1 files changed, 52 insertions, 0 deletions
diff --git a/js/src/threading/LockGuard.h b/js/src/threading/LockGuard.h
new file mode 100644
index 000000000..45b023a90
--- /dev/null
+++ b/js/src/threading/LockGuard.h
@@ -0,0 +1,52 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef threading_LockGuard_h
+#define threading_LockGuard_h
+
+namespace js {
+
+template <typename Mutex> class MOZ_RAII UnlockGuard;
+
+template <typename Mutex>
+class MOZ_RAII LockGuard
+{
+  friend class UnlockGuard<Mutex>;
+  friend class ConditionVariable;
+  Mutex& lock;
+
+public:
+  explicit LockGuard(Mutex& aLock)
+    : lock(aLock)
+  {
+    lock.lock();
+  }
+
+  ~LockGuard() {
+    lock.unlock();
+  }
+};
+
+template <typename Mutex>
+class MOZ_RAII UnlockGuard
+{
+  Mutex& lock;
+
+public:
+  explicit UnlockGuard(LockGuard<Mutex>& aGuard)
+    : lock(aGuard.lock)
+  {
+    lock.unlock();
+  }
+
+  ~UnlockGuard() {
+    lock.lock();
+  }
+};
+
+} // namespace js
+
+#endif // threading_LockGuard_h