00263 {
00264    if (!strcasecmp(val, "NOT_INUSE"))
00265       return AST_DEVICE_NOT_INUSE;
00266    else if (!strcasecmp(val, "INUSE"))
00267       return AST_DEVICE_INUSE;
00268    else if (!strcasecmp(val, "BUSY"))
00269       return AST_DEVICE_BUSY;
00270    else if (!strcasecmp(val, "INVALID"))
00271       return AST_DEVICE_INVALID;
00272    else if (!strcasecmp(val, "UNAVAILABLE"))
00273       return AST_DEVICE_UNAVAILABLE;
00274    else if (!strcasecmp(val, "RINGING"))
00275       return AST_DEVICE_RINGING;
00276    else if (!strcasecmp(val, "RINGINUSE"))
00277       return AST_DEVICE_RINGINUSE;
00278    else if (!strcasecmp(val, "ONHOLD"))
00279       return AST_DEVICE_ONHOLD;
00280 
00281    return AST_DEVICE_UNKNOWN;
00282 }
00283 
00284 /*! \brief Find out if device is active in a call or not 
00285    \note find channels with the device's name in it
00286    This function is only used for channels that does not implement 
00287    devicestate natively
00288 */
00289 enum ast_device_state ast_parse_device_state(const char *device)
00290 {
00291    struct ast_channel *chan;
00292    char match[AST_CHANNEL_NAME];
00293    enum ast_device_state res;
00294 
00295    ast_copy_string(match, device, sizeof(match)-1);
00296    strcat(match, "-");
00297    chan = ast_get_channel_by_name_prefix_locked(match, strlen(match));
00298 
00299    if (!chan)
00300       return AST_DEVICE_UNKNOWN;
00301 
00302    if (chan->_state == AST_STATE_RINGING)
00303       res = AST_DEVICE_RINGING;
00304    else
00305       res = AST_DEVICE_INUSE;
00306    
00307    ast_channel_unlock(chan);
00308 
00309    return res;
00310 }
00311 
00312 static enum ast_device_state devstate_cached(const char *device)
00313 {
00314    enum ast_device_state res = AST_DEVICE_UNKNOWN;
00315    struct ast_event *event;
00316 
00317    event = ast_event_get_cached(AST_EVENT_DEVICE_STATE,
00318       AST_EVENT_IE_DEVICE, AST_EVENT_IE_PLTYPE_STR, device,
00319       AST_EVENT_IE_END);
00320 
00321    if (!event)
00322       return res;
00323 
00324    res = ast_event_get_ie_uint(event, AST_EVENT_IE_STATE);
00325 
00326    ast_event_destroy(event);
00327 
00328    return res;
00329 }
00330 
00331 /*! \brief Check device state through channel specific function or generic function */
00332 static enum ast_device_state _ast_device_state(const char *device, int check_cache)
00333 {
00334    char *buf;
00335    char *number;
00336    const struct ast_channel_tech *chan_tech;
00337    enum ast_device_state res;
00338    /*! \brief Channel driver that provides device state */
00339    char *tech;
00340    /*! \brief Another provider of device state */
00341    char *provider = NULL;
00342 
00343    /* If the last known state is cached, just return that */
00344    if (check_cache) {
00345       res = devstate_cached(device);
00346       if (res != AST_DEVICE_UNKNOWN) {
00347          return res;
00348       }
00349    }
00350 
00351    buf = ast_strdupa(device);
00352    tech = strsep(&buf, "/");
00353    if (!(number = buf)) {
00354       if (!(provider = strsep(&tech, ":")))
00355          return AST_DEVICE_INVALID;
00356       /* We have a provider */
00357       number = tech;
00358       tech = NULL;
00359    }
00360 
00361    if (provider)  {
00362       ast_debug(3, "Checking if I can find provider for \"%s\" - number: %s\n", provider, number);
00363       return getproviderstate(provider, number);
00364    }
00365 
00366    ast_debug(4, "No provider found, checking channel drivers for %s - %s\n", tech, number);
00367 
00368    if (!(chan_tech = ast_get_channel_tech(tech)))
00369       return AST_DEVICE_INVALID;
00370 
00371    if (!(chan_tech->devicestate)) /* Does the channel driver support device state notification? */
00372       return ast_parse_device_state(device); /* No, try the generic function */
00373 
00374    res = chan_tech->devicestate(number);
00375 
00376    if (res != AST_DEVICE_UNKNOWN)
00377       return res;
