gold/timer.cc

   1 // timer.cc -- helper class for time accounting
   2
   3 // Copyright 2009, 2010 Free Software Foundation, Inc.
   4 // Written by Rafael Avila de Espindola <espindola@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #ifdef HAVE_TIMES
  26 #include <sys/times.h>
  27 #endif
  28
  29 #include "libiberty.h"
  30
  31 #include "timer.h"
  32
  33 namespace gold
  34 {
  35
  36 // Class Timer
  37
  38 Timer::Timer()
  39 {
  40   this->start_time_.wall = 0;
  41   this->start_time_.user = 0;
  42   this->start_time_.sys = 0;
  43 }
  44
  45 // Start counting the time.
  46 void
  47 Timer::start()
  48 {
  49   this->get_time(&this->start_time_);
  50 }
  51
  52 #if HAVE_SYSCONF && defined _SC_CLK_TCK
  53 # define TICKS_PER_SECOND sysconf (_SC_CLK_TCK) /* POSIX 1003.1-1996 */
  54 #else
  55 # ifdef CLK_TCK
  56 #  define TICKS_PER_SECOND CLK_TCK /* POSIX 1003.1-1988; obsolescent */
  57 # else
  58 #  ifdef HZ
  59 #   define TICKS_PER_SECOND HZ  /* traditional UNIX */
  60 #  else
  61 #   define TICKS_PER_SECOND 100 /* often the correct value */
  62 #  endif
  63 # endif
  64 #endif
  65
  66 // times returns statistics in clock_t units.  This variable will hold the
  67 // conversion factor to seconds.  We use a variable that is initialized once
  68 // because sysconf can be slow.
  69 static long ticks_per_sec;
  70 class Timer_init
  71 {
  72  public:
  73   Timer_init()
  74   {
  75     ticks_per_sec = TICKS_PER_SECOND;
  76   }
  77 };
  78 Timer_init timer_init;
  79
  80 // Write the current time information.
  81 void
  82 Timer::get_time(TimeStats *now)
  83 {
  84 #ifdef HAVE_TIMES
  85   tms t;
  86   now->wall = (times(&t) * 1000) / ticks_per_sec;
  87   now->user = (t.tms_utime * 1000) / ticks_per_sec;
  88   now->sys  = (t.tms_stime * 1000) / ticks_per_sec;
  89 #else
  90   now->wall = get_run_time() / 1000;
  91   now->user = 0;
  92   now->sys = 0;
  93 #endif
  94 }
  95
  96 // Return the stats since start was called.
  97 Timer::TimeStats
  98 Timer::get_elapsed_time()
  99 {
 100   TimeStats now;
 101   this->get_time(&now);
 102   TimeStats delta;
 103   delta.wall = now.wall - this->start_time_.wall;
 104   delta.user = now.user - this->start_time_.user;
 105   delta.sys = now.sys - this->start_time_.sys;
 106   return delta;
 107 }
 108
 109 }