Merged revisions 163448 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
r163448 | russell | 2008-12-12 07:44:08 -0600 (Fri, 12 Dec 2008) | 26 lines

Resolve issues that could cause DTMF to be processed out of order.

These changes come from team/russell/issue_12658

1) Change autoservice to put digits on the head of the channel's frame readq 
   instead of the tail.  If there were frames on the readq that autoservice 
   had not yet read, the previous code would have resulted in out of order 
   processing.  This required a new API call to queue a frame to the head 
   of the queue instead of the tail.

2) Change up the processing of DTMF in ast_read().  Some of the problems 
   were the result of having two sources of pending DTMF frames.  There 
   was the dtmfq and the more generic readq.  Both were used for pending 
   DTMF in various scenarios.  Simplifying things to only use the frame 
   readq avoids some of the problems.

3) Fix a bug where a DTMF END frame could get passed through when it 
   shouldn't have.  If code set END_DTMF_ONLY in the middle of digit emulation,
   and a digit arrived before emulation was complete, digits would get 
   processed out of order.

(closes issue #12658)
Reported by: dimas
Tested by: russell, file
Review: http://reviewboard.digium.com/r/85/

........


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@163449 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 92 insertions, 41 deletions

diff --git a/main/channel.c b/main/channel.c
index d4d24b6a1..3debac5d9 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -953,7 +953,7 @@ alertpipe_failed:
 }
 
 /*! \brief Queue an outgoing media frame */
-int ast_queue_frame(struct ast_channel *chan, struct ast_frame *fin)
+static int __ast_queue_frame(struct ast_channel *chan, struct ast_frame *fin, int head)
 {
 	struct ast_frame *f;
 	struct ast_frame *cur;
@@ -962,9 +962,9 @@ int ast_queue_frame(struct ast_channel *chan, struct ast_frame *fin)
 
 	/* Build us a copy and free the original one */
 	if (!(f = ast_frdup(fin))) {
-		ast_log(LOG_WARNING, "Unable to duplicate frame\n");
 		return -1;
 	}
+
 	ast_channel_lock(chan);
 
 	/* See if the last frame on the queue is a hangup, if so don't queue anything */
@@ -991,20 +991,39 @@ int ast_queue_frame(struct ast_channel *chan, struct ast_frame *fin)
 			return 0;
 		}
 	}
-	AST_LIST_INSERT_TAIL(&chan->readq, f, frame_list);
+
+	if (head) {
+		AST_LIST_INSERT_HEAD(&chan->readq, f, frame_list);
+	} else {
+		AST_LIST_INSERT_TAIL(&chan->readq, f, frame_list);
+	}
+
 	if (chan->alertpipe[1] > -1) {
-		if (write(chan->alertpipe[1], &blah, sizeof(blah)) != sizeof(blah))
+		if (write(chan->alertpipe[1], &blah, sizeof(blah)) != sizeof(blah)) {
 			ast_log(LOG_WARNING, "Unable to write to alert pipe on %s, frametype/subclass %d/%d (qlen = %d): %s!\n",
 				chan->name, f->frametype, f->subclass, qlen, strerror(errno));
+		}
 	} else if (chan->timingfd > -1) {
 		ast_timer_enable_continuous(chan->timingfd);
 	} else if (ast_test_flag(chan, AST_FLAG_BLOCKING)) {
 		pthread_kill(chan->blocker, SIGURG);
 	}
+
 	ast_channel_unlock(chan);
+
 	return 0;
 }
 
+int ast_queue_frame(struct ast_channel *chan, struct ast_frame *fin)
+{
+	return __ast_queue_frame(chan, fin, 0);
+}
+
+int ast_queue_frame_head(struct ast_channel *chan, struct ast_frame *fin)
+{
+	return __ast_queue_frame(chan, fin, 1);
+}
+
 /*! \brief Queue a hangup frame for channel */
 int ast_queue_hangup(struct ast_channel *chan)
 {
@@ -2370,6 +2389,42 @@ static void ast_read_generator_actions(struct ast_channel *chan, struct ast_fram
 	}
 }
 
