1 files changed, 43 insertions, 0 deletions
diff --git a/js/src/threading/LockGuard.h b/js/src/threading/LockGuard.h
new file mode 100644
index 0000000000..80647012b9
--- /dev/null
+++ b/js/src/threading/LockGuard.h
@@ -0,0 +1,43 @@
+/* -*- 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
+
+#include "mozilla/Attributes.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