rb_mutex_trylock  901 include/ruby/intern.h VALUE rb_mutex_trylock(VALUE mutex);
rb_mutex_trylock  252 thread_sync.c      if (rb_mutex_trylock(self) == Qfalse) {
rb_mutex_trylock 1244 thread_sync.c      rb_define_method(rb_cMutex, "try_lock", rb_mutex_trylock, 0);