From bbad54b2ee48cd3c33ea359be2f57a01528e4834 Mon Sep 17 00:00:00 2001
From: Chris Hanson <org/chris-hanson/cph>
Date: Thu, 16 Aug 1990 22:33:54 +0000
Subject: [PATCH] Add memoization to `UX_SC_CLK_TCK'.

---
 v7/src/microcode/ux.c | 12 +++++++++++-
 v7/src/microcode/ux.h |  4 ++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/v7/src/microcode/ux.c b/v7/src/microcode/ux.c
index cafcdd2a6..6ce4ec89d 100644
--- a/v7/src/microcode/ux.c
+++ b/v7/src/microcode/ux.c
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/ux.c,v 1.1 1990/06/20 19:36:57 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/ux.c,v 1.2 1990/08/16 22:33:42 cph Exp $
 
 Copyright (c) 1990 Massachusetts Institute of Technology
 
@@ -400,4 +400,14 @@ DEFUN (UX_PC_VDISABLE, (fildes), int fildes)
      : result);
 }
 
+static clock_t memoized_clk_tck = 0;
+
+clock_t
+DEFUN_VOID (UX_SC_CLK_TCK)
+{
+  if (memoized_clk_tck == 0)
+    memoized_clk_tck = ((clock_t) (sysconf (_SC_CLK_TCK)));
+  return (memoized_clk_tck);
+}
+
 #endif /* _POSIX */
diff --git a/v7/src/microcode/ux.h b/v7/src/microcode/ux.h
index e2f5c652b..fb7721c63 100644
--- a/v7/src/microcode/ux.h
+++ b/v7/src/microcode/ux.h
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/ux.h,v 1.8 1990/08/10 02:13:28 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/ux.h,v 1.9 1990/08/16 22:33:54 cph Exp $
 
 Copyright (c) 1988, 1989, 1990 Massachusetts Institute of Technology
 
@@ -747,9 +747,9 @@ extern int EXFUN (UX_kill, (pid_t pid, int sig));
 #ifdef _POSIX
 
 extern cc_t EXFUN (UX_PC_VDISABLE, (int fildes));
+extern clock_t EXFUN (UX_SC_CLK_TCK, (void));
 #define UX_SC_OPEN_MAX() ((size_t) (sysconf (_SC_OPEN_MAX)))
 #define UX_SC_CHILD_MAX() ((size_t) (sysconf (_SC_CHILD_MAX)))
-#define UX_SC_CLK_TCK() ((clock_t) (sysconf (_SC_CLK_TCK)))
 
 #ifdef _POSIX_JOB_CONTROL
 #define UX_SC_JOB_CONTROL() 1
-- 
2.25.1