[src/trunk]: src/lib/libc/gen make sysconf(_SC_CLK_TCK) return the kernel hz ...

[perry <perry%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1be0c8bb68af
branches:  trunk
changeset: 533172:1be0c8bb68af
user:      perry <perry%NetBSD.org@localhost>
date:      Sun Jun 23 19:19:01 2002 +0000

description:
make sysconf(_SC_CLK_TCK) return the kernel hz value, instead of a
fixed constant, as is done on Solaris, Linux, etc.

Technically, standards don't *require* this, but having it return a
constant is a violation of the spirit, and screws up programs that
(perhaps improperly) assume that it will return kernel hz.

diffstat:

 lib/libc/gen/sysconf.c |  22 +++++++++++++++++++---
 1 files changed, 19 insertions(+), 3 deletions(-)

diffs (50 lines):

diff -r f187322fd635 -r 1be0c8bb68af lib/libc/gen/sysconf.c
--- a/lib/libc/gen/sysconf.c    Sun Jun 23 19:16:43 2002 +0000
+++ b/lib/libc/gen/sysconf.c    Sun Jun 23 19:19:01 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sysconf.c,v 1.14 2002/01/31 00:32:47 kleink Exp $      */
+/*     $NetBSD: sysconf.c,v 1.15 2002/06/23 19:19:01 perry Exp $       */
 
 /*-
  * Copyright (c) 1993
@@ -41,7 +41,7 @@
 #if 0
 static char sccsid[] = "@(#)sysconf.c  8.2 (Berkeley) 3/20/94";
 #else
-__RCSID("$NetBSD: sysconf.c,v 1.14 2002/01/31 00:32:47 kleink Exp $");
+__RCSID("$NetBSD: sysconf.c,v 1.15 2002/06/23 19:19:01 perry Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -78,6 +78,8 @@
        struct rlimit rl;
        size_t len;
        int mib[2], value;
+       struct clockinfo tmpclock;
+       static int clk_tck;
 
        len = sizeof(value);
 
@@ -90,7 +92,21 @@
        case _SC_CHILD_MAX:
                return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur);
        case _SC_CLK_TCK:
-               return (CLK_TCK);
+               /*
+                * Has to be handled specially because it returns a
+                * struct clockinfo instead of an integer. Also, since
+                * this might be called often by some things that
+                * don't grok CLK_TCK can be a macro expanding to a
+                * function, cache the value.
+                */
+               if (clk_tck == 0) {
+                       mib[0] = CTL_KERN;
+                       mib[1] = KERN_CLOCKRATE;
+                       len = sizeof(struct clockinfo);
+                       clk_tck = sysctl(mib, 2, &tmpclock, &len, NULL, 0)
+                           == -1 ? -1 : tmpclock.hz;
+               }
+               return(clk_tck);
        case _SC_JOB_CONTROL:
                mib[0] = CTL_KERN;
                mib[1] = KERN_JOB_CONTROL;