The problem in this case is that the C code receives a pointer `x' to a GC-managed object, and the object at that memory moves during the callback to filler(), so that memcpy(x, ....) copies to the wrong place.
Ahhh, I should have figured that. Thanks!
Assuming that your C code will remain oblivious to GC, you'll have to change the call to myfunc2() to pass a reference to an object that is either not GC-managed or won't be moved by a GC (i.e., allocated using 'atomic-interior mode):
Yes, it works great with make-f64vector/immobile, thanks! As a general inquiry, what are the rules for GC about collecting malloc-ed objects? Can I be sure that it does not collect my vector while the C call or callback who uses it is still executing? (I see that I can be sure in this case, because "vec" is used after the "myfunc2" call, but that is not always the case.) Best regards, Dmitry ____________________ Racket Users list: http://lists.racket-lang.org/users
