Re: 3.15.0.2: Shutdown issues

[Michael Davidsaver <mdavidsaver@bnl.gov>]

On 11/18/2014 11:37 AM, Michael Davidsaver wrote:
> ...
> From a quick look I would guess that at least dbBkptExit(),
> dbLockExit(), and errlogExitHandler() can cause similar problems.  So
> I'll look at making these conditional as well.

Ok, so I think I've backed out enough of the DB cleanup to prevent
crashing due to shutdown races.

I think the remaining atexit hooks for softIoc shouldn't crash.  What is
done is:

> atExit exitDatabase((nil))

For a real IOC (as opposed to a unittest) only doCloseLinks() runs to
cleanup CA_LINK.  For records with extended device support it also
disables "I/O Intr" scans and call del_record().

> atExit ca_client_exit_handler((nil))

Frees a thread local variable.

> atExit dbCaExit((nil))

Stops the CA link worker.

> atExit cacExitHandler((nil))

Frees a thread local variable.

> atExit twdShutdown((nil))

Stops the watchdog thread.

> atExit errlogExitHandler((nil))

Stops the errlog thread

> atExit ClockTime_Shutdown((nil))

Stops the ClockTimeSync() thread.


None of these should free any global locks so that concurrent operations
using these locks shouldn't operate on free'd memory.