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Date:	Mon, 4 Mar 2002 12:12:32 +0100 (CET)
From:	Ivan Szanto <szivan AT bitbybit-is DOT nl>
To:	cygwin AT cygwin DOT com
Subject:	Hang problem related to signals and process priority
Message-ID:	<Pine.LNX.4.21.0203041108020.5026-200000@appel.bitbybit>
MIME-Version:	1.0

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Content-ID: <Pine DOT LNX DOT 4 DOT 21 DOT 0203041151571 DOT 5062 AT appel DOT bitbybit>


Hello cywin guru,                                                                                                                 


Maybe you can help me with the following problem.
We are running Cygwin version 1.3.10 on Windows NT.
We use sigaction to redirect the SIGIO signal to our
own signal handler in a client/server app. 

When running several processes of the same client program 
in the background, a couple of them seem to hang.

It is interesting that this problem does not surface when
we have all those processes running in the foreground or
when we start them using "cmd start /high ..."

Please find attached the relevant code for reproducing
the problem. It is a client program that tries to connect
to a telnetd. It expects the machine name where telnetd is
running as well as the repeat count for the send loop.
I reproduced the problem as follows

  1. opened an xterm with a bash
  2. in the xterm I typed the following
   
     for i in 1 2 3
     do
       ./a.exe localhost 300 &
     done

The result was that one process did well, but the other two hanged.

Is this behavior related to a known CYGWIN problem?
Do you think we can change our code in some way to avoid this problem?
We will greatly appreciate your expert advice on this matter.


Greetings,


  Ivan

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