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_timeout_helper.hpp

@@ -0,0 +1,63 @@
+/*
+ * 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_common_types.hpp"
+
+namespace ams::os {
+
+    class TimeoutHelper {
+        private:
+            u64 end_tick;
+        public:
+            TimeoutHelper(u64 ns) {
+                /* Special case zero-time timeouts. */
+                if (ns == 0) {
+                    end_tick = 0;
+                    return;
+                }
+
+                u64 cur_tick = armGetSystemTick();
+                this->end_tick = cur_tick + NsToTick(ns) + 1;
+            }
+
+            static constexpr inline u64 NsToTick(u64 ns) {
+                return (ns * 12) / 625;
+            }
+
+            static constexpr inline u64 TickToNs(u64 tick) {
+                return (tick * 625) / 12;
+            }
+
+            inline bool TimedOut() const {
+                if (this->end_tick == 0) {
+                    return true;
+                }
+
+                return armGetSystemTick() >= this->end_tick;
+            }
+
+            inline u64 NsUntilTimeout() const {
+                u64 diff = TickToNs(this->end_tick - armGetSystemTick());
+
+                if (this->TimedOut()) {
+                    return 0;
+                }
+
+                return diff;
+            }
+    };
+
+}