+static inline void queue_dtmf_readq(struct ast_channel *chan, struct ast_frame *f)
+{
+	struct ast_frame *fr = &chan->dtmff;
+
+	fr->frametype = AST_FRAME_DTMF_END;
+	fr->subclass = f->subclass;
+	fr->len = f->len;
+
+	/* The only time this function will be called is for a frame that just came
+	 * out of the channel driver.  So, we want to stick it on the tail of the
+	 * readq. */
+
+	ast_queue_frame(chan, fr);
+}
+
+/*!
+ * \brief Determine whether or not we should ignore DTMF in the readq
+ */
+static inline int should_skip_dtmf(struct ast_channel *chan)
+{
+	if (ast_test_flag(chan, AST_FLAG_DEFER_DTMF | AST_FLAG_EMULATE_DTMF)) {
+		/* We're in the middle of emulating a digit, or DTMF has been
+		 * explicitly deferred.  Skip this digit, then. */
+		return 1;
+	}
+			
+	if (!ast_tvzero(chan->dtmf_tv) && 
+			ast_tvdiff_ms(ast_tvnow(), chan->dtmf_tv) < AST_MIN_DTMF_GAP) {
+		/* We're not in the middle of a digit, but it hasn't been long enough
+		 * since the last digit, so we'll have to skip DTMF for now. */
+		return 1;
+	}
+
+	return 0;
+}
+
 static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
 {
 	struct ast_frame *f = NULL;	/* the return value */
@@ -2403,28 +2458,6 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
 	}
 	prestate = chan->_state;
 
-	if (!ast_test_flag(chan, AST_FLAG_DEFER_DTMF | AST_FLAG_EMULATE_DTMF | AST_FLAG_IN_DTMF) && 
-	    !ast_strlen_zero(chan->dtmfq) && 
-		(ast_tvzero(chan->dtmf_tv) || ast_tvdiff_ms(ast_tvnow(), chan->dtmf_tv) > AST_MIN_DTMF_GAP) ) {
-		/* We have DTMF that has been deferred.  Return it now */
-		chan->dtmff.subclass = chan->dtmfq[0];
-		/* Drop first digit from the buffer */
-		memmove(chan->dtmfq, chan->dtmfq + 1, sizeof(chan->dtmfq) - 1);
-		f = &chan->dtmff;
-		if (ast_test_flag(chan, AST_FLAG_END_DTMF_ONLY)) {
-			ast_log(LOG_DTMF, "DTMF end emulation of '%c' queued on %s\n", f->subclass, chan->name);
-			chan->dtmff.frametype = AST_FRAME_DTMF_END;
-		} else {
-			ast_log(LOG_DTMF, "DTMF begin emulation of '%c' with duration %d queued on %s\n", f->subclass, AST_DEFAULT_EMULATE_DTMF_DURATION, chan->name);
-			chan->dtmff.frametype = AST_FRAME_DTMF_BEGIN;
-			ast_set_flag(chan, AST_FLAG_EMULATE_DTMF);
-			chan->emulate_dtmf_digit = f->subclass;
-			chan->emulate_dtmf_duration = AST_DEFAULT_EMULATE_DTMF_DURATION;
-		}
-		chan->dtmf_tv = ast_tvnow();
-		goto done;
-	}
-	
 	/* Read and ignore anything on the alertpipe, but read only
 	   one sizeof(blah) per frame that we send from it */
 	if (chan->alertpipe[0] > -1) {
@@ -2492,7 +2525,35 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
 
