git subrepo clone https://github.com/Atmosphere-NX/Atmosphere-libs libraries

subrepo:
  subdir:   "libraries"
  merged:   "07af583b"
upstream:
  origin:   "https://github.com/Atmosphere-NX/Atmosphere-libs"
  branch:   "master"
  commit:   "07af583b"
git-subrepo:
  version:  "0.4.0"
  origin:   "https://github.com/ingydotnet/git-subrepo"
  commit:   "5d6aba9"

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

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2018-2019 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 "os_mutex.hpp"
+#include "os_condvar.hpp"
+
+namespace ams::os {
+
+    namespace impl {
+
+        class WaitableObjectList;
+        class WaitableHolderOfSemaphore;
+
+    }
+
+    class Semaphore {
+        friend class impl::WaitableHolderOfSemaphore;
+        NON_COPYABLE(Semaphore);
+        NON_MOVEABLE(Semaphore);
+        private:
+            util::TypedStorage<impl::WaitableObjectList, sizeof(util::IntrusiveListNode), alignof(util::IntrusiveListNode)> waitlist;
+            os::Mutex mutex;
+            os::ConditionVariable condvar;
+            int count;
+            int max_count;
+        public:
+            explicit Semaphore(int c, int mc);
+            ~Semaphore();
+
+            void Acquire();
+            bool TryAcquire();
+            bool TimedAcquire(u64 timeout);
+
+            void Release();
+            void Release(int count);
+
+            constexpr inline int GetCurrentCount() const {
+                return this->count;
+            }
+    };
+
+}