memset (&cb, 0, sizeof (cb));
cb.mono_method_is_critical = mono_runtime_is_critical_method;
cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
memset (&cb, 0, sizeof (cb));
cb.mono_method_is_critical = mono_runtime_is_critical_method;
cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;