[asterisk-dev] [Code Review] Fix broken redirect out of MeetMe() as well as the deeper issue at hand

Russell Bryant reviewboard at asterisk.org
Mon Jan 24 13:07:03 CST 2011

This is an automatically generated e-mail. To reply, visit:

(Updated 2011-01-24 13:07:03.100156)

Review request for Asterisk Developers.


Updated patch to address Richard's comments.


Mantis issue #18585 reports that a channel redirect out of MeetMe() stopped working properly.  This issue includes a patch that resolves the issue by removing a call to ast_check_hangup() from app_meetme.c.  I left that in my patch, as it doesn't need to be there.  However, the rest of the patch fixes this problem with or without the change to app_meetme.

The key difference between what happens before and after this patch is the effect of the END_OF_Q control frame.  After END_OF_Q is hit in ast_read(), ast_read() will return NULL.  With the ast_check_hangup() removed, app_meetme sees this which causes it to exit as intended.  Checking ast_check_hangup() caused app_meetme to exit earlier in the process, and the target of the redirect saw the condition where ast_read() returned NULL.

Removing ast_check_hangup() works around the issue in app_meetme, but doesn't solve the issue if another application did the same thing.  There are also other edge cases where if an application finishes at the same time that a redirect happens, the target of the redirect will think that the channel hung up.  So, I made some changes in pbx.c to resolve it at a deeper level.  There are already places that unset the SOFTHANGUP_ASYNCGOTO flag in an attempt to abort the hangup process.  My patch extends this to remove the END_OF_Q frame from the channel's read queue, making the "abort hangup" more complete. 

This addresses bug 18585.

Diffs (updated)

  /branches/1.8/apps/app_meetme.c 303508 
  /branches/1.8/include/asterisk/channel.h 303508 
  /branches/1.8/main/channel.c 303508 
  /branches/1.8/main/features.c 303508 
  /branches/1.8/main/pbx.c 303508 

Diff: https://reviewboard.asterisk.org/r/1082/diff


I replicated the bug easily.  I verified that removing ast_check_hangup() fixes the issue and determined why it fixes it.  I also verified that the issue is resolved with the pbx.c changes, both with and without ast_check_hangup() still used in app_meetme.



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.digium.com/pipermail/asterisk-dev/attachments/20110124/be95d5f1/attachment.htm>

More information about the asterisk-dev mailing list