Merged revisions 119156 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4 ........ r119156 | russell | 2008-05-29 17:24:29 -0500 (Thu, 29 May 2008) | 10 lines Fix a race condition in channel autoservice. There was still a small window of opportunity for a DTMF frame, or some other deferred frame type, to come in and get dropped. (closes issue #12656) (closes issue #12656) Reported by: dimas Patches: v3-12656.patch uploaded by dimas (license 88) -- with some modifications by me ........ git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@119157 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Russell Bryant
parent
5b8e1963c5
commit
f98e98819e
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@ -56,7 +56,7 @@ struct asent {
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* it gets stopped for the last time. */
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unsigned int use_count;
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unsigned int orig_end_dtmf_flag:1;
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AST_LIST_HEAD_NOLOCK(, ast_frame) dtmf_frames;
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AST_LIST_HEAD_NOLOCK(, ast_frame) deferred_frames;
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AST_LIST_ENTRY(asent) list;
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};
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@ -67,27 +67,16 @@ static pthread_t asthread = AST_PTHREADT_NULL;
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static int as_chan_list_state;
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static void defer_frame(struct ast_channel *chan, struct ast_frame *f)
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{
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struct ast_frame *dup_f;
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struct asent *as;
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AST_LIST_LOCK(&aslist);
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AST_LIST_TRAVERSE(&aslist, as, list) {
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if (as->chan != chan)
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continue;
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if ((dup_f = ast_frdup(f)))
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AST_LIST_INSERT_TAIL(&as->dtmf_frames, dup_f, frame_list);
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}
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AST_LIST_UNLOCK(&aslist);
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}
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static void *autoservice_run(void *ign)
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{
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for (;;) {
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struct ast_channel *mons[MAX_AUTOMONS], *chan;
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struct ast_channel *mons[MAX_AUTOMONS];
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struct asent *ents[MAX_AUTOMONS];
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struct ast_channel *chan;
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struct asent *as;
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int x = 0, ms = 50;
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int i, x = 0, ms = 50;
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struct ast_frame *f = NULL;
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struct ast_frame *defer_frame = NULL;
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AST_LIST_LOCK(&aslist);
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@ -95,42 +84,48 @@ static void *autoservice_run(void *ign)
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* to get used again. */
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as_chan_list_state++;
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if (AST_LIST_EMPTY(&aslist))
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if (AST_LIST_EMPTY(&aslist)) {
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ast_cond_wait(&as_cond, &aslist.lock);
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}
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AST_LIST_TRAVERSE(&aslist, as, list) {
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if (!ast_check_hangup(as->chan)) {
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if (x < MAX_AUTOMONS)
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if (x < MAX_AUTOMONS) {
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ents[x] = as;
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mons[x++] = as->chan;
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else
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} else {
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ast_log(LOG_WARNING, "Exceeded maximum number of automatic monitoring events. Fix autoservice.c\n");
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}
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}
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}
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AST_LIST_UNLOCK(&aslist);
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if ((chan = ast_waitfor_n(mons, x, &ms))) {
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struct ast_frame *f = ast_read(chan);
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chan = ast_waitfor_n(mons, x, &ms);
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if (!chan) {
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continue;
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}
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f = ast_read(chan);
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if (!f) {
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struct ast_frame hangup_frame = { 0, };
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/* No frame means the channel has been hung up.
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* A hangup frame needs to be queued here as ast_waitfor() may
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* never return again for the condition to be detected outside
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* of autoservice. So, we'll leave a HANGUP queued up so the
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* thread in charge of this channel will know. */
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if (!f) {
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struct ast_frame hangup_frame = { 0, };
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/* No frame means the channel has been hung up.