00378 
00379    res = ast_parse_device_state(device);
00380 
00381    if (res == AST_DEVICE_UNKNOWN)
00382       return AST_DEVICE_NOT_INUSE;
00383 
00384    return res;
00385 }
00386 
00387 enum ast_device_state ast_device_state(const char *device)
00388 {
00389    /* This function is called from elsewhere in the code to find out the
00390     * current state of a device.  Check the cache, first. */
00391 
00392    return _ast_device_state(device, 1);
00393 }
00394 
00395 /*! \brief Add device state provider */
00396 int ast_devstate_prov_add(const char *label, ast_devstate_prov_cb_type callback)
00397 {
00398    struct devstate_prov *devprov;
00399 
00400    if (!callback || !(devprov = ast_calloc(1, sizeof(*devprov))))
00401       return -1;
00402 
00403    devprov->callback = callback;
00404    ast_copy_string(devprov->label, label, sizeof(devprov->label));
00405 
00406    AST_RWLIST_WRLOCK(&devstate_provs);
00407    AST_RWLIST_INSERT_HEAD(&devstate_provs, devprov, list);
00408    AST_RWLIST_UNLOCK(&devstate_provs);
00409 
00410    return 0;
00411 }
00412 
00413 /*! \brief Remove device state provider */
00414 int ast_devstate_prov_del(const char *label)
00415 {
00416    struct devstate_prov *devcb;
00417    int res = -1;
00418 
00419    AST_RWLIST_WRLOCK(&devstate_provs);
00420    AST_RWLIST_TRAVERSE_SAFE_BEGIN(&devstate_provs, devcb, list) {
00421       if (!strcasecmp(devcb->label, label)) {
00422          AST_RWLIST_REMOVE_CURRENT(list);
00423          ast_free(devcb);
00424          res = 0;
00425          break;
00426       }
00427    }
00428    AST_RWLIST_TRAVERSE_SAFE_END;
00429    AST_RWLIST_UNLOCK(&devstate_provs);
00430 
00431    return res;
00432 }
00433 
00434 /*! \brief Get provider device state */
00435 static int getproviderstate(const char *provider, const char *address)
00436 {
00437    struct devstate_prov *devprov;
00438    int res = AST_DEVICE_INVALID;
00439 
00440    AST_RWLIST_RDLOCK(&devstate_provs);
00441    AST_RWLIST_TRAVERSE(&devstate_provs, devprov, list) {
00442       ast_debug(5, "Checking provider %s with %s\n", devprov->label, provider);
00443 
00444       if (!strcasecmp(devprov->label, provider)) {
00445          res = devprov->callback(address);
00446          break;
00447       }
00448    }
00449    AST_RWLIST_UNLOCK(&devstate_provs);
00450 
00451    return res;
00452 }
00453 
00454 static void devstate_event(const char *device, enum ast_device_state state)
00455 {
00456    struct ast_event *event;
00457    enum ast_event_type event_type;
00458 
00459    if (devstate_collector.enabled) {
00460       /* Distributed device state is enabled, so this state change is a change
00461        * for a single server, not the real state. */
00462       event_type = AST_EVENT_DEVICE_STATE_CHANGE;
00463    } else {
00464       event_type = AST_EVENT_DEVICE_STATE;
00465    }
00466 
00467    ast_debug(3, "device '%s' state '%d'\n", device, state);
00468 
00469    if (!(event = ast_event_new(event_type,
00470          AST_EVENT_IE_DEVICE, AST_EVENT_IE_PLTYPE_STR, device,
00471          AST_EVENT_IE_STATE, AST_EVENT_IE_PLTYPE_UINT, state,
00472          AST_EVENT_IE_END))) {
00473       return;
00474    }
00475 
00476    ast_event_queue_and_cache(event);
00477 }
00478 
00479 /*! Called by the state change thread to find out what the state is, and then
00480  *  to queue up the state change event */
00481 static void do_state_change(const char *device)
00482 {
00483    enum ast_device_state state;
00484 
00485    state = _ast_device_state(device, 0);
00486 
00487    ast_debug(3, "Changing state for %s - state %d (%s)\n", device, state, devstate2str(state));
00488 
00489    devstate_event(device, state);
00490 }
00491 
00492 int ast_devstate_changed_literal(enum ast_device_state state, const char *device)
00493 {
00494    struct state_change *change;
00495 
00496    /* 
00497     * If we know the state change (how nice of the caller of this function!)
