add new functions mrb_gc_register/unregister; close #1411

some routines need to refer mruby objects (e.g. callbacks), in that case
you have to protect your objects from garbage collection. the new functions
mrb_gc_register() keeps those objects from GC. you have to remove your
objects using mrb_gc_unregister() when your C routines use mruby objects
any longer, otherwise objects will leak.

1 files changed, 6 insertions, 0 deletions

diff --git a/include/mruby.h b/include/mruby.h
index dedbd0748..a262a0fbf 100644
--- a/include/mruby.h
+++ b/include/mruby.h
@@ -408,7 +408,13 @@ MRB_API mrb_value mrb_yield(mrb_state *mrb, mrb_value b, mrb_value arg);
 MRB_API mrb_value mrb_yield_argv(mrb_state *mrb, mrb_value b, mrb_int argc, const mrb_value *argv);
 MRB_API mrb_value mrb_yield_with_class(mrb_state *mrb, mrb_value b, mrb_int argc, const mrb_value *argv, mrb_value self, struct RClass *c);
 
+/* mrb_gc_protect() leaves the object in the arena */
 MRB_API void mrb_gc_protect(mrb_state *mrb, mrb_value obj);
+/* mrb_gc_register() keeps the object from GC. */
+MRB_API void mrb_gc_register(mrb_state *mrb, mrb_value obj);
+/* mrb_gc_unregister() removes the object from GC root. */
+MRB_API void mrb_gc_unregister(mrb_state *mrb, mrb_value obj);
+
 MRB_API mrb_value mrb_to_int(mrb_state *mrb, mrb_value val);
 #define mrb_int(mrb, val) mrb_fixnum(mrb_to_int(mrb, val))
 MRB_API void mrb_check_type(mrb_state *mrb, mrb_value x, enum mrb_vtype t);