Re: AIX and Interix also do early PID recycling.

[Chet Ramey]

On 7/25/12 1:08 PM, Chet Ramey wrote:
> On 7/25/12 11:33 AM, Andreas Schwab wrote:
> 
>> I cannot see how CHILD_MAX is related to pid reuse.  CHILD_MAX is a
>> per-user limit, but the pid namespace is global.  If the shell forks a
>> new process, and the pid of it matches one of the previously used pids
>> for asynchronous jobs it can surely discard the remembered status for
>> that job.
> 
> Thanks, that's a good restatement of the problem.  Your proposed solution
> is one of the possibles.  The question is whether or not it's necessary
> (apparently on some systems) and sufficient (probably).

OK, we have some data, we have a hypothesis, and we have a way to test it.
Let's test it.

Michael, please apply the attached patch, disable RECYCLES_PIDS, and run
your tests again.  This makes the check for previously-saved exit statuses
unconditional.

Let's see if this is the one change of significance.

Chet

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/

pid-recycle.patch
Description: Source code patch