asterisk users - Dec 2004 - Asterisk consuming 100% CPU - CDR loop

Hi,

I had Asterisk threads consuming 100% CPU at times since last week. Of  
course, last week an extra card was installed (we had a 1PRI, a 4PRI was  
added) so search concentrated on that, but to no avail. Today, I installed  
DDD on the machine and quickly found out that it was looping because  
cdr->next->next == cdr in ast_cdr_setapp().

I patched this up with some simple code in ast_cdr_append(), but that's  
just masking the bug.

The only place were cdr->next is set is in ast_cdr_append(), and this (as  
far as I can tell) code is called from ForkCDR() and the Zap channel  
transfer logic (also from SIP, but SIP is not involved here). I do a  
ForkCDR() somewhere before Dial() so I think my dialplan hits both (people  
dial in through Zap and out again through Zap). And the trouble started  
when I added ForkCDR() to the dialplan.

I suspect the code in chan_zap.c:attempt_transfer() is flawed somewhere  
w.r.t. blindingly glueing CDR's together, but I'm not completely sure:  
first, I am not even sure whether I hit this function, second, it *seems*  
to happen just now and then which would indicate a race condition. The  
system is a production system, all the calls are essentially the same:  
people call in, go through some IVR, enter a number to dial out, the  
system does a Dial().

Anyone else had this problem?

To follow up on this issue: it apparently had to do with ForkCDR()'ing  
multiple times in a call. I'll take this to asterisk-dev to see what's  
really going on under the hood.