00498     * then we can just generate a device state event. 
00499     *
00500     * Otherwise, we do the following:
00501     *   - Queue an event up to another thread that the state has changed
00502     *   - In the processing thread, it calls the callback provided by the
00503     *     device state provider (which may or may not be a channel driver)
00504     *     to determine the state.
00505     *   - If the device state provider does not know the state, or this is
00506     *     for a channel and the channel driver does not implement a device
00507     *     state callback, then we will look through the channel list to
00508     *     see if we can determine a state based on active calls.
00509     *   - Once a state has been determined, a device state event is generated.
00510     */
00511 
00512    if (state != AST_DEVICE_UNKNOWN) {
00513       devstate_event(device, state);
00514    } else if (change_thread == AST_PTHREADT_NULL || !(change = ast_calloc(1, sizeof(*change) + strlen(device)))) {
00515       /* we could not allocate a change struct, or */
00516       /* there is no background thread, so process the change now */
00517       do_state_change(device);
00518    } else {
00519       /* queue the change */
00520       strcpy(change->device, device);
00521       AST_LIST_LOCK(&state_changes);
00522       AST_LIST_INSERT_TAIL(&state_changes, change, list);
00523       ast_cond_signal(&change_pending);
00524       AST_LIST_UNLOCK(&state_changes);
00525    }
00526 
00527    return 1;
00528 }
00529 
00530 int ast_device_state_changed_literal(const char *dev)
00531 {
00532    return ast_devstate_changed_literal(AST_DEVICE_UNKNOWN, dev);
00533 }
00534 
00535 int ast_devstate_changed(enum ast_device_state state, const char *fmt, ...) 
00536 {
00537    char buf[AST_MAX_EXTENSION];
00538    va_list ap;
00539 
00540    va_start(ap, fmt);
00541    vsnprintf(buf, sizeof(buf), fmt, ap);
00542    va_end(ap);
00543 
00544    return ast_devstate_changed_literal(state, buf);
00545 }
00546 
00547 int ast_device_state_changed(const char *fmt, ...) 
