add another usertest

 Conflicts:

	usertest/src/main.rs

usertest/src/main.rs

@@ -151,10 +151,25 @@ fn test_futex() {
 
 fn test_rust_mutex() {
     use std::sync::{Arc, Mutex};
-    use std::thread;
 
     print!("Testing Rust Mutex ...");
     let mutex = Arc::new(Mutex::new(0));
+    let mtx_clone = Arc::clone(&mutex);
+    let mut num = mtx_clone.lock().unwrap();
+    *num += 1;
+    let final_count = *mutex.lock().unwrap();
+    if final_count != 1 {
+        panic!("Mutex test failed, expected 1 but got {}", final_count);
+    }
+    println!(" OK");
+}
+
+fn test_rust_mutex_contention() {
+    use std::sync::{Arc, Mutex};
+    use std::thread;
+
+    print!("Testing Rust Mutex w/contention ...");
+    let mutex = Arc::new(Mutex::new(0));
     let mut handles = vec![];
 
     for _ in 0..10 {
@@ -246,6 +261,7 @@ fn main() {
     run_test(test_write);
     run_test(test_futex);
     run_test(test_rust_mutex);
+    run_test(test_rust_mutex_contention);
     run_test(test_rust_file);
     run_test(test_rust_dir);
     let end = std::time::Instant::now();