1 files changed, 113 insertions, 0 deletions
diff --git a/mozglue/misc/TimeStamp_windows.h b/mozglue/misc/TimeStamp_windows.h
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+++ b/mozglue/misc/TimeStamp_windows.h
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+/* -*- 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_TimeStamp_windows_h
+#define mozilla_TimeStamp_windows_h
+
+#include "mozilla/Types.h"
+
+namespace mozilla {
+
+/**
+ * The [mt] unit:
+ *
+ * Many values are kept in ticks of the Performance Counter x 1000,
+ * further just referred as [mt], meaning milli-ticks.
+ *
+ * This is needed to preserve maximum precision of the performance frequency
+ * representation.  GetTickCount64 values in milliseconds are multiplied with
+ * frequency per second.  Therefore we need to multiply QPC value by 1000 to
+ * have the same units to allow simple arithmentic with both QPC and GTC.
+ */
+#define ms2mt(x) ((x) * mozilla::GetQueryPerformanceFrequencyPerSec())
+#define mt2ms(x) ((x) / mozilla::GetQueryPerformanceFrequencyPerSec())
+#define mt2ms_f(x) (double(x) / mozilla::GetQueryPerformanceFrequencyPerSec())
+
+MFBT_API uint64_t GetQueryPerformanceFrequencyPerSec();
+
+class TimeStamp;
+class TimeStampValue;
+class TimeStampValueTests;
+class TimeStampTests;
+
+TimeStampValue NowInternal(bool aHighResolution);
+
+class TimeStampValue {
+  friend TimeStampValue NowInternal(bool);
+  friend bool IsCanonicalTimeStamp(TimeStampValue);
+  friend struct IPC::ParamTraits<mozilla::TimeStampValue>;
+  friend class TimeStamp;
+  friend class TimeStampValueTests;
+  friend class TimeStampTests;
+
+  // Both QPC and GTC are kept in [mt] units.
+  uint64_t mGTC;
+  uint64_t mQPC;
+
+  bool mIsNull;
+  bool mHasQPC;
+
+  constexpr MFBT_API TimeStampValue(uint64_t aGTC, uint64_t aQPC, bool aHasQPC)
+      : mGTC(aGTC),
+        mQPC(aQPC),
+        mIsNull(aGTC == 0 && aQPC == 0),
+        mHasQPC(aHasQPC) {}
+
+  // This constructor should be explicit but it is replacing a constructor that
+  // was MOZ_IMPLICIT and there are many locations that are using the automatic
+  // conversion.
+  constexpr MOZ_IMPLICIT MFBT_API TimeStampValue(uint64_t aGTCAndQPC)
+      : TimeStampValue(aGTCAndQPC, aGTCAndQPC, true) {}
+
+  MFBT_API uint64_t CheckQPC(const TimeStampValue& aOther) const;
+
+ public:
+  MFBT_API uint64_t operator-(const TimeStampValue& aOther) const;
+
+  TimeStampValue operator+(const int64_t aOther) const {
+    return TimeStampValue(mGTC + aOther, mQPC + aOther, mHasQPC);
+  }
+  TimeStampValue operator-(const int64_t aOther) const {
+    return TimeStampValue(mGTC - aOther, mQPC - aOther, mHasQPC);
+  }
+  MFBT_API TimeStampValue& operator+=(const int64_t aOther);
+  MFBT_API TimeStampValue& operator-=(const int64_t aOther);
+
+  constexpr bool operator<(const TimeStampValue& aOther) const {
+    return mHasQPC && aOther.mHasQPC ? mQPC < aOther.mQPC : mGTC < aOther.mGTC;
+  }
+  constexpr bool operator>(const TimeStampValue& aOther) const {
+    return mHasQPC && aOther.mHasQPC ? mQPC > aOther.mQPC : mGTC > aOther.mGTC;
+  }
+  constexpr bool operator<=(const TimeStampValue& aOther) const {
+    return mHasQPC && aOther.mHasQPC ? mQPC <= aOther.mQPC
+                                     : mGTC <= aOther.mGTC;
+  }
+  constexpr bool operator>=(const TimeStampValue& aOther) const {
+    return mHasQPC && aOther.mHasQPC ? mQPC >= aOther.mQPC
+                                     : mGTC >= aOther.mGTC;
+  }
+  constexpr bool operator==(const TimeStampValue& aOther) const {
+    return mHasQPC && aOther.mHasQPC ? mQPC == aOther.mQPC
+                                     : mGTC == aOther.mGTC;
+  }
+  constexpr bool operator!=(const TimeStampValue& aOther) const {
+    return mHasQPC && aOther.mHasQPC ? mQPC != aOther.mQPC
+                                     : mGTC != aOther.mGTC;
+  }
+  constexpr bool IsNull() const { return mIsNull; }
+
+#if defined(DEBUG)
+  uint64_t GTC() const { return mGTC; }
+  uint64_t QPC() const { return mQPC; }
+
+  bool HasQPC() const { return mHasQPC; }
+#endif
+};
+
+}  // namespace mozilla
+
+#endif /* mozilla_TimeStamp_h */