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Re: A C pointer passed to LISP
- To: shen@dolphin.Jpl.Nasa.Gov (Sheldon Shen)
- Subject: Re: A C pointer passed to LISP
- From: moon (David A. Moon)
- Date: Tue, 11 Feb 92 11:31:57 EST
- Cc: firstname.lastname@example.org
> Date: Mon, 10 Feb 92 20:29:23 PST
> From: shen@dolphin.Jpl.Nasa.Gov (Sheldon Shen)
> It is mentioned in the Foreign Function Interface chapter that "Passing a pointer to LISP
> data is not safe, because such data can be relocated at any time".
> In my program, I pass a C pointer to LISP. It is a pointer to a STRUCT that maintains the
> status of a database.
The text from the manual you quoted means "A pointer that points at Lisp data cannot be passed
to a foreign function, because the Lisp data can be relocated at any time." You're doing
the opposite, passing a pointer that points at C data to a Lisp function, so that's not
I couldn't guess from the rest of your message what the actual problem that's causing
a crash is.