rb_fiber_alive_p 1706 cont.c             rb_define_method(rb_cFiber, "alive?", rb_fiber_alive_p, 0);
rb_fiber_alive_p  650 enumerator.c       if (!e->fib || !rb_fiber_alive_p(e->fib)) {
rb_fiber_alive_p  222 include/ruby/intern.h VALUE rb_fiber_alive_p(VALUE);