gh-116738: Add critical section to dbm/gdbm context manager

Author: yoney

Modules/_dbmmodule.c

@@ -515,8 +515,12 @@ dbm__enter__(PyObject *self, PyObject *Py_UNUSED(dummy))
 static PyObject *
 dbm__exit__(PyObject *self, PyObject *Py_UNUSED(args))
 {
+    PyObject *result;
     dbmobject *dp = dbmobject_CAST(self);
-    return _dbm_dbm_close_impl(dp);
+    Py_BEGIN_CRITICAL_SECTION(self);
+    result = _dbm_dbm_close_impl(dp);
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 static PyMethodDef dbm_methods[] = {

Modules/_gdbmmodule.c

@@ -690,7 +690,11 @@ gdbm__enter__(PyObject *self, PyObject *args)
 static PyObject *
 gdbm__exit__(PyObject *self, PyObject *args)
 {
-    return _gdbm_gdbm_close_impl((gdbmobject *)self);
+    PyObject *result;
+    Py_BEGIN_CRITICAL_SECTION(self);
+    result = _gdbm_gdbm_close_impl((gdbmobject *)self);
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 static PyMethodDef gdbm_methods[] = {