Now with Atomicity

tests/advanced4.rs

@@ -1,12 +1,11 @@
 extern crate rustijvm;
 
-use std::rc::Rc;
-use std::sync::Mutex;
+use std::sync::{Arc, Mutex};
 use std::io::{Cursor, Seek, SeekFrom, Read};
 
 #[test]
 fn advanced4_tanenbaum() {
-    let rc = Rc::new(Mutex::new(Cursor::new(Vec::new())));
+    let rc = Arc::new(Mutex::new(Cursor::new(Vec::new())));
     let mut machine = rustijvm::Machine::new_from_file("files/advanced/Tanenbaum.ijvm").unwrap();
     machine.set_output(rc.clone());
     machine.run().unwrap();