00548 {
00549    char buf[AST_MAX_EXTENSION];
00550    va_list ap;
00551 
00552    va_start(ap, fmt);
00553    vsnprintf(buf, sizeof(buf), fmt, ap);
00554    va_end(ap);
00555 
00556    return ast_devstate_changed_literal(AST_DEVICE_UNKNOWN, buf);
00557 }
00558 
00559 /*! \brief Go through the dev state change queue and update changes in the dev state thread */
00560 static void *do_devstate_changes(void *data)
00561 {
00562    struct state_change *next, *current;
00563 
00564    for (;;) {
00565       /* This basically pops off any state change entries, resets the list back to NULL, unlocks, and processes each state change */
00566       AST_LIST_LOCK(&state_changes);
00567       if (AST_LIST_EMPTY(&state_changes))
00568          ast_cond_wait(&change_pending, &state_changes.lock);
00569       next = AST_LIST_FIRST(&state_changes);
00570       AST_LIST_HEAD_INIT_NOLOCK(&state_changes);
00571       AST_LIST_UNLOCK(&state_changes);
00572 
00573       /* Process each state change */
00574       while ((current = next)) {
00575          next = AST_LIST_NEXT(current, list);
00576          do_state_change(current->device);
00577          ast_free(current);
00578       }
00579    }
00580 
00581    return NULL;
00582 }
00583 
00584 static void destroy_devstate_change(struct devstate_change *sc)
00585 {
00586    ast_free(sc);
00587 }
00588 
00589 #define MAX_SERVERS 64
00590 struct change_collection {
00591    struct devstate_change states[MAX_SERVERS];
00592    size_t num_states;
00593 };
00594 
00595 static void devstate_cache_cb(const struct ast_event *event, void *data)
00596 {
00597    struct change_collection *collection = data;
00598    int i;
00599    const struct ast_eid *eid;
00600 
00601    if (collection->num_states == ARRAY_LEN(collection->states)) {
00602       ast_log(LOG_ERROR, "More per-server state values than we have room for (MAX_SERVERS is %d)\n",
00603          MAX_SERVERS);
00604       return;
00605    }
00606 
00607    if (!(eid = ast_event_get_ie_raw(event, AST_EVENT_IE_EID))) {
00608       ast_log(LOG_ERROR, "Device state change event with no EID\n");
00609       return;
00610    }
00611 
00612    i = collection->num_states;
00613 
00614    collection->states[i].state = ast_event_get_ie_uint(event, AST_EVENT_IE_STATE);
00615    collection->states[i].eid = *eid;
00616 
00617    collection->num_states++;
00618 }
00619 
00620 static void process_collection(const char *device, struct change_collection *collection)
00621 {
00622    int i;
00623    struct ast_devstate_aggregate agg;
00624    enum ast_device_state state;
00625    struct ast_event *event;
00626 
00627    ast_devstate_aggregate_init(&agg);
00628 
00629    for (i = 0; i < collection->num_states; i++) {
00630       ast_debug(1, "Adding per-server state of '%s' for '%s'\n", 
00631          devstate2str(collection->states[i].state), device);
00632       ast_devstate_aggregate_add(&agg, collection->states[i].state);
00633    }
00634 
00635    state = ast_devstate_aggregate_result(&agg);
00636 
00637    ast_debug(1, "Aggregate devstate result is %d\n", state);
00638 
00639    event = ast_event_get_cached(AST_EVENT_DEVICE_STATE,
00640       AST_EVENT_IE_DEVICE, AST_EVENT_IE_PLTYPE_STR, device,
00641       AST_EVENT_IE_END);
00642    
00643    if (event) {
00644       enum ast_device_state old_state;
00645 
00646       old_state = ast_event_get_ie_uint(event, AST_EVENT_IE_STATE);
00647       
00648       ast_event_destroy(event);
00649 
00650       if (state == old_state) {
00651          /* No change since last reported device state */
