set_unblock_function  114 thread.c       static int set_unblock_function(rb_thread_t *th, rb_unblock_function_t *func, void *arg,
set_unblock_function 1256 thread.c           if (set_unblock_function(th, ubf, arg, &region->oldubf, fail_if_interrupted)) {
set_unblock_function  263 thread_sync.c  	    set_unblock_function(th, lock_interrupt, mutex, &oldubf, FALSE);