rb_threadptr_remove_event_hook  192 vm_trace.c         return rb_threadptr_remove_event_hook(thval2thread_t(thval), func, Qundef);
rb_threadptr_remove_event_hook  198 vm_trace.c         return rb_threadptr_remove_event_hook(thval2thread_t(thval), func, data);
rb_threadptr_remove_event_hook  220 vm_trace.c     	rb_threadptr_remove_event_hook(th, 0, Qundef);
rb_threadptr_remove_event_hook  553 vm_trace.c         rb_threadptr_remove_event_hook(th, call_trace_func, Qundef);