mirror of
https://github.com/yuzu-emu/ext-boost.git
synced 2024-12-22 19:15:28 +00:00
234 lines
8.5 KiB
C++
234 lines
8.5 KiB
C++
// boost/chrono/system_clocks.hpp --------------------------------------------------------------//
|
|
|
|
// Copyright 2008 Howard Hinnant
|
|
// Copyright 2008 Beman Dawes
|
|
// Copyright 2009-2011 Vicente J. Botet Escriba
|
|
|
|
// Distributed under the Boost Software License, Version 1.0.
|
|
// See http://www.boost.org/LICENSE_1_0.txt
|
|
|
|
/*
|
|
|
|
This code was derived by Beman Dawes from Howard Hinnant's time2_demo prototype.
|
|
Many thanks to Howard for making his code available under the Boost license.
|
|
The original code was modified to conform to Boost conventions and to section
|
|
20.9 Time utilities [time] of the C++ committee's working paper N2798.
|
|
See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf.
|
|
|
|
time2_demo contained this comment:
|
|
|
|
Much thanks to Andrei Alexandrescu,
|
|
Walter Brown,
|
|
Peter Dimov,
|
|
Jeff Garland,
|
|
Terry Golubiewski,
|
|
Daniel Krugler,
|
|
Anthony Williams.
|
|
*/
|
|
|
|
/*
|
|
|
|
TODO:
|
|
|
|
* Fully implement error handling, with test cases.
|
|
* Consider issues raised by Michael Marcin:
|
|
|
|
> In the past I've seen QueryPerformanceCounter give incorrect results,
|
|
> especially with SpeedStep processors on laptops. This was many years ago and
|
|
> might have been fixed by service packs and drivers.
|
|
>
|
|
> Typically you check the results of QPC against GetTickCount to see if the
|
|
> results are reasonable.
|
|
> http://support.microsoft.com/kb/274323
|
|
>
|
|
> I've also heard of problems with QueryPerformanceCounter in multi-processor
|
|
> systems.
|
|
>
|
|
> I know some people SetThreadAffinityMask to 1 for the current thread call
|
|
> their QueryPerformance* functions then restore SetThreadAffinityMask. This
|
|
> seems horrible to me because it forces your program to jump to another
|
|
> physical processor if it isn't already on cpu0 but they claim it worked well
|
|
> in practice because they called the timing functions infrequently.
|
|
>
|
|
> In the past I have chosen to use timeGetTime with timeBeginPeriod(1) for
|
|
> high resolution timers to avoid these issues.
|
|
|
|
*/
|
|
|
|
#ifndef BOOST_CHRONO_SYSTEM_CLOCKS_HPP
|
|
#define BOOST_CHRONO_SYSTEM_CLOCKS_HPP
|
|
|
|
#include <boost/chrono/config.hpp>
|
|
#include <boost/chrono/duration.hpp>
|
|
#include <boost/chrono/time_point.hpp>
|
|
#include <boost/chrono/detail/system.hpp>
|
|
#include <boost/chrono/clock_string.hpp>
|
|
|
|
#include <ctime>
|
|
|
|
# if defined( BOOST_CHRONO_POSIX_API )
|
|
# if ! defined(CLOCK_REALTIME) && ! defined (__hpux__)
|
|
# error <time.h> does not supply CLOCK_REALTIME
|
|
# endif
|
|
# endif
|
|
|
|
#ifdef BOOST_CHRONO_WINDOWS_API
|
|
// The system_clock tick is 100 nanoseconds
|
|
# define BOOST_SYSTEM_CLOCK_DURATION boost::chrono::duration<boost::int_least64_t, ratio<BOOST_RATIO_INTMAX_C(1), BOOST_RATIO_INTMAX_C(10000000)> >
|
|
#else
|
|
# define BOOST_SYSTEM_CLOCK_DURATION boost::chrono::nanoseconds
|
|
#endif
|
|
|
|
// this must occur after all of the includes and before any code appears:
|
|
#ifndef BOOST_CHRONO_HEADER_ONLY
|
|
#include <boost/config/abi_prefix.hpp> // must be the last #include
|
|
#endif
|
|
|
|
|
|
//----------------------------------------------------------------------------//
|
|
// //
|
|
// 20.9 Time utilities [time] //
|
|
// synopsis //
|
|
// //
|
|
//----------------------------------------------------------------------------//
|
|
|
|
namespace boost {
|
|
namespace chrono {
|
|
|
|
// Clocks
|
|
class system_clock;
|
|
#ifdef BOOST_CHRONO_HAS_CLOCK_STEADY
|
|
class steady_clock;
|
|
#endif
|
|
|
|
#ifdef BOOST_CHRONO_HAS_CLOCK_STEADY
|
|
typedef steady_clock high_resolution_clock; // as permitted by [time.clock.hires]
|
|
#else
|
|
typedef system_clock high_resolution_clock; // as permitted by [time.clock.hires]
|
|
#endif
|
|
|
|
//----------------------------------------------------------------------------//
|
|
// //
|
|
// 20.9.5 Clocks [time.clock] //
|
|
// //
|
|
//----------------------------------------------------------------------------//
|
|
|
|
// If you're porting, clocks are the system-specific (non-portable) part.
|
|
// You'll need to know how to get the current time and implement that under now().
