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Date:	Thu, 2 May 2002 18:53:27 +0300 (IDT)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender:	eliz AT is
To:	ahelm AT gmx DOT net
cc:	djgpp AT delorie DOT com
Subject:	Re: segfault on context switch
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On Thu, 2 May 2002 ahelm AT gmx DOT net wrote:

> Usually it means that memory is corrupted somewhere before
> malloc() is called, but why does this only happen on Alt-TAB???
> 
> The segfault doesn't happen at the same malloc() call each time. 
> But so far I've only seen it originating from functions invoked 
> by the bison parser I use for parsing the serial input (which
> isn't really surprising as it is running most of the time).

Is it possible that a context switch exposes some bug in handling the 
serial input?  It could do that if the code which receives characters 
from the serial port doesn't cope well with some phenomenon that happens 
during the context switch.  Such a phenomenon could be related to the 
fact that a context switch might cause Windows to change something in its 
DOS emulation's handling of serial input (since Windows needs to 
virtualize the COM port).

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