From: nobu@...
Date: 2006-07-06T11:46:15+09:00
Subject: Re: bug in Process.times?

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();


-- 
Nobu Nakada