[racket] FFI/3m and Boehm GC compatibility

Folks,

I posted this on IRC earlier today with no response:
   "With ffi, i have a function which returns a pointer which has been
    malloc'd using a GC_malloc (linked with my foreign library).

   "I need this pointer to remain visible within racket (i.e. on the stack
    or anywhere else that the CGC would find it). This is fine for
    racketcgc (since GC_malloc is shared between my library and racket)
    but how do i keep a pointer visible with racket3m?

   "[if possible, without "remembering" it explicitly in my library]"

Does anyone have any idea how to hint to the FFI that I want this reference
kept visible?

Regards,

Tim

-- 
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