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From: Achim Gratz <Stromeko AT nexgo DOT de>
Subject: Re: ruby rebase / remap problems
Date: Fri, 25 Jan 2013 07:24:36 +0100
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David Stacey writes:
> Forgive my naive understanding of this, but I gather that rebaseall
> allocates a portion of memory for each Cygwin dll. Presumably, this
> bucket of memory is finite, so is it possible that Cygwin could ever
> grow to a size where it effectively runs out of rebasing address space
> particularly on XP, which doesn't support Address Space Layout
> Randomization?

It's possible to end up with an address map that goes to very low
addresses, but I haven't seen it exhaust the memory yet (but I guess
installing _everything_ plus ports would come close).  But more often,
you will have a non-Cygwin application that already uses part of the
memory that a Cygwin DLL got rebased to, since rebase only knows about
those DLL within Cygwin.  When that application is already loaded and a
Cygwin DLL that occupies the same address space is used, it will
generally not end up where rebase said it should be and it will appear
on different addresses on each fork (most often I see it flip-flopping
between two not-too-distant, but very low addresses).


Regards,
Achim.
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