The GC and Guardians

[Han-Wen Nienhuys]

address@hidden writes:
> int foo(...)
> {
>   SCM mysmob;
> 
>   mysmob = create_mysmob(...);
>   scm_define(scm_str2symbol(...), mysmob);
> 
>   return;
> }
> 
> My understanding is that since the SMOB bound to the top level
> environment, the garbage collector should not destroy it since
> its referenced by the top root. I do later undefine it when I no
> longer care about it.

Yup, this looks ok.

> Also, on an unrelated problem, I want to be able to create a C
> structure and have it reference non-immediate SCM data, but I
> cannot turn this C structure into a SMOB. Unfortunately the folks
> using my code may not be happy dealing with guile
> directly. Should I use a guardian on the SCM data like so?
> 
> foo_t *foo_create(void)
> {
>   foo_t *foo = create_foo();
>   SCM guardian;
> 
>   foo->mylist = SCM_EOL;
>   guardian = scm_make_guardian(...);
> 
>   scm_apply(....); /* protect foo->mylist with the guardian procedure */
> 
>   return foo;
> }

I don't know anything about guardians, but why don't you simply use
scm_gc_(un)protect_object()?

--
Han-Wen Nienhuys   |   address@hidden   |   http://www.xs4all.nl/~hanwen