[asterisk-dev] [Code Review] Modify bridging to properly evaluate DTMF after first warning is played

[Kaloyan Kovachev]

Hello,
 probably a bit OT here, but still in place, because this patch is just a
workaround (see below)

On Mon, 16 Feb 2009 23:19:29 -0000, Jeff Peeler wrote
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://reviewboard.digium.com/r/163/
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> 
> Review request for Asterisk Developers.
> 
> Summary
> -------
> 
> The main problem is currently if the Dial flag L is used with a warning
sound, DTMF is not evaluated after the first warning sound.
> 
> These changes are actually pretty simple in retrospect. ast_generic_bridge
has been modified to:
> - return AST_BRIDGE_COMPLETE when DTMF is detected so that possible feature
matches are evaluated in res_features
> - set a flag for playing the warning which ensures that if a scheduled
warning is missed multiple warnings are not played back to back (due to a
feature evaluation or waiting for digits)
> 
> ast_channel_bridge was modified to store the nexteventts in the
ast_bridge_config structure as that information was lost every time
ast_channel_bridge was reentered, causing a hangup due to incorrect time
calculations.

the later was part of the patch for http://bugs.digium.com/view.php?id=6335,
but i don't think it is the best fix. The problem is that nexteventts is used
for both playing the warning and timing out the feature request ... thats why
later it was necessary to change:
if (to <= 0) {
	res = AST_BRIDGE_COMPLETE;
	break;
...
to
if (to <= 0) {
 	if (!config->timelimit) {
 	res = AST_BRIDGE_COMPLETE;
 	break;

to prevent dropping the call before the limit is reached, but when a feature
is attempted and L() is used.

 So the best fix would be not to use nexeteventts for both and i think the
place of the warnings is not inside the bridge ... is it possible by using the
new audiohooks API to play the warnings to the channels from a different thread?
 Combined with the new bridging API (or using the method from bug 6335) with a
scheduled execution for the warnings will free the bridge from that code and
will leave nexeteventts for the features only ... this what I am planning to
do when the bridging API i included (as another attemt for RTCC patch), but
still can't figure out how to play a file to the channel via adiohooks.

> 
> This addresses bug 14315.
>     http://bugs.digium.com/view.php?id=14315
> 
> Diffs
> -----
> 
>   /branches/1.4/include/asterisk/channel.h 176209 
>   /branches/1.4/main/channel.c 176209 
>   /branches/1.4/res/res_features.c 176209
> 
> Diff: http://reviewboard.digium.com/r/163/diff
> 
> Testing
> -------
> 
> Tested exact scenario pretty extensively. Also made sure normal bridging
works as expected as well as a time limited bridge with no warning.
> 
> Thanks,
> 
> Jeff
> 
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