// Copyright (c) 2005-2010 Hartmut Kaiser
// Copyright (c) 2009 Edward Grace
//
// 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)
#if !defined(HIGH_RESOLUTION_TIMER_MAR_24_2008_1222PM)
#define HIGH_RESOLUTION_TIMER_MAR_24_2008_1222PM
#include <boost/config.hpp>
#include <boost/throw_exception.hpp>
#if defined(BOOST_HAS_UNISTD_H)
#include <unistd.h>
#endif
#include <time.h>
#include <stdexcept>
#include <limits>
#if defined(BOOST_WINDOWS)
#include <windows.h>
namespace boost {
namespace archive {
namespace xml {
///////////////////////////////////////////////////////////////////////////////
//
// high_resolution_timer
// A timer object measures elapsed time.
// CAUTION: Windows only!
//
///////////////////////////////////////////////////////////////////////////////
class high_resolution_timer
{
public:
high_resolution_timer()
{
restart();
}
high_resolution_timer(double t)
{
LARGE_INTEGER frequency;
if (!QueryPerformanceFrequency(&frequency))
boost::throw_exception(std::runtime_error("Couldn't acquire frequency"));
start_time.QuadPart = (LONGLONG)(t * frequency.QuadPart);
}
high_resolution_timer(high_resolution_timer const& rhs)
: start_time(rhs.start_time)
{
}
static double now()
{
SYSTEMTIME st;
GetSystemTime(&st);
FILETIME ft;
SystemTimeToFileTime(&st, &ft);
LARGE_INTEGER now;
now.LowPart = ft.dwLowDateTime;
now.HighPart = ft.dwHighDateTime;
// FileTime is in 100ns increments, result needs to be in [s]
return now.QuadPart * 1e-7;
}
void restart()
{
if (!QueryPerformanceCounter(&start_time))
boost::throw_exception(std::runtime_error("Couldn't initialize start_time"));
}
double elapsed() const // return elapsed time in seconds
{
LARGE_INTEGER now;
if (!QueryPerformanceCounter(&now))
boost::throw_exception(std::runtime_error("Couldn't get current time"));
LARGE_INTEGER frequency;
if (!QueryPerformanceFrequency(&frequency))
boost::throw_exception(std::runtime_error("Couldn't acquire frequency"));
return double(now.QuadPart - start_time.QuadPart) / frequency.QuadPart;
}
double elapsed_max() const // return estimated maximum value for elapsed()
{
LARGE_INTEGER frequency;
if (!QueryPerformanceFrequency(&frequency))
boost::throw_exception(std::runtime_error("Couldn't acquire frequency"));
return double((std::numeric_limits<LONGLONG>::max)() - start_time.QuadPart) /
double(frequency.QuadPart);
}
double elapsed_min() const // return minimum value for elapsed()
{
LARGE_INTEGER frequency;
if (!QueryPerformanceFrequency(&frequency))
boost::throw_exception(std::runtime_error("Couldn't acquire frequency"));
return 1.0 / frequency.QuadPart;
}
private:
LARGE_INTEGER start_time;
};
} // xml
} // archive
} // boost
#elif defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0 && defined(_POSIX_THREAD_CPUTIME)
#if _POSIX_THREAD_CPUTIME > 0 // timer always supported
namespace boost {
namespace archive {
namespace xml {
///////////////////////////////////////////////////////////////////////////////
//
// high_resolution_timer
// A timer object measures elapsed time.
