diff options
| -rw-r--r-- | channels/chan_agent.c | 169 |
1 files changed, 133 insertions, 36 deletions
diff --git a/channels/chan_agent.c b/channels/chan_agent.c index 733341fb9..ca9a9ed21 100644 --- a/channels/chan_agent.c +++ b/channels/chan_agent.c @@ -1,7 +1,7 @@ /* * Asterisk -- An open source telephony toolkit. * - * Copyright (C) 1999 - 2006, Digium, Inc. + * Copyright (C) 1999 - 2012, Digium, Inc. * * Mark Spencer <markster@digium.com> * @@ -374,6 +374,43 @@ static struct ast_channel_tech agent_tech = { }; /*! + * \brief Locks the owning channel for a LOCKED pvt while obeying locking order. The pvt + * must enter this function locked and will be returned locked, but this function will + * unlock the pvt for a short time, so it can't be used while expecting the pvt to remain + * static. If function returns a non NULL channel, it will need to be unlocked and + * unrefed once it is no longer needed. + * + * \param pvt Pointer to the LOCKED agent_pvt for which the owner is needed + * \ret locked channel which owns the pvt at the time of completion. NULL if not available. + */ +static struct ast_channel *agent_lock_owner(struct agent_pvt *pvt) +{ + struct ast_channel *owner; + + for (;;) { + if (!pvt->owner) { /* No owner. Nothing to do. */ + return NULL; + } + + /* If we don't ref the owner, it could be killed when we unlock the pvt. */ + owner = ast_channel_ref(pvt->owner); + + /* Locking order requires us to lock channel, then pvt. */ + ast_mutex_unlock(&pvt->lock); + ast_channel_lock(owner); + ast_mutex_lock(&pvt->lock); + + /* Check if owner changed during pvt unlock period */ + if (owner != pvt->owner) { /* Channel changed. Unref and do another pass. */ + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); + } else { /* Channel stayed the same. Return it. */ + return owner; + } + } +} + +/*! * Adds an agent to the global list of agents. * * \param agent A string with the username, password and real name of an agent. As defined in agents.conf. Example: "13,169,John Smith" @@ -553,7 +590,11 @@ static struct ast_frame *agent_read(struct ast_channel *ast) struct ast_frame *f = NULL; static struct ast_frame answer_frame = { AST_FRAME_CONTROL, { AST_CONTROL_ANSWER } }; int cur_time = time(NULL); + struct ast_channel *owner; + ast_mutex_lock(&p->lock); + owner = agent_lock_owner(p); + CHECK_FORMATS(ast, p); if (!p->start) { p->start = cur_time; @@ -583,13 +624,11 @@ static struct ast_frame *agent_read(struct ast_channel *ast) int howlong = cur_time - p->start; if (p->autologoff && (howlong >= p->autologoff)) { ast_log(LOG_NOTICE, "Agent '%s' didn't answer/confirm within %d seconds (waited %d)\n", p->name, p->autologoff, howlong); - if (p->owner || p->chan) { - while (p->owner && ast_channel_trylock(p->owner)) { - DEADLOCK_AVOIDANCE(&p->lock); - } - if (p->owner) { - ast_softhangup(p->owner, AST_SOFTHANGUP_EXPLICIT); - ast_channel_unlock(p->owner); + if (owner || p->chan) { + if (owner) { + ast_softhangup(owner, AST_SOFTHANGUP_EXPLICIT); + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); } while (p->chan && ast_channel_trylock(p->chan)) { @@ -651,6 +690,11 @@ static struct ast_frame *agent_read(struct ast_channel *ast) } } + if (owner) { + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); + } + CLEANUP(ast,p); if (p->chan && !p->chan->_bridge) { if (strcasecmp(p->chan->tech->type, "Local")) { @@ -888,6 +932,14 @@ int agent_set_base_channel(struct ast_channel *chan, struct ast_channel *base) static int agent_hangup(struct ast_channel *ast) { struct agent_pvt *p = ast->tech_pvt; + struct ast_channel *indicate_chan = NULL; + char *tmp_moh; /* moh buffer for indicating after unlocking p */ + + if (p->pending) { + AST_LIST_LOCK(&agents); + AST_LIST_REMOVE(&agents, p, list); + AST_LIST_UNLOCK(&agents); + } ast_mutex_lock(&p->lock); p->owner = NULL; @@ -910,7 +962,7 @@ static int agent_hangup(struct ast_channel *ast) if (p->start && (ast->_state != AST_STATE_UP)) { p->start = 0; } else - p->start = 0; + p->start = 0; if (p->chan) { p->chan->_bridge = NULL; /* If they're dead, go ahead and hang up on the agent now */ @@ -919,15 +971,21 @@ static int agent_hangup(struct ast_channel *ast) ast_softhangup(p->chan, AST_SOFTHANGUP_EXPLICIT); ast_channel_unlock(p->chan); } else if (p->loginstart) { - ast_channel_lock(p->chan); - ast_indicate_data(p->chan, AST_CONTROL_HOLD, - S_OR(p->moh, NULL), - !ast_strlen_zero(p->moh) ? strlen(p->moh) + 1 : 0); - ast_channel_unlock(p->chan); + indicate_chan = ast_channel_ref(p->chan); + tmp_moh = ast_strdupa(p->moh); } } ast_mutex_unlock(&p->lock); + if (indicate_chan) { + ast_channel_lock(indicate_chan); + ast_indicate_data(indicate_chan, AST_CONTROL_HOLD, + S_OR(tmp_moh, NULL), + !ast_strlen_zero(tmp_moh) ? strlen(tmp_moh) + 1 : 0); + ast_channel_unlock(indicate_chan); + indicate_chan = ast_channel_unref(indicate_chan); + } + /* Only register a device state change if the agent is still logged in */ if (!p->loginstart) { p->logincallerid[0] = '\0'; @@ -935,11 +993,6 @@ static int agent_hangup(struct ast_channel *ast) ast_devstate_changed(AST_DEVICE_NOT_INUSE, "Agent/%s", p->agent); } - if (p->pending) { - AST_LIST_LOCK(&agents); - AST_LIST_REMOVE(&agents, p, list); - AST_LIST_UNLOCK(&agents); - } if (p->abouttograb) { /* Let the "about to grab" thread know this isn't valid anymore, and let it kill it later */ @@ -1492,6 +1545,8 @@ static force_inline int powerof(unsigned int d) /*! * Lists agents and their status to the Manager API. * It is registered on load_module() and it gets called by the manager backend. + * This function locks both the pvt and the channel that owns it for a while, but + * does not keep these locks. * \param s * \param m * \returns @@ -1514,7 +1569,9 @@ static int action_agents(struct mansession *s, const struct message *m) astman_send_ack(s, m, "Agents will follow"); AST_LIST_LOCK(&agents); AST_LIST_TRAVERSE(&agents, p, list) { - ast_mutex_lock(&p->lock); + struct ast_channel *owner; + ast_mutex_lock(&p->lock); + owner = agent_lock_owner(p); /* Status Values: AGENT_LOGGEDOFF - Agent isn't logged in @@ -1529,16 +1586,14 @@ static int action_agents(struct mansession *s, const struct message *m) if (p->chan) { loginChan = ast_strdupa(ast_channel_name(p->chan)); - if (p->owner && p->owner->_bridge) { + if (owner && owner->_bridge) { talkingto = S_COR(p->chan->caller.id.number.valid, p->chan->caller.id.number.str, "n/a"); - ast_channel_lock(p->owner); - if ((bridge = ast_bridged_channel(p->owner))) { + if ((bridge = ast_bridged_channel(owner))) { talkingtoChan = ast_strdupa(ast_channel_name(bridge)); } else { talkingtoChan = "n/a"; } - ast_channel_unlock(p->owner); status = "AGENT_ONCALL"; } else { talkingto = "n/a"; @@ -1552,6 +1607,11 @@ static int action_agents(struct mansession *s, const struct message *m) status = "AGENT_LOGGEDOFF"; } + if (owner) { + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); + } + astman_append(s, "Event: Agents\r\n" "Agent: %s\r\n" "Name: %s\r\n" @@ -1583,14 +1643,14 @@ static int agent_logoff(const char *agent, int soft) ret = 0; if (p->owner || p->chan) { if (!soft) { + struct ast_channel *owner; ast_mutex_lock(&p->lock); + owner = agent_lock_owner(p); - while (p->owner && ast_channel_trylock(p->owner)) { - DEADLOCK_AVOIDANCE(&p->lock); - } - if (p->owner) { - ast_softhangup(p->owner, AST_SOFTHANGUP_EXPLICIT); - ast_channel_unlock(p->owner); + if (owner) { + ast_softhangup(owner, AST_SOFTHANGUP_EXPLICIT); + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); } while (p->chan && ast_channel_trylock(p->chan)) { @@ -1727,7 +1787,9 @@ static char *agents_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args * AST_LIST_LOCK(&agents); AST_LIST_TRAVERSE(&agents, p, list) { + struct ast_channel *owner; ast_mutex_lock(&p->lock); + owner = agent_lock_owner(p); if (p->pending) { if (p->group) ast_cli(a->fd, "-- Pending call to group %d\n", powerof(p->group)); @@ -1740,10 +1802,11 @@ static char *agents_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args * username[0] = '\0'; if (p->chan) { snprintf(location, sizeof(location), "logged in on %s", ast_channel_name(p->chan)); - if (p->owner && ast_bridged_channel(p->owner)) + if (owner && ast_bridged_channel(owner)) { snprintf(talkingto, sizeof(talkingto), " talking to %s", ast_channel_name(ast_bridged_channel(p->owner))); - else + } else { strcpy(talkingto, " is idle"); + } online_agents++; } else { strcpy(location, "not logged in"); @@ -1756,6 +1819,11 @@ static char *agents_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args * username, location, talkingto, music); count_agents++; } + + if (owner) { + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); + } ast_mutex_unlock(&p->lock); } AST_LIST_UNLOCK(&agents); @@ -1796,21 +1864,32 @@ static char *agents_show_online(struct ast_cli_entry *e, int cmd, struct ast_cli AST_LIST_LOCK(&agents); AST_LIST_TRAVERSE(&agents, p, list) { + struct ast_channel *owner; + agent_status = 0; /* reset it to offline */ ast_mutex_lock(&p->lock); + owner = agent_lock_owner(p); + if (!ast_strlen_zero(p->name)) snprintf(username, sizeof(username), "(%s) ", p->name); else username[0] = '\0'; if (p->chan) { snprintf(location, sizeof(location), "logged in on %s", ast_channel_name(p->chan)); - if (p->owner && ast_bridged_channel(p->owner)) + if (p->owner && ast_bridged_channel(p->owner)) { snprintf(talkingto, sizeof(talkingto), " talking to %s", ast_channel_name(ast_bridged_channel(p->owner))); - else + } else { strcpy(talkingto, " is idle"); + } agent_status = 1; online_agents++; } + + if (owner) { + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); + } + if (!ast_strlen_zero(p->moh)) snprintf(music, sizeof(music), " (musiconhold is '%s')", p->moh); if (agent_status) @@ -2386,12 +2465,16 @@ static int agents_data_provider_get(const struct ast_data_search *search, AST_LIST_LOCK(&agents); AST_LIST_TRAVERSE(&agents, p, list) { + struct ast_channel *owner; + data_agent = ast_data_add_node(data_root, "agent"); if (!data_agent) { continue; } ast_mutex_lock(&p->lock); + owner = agent_lock_owner(p); + if (!(p->pending)) { ast_data_add_str(data_agent, "id", p->agent); ast_data_add_structure(agent_pvt, data_agent, p); @@ -2402,17 +2485,25 @@ static int agents_data_provider_get(const struct ast_data_search *search, if (!data_channel) { ast_mutex_unlock(&p->lock); ast_data_remove_node(data_root, data_agent); + if (owner) { + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); + } continue; } ast_channel_data_add_structure(data_channel, p->chan, 0); - if (p->owner && ast_bridged_channel(p->owner)) { + if (owner && ast_bridged_channel(owner)) { data_talkingto = ast_data_add_node(data_agent, "talkingto"); if (!data_talkingto) { ast_mutex_unlock(&p->lock); ast_data_remove_node(data_root, data_agent); + if (owner) { + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); + } continue; } - ast_channel_data_add_structure(data_talkingto, ast_bridged_channel(p->owner), 0); + ast_channel_data_add_structure(data_talkingto, ast_bridged_channel(owner), 0); } } else { ast_data_add_node(data_agent, "talkingto"); @@ -2420,6 +2511,12 @@ static int agents_data_provider_get(const struct ast_data_search *search, } ast_data_add_str(data_agent, "musiconhold", p->moh); } + + if (owner) { + ast_channel_unlock(owner); + owner = ast_channel_unref(owner); + } + ast_mutex_unlock(&p->lock); /* if this agent doesn't match remove the added agent. */ |