asterisk/main/autoservice.c

385 lines
9.5 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2008, Digium, Inc.
*
* Mark Spencer <markster@digium.com>
* Russell Bryant <russell@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
*
* \brief Automatic channel service routines
*
* \author Mark Spencer <markster@digium.com>
* \author Russell Bryant <russell@digium.com>
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include <sys/time.h>
#include <signal.h>
#include "asterisk/_private.h" /* prototype for ast_autoservice_init() */
#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"
#define MAX_AUTOMONS 1500
struct asent {
struct ast_channel *chan;
/*! This gets incremented each time autoservice gets started on the same
* channel. It will ensure that it doesn't actually get stopped until
* it gets stopped for the last time. */
unsigned int use_count;
unsigned int orig_end_dtmf_flag:1;
unsigned int video_update:1;
unsigned int ignore_frame_types;
/*! Frames go on at the head of deferred_frames, so we have the frames
* from newest to oldest. As we put them at the head of the readq, we'll
* end up with them in the right order for the channel's readq. */
AST_LIST_HEAD_NOLOCK(, ast_frame) deferred_frames;
AST_LIST_ENTRY(asent) list;
};
static AST_LIST_HEAD_STATIC(aslist, asent);
static ast_cond_t as_cond;
static pthread_t asthread = AST_PTHREADT_NULL;
static volatile int asexit = 0;
static int as_chan_list_state;
static void *autoservice_run(void *ign)
{
ast_callid callid = 0;
struct ast_frame hangup_frame = {
.frametype = AST_FRAME_CONTROL,
.subclass.integer = AST_CONTROL_HANGUP,
};
while (!asexit) {
struct ast_channel *mons[MAX_AUTOMONS];
struct asent *ents[MAX_AUTOMONS];
struct ast_channel *chan;
struct asent *as;
int i, x = 0, ms = 50;
struct ast_frame *f = NULL;
struct ast_frame *defer_frame = NULL;
AST_LIST_LOCK(&aslist);
/* At this point, we know that no channels that have been removed are going
* to get used again. */
as_chan_list_state++;
if (AST_LIST_EMPTY(&aslist)) {
ast_cond_wait(&as_cond, &aslist.lock);
}
AST_LIST_TRAVERSE(&aslist, as, list) {
if (!ast_check_hangup(as->chan)) {
if (x < MAX_AUTOMONS) {
ents[x] = as;
mons[x++] = as->chan;
} else {
ast_log(LOG_WARNING, "Exceeded maximum number of automatic monitoring events. Fix autoservice.c\n");
}
}
}
AST_LIST_UNLOCK(&aslist);
if (!x) {
/* If we don't sleep, this becomes a busy loop, which causes
* problems when Asterisk runs at a different priority than other
* user processes. As long as we check for new channels at least
* once every 10ms, we should be fine. */
usleep(10000);
continue;
}
chan = ast_waitfor_n(mons, x, &ms);
if (!chan) {
continue;
}
callid = ast_channel_callid(chan);
ast_callid_threadassoc_change(callid);
f = ast_read(chan);
if (!f) {
/* No frame means the channel has been hung up.
* A hangup frame needs to be queued here as ast_waitfor() may
* never return again for the condition to be detected outside
* of autoservice. So, we'll leave a HANGUP queued up so the
* thread in charge of this channel will know. */
defer_frame = &hangup_frame;
} else if (ast_is_deferrable_frame(f)) {
defer_frame = f;
} else {
/* Can't defer. Discard and continue with next. */
ast_frfree(f);
continue;
}
for (i = 0; i < x; i++) {
struct ast_frame *dup_f;
if (mons[i] != chan) {
continue;
}
if (!f) { /* defer_frame == &hangup_frame */
if ((dup_f = ast_frdup(defer_frame))) {
AST_LIST_INSERT_HEAD(&ents[i]->deferred_frames, dup_f, frame_list);
}
} else {
if (defer_frame->frametype == AST_FRAME_CONTROL &&
defer_frame->subclass.integer == AST_CONTROL_VIDUPDATE) {
/* If a video update is already queued don't needlessly queue another */
if (ents[i]->video_update) {
ast_frfree(defer_frame);
break;
}
ents[i]->video_update = 1;
}
if ((dup_f = ast_frisolate(defer_frame))) {
AST_LIST_INSERT_HEAD(&ents[i]->deferred_frames, dup_f, frame_list);
}
if (dup_f != defer_frame) {
ast_frfree(defer_frame);
}
}
break;
}
/* The ast_waitfor_n() call will only read frames from
* the channels' file descriptors. If ast_waitfor_n()
* returns non-NULL, then one of the channels in the
* mons array must have triggered the return. It's
* therefore impossible that we got here while (i >= x).
