os: implement Tick api, make build with -Werror

libraries/libstratosphere/source/os/impl/os_tick_manager_impl.cpp

@@ -0,0 +1,84 @@
+/*
+ * 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/>.
+ */
+#include <stratosphere.hpp>
+#include "os_tick_manager.hpp"
+
+namespace ams::os::impl {
+
+    TimeSpan TickManager::ConvertToTimeSpan(Tick tick) const {
+        /* Get the tick value. */
+        const s64 tick_val  = tick.GetInt64Value();
+
+        /* Get the tick frequency. */
+        const s64 tick_freq = GetTickFrequency();
+        AMS_AUDIT(tick_freq < MaxTickFrequency);
+
+        /* Clamp tick to range. */
+        if (tick_val > GetMaxTick()) {
+            return TimeSpan::FromNanoSeconds(std::numeric_limits<s64>::max());
+        } else if (tick_val < -GetMaxTick()) {
+            return TimeSpan::FromNanoSeconds(std::numeric_limits<s64>::min());
+        } else {
+            /* Convert to timespan. */
+            constexpr s64 NanoSecondsPerSecond = TimeSpan::FromSeconds(1).GetNanoSeconds();
+            const s64 seconds = tick_val / tick_freq;
+            const s64 frac    = tick_val % tick_freq;
+            const TimeSpan ts = TimeSpan::FromSeconds(seconds) + TimeSpan::FromNanoSeconds(frac * NanoSecondsPerSecond / tick_freq);
+
+            constexpr TimeSpan ZeroTS    = TimeSpan::FromNanoSeconds(0);
+            AMS_ASSERT(!((tick_val > 0 && ts < ZeroTS) || (tick_val < 0 && ts > ZeroTS)));
+
+            return ts;
+        }
+    }
+
+    Tick TickManager::ConvertToTick(TimeSpan ts) const {
+        /* Get the TimeSpan in nanoseconds. */
+        const s64 ns = ts.GetNanoSeconds();
+
+        /* Clamp ns to range. */
+        if (ns > GetMaxTimeSpanNs()) {
+            return Tick(std::numeric_limits<s64>::max());
+        } else if (ns < -GetMaxTimeSpanNs()) {
+            return Tick(std::numeric_limits<s64>::min());
+        } else {
+            /* Get the tick frequency. */
+            const s64 tick_freq = GetTickFrequency();
+            AMS_AUDIT(tick_freq < MaxTickFrequency);
+
+            /* Convert to tick. */
+            constexpr s64 NanoSecondsPerSecond = TimeSpan::FromSeconds(1).GetNanoSeconds();
+            const bool negative = ns < 0;
+            s64 seconds   = ns / NanoSecondsPerSecond;
+            s64 frac      = ns % NanoSecondsPerSecond;
+
+            /* If negative, negate seconds/frac. */
+            if (negative) {
+                seconds = -seconds;
+                frac    = -frac;
+            }
+
+            /* Calculate the tick, and invert back to negative if needed. */
+            s64 tick = (seconds * tick_freq) + ((frac * tick_freq + NanoSecondsPerSecond - 1) / NanoSecondsPerSecond);
+            if (negative) {
+                tick = -tick;
+            }
+
+            return Tick(tick);
+        }
+    }
+
+}