 	/* Check for pending read queue */
 	if (!AST_LIST_EMPTY(&chan->readq)) {
-		f = AST_LIST_REMOVE_HEAD(&chan->readq, frame_list);
+		int skip_dtmf = should_skip_dtmf(chan);
+
+		AST_LIST_TRAVERSE_SAFE_BEGIN(&chan->readq, f, frame_list) {
+			/* We have to be picky about which frame we pull off of the readq because
+			 * there are cases where we want to leave DTMF frames on the queue until
+			 * some later time. */
+
+			if ( (f->frametype == AST_FRAME_DTMF_BEGIN || f->frametype == AST_FRAME_DTMF_END) && skip_dtmf) {
+				continue;
+			}
+
+			AST_LIST_REMOVE_CURRENT(frame_list);
+			break;
+		}
+		AST_LIST_TRAVERSE_SAFE_END
+		
+		if (!f) {
+			/* There were no acceptable frames on the readq. */
+			f = &ast_null_frame;
+			if (chan->alertpipe[0] > -1) {
+				int poke = 0;
+				/* Restore the state of the alertpipe since we aren't ready for any
+				 * of the frames in the readq. */
+				if (write(chan->alertpipe[1], &poke, sizeof(poke)) != sizeof(poke)) {
+					ast_log(LOG_ERROR, "Failed to write to alertpipe: %s\n", strerror(errno));
+				}
+			}
+		}
+
 		/* Interpret hangup and return NULL */
 		/* XXX why not the same for frames from the channel ? */
 		if (f->frametype == AST_FRAME_CONTROL && f->subclass == AST_CONTROL_HANGUP) {
@@ -2549,26 +2610,16 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
 		case AST_FRAME_DTMF_END:
 			send_dtmf_event(chan, "Received", f->subclass, "No", "Yes");
 			ast_log(LOG_DTMF, "DTMF end '%c' received on %s, duration %ld ms\n", f->subclass, chan->name, f->len);
-			/* Queue it up if DTMF is deffered, or if DTMF emulation is forced.
-			 * However, only let emulation be forced if the other end cares about BEGIN frames */
-			if ( ast_test_flag(chan, AST_FLAG_DEFER_DTMF) ||
-				(ast_test_flag(chan, AST_FLAG_EMULATE_DTMF) && !ast_test_flag(chan, AST_FLAG_END_DTMF_ONLY)) ) {
-				if (strlen(chan->dtmfq) < sizeof(chan->dtmfq) - 2) {
-					ast_log(LOG_DTMF, "DTMF end '%c' put into dtmf queue on %s\n", f->subclass, chan->name);
-					chan->dtmfq[strlen(chan->dtmfq)] = f->subclass;
-				} else
-					ast_log(LOG_WARNING, "Dropping deferred DTMF digits on %s\n", chan->name);
+			/* Queue it up if DTMF is deferred, or if DTMF emulation is forced. */
+			if (ast_test_flag(chan, AST_FLAG_DEFER_DTMF) || ast_test_flag(chan, AST_FLAG_EMULATE_DTMF)) {
+				queue_dtmf_readq(chan, f);
 				ast_frfree(f);
 				f = &ast_null_frame;
 			} else if (!ast_test_flag(chan, AST_FLAG_IN_DTMF | AST_FLAG_END_DTMF_ONLY)) {
 				if (!ast_tvzero(chan->dtmf_tv) && 
 				    ast_tvdiff_ms(ast_tvnow(), chan->dtmf_tv) < AST_MIN_DTMF_GAP) {
 					/* If it hasn't been long enough, defer this digit */
-					if (strlen(chan->dtmfq) < sizeof(chan->dtmfq) - 2) {
-						ast_log(LOG_DTMF, "DTMF end '%c' put into dtmf queue on %s\n", f->subclass, chan->name);
-						chan->dtmfq[strlen(chan->dtmfq)] = f->subclass;
-					} else
-						ast_log(LOG_WARNING, "Dropping deferred DTMF digits on %s\n", chan->name);
+					queue_dtmf_readq(chan, f);
 					ast_frfree(f);
 					f = &ast_null_frame;
 				} else {