os: implement ReadWriteLock

libraries/libstratosphere/include/stratosphere/os/os_rw_lock_common.hpp

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#include <vapours.hpp>
+
+namespace ams::os {
+
+    constexpr inline s32 ReadWriteLockCountMax       = (1 << (BITSIZEOF(u16) - 1)) - 1;
+    constexpr inline s32 ReadWriteLockWaiterCountMax = (1 << BITSIZEOF(u8)) - 1;
+
+}