00652          ast_debug(1, "Aggregate state for device '%s' has not changed from '%s'\n",
00653             device, devstate2str(state));
00654          return;
00655       }
00656    }
00657 
00658    ast_debug(1, "Aggregate state for device '%s' has changed to '%s'\n",
00659       device, devstate2str(state));
00660 
00661    event = ast_event_new(AST_EVENT_DEVICE_STATE,
00662       AST_EVENT_IE_DEVICE, AST_EVENT_IE_PLTYPE_STR, device,
00663       AST_EVENT_IE_STATE, AST_EVENT_IE_PLTYPE_UINT, state,
00664       AST_EVENT_IE_END);
00665 
00666    if (!event) {
00667       return;
00668    }
00669 
00670    ast_event_queue_and_cache(event);
00671 }
00672 
00673 static void handle_devstate_change(struct devstate_change *sc)
00674 {
00675    struct ast_event_sub *tmp_sub;
00676    struct change_collection collection = {
00677       .num_states = 0,
00678    };
00679 
00680    ast_debug(1, "Processing device state change for '%s'\n", sc->device);
00681 
00682    if (!(tmp_sub = ast_event_subscribe_new(AST_EVENT_DEVICE_STATE_CHANGE, devstate_cache_cb, &collection))) {
00683       ast_log(LOG_ERROR, "Failed to create subscription\n");
00684       return;
00685    }
00686 
00687    if (ast_event_sub_append_ie_str(tmp_sub, AST_EVENT_IE_DEVICE, sc->device)) {
00688       ast_log(LOG_ERROR, "Failed to append device IE\n");
00689       ast_event_sub_destroy(tmp_sub);
00690       return;
00691    }
00692 
00693    /* Populate the collection of device states from the cache */
00694    ast_event_dump_cache(tmp_sub);
00695 
00696    process_collection(sc->device, &collection);
00697 
00698    ast_event_sub_destroy(tmp_sub);
00699 }
00700 
00701 static void *run_devstate_collector(void *data)
00702 {
00703    for (;;) {
00704       struct devstate_change *sc;
00705 
00706       ast_mutex_lock(&devstate_collector.lock);
00707       while (!(sc = AST_LIST_REMOVE_HEAD(&devstate_collector.devstate_change_q, entry)))
00708          ast_cond_wait(&devstate_collector.cond, &devstate_collector.lock);
00709       ast_mutex_unlock(&devstate_collector.lock);
00710 
00711       handle_devstate_change(sc);
00712 
00713       destroy_devstate_change(sc);
00714    }
00715 
00716    return NULL;
00717 }
00718 
00719 static void devstate_change_collector_cb(const struct ast_event *event, void *data)
00720 {
00721    struct devstate_change *sc;
00722    const char *device;
00723    const struct ast_eid *eid;
00724    uint32_t state;
00725 
00726    device = ast_event_get_ie_str(event, AST_EVENT_IE_DEVICE);
00727    eid = ast_event_get_ie_raw(event, AST_EVENT_IE_EID);
00728    state = ast_event_get_ie_uint(event, AST_EVENT_IE_STATE);
00729 
00730    if (ast_strlen_zero(device) || !eid) {
00731       ast_log(LOG_ERROR, "Invalid device state change event received\n");
00732       return;
00733    }
00734 
00735    if (!(sc = ast_calloc(1, sizeof(*sc) + strlen(device))))
00736       return;
00737 
00738    strcpy(sc->device, device);
00739    sc->eid = *eid;
00740    sc->state = state;
00741 
00742    ast_mutex_lock(&devstate_collector.lock);
00743    AST_LIST_INSERT_TAIL(&devstate_collector.devstate_change_q, sc, entry);
00744    ast_cond_signal(&devstate_collector.cond);
00745    ast_mutex_unlock(&devstate_collector.lock);
00746 }
00747 
00748 /*! \brief Initialize the device state engine in separate thread */
00749 int ast_device_state_engine_init(void)
00750 {
00751    ast_cond_init(&change_pending, NULL);
00752    if (ast_pthread_create_background(&change_thread, NULL, do_devstate_changes, NULL) < 0) {
00753       ast_log(LOG_ERROR, "Unable to start device state change thread.\n");
