INFORMIX SERVER / 5725A3900 / C10 - IDS 12.10

There appears to be a race condition between a thread exiting
due to somehow getting into destroy_session, and a poll thread
having to handle urgent/expidited data which causes it to go
into break_session(), which can cause invalid mutex type
assertions because by the time the poll thread tries to do it's
work, the thread has already exited and freed up the
scb->threadlatch mutex.  The assertion failure looks like this:

04:00:41  Assert Failed: Invalid Mutex Type
04:00:41   Who: Session(3, informix@, 0, (nil))
        Thread(12, soctcppoll, 0, 18)
        File: mt.c Line: 8975

afstack
afhandler
afcrash_interface
mt_lock
break_session
soctcp_sighand
interupt_input
soc_devpoll_thread
startup

The problem being that the session we are trying to break no
longer exists in the server.

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* USERS AFFECTED:                                              *
* Any                                                          *
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* PROBLEM DESCRIPTION:                                         *
* See Error Description                                        *
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* RECOMMENDATION:                                              *
* Update to IBM Informix Server 12.10.xC8                      *
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not known / see Local fix

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

02.05.2016
09.12.2016
09.12.2016

12.10.xC8