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* A hangup frame needs to be queued here as ast_waitfor() may
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* never return again for the condition to be detected outside
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* of autoservice. So, we'll leave a HANGUP queued up so the
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* thread in charge of this channel will know. */
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hangup_frame.frametype = AST_FRAME_CONTROL;
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hangup_frame.subclass = AST_CONTROL_HANGUP;
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hangup_frame.frametype = AST_FRAME_CONTROL;
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hangup_frame.subclass = AST_CONTROL_HANGUP;
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defer_frame(chan, &hangup_frame);
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defer_frame = &hangup_frame;
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} else {
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continue;
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}
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/* Do not add a default entry in this switch statement. Each new
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* frame type should be addressed directly as to whether it should
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* be queued up or not. */
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switch (f->frametype) {
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/* Save these frames */
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case AST_FRAME_DTMF_END:
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@ -138,7 +133,7 @@ static void *autoservice_run(void *ign)
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case AST_FRAME_TEXT:
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case AST_FRAME_IMAGE:
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case AST_FRAME_HTML:
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defer_frame(chan, f);
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defer_frame = f;
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break;
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/* Throw these frames away */
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@ -151,9 +146,31 @@ static void *autoservice_run(void *ign)
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case AST_FRAME_MODEM:
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break;
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}
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}
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if (f)
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if (!defer_frame) {
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if (f) {
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ast_frfree(f);
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}
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continue;
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}
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for (i = 0; i < x; i++) {
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struct ast_frame *dup_f;
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if (mons[i] != chan) {
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continue;
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}
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if ((dup_f = ast_frdup(f))) {
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AST_LIST_INSERT_TAIL(&ents[i]->deferred_frames, dup_f, frame_list);
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}
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break;
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}
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if (f) {
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ast_frfree(f);
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}
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}
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@ -224,15 +241,10 @@ int ast_autoservice_start(struct ast_channel *chan)
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int ast_autoservice_stop(struct ast_channel *chan)
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{
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int res = -1;
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struct asent *as;
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AST_LIST_HEAD_NOLOCK(, ast_frame) dtmf_frames;
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struct asent *as, *removed = NULL;
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struct ast_frame *f;
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int removed = 0;
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int orig_end_dtmf_flag = 0;
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int chan_list_state;
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AST_LIST_HEAD_INIT_NOLOCK(&dtmf_frames);
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AST_LIST_LOCK(&aslist);
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/* Save the autoservice channel list state. We _must_ verify that the channel
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@ -241,41 +253,52 @@ int ast_autoservice_stop(struct ast_channel *chan)
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* it after its gone! */
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chan_list_state = as_chan_list_state;
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/* Find the entry, but do not free it because it still can be in the
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autoservice thread array */
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AST_LIST_TRAVERSE_SAFE_BEGIN(&aslist, as, list) {
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if (as->chan == chan) {
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AST_LIST_REMOVE_CURRENT(list);
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as->use_count--;
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if (as->use_count)
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break;
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AST_LIST_APPEND_LIST(&dtmf_frames, &as->dtmf_frames, frame_list);
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orig_end_dtmf_flag = as->orig_end_dtmf_flag;
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ast_free(as);
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removed = 1;
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if (!ast_check_hangup(chan))
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res = 0;
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if (as->use_count < 1) {
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AST_LIST_REMOVE_CURRENT(list);
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removed = as;
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}
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break;
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}
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}
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AST_LIST_TRAVERSE_SAFE_END;
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if (removed && asthread != AST_PTHREADT_NULL)
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if (removed && asthread != AST_PTHREADT_NULL) {
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pthread_kill(asthread, SIGURG);
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}
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AST_LIST_UNLOCK(&aslist);
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if (!removed)
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if (!removed) {
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return 0;
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}
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if (!orig_end_dtmf_flag)
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/* Wait while autoservice thread rebuilds its list. */
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while (chan_list_state == as_chan_list_state) {
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usleep(1000);
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}
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/* Now autoservice thread should have no references to our entry
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and we can safely destroy it */
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if (!chan->_softhangup) {
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res = 0;
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}
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if (!as->orig_end_dtmf_flag) {
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ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
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}
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while ((f = AST_LIST_REMOVE_HEAD(&dtmf_frames, frame_list))) {
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while ((f = AST_LIST_REMOVE_HEAD(&as->deferred_frames, frame_list))) {
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ast_queue_frame(chan, f);
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ast_frfree(f);
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}
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while (chan_list_state == as_chan_list_state)
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usleep(1000);
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free(as);
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return res;
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}
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