00754       return -1;
00755    }
00756 
00757    return 0;
00758 }
00759 
00760 void ast_devstate_aggregate_init(struct ast_devstate_aggregate *agg)
00761 {
00762    memset(agg, 0, sizeof(*agg));
00763 
00764    agg->all_unavail = 1;
00765    agg->all_busy = 1;
00766    agg->all_free = 1;
00767    agg->all_on_hold = 1;
00768 }
00769 
00770 void ast_devstate_aggregate_add(struct ast_devstate_aggregate *agg, enum ast_device_state state)
00771 {
00772    switch (state) {
00773    case AST_DEVICE_NOT_INUSE:
00774       agg->all_unavail = 0;
00775       agg->all_busy = 0;
00776       agg->all_on_hold = 0;
00777       break;
00778    case AST_DEVICE_INUSE:
00779       agg->in_use = 1;
00780       agg->all_busy = 0;
00781       agg->all_unavail = 0;
00782       agg->all_free = 0;
00783       agg->all_on_hold = 0;
00784       break;
00785    case AST_DEVICE_RINGING:
00786       agg->ring = 1;
00787       agg->all_busy = 0;
00788       agg->all_unavail = 0;
00789       agg->all_free = 0;
00790       agg->all_on_hold = 0;
00791       break;
00792    case AST_DEVICE_RINGINUSE:
00793       agg->in_use = 1;
00794       agg->ring = 1;
00795       agg->all_busy = 0;
00796       agg->all_unavail = 0;
00797       agg->all_free = 0;
00798       agg->all_on_hold = 0;
00799       break;
00800    case AST_DEVICE_ONHOLD:
00801       agg->all_unavail = 0;
00802       agg->all_free = 0;
00803       break;
00804    case AST_DEVICE_BUSY:
00805       agg->all_unavail = 0;
00806       agg->all_free = 0;
00807       agg->all_on_hold = 0;
00808       agg->busy = 1;
00809       break;
00810    case AST_DEVICE_UNAVAILABLE:
00811    case AST_DEVICE_INVALID:
00812       agg->all_busy = 0;
00813       agg->all_free = 0;
00814       agg->all_on_hold = 0;
00815       break;
00816    case AST_DEVICE_UNKNOWN:
00817       break;
00818    }
00819 }
00820 
00821 enum ast_device_state ast_devstate_aggregate_result(struct ast_devstate_aggregate *agg)
00822 {
00823    if (agg->all_free)
00824       return AST_DEVICE_NOT_INUSE;
00825    
00826    if (agg->all_on_hold)
00827       return AST_DEVICE_ONHOLD;
00828    
00829    if (agg->all_busy)
00830       return AST_DEVICE_BUSY;
00831 
00832    if (agg->all_unavail)
00833       return AST_DEVICE_UNAVAILABLE;
00834    
00835    if (agg->ring)
00836       return agg->in_use ? AST_DEVICE_RINGINUSE : AST_DEVICE_RINGING;
00837 
00838    if (agg->in_use)
00839       return AST_DEVICE_INUSE;
00840 
00841    if (agg->busy)
00842       return AST_DEVICE_BUSY;
00843    
00844    return AST_DEVICE_NOT_INUSE;
00845 }
00846 
00847 int ast_enable_distributed_devstate(void)
00848 {
00849    if (devstate_collector.enabled) {
00850       return 0;
00851    }
00852 
00853    devstate_collector.event_sub = ast_event_subscribe(AST_EVENT_DEVICE_STATE_CHANGE,
00854       devstate_change_collector_cb, NULL, AST_EVENT_IE_END);
00855 
00856    if (!devstate_collector.event_sub) {
00857       ast_log(LOG_ERROR, "Failed to create subscription for the device state change collector\n");
00858       return -1;
00859    }
00860 
00861    ast_mutex_init(&devstate_collector.lock);
00862    ast_cond_init(&devstate_collector.cond, NULL);
00863    if (ast_pthread_create_background(&devstate_collector.thread, NULL, run_devstate_collector, NULL) < 0) {
00864       ast_log(LOG_ERROR, "Unable to start device state collector thread.\n");
00865       return -1;
00866    }
00867 
00868    devstate_collector.enabled = 1;
00869 
00870    return 0;
00871 }

Generated on Fri Jun 19 12:09:42 2009 for Asterisk - the Open Source PBX by  doxygen 1.4.7