py: Implement a simple global interpreter lock.

This makes the VM/runtime thread safe, at the cost of not being able to
run code in parallel.

1 files changed, 4 insertions, 0 deletions

diff --git a/py/vm.c b/py/vm.c
index bd5bae115..65801401d 100644
--- a/py/vm.c
+++ b/py/vm.c
@@ -1263,6 +1263,10 @@ pending_exception_check:
                     RAISE(obj);
                 }
 
+                // TODO make GIL release more efficient
+                MP_THREAD_GIL_EXIT();
+                MP_THREAD_GIL_ENTER();
+
             } // for loop
 
         } else {