From: Bill Kelly <billk@...>
Date: 2008-08-13T06:07:15+09:00
Subject: Re: Non-Threaded Timeout?


From: "ara.t.howard" <ara.t.howard@gmail.com>
> 
> On Aug 12, 2008, at 12:38 PM, Bryan Richardson wrote:
>
>> However, it seems as though when creating the watchdog in the timeout
>> method IO.popen sometimes blocks execution.  I can't tell if it's due
>> to the external (OLE) application blocking or something else.  If I
>> don't use the timeout method the OLE application blocks at a different
>> time in the simulation, so I'm thinking it's not due to the OLE
>> application blocking...
> 
> can you prove that it's popen blocking?  seems very strange...

I'm just jumping into the middle of the thread, so apologies if
I've missed something; but ...

popen blocks ALL ruby threads on windows.  This has been the bane
of my existence for the past eight years.  :)

The problem is due to Microsoft's venerable design strategy: You are
lost in a twisty little maze of API's, all incompatible.

On Windows, the "file handle" returned by popen is not a "socket",
and therefore is incompatible with "select".

/me raises a cup of hemlock in toast to Redmond


Note: Now that 1.9 ruby uses native threads, it should be possible
to implement a nonblocking popen.  However, last time I tested 1.9
for this behavior, it still blocked.  (This was several months ago.)


Regards,

Bill