Tidy up rust-lang#1

tests/compile-fail/live_lock/live_lock_condvar.rs

@@ -1,5 +1,5 @@
 // compile-flags: -Zmiri-disable-isolation
-// ignore-windows: No libc on Windows
+// ignore-windows: Concurrency on Windows is not supported yet.
 
 // FIXME: the implicit mutex unlock & lock counts as forward progress with the current detector,
 // so this runs forever. Ideally this case should be detected.
@@ -29,4 +29,4 @@ fn main() {
             }
         }
     }
-}
+}

tests/compile-fail/live_lock/live_lock_contention.rs

@@ -1,4 +1,4 @@
-// ignore-windows: No libc on Windows
+// ignore-windows: Concurrency on Windows is not supported yet.
 
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;

tests/compile-fail/live_lock/live_lock_deadlock.rs

@@ -1,4 +1,4 @@
-// ignore-windows: No libc on Windows
+// ignore-windows: Concurrency on Windows is not supported yet.
 
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;

tests/compile-fail/live_lock/live_lock_separate.rs

@@ -1,4 +1,4 @@
-// ignore-windows: No libc on Windows
+// ignore-windows: Concurrency on Windows is not supported yet.
 
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;

tests/compile-fail/live_lock/live_lock_spin_deadlock.rs

@@ -0,0 +1,51 @@
+// ignore-windows: Concurrency on Windows is not supported yet.
+
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+use std::thread::spawn;
+
+extern "Rust" {
+    fn miri_yield_thread();
+}
+
+struct SpinLock(AtomicUsize);
+impl SpinLock {
+    fn new() -> Self {
+        Self(AtomicUsize::new(0))
+    }
+    fn lock(&self) {
+        loop {
+            if let Ok(_) = self.0.compare_exchange_weak(0, 1, Ordering::Acquire, Ordering::Relaxed) {
+                break
+            } else {
+                unsafe { miri_yield_thread(); } //~ERROR livelock
+            }
+        }
+    }
+    fn unlock(&self) {
+        self.0.store(0, Ordering::Release);
+    }
+}
+
+fn main() {
+    // forces a deadlock via yield points
+    let shared = Arc::new((SpinLock::new(),SpinLock::new()));
+    let s1 = shared.clone();
+    let s2 = shared.clone();
+    let j1 = spawn(move || {
+        s1.0.lock();
+        std::thread::yield_now();
+        s1.1.lock();
+        s1.1.unlock();
+        s1.0.unlock();
+    });
+    let j2 = spawn(move || {
+        s2.1.lock();
+        std::thread::yield_now();
+        s2.0.lock();
+        s2.0.unlock();
+        s2.1.unlock();
+    });
+    j1.join().unwrap();
+    j2.join().unwrap();
+}

tests/compile-fail/live_lock/live_lock_try_mutex.rs

@@ -1,4 +1,4 @@
-// ignore-windows: No libc on Windows
+// ignore-windows: Concurrency on Windows is not supported yet.
 
 use std::sync::{Arc, Mutex};
 use std::thread::spawn;
@@ -17,7 +17,7 @@ fn main() {
             // yield loop for try-lock.
             if let Ok(guard) = s1.try_lock() {
                 break guard
-            }else{
+            } else {
                 unsafe { miri_yield_thread(); } //~ERROR livelock
             }
         };
@@ -26,4 +26,4 @@ fn main() {
 
     j1.join().unwrap();
     *s_guard = 1;
-}
+}

tests/compile-fail/live_lock/live_lock_try_rwlock_read.rs

@@ -1,4 +1,4 @@
-// ignore-windows: No libc on Windows
+// ignore-windows: Concurrency on Windows is not supported yet.
 
 use std::sync::{Arc, RwLock};
 use std::thread::spawn;
@@ -17,12 +17,12 @@ fn main() {
             // yield loop for try-lock.
             if let Ok(guard) = s1.try_read() {
                 break guard
-            }else{
+            } else {
                 unsafe { miri_yield_thread(); } //~ERROR livelock
             }
         };
     });
 
     j1.join().unwrap();
     *s_guard = 1;
-}
+}

tests/compile-fail/live_lock/live_lock_try_rwlock_write.rs

@@ -1,4 +1,4 @@
-// ignore-windows: No libc on Windows
+// ignore-windows: Concurrency on Windows is not supported yet.
 
 use std::sync::{Arc, RwLock};
 use std::thread::spawn;
@@ -17,7 +17,7 @@ fn main() {
             // yield loop for try-lock.
             if let Ok(guard) = s1.try_write() {
                 break guard
-            }else{
+            } else {
                 unsafe { miri_yield_thread(); } //~ERROR livelock
             }
         };
@@ -26,4 +26,4 @@ fn main() {
 
     j1.join().unwrap();
     *s_guard = 1;
-}
+}