From: Mark Slagell <ms@...>
Date: 2002-05-06T04:09:38+09:00
Subject: Re: defunct child process

neil wrote:

>Mark Slagell wrote:
>  
>
>>neil wrote:
>>
>>    
>>
>>>neil wrote:
>>>
>>>
>>>      
>>>
>>>>I cannot claim this the correct way,
>>>>though it is based on some Pick Axe
>>>>code,
>>>>
>>>>
>>>>        
>>>>
>>>Sorry that got mangled,
>>>
>>>trap("CLD"){ # child finished
>>>        begin
>>>          waitpid(Process.wait,
>>>Process::WNOHANG)
>>>          rescue StandardError
>>>            break
>>>          end
>>>       }
>>>
>>>and get the Procees.uid if you want to
>>>
>>>
>>>      
>>>
>>Or you might find it sufficient to say
>>
>>trap('CLD') {Process.wait2}
>>
>>  -- Mark
>>    
>>
>
> True, though without the rescue you can
>get an fatal error 
> with Process.wait2, "failed to convert
>array into an integer"
> and again fatal with
>Process.wait::WNOHANG No child processes
>(Errno::ECHILD) 
> The break is redundant, sorry is a bit
>of left over code.
>
> Neil
>  
>
Neil, I'm not sure where the array conversion error could come from 
(have you seen it happen?).  If a bogus SIGCHLD signal came through, I 
see that wait2 should still fail with "No child processes,"  but can we 
not trust the OS about that? Under what circumstances would there ever 
be a SIGCHLD signal and no child to go along with it?

  Mark