//
///////////////////////////////////////////////////////////////////////////////
class high_resolution_timer
{
public:
high_resolution_timer()
{
start_time.tv_sec = 0;
start_time.tv_nsec = 0;
restart();
}
high_resolution_timer(double t)
{
start_time.tv_sec = time_t(t);
start_time.tv_nsec = (t - start_time.tv_sec) * 1e9;
}
high_resolution_timer(high_resolution_timer const& rhs)
: start_time(rhs.start_time)
{
}
static double now()
{
timespec now;
if (-1 == clock_gettime(CLOCK_REALTIME, &now))
boost::throw_exception(std::runtime_error("Couldn't get current time"));
return double(now.tv_sec) + double(now.tv_nsec) * 1e-9;
}
void restart()
{
if (-1 == clock_gettime(CLOCK_REALTIME, &start_time))
boost::throw_exception(std::runtime_error("Couldn't initialize start_time"));
}
double elapsed() const // return elapsed time in seconds
{
timespec now;
if (-1 == clock_gettime(CLOCK_REALTIME, &now))
boost::throw_exception(std::runtime_error("Couldn't get current time"));
if (now.tv_sec == start_time.tv_sec)
return double(now.tv_nsec - start_time.tv_nsec) * 1e-9;
return double(now.tv_sec - start_time.tv_sec) +
(double(now.tv_nsec - start_time.tv_nsec) * 1e-9);
}
double elapsed_max() const // return estimated maximum value for elapsed()
{
return double((std::numeric_limits<time_t>::max)() - start_time.tv_sec);
}
double elapsed_min() const // return minimum value for elapsed()
{
timespec resolution;
if (-1 == clock_getres(CLOCK_REALTIME, &resolution))
boost::throw_exception(std::runtime_error("Couldn't get resolution"));
return double(resolution.tv_sec + resolution.tv_nsec * 1e-9);
}
private:
timespec start_time;
};
} // xml
} // archive
} // boost
#else // _POSIX_THREAD_CPUTIME > 0
#include <boost/timer.hpp>
// availability of high performance timers must be checked at runtime
namespace boost {
namespace archive {
namespace xml {
///////////////////////////////////////////////////////////////////////////////
//
// high_resolution_timer
// A timer object measures elapsed time.
//
///////////////////////////////////////////////////////////////////////////////
class high_resolution_timer
{
public:
high_resolution_timer()
: use_backup(sysconf(_SC_THREAD_CPUTIME) <= 0)
{
if (!use_backup) {
start_time.tv_sec = 0;
start_time.tv_nsec = 0;
}
restart();
}
high_resolution_timer(double t)
: use_backup(sysconf(_SC_THREAD_CPUTIME) <= 0)
{
if (!use_backup) {
start_time.tv_sec = time_t(t);
start_time.tv_nsec = (t - start_time.tv_sec) * 1e9;
}
}
high_resolution_timer(high_resolution_timer const& rhs)
: use_backup(sysconf(_SC_THREAD_CPUTIME) <= 0),
start_time(rhs.start_time)
{
}
static double now()
{
if (sysconf(_SC_THREAD_CPUTIME) <= 0)
return double(std::clock());
timespec now;
if (-1 == clock_gettime(CLOCK_REALTIME, &now))
boost::throw_exception(std::runtime_error("Couldn't get current time"));
return double(now.tv_sec) + double(now.tv_nsec) * 1e-9;
}
void restart()
{
if (use_backup)
start_time_backup.restart();
else if (-1 == clock_gettime(CLOCK_REALTIME, &start_time))
boost::throw_exception(std::runtime_error("Couldn't initialize start_time"));
}
double elapsed() const // return elapsed time in seconds
{
if (use_backup)
return start_time_backup.elapsed();
timespec now;
if (-1 == clock_gettime(CLOCK_REALTIME, &now))
boost::throw_exception(std::runtime_error("Couldn't get current time"));
if (now.tv_sec == start_time.tv_sec)
return double(now.tv_nsec - start_time.tv_nsec) * 1e-9;
return double(now.tv_sec - start_time.tv_sec) +
(double(now.tv_nsec - start_time.tv_nsec) * 1e-9);
}
double elapsed_max() const // return estimated maximum value for elapsed()
{
if (use_backup)
start_time_backup.elapsed_max();
return double((std::numeric_limits<time_t>::max)() - start_time.tv_sec);
}
double elapsed_min() const // return minimum value for elapsed()
{
if (use_backup)
start_time_backup.elapsed_min();
timespec resolution;
if (-1 == clock_getres(CLOCK_REALTIME, &resolution))
boost::throw_exception(std::runtime_error("Couldn't get resolution"));
return double(resolution.tv_sec + resolution.tv_nsec * 1e-9);
}
private:
bool use_backup;
timespec start_time;
boost::timer start_time_backup;
};
} // xml
} // archive
} // boost
#endif // _POSIX_THREAD_CPUTIME > 0
#else // !defined(BOOST_WINDOWS) && (!defined(_POSIX_TIMERS)
// || _POSIX_TIMERS <= 0
// || !defined(_POSIX_THREAD_CPUTIME)
// || _POSIX_THREAD_CPUTIME <= 0)
#if defined(BOOST_HAS_GETTIMEOFDAY)
// For platforms that do not support _POSIX_TIMERS but do have
// GETTIMEOFDAY, which is still preferable to std::clock()
#include <sys/time.h>
namespace boost {
namespace archive {
namespace xml {
///////////////////////////////////////////////////////////////////////////
//
// high_resolution_timer
// A timer object measures elapsed time.
