Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/lldb/tools/lldb-perf/lib/Timer.h

@@ -0,0 +1,49 @@
+//===-- Timer.h -------------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __PerfTestDriver__Timer__
+#define __PerfTestDriver__Timer__
+
+#include "Gauge.h"
+
+#include <chrono>
+
+using namespace std::chrono;
+
+namespace lldb_perf {
+class TimeGauge : public Gauge<double> {
+public:
+  TimeGauge();
+
+  virtual ~TimeGauge() {}
+
+  void Start();
+
+  double Stop();
+
+  virtual double GetStartValue() const;
+
+  virtual double GetStopValue() const;
+
+  virtual double GetDeltaValue() const;
+
+private:
+  enum class State { eNeverUsed, eCounting, eStopped };
+
+  typedef high_resolution_clock::time_point TimeType;
+  TimeType m_start;
+  TimeType m_stop;
+  double m_delta;
+  State m_state;
+
+  TimeType Now();
+};
+}
+
+#endif /* defined(__PerfTestDriver__Timer__) */