py: Make gc.enable/disable just control auto-GC; alloc is still allowed.

gc.enable/disable are now the same as CPython: they just control whether
automatic garbage collection is enabled or not.  If disabled, you can
still allocate heap memory, and initiate a manual collection.

1 files changed, 5 insertions, 0 deletions

diff --git a/py/gc.h b/py/gc.h
index dc276dd2b..69fe83752 100644
--- a/py/gc.h
+++ b/py/gc.h
@@ -32,6 +32,11 @@ void gc_lock(void);
 void gc_unlock(void);
 bool gc_is_locked(void);
 
+// This variable controls auto garbage collection.  If set to 0 then the
+// GC won't automatically run when gc_alloc can't find enough blocks.  But
+// you can still allocate/free memory and also explicitly call gc_collect.
+extern uint16_t gc_auto_collect_enabled;
+
 // A given port must implement gc_collect by using the other collect functions.
 void gc_collect(void);
 void gc_collect_start(void);