//
// Implemented with gettimeofday() for platforms that support it,
// such as Darwin (OS X) but do not support the previous options.
//
// Copyright (c) 2009 Edward Grace
//
///////////////////////////////////////////////////////////////////////////
class high_resolution_timer
{
private:
template <typename U>
static inline double unsigned_diff(const U &a, const U &b)
{
if (a > b)
return static_cast<double>(a-b);
return -static_cast<double>(b-a);
}
// @brief Return the difference between two timeval types.
//
// @param t1 The most recent timeval.
// @param t0 The historical timeval.
//
// @return The difference between the two in seconds.
double elapsed(const timeval &t1, const timeval &t0) const
{
if (t1.tv_sec == t0.tv_sec)
return unsigned_diff(t1.tv_usec,t0.tv_usec) * 1e-6;
// We do it this way as the result of the difference of the
// microseconds can be negative if the clock is implemented so
// that the seconds timer increases in large steps.
//
// Naive subtraction of the unsigned types and conversion to
// double can wreak havoc!
return unsigned_diff(t1.tv_sec,t0.tv_sec) +
unsigned_diff(t1.tv_usec,t0.tv_usec) * 1e-6;
}
public:
high_resolution_timer()
{
start_time.tv_sec = 0;
start_time.tv_usec = 0;
restart();
}
high_resolution_timer(double t)
{
start_time.tv_sec = time_t(t);
start_time.tv_usec = (t - start_time.tv_sec) * 1e6;
}
high_resolution_timer(high_resolution_timer const& rhs)
: start_time(rhs.start_time)
{
}
static double now()
{
// Under some implementations gettimeofday() will always
// return zero. If it returns anything else however then
// we accept this as evidence of an error. Note we are
// not assuming that -1 explicitly indicates the error
// condition, just that non zero is indicative of the
// error.
timeval now;
if (gettimeofday(&now, NULL))
boost::throw_exception(std::runtime_error("Couldn't get current time"));
return double(now.tv_sec) + double(now.tv_usec) * 1e-6;
}
void restart()
{
if (gettimeofday(&start_time, NULL))
boost::throw_exception(std::runtime_error("Couldn't initialize start_time"));
}
double elapsed() const // return elapsed time in seconds
{
timeval now;
if (gettimeofday(&now, NULL))
boost::throw_exception(std::runtime_error("Couldn't get current time"));
return elapsed(now,start_time);
}
double elapsed_max() const // return estimated maximum value for elapsed()
{
return double((std::numeric_limits<time_t>::max)() - start_time.tv_sec);
}
double elapsed_min() const // return minimum value for elapsed()
{
// On systems without an explicit clock_getres or similar
// we can only estimate an upper bound on the resolution
// by repeatedly calling the gettimeofday function. This
// is often likely to be indicative of the true
// resolution.
timeval t0, t1;
double delta(0);
if (gettimeofday(&t0, NULL))
boost::throw_exception(std::runtime_error("Couldn't get resolution."));
// Spin around in a tight loop until we observe a change
// in the reported timer value.
do {
if (gettimeofday(&t1, NULL))
boost::throw_exception(std::runtime_error("Couldn't get resolution."));
delta = elapsed(t1, t0);
} while (delta <= 0.0);
return delta;
}
private:
timeval start_time;
};
} // xml
} // archive
} // boost
#else // BOOST_HAS_GETTIMEOFDAY
// For platforms other than Windows or Linux, or not implementing gettimeofday
// simply fall back to boost::timer
#include <boost/timer.hpp>
namespace boost {
namespace archive {
namespace xml {
struct high_resolution_timer
: boost::timer
{
static double now()
{
return double(std::clock());
}
};
} // xml
} // archive
} // boost
#endif
#endif
#endif // HIGH_RESOLUTION_TIMER_AUG_14_2009_0425PM
//
// $Log: high_resolution_timer.hpp,v $
// Revision 1.4 2009/08/14 15:28:10 graceej
// * It is entirely possible for the updating clock to increment the
// * seconds and *decrement* the microseconds field. Consequently
// * when subtracting these unsigned microseconds fields a wrap-around
// * error can occur. For this reason elapsed(t1, t0) is used in a
// * similar maner to cycle.h this preserves the sign of the
// * difference.
//
