gold/timer.cc

   1 // timer.cc -- helper class for time accounting
   2
   3 // Copyright 2009 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 #include <sys/times.h>
  26
  27 #include "libiberty.h"
  28
  29 #include "timer.h"
  30
  31 namespace gold
  32 {
  33
  34 // Class Timer
  35
  36 Timer::Timer()
  37 {
  38   this->start_time_.wall = 0;
  39   this->start_time_.user = 0;
  40   this->start_time_.sys = 0;
  41 }
  42
  43 // Start couting the time.
  44 void
  45 Timer::start ()
  46 {
  47   this->get_time(&this->start_time_);
  48 }
  49
  50 #if HAVE_SYSCONF && defined _SC_CLK_TCK
  51 # define TICKS_PER_SECOND sysconf (_SC_CLK_TCK) /* POSIX 1003.1-1996 */
  52 #else
  53 # ifdef CLK_TCK
  54 #  define TICKS_PER_SECOND CLK_TCK /* POSIX 1003.1-1988; obsolescent */
  55 # else
  56 #  ifdef HZ
  57 #   define TICKS_PER_SECOND HZ  /* traditional UNIX */
  58 #  else
  59 #   define TICKS_PER_SECOND 100 /* often the correct value */
  60 #  endif
  61 # endif
  62 #endif
  63
  64 // times returns statistics in clock_t units. This variable will hold the
  65 // conversion factor to seconds. We use a variable that is initialize once
  66 // because sysconf can be slow.
  67 static long ticks_per_sec;
  68 class Timer_init
  69 {
  70  public:
  71   Timer_init()
  72   {
  73     ticks_per_sec = TICKS_PER_SECOND;
  74   }
  75 };
  76 Timer_init timer_init;
  77
  78 // Write the current time infortamion.
  79 void
  80 Timer::get_time (TimeStats *now)
  81 {
  82 #ifdef HAVE_TIMES
  83   tms t;
  84   now->wall = (times(&t) * 1000) / ticks_per_sec;
  85   now->user = (t.tms_utime * 1000) / ticks_per_sec;
  86   now->sys  = (t.tms_stime * 1000) / ticks_per_sec;
  87 #else
  88   now->wall = get_run_time() / 1000;
  89   now->user = 0;
  90   now->sys = 0;
  91 #endif
  92 }
  93
  94 // Return the stats since start was called.
  95 Timer::TimeStats
  96 Timer::get_elapsed_time ()
  97 {
  98   TimeStats now;
  99   this->get_time(&now);
 100   TimeStats delta;
 101   delta.wall = now.wall - this->start_time_.wall;
 102   delta.user = now.user - this->start_time_.user;
 103   delta.sys = now.sys - this->start_time_.sys;
 104   return delta;
 105 }
 106
 107 }