|
|
// You'll need to know what units (tick period) and representation makes the most
|
|
// sense for your clock and set those accordingly.
|
|
// If you know how to map this clock to time_t (perhaps your clock is std::time, which
|
|
// makes that trivial), then you can fill out system_clock's to_time_t() and from_time_t().
|
|
|
|
//----------------------------------------------------------------------------//
|
|
// 20.9.5.1 Class system_clock [time.clock.system] //
|
|
//----------------------------------------------------------------------------//
|
|
|
|
class BOOST_CHRONO_DECL system_clock
|
|
{
|
|
public:
|
|
typedef BOOST_SYSTEM_CLOCK_DURATION duration;
|
|
typedef duration::rep rep;
|
|
typedef duration::period period;
|
|
typedef chrono::time_point<system_clock> time_point;
|
|
BOOST_STATIC_CONSTEXPR bool is_steady = false;
|
|
|
|
static BOOST_CHRONO_INLINE time_point now() BOOST_NOEXCEPT;
|
|
#if !defined BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING
|
|
static BOOST_CHRONO_INLINE time_point now(system::error_code & ec);
|
|
#endif
|
|
|
|
static BOOST_CHRONO_INLINE std::time_t to_time_t(const time_point& t) BOOST_NOEXCEPT;
|
|
static BOOST_CHRONO_INLINE time_point from_time_t(std::time_t t) BOOST_NOEXCEPT;
|
|
};
|
|
|
|
//----------------------------------------------------------------------------//
|
|
// 20.9.5.2 Class steady_clock [time.clock.steady] //
|
|
//----------------------------------------------------------------------------//
|
|
|
|
// As permitted by [time.clock.steady]
|
|
// The class steady_clock is conditionally supported.
|
|
|
|
#ifdef BOOST_CHRONO_HAS_CLOCK_STEADY
|
|
class BOOST_CHRONO_DECL steady_clock
|
|
{
|
|
public:
|
|
typedef nanoseconds duration;
|
|
typedef duration::rep rep;
|
|
typedef duration::period period;
|
|
typedef chrono::time_point<steady_clock> time_point;
|
|
BOOST_STATIC_CONSTEXPR bool is_steady = true;
|
|
|
|
static BOOST_CHRONO_INLINE time_point now() BOOST_NOEXCEPT;
|
|
#if !defined BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING
|
|
static BOOST_CHRONO_INLINE time_point now(system::error_code & ec);
|
|
#endif
|
|
};
|
|
#endif
|
|
//----------------------------------------------------------------------------//
|
|
// 20.9.5.3 Class high_resolution_clock [time.clock.hires] //
|
|
//----------------------------------------------------------------------------//
|
|
|
|
// As permitted, steady_clock or system_clock is a typedef for high_resolution_clock.
|
|
// See synopsis.
|
|
|
|
|
|
template<class CharT>
|
|
struct clock_string<system_clock, CharT>
|
|
{
|
|
static std::basic_string<CharT> name()
|
|
{
|
|
static const CharT u[] =
|
|
{ 's', 'y', 's', 't', 'e', 'm', '_', 'c', 'l', 'o', 'c', 'k' };
|
|
static const std::basic_string<CharT> str(u, u + sizeof(u)
|
|
/ sizeof(u[0]));
|
|
return str;
|
|
}
|
|
static std::basic_string<CharT> since()
|
|
{
|
|
static const CharT
|
|
u[] =
|
|
{ ' ', 's', 'i', 'n', 'c', 'e', ' ', 'J', 'a', 'n', ' ', '1', ',', ' ', '1', '9', '7', '0' };
|
|
static const std::basic_string<CharT> str(u, u + sizeof(u)
|
|
/ sizeof(u[0]));
|
|
return str;
|
|
}
|
|
};
|
|
|
|
#ifdef BOOST_CHRONO_HAS_CLOCK_STEADY
|
|
|
|
template<class CharT>
|
|
struct clock_string<steady_clock, CharT>
|
|
{
|
|
static std::basic_string<CharT> name()
|
|
{
|
|
static const CharT
|
|
u[] =
|
|
{ 's', 't', 'e', 'a', 'd', 'y', '_', 'c', 'l', 'o', 'c', 'k' };
|
|
static const std::basic_string<CharT> str(u, u + sizeof(u)
|
|
/ sizeof(u[0]));
|
|
return str;
|
|
}
|
|
static std::basic_string<CharT> since()
|
|
{
|
|
const CharT u[] =
|
|
{ ' ', 's', 'i', 'n', 'c', 'e', ' ', 'b', 'o', 'o', 't' };
|
|
const std::basic_string<CharT> str(u, u + sizeof(u) / sizeof(u[0]));
|
|
return str;
|
|
}
|
|
};
|
|
|
|
#endif
|
|
|
|
} // namespace chrono
|
|
} // namespace boost
|
|
|
|
#ifndef BOOST_CHRONO_HEADER_ONLY
|
|
// the suffix header occurs after all of our code:
|
|
#include <boost/config/abi_suffix.hpp> // pops abi_prefix.hpp pragmas
|
|
#else
|
|
#include <boost/chrono/detail/inlined/chrono.hpp>
|
|
#endif
|
|
|
|
#endif // BOOST_CHRONO_SYSTEM_CLOCKS_HPP
|