From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2005-09-22T06:52:23+09:00
Subject: Re: signals and win32

On Thu, 22 Sep 2005, Berger, Daniel wrote:

>> basically i'm doing this in one irb session
>>
>>    irb > Process::pid
>>    1234
>>    irb > trap(2){ STDERR.puts "got 2"}
>>
>> and then, in another command window
>>
>>    irb > require 'win32/process'
>>    irb > Process::kill 2, 1234
>>
>> but this doesn't work.  of course i've tried with scripts too
>> in order to make sure irb didn't have some signal handlers of
>> it's own.  i always end up getting errors from the kill or,
>> if the kill works, the trap does not: the other process
>> simply exits no matter what - eg. trap doesn't seem to work.
>>
>> hope that is enough info - i'm away from that machine right now.
>>
>> cheers.
>>
>> -a
>
> Oh, right, now I remember.  The problem is that signals 2 and 3 will
> only be caught on processes created, via CreateProcess(), with the
> CREATE_NEW_PROCESS_GROUP flag.  This is, unfortunately, just the way
> that GenerateConsoleCtrlEvent() works.
>
> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc
> /base/generateconsolectrlevent.asp
>
> So, I'm guessing that in most cases, it's not very useful.

hmm.  no way to specifcally allow unrelated process to signal you then eh?

oh well - i re-implemented acgi to use no locking or pipes and signals
instead.  big suprise - it was __slower__.  so i'm back to pipes.  what's your
feeling on pipes in win32 - do they have the same blocking semantics as in
unix?

cheers.

-a
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