libstdc++-v3/src/chrono.cc

   1 // chrono -*- C++ -*-
   2
   3 // Copyright (C) 2008 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 #include <chrono>
  31
  32 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
  33
  34 // conditional inclusion of sys/time.h for gettimeofday
  35 #if !defined(_GLIBCXX_USE_CLOCK_MONOTONIC) && \
  36     !defined(_GLIBCXX_USE_CLOCK_REALTIME) && \
  37      defined(_GLIBCXX_USE_GETTIMEOFDAY)
  38 #include <sys/time.h>
  39 #endif
  40
  41 namespace std
  42 {
  43   namespace chrono
  44   {
  45     const bool system_clock::is_monotonic;
  46
  47     system_clock::time_point
  48     system_clock::now()
  49     {
  50 #ifdef _GLIBCXX_USE_CLOCK_REALTIME
  51       timespec tp;
  52       // -EINVAL, -EFAULT
  53       clock_gettime(CLOCK_REALTIME, &tp);
  54       return time_point(duration(chrono::seconds(tp.tv_sec)
  55                                  + chrono::nanoseconds(tp.tv_nsec)));
  56 #elif defined(_GLIBCXX_USE_GETTIMEOFDAY)
  57       timeval tv;
  58       // EINVAL, EFAULT
  59       gettimeofday(&tv, NULL);
  60       return time_point(duration(chrono::seconds(tv.tv_sec)
  61                                  + chrono::microseconds(tv.tv_usec)));
  62 #else
  63       std::time_t __sec = std::time(0);
  64       return system_clock::from_time_t(__sec);
  65 #endif
  66     }
  67
  68 #ifdef _GLIBCXX_USE_CLOCK_MONOTONIC
  69     const bool monotonic_clock::is_monotonic;
  70
  71     monotonic_clock::time_point
  72     monotonic_clock::now()
  73     {
  74       timespec tp;
  75       // -EINVAL, -EFAULT
  76       clock_gettime(CLOCK_MONOTONIC, &tp);
  77       return time_point(duration(chrono::seconds(tp.tv_sec)
  78                                  + chrono::nanoseconds(tp.tv_nsec)));
  79     }
  80 #endif
  81   }
  82 }
  83
  84 #endif // _GLIBCXX_USE_C99_STDINT_TR1