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Date: Mon, 11 Feb 2002 21:29:57 +0200
From: "Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
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To: Eric Rudd <rudd AT cyberoptics DOT com>
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In-reply-to: <3C67E0CB.344A3981@cyberoptics.com> (message from Eric Rudd on
	Mon, 11 Feb 2002 09:18:35 -0600)
Subject: Re: Alignment problem
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> Date: Mon, 11 Feb 2002 09:18:35 -0600
> From: Eric Rudd <rudd AT cyberoptics DOT com>
> 
> Perhaps the first thing I should do is to figure out the format of the block
> headers.  Does anyone know what this is?

There's a 4-byte header and a 4-byte trailer.  When a block is
allocated, the header records the size.  When it's free, there's a
pointer to the next free block there.  (There's also the LSB that is
used for something I don't recall, since pointers are aligned, and so
their last bit is always zero.)

See the definition of struct BLOCK for more details, and also the
macros such as DATA used by malloc.c.