From: Daniel Berger <djberg96@...>
Date: 2006-07-06T12:17:30+09:00
Subject: Re: bug in Process.times?

nobu@ruby-lang.org wrote:
> Hi,
>
> At Thu, 6 Jul 2006 08:59:02 +0900,
> Robert Joseph Sheehan wrote in [ruby-talk:200293]:
>   
>> Unfortunately on several versions of Linux I have tried, including the
>> latest Fedora and Ubuntu, this seems to give a HZ value of 60 rather
>> than the correct 100, from "getconf CLK_TCK". (I haven't looked any
>> further into the Ruby source to examine other places the constants may
>> be set.)
>>
>> If I correct for this, my benchmark times now make complete sense with
>> real time closely approximating user+system times on a lightly loaded
>> system.
>>
>> Is this a bug or have I overlooked something?
>>     
>
> Seems a bug.
>
> 
> Index: configure.in
> ===================================================================
> RCS file: /cvs/ruby/src/ruby/configure.in,v
> retrieving revision 1.304
> diff -p -u -2 -r1.304 configure.in
> --- configure.in	1 Jul 2006 16:40:13 -0000	1.304
> +++ configure.in	6 Jul 2006 02:26:37 -0000
> @@ -511,5 +511,5 @@ AC_CHECK_FUNCS(fmod killpg wait4 waitpid
>  	      setrgid setegid setregid setresgid issetugid pause lchown lchmod\
>  	      getpgrp setpgrp getpgid setpgid initgroups getgroups setgroups\
> -	      getpriority getrlimit setrlimit\
> +	      getpriority getrlimit setrlimit sysconf\
>  	      dlopen sigprocmask sigaction _setjmp vsnprintf snprintf\
>  	      setsid telldir seekdir fchmod mktime timegm cosh sinh tanh log2\
> @@ -729,4 +729,20 @@ if test $rb_cv_huge_st_ino = yes; then
>  fi
>  
> +if test "$ac_cv_func_sysconf" = yes; then
> +  AC_DEFUN(RUBY_CHECK_SYSCONF, [dnl
> +  AC_CACHE_CHECK([whether _SC_$1 is supported], rb_cv_have_sc_[]m4_tolower($1),
> +    [AC_TRY_COMPILE([#include <unistd.h>
> +      ],
> +      [_SC_$1 >= 0],
> +      rb_cv_have_sc_[]m4_tolower($1)=yes,
> +      rb_cv_have_sc_[]m4_tolower($1)=no)
> +    ])
> +  if test "$rb_cv_have_sc_[]m4_tolower($1)" = yes; then
> +    AC_DEFINE(HAVE__SC_$1)
> +  fi
> +  ])
> +  RUBY_CHECK_SYSCONF(CLK_TCK)
> +fi
> +
>  case "$target_cpu" in
>  m68*|i?86|ia64|sparc*|alpha*) rb_cv_stack_grow_dir=-1;;
> Index: process.c
> ===================================================================
> RCS file: /cvs/ruby/src/ruby/process.c,v
> retrieving revision 1.145
> diff -p -u -2 -r1.145 process.c
> --- process.c	15 Jun 2006 06:43:17 -0000	1.145
> +++ process.c	6 Jul 2006 02:33:23 -0000
> @@ -3517,4 +3517,8 @@ rb_proc_times(VALUE obj)
>  {
>  #if defined(HAVE_TIMES) && !defined(__CHECKER__)
> +    const double hz =
> +#ifdef HAVE__SC_CLK_TCK
> +	(double)sysconf(_SC_CLK_TCK);
> +#else
>  #ifndef HZ
>  # ifdef CLK_TCK
> @@ -3524,4 +3528,6 @@ rb_proc_times(VALUE obj)
>  # endif
>  #endif /* HZ */
> +	HZ;
> +#endif
>      struct tms buf;
>      volatile VALUE utime, stime, cutime, sctime;
> @@ -3529,8 +3535,8 @@ rb_proc_times(VALUE obj)
>      times(&buf);
>      return rb_struct_new(S_Tms,
> -			 utime = rb_float_new((double)buf.tms_utime / HZ),
> -			 stime = rb_float_new((double)buf.tms_stime / HZ),
> -			 cutime = rb_float_new((double)buf.tms_cutime / HZ),
> -			 sctime = rb_float_new((double)buf.tms_cstime / HZ));
> +			 utime = rb_float_new(buf.tms_utime / hz),
> +			 stime = rb_float_new(buf.tms_stime / hz),
> +			 cutime = rb_float_new(buf.tms_cutime / hz),
> +			 sctime = rb_float_new(buf.tms_cstime / hz));
>  #else
>      rb_notimplement();
> 
>
>   
Shouldn't we try sysconf(CLOCKS_PER_SEC) if _SC_CLK_TCK isn't defined first?

- Dan