high_res_clock.hpp
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//
// high_res_clock.hpp
// ~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef HIGH_RES_CLOCK_HPP
#define HIGH_RES_CLOCK_HPP
#include <boost/config.hpp>
#include <boost/cstdint.hpp>
#if defined(ASIO_WINDOWS)
inline boost::uint64_t high_res_clock()
{
LARGE_INTEGER i;
QueryPerformanceCounter(&i);
return i.QuadPart;
}
#elif defined(__GNUC__) && defined(__x86_64__)
inline boost::uint64_t high_res_clock()
{
unsigned long low, high;
__asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high));
return (((boost::uint64_t)high) << 32) | low;
}
#else
#include <boost/date_time/posix_time/posix_time_types.hpp>
inline boost::uint64_t high_res_clock()
{
boost::posix_time::ptime now =
boost::posix_time::microsec_clock::universal_time();
boost::posix_time::ptime epoch(
boost::gregorian::date(1970, 1, 1),
boost::posix_time::seconds(0));
return (now - epoch).total_microseconds();
}
#endif
#endif // HIGH_RES_CLOCK_HPP