1 files changed, 50 insertions, 0 deletions
diff --git a/mozglue/misc/PlatformRWLock.h b/mozglue/misc/PlatformRWLock.h
new file mode 100644
index 0000000000..0acd09b25b
--- /dev/null
+++ b/mozglue/misc/PlatformRWLock.h
@@ -0,0 +1,50 @@
+/* -*- 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 mozilla_PlatformRWLock_h
+#define mozilla_PlatformRWLock_h
+
+#include "mozilla/Types.h"
+
+#ifndef XP_WIN
+#  include <pthread.h>
+#endif
+
+namespace mozilla::detail {
+
+class RWLockImpl {
+ public:
+  explicit MFBT_API RWLockImpl();
+  MFBT_API ~RWLockImpl();
+
+ protected:
+  [[nodiscard]] MFBT_API bool tryReadLock();
+  MFBT_API void readLock();
+  MFBT_API void readUnlock();
+
+  [[nodiscard]] MFBT_API bool tryWriteLock();
+  MFBT_API void writeLock();
+  MFBT_API void writeUnlock();
+
+ private:
+  RWLockImpl(const RWLockImpl&) = delete;
+  void operator=(const RWLockImpl&) = delete;
+  RWLockImpl(RWLockImpl&&) = delete;
+  void operator=(RWLockImpl&&) = delete;
+  bool operator==(const RWLockImpl& rhs) = delete;
+
+#ifndef XP_WIN
+  pthread_rwlock_t mRWLock;
+#else
+  // SRWLock is pointer-sized. We declare it in such a fashion here to avoid
+  // pulling in windows.h wherever this header is used.
+  void* mRWLock;
+#endif
+};
+
+}  // namespace mozilla::detail
+
+#endif  // mozilla_PlatformRWLock_h