* If we did, we'd need to ast_frfree(f) if (f). */
}
ast_callid_threadassoc_change(0);
asthread = AST_PTHREADT_NULL;
return NULL;
}
int ast_autoservice_start(struct ast_channel *chan)
{
int res = 0;
struct asent *as;
if (ast_thread_is_user_interface()) {
/* User interface threads do not handle channel media. */
ast_debug(1, "Thread is a user interface, not putting channel %s into autoservice\n",
ast_channel_name(chan));
return 0;
}
AST_LIST_LOCK(&aslist);
AST_LIST_TRAVERSE(&aslist, as, list) {
if (as->chan == chan) {
as->use_count++;
break;
}
}
AST_LIST_UNLOCK(&aslist);
if (as) {
/* Entry exists, autoservice is already handling this channel */
return 0;
}
if (!(as = ast_calloc(1, sizeof(*as))))
return -1;
/* New entry created */
as->chan = chan;
as->use_count = 1;
ast_channel_lock(chan);
as->orig_end_dtmf_flag = ast_test_flag(ast_channel_flags(chan), AST_FLAG_END_DTMF_ONLY) ? 1 : 0;
if (!as->orig_end_dtmf_flag)
ast_set_flag(ast_channel_flags(chan), AST_FLAG_END_DTMF_ONLY);
ast_channel_unlock(chan);
AST_LIST_LOCK(&aslist);
if (AST_LIST_EMPTY(&aslist) && asthread != AST_PTHREADT_NULL) {
ast_cond_signal(&as_cond);
}
AST_LIST_INSERT_HEAD(&aslist, as, list);
if (asthread == AST_PTHREADT_NULL) { /* need start the thread */
if (ast_pthread_create_background(&asthread, NULL, autoservice_run, NULL)) {
ast_log(LOG_WARNING, "Unable to create autoservice thread :(\n");
/* There will only be a single member in the list at this point,
the one we just added. */
AST_LIST_REMOVE(&aslist, as, list);
ast_free(as);
asthread = AST_PTHREADT_NULL;
res = -1;
} else {
pthread_kill(asthread, SIGURG);
}
}
AST_LIST_UNLOCK(&aslist);
return res;
}
int ast_autoservice_stop(struct ast_channel *chan)
{
int res = -1;
struct asent *as, *removed = NULL;
struct ast_frame *f;
int chan_list_state;
if (ast_thread_is_user_interface()) {
/* User interface threads do not handle channel media. */
ast_debug(1, "Thread is a user interface, not removing channel %s from autoservice\n",
ast_channel_name(chan));
return 0;
}
AST_LIST_LOCK(&aslist);
/* Save the autoservice channel list state. We _must_ verify that the channel
* list has been rebuilt before we return. Because, after we return, the channel
* could get destroyed and we don't want our poor autoservice thread to step on
* it after its gone! */
chan_list_state = as_chan_list_state;
/* Find the entry, but do not free it because it still can be in the
autoservice thread array */
AST_LIST_TRAVERSE_SAFE_BEGIN(&aslist, as, list) {
if (as->chan == chan) {
as->use_count--;
if (as->use_count < 1) {
AST_LIST_REMOVE_CURRENT(list);
removed = as;
}
break;
}
}
AST_LIST_TRAVERSE_SAFE_END;
if (removed && asthread != AST_PTHREADT_NULL) {
pthread_kill(asthread, SIGURG);
}
AST_LIST_UNLOCK(&aslist);
if (!removed) {
return 0;
}
/* Wait while autoservice thread rebuilds its list. */
while (chan_list_state == as_chan_list_state) {
usleep(1000);
}
/* Now autoservice thread should have no references to our entry
and we can safely destroy it */
if (!ast_channel_softhangup_internal_flag(chan)) {
res = 0;
}
ast_channel_lock(chan);
if (!as->orig_end_dtmf_flag) {
ast_clear_flag(ast_channel_flags(chan), AST_FLAG_END_DTMF_ONLY);
}
while ((f = AST_LIST_REMOVE_HEAD(&as->deferred_frames, frame_list))) {
if (!((1 << f->frametype) & as->ignore_frame_types)) {
ast_queue_frame_head(chan, f);
}
ast_frfree(f);
}
ast_channel_unlock(chan);
ast_free(as);
return res;
}
void ast_autoservice_chan_hangup_peer(struct ast_channel *chan, struct ast_channel *peer)
{
if (chan && !ast_autoservice_start(chan)) {
ast_hangup(peer);
ast_autoservice_stop(chan);
} else {
ast_hangup(peer);
}
}
int ast_autoservice_ignore(struct ast_channel *chan, enum ast_frame_type ftype)
{
struct asent *as;
int res = -1;
AST_LIST_LOCK(&aslist);
AST_LIST_TRAVERSE(&aslist, as, list) {
if (as->chan == chan) {
res = 0;
as->ignore_frame_types |= (1 << ftype);
break;
}
}
AST_LIST_UNLOCK(&aslist);
return res;
}
static void autoservice_shutdown(void)
{
pthread_t th = asthread;
asexit = 1;
if (th != AST_PTHREADT_NULL) {
ast_cond_signal(&as_cond);
pthread_kill(th, SIGURG);
pthread_join(th, NULL);
}
}
void ast_autoservice_init(void)
{
ast_register_cleanup(autoservice_shutdown);
ast_cond_init(&as_cond, NULL);
}