Squashed 'third_party/boostorg/serialization/' content from commit 738695b
Change-Id: I48528198ad1f62b90288d249eb2243d4db02fd5d
git-subtree-dir: third_party/boostorg/serialization
git-subtree-split: 738695b70733f9d592a570fb17a505d6a029b48a
diff --git a/performance/xml/high_resolution_timer.hpp b/performance/xml/high_resolution_timer.hpp
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+// 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.
+//