From 9e0686be39cdcfc5aea3910f774dd7ad75618f47 Mon Sep 17 00:00:00 2001
From: Mark Friedman <edu/mit/csail/zurich/markf>
Date: Tue, 8 Oct 1991 21:46:43 +0000
Subject: [PATCH] Cached the current working directory to avoid needless calls
 to the unix getcwd. It is put here, so that the call to get_wd() in options.c
 will cause the cache to fill BEFORE the heap and constant spaces get
 allocated. This way it is much more likely that the fork that getcwd tries to
 do will be successful.

---
 v7/src/microcode/uxenv.c | 46 ++++++++++++++++++++++++++++------------
 1 file changed, 33 insertions(+), 13 deletions(-)

diff --git a/v7/src/microcode/uxenv.c b/v7/src/microcode/uxenv.c
index ddb92eb70..4f2269698 100644
--- a/v7/src/microcode/uxenv.c
+++ b/v7/src/microcode/uxenv.c
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/uxenv.c,v 1.5 1991/07/31 14:37:20 jinx Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/uxenv.c,v 1.6 1991/10/08 21:46:43 markf Exp $
 
 Copyright (c) 1990-91 Massachusetts Institute of Technology
 
@@ -265,32 +265,37 @@ DEFUN_VOID (UX_initialize_environment)
 #endif
 }
 
+static size_t current_dir_path_size = 0;
+static char * current_dir_path = 0;
+
 CONST char *
 DEFUN_VOID (OS_working_dir_pathname)
 {
-  static size_t path_size = 0;
-  static char * path;
-  if (path_size == 0)
+  if (current_dir_path) {
+    return (current_dir_path);
+  }
+  if (current_dir_path_size == 0)
     {
-      path = (UX_malloc (1024));
-      if (path == 0)
+      current_dir_path = (UX_malloc (1024));
+      if (current_dir_path == 0)
 	error_system_call (ENOMEM, syscall_malloc);
-      path_size = 1024;
+      current_dir_path_size = 1024;
     }
   while (1)
     {
-      if ((UX_getcwd (path, path_size)) != 0)
-	return (path);
+      if ((UX_getcwd (current_dir_path, current_dir_path_size)) != 0)
+	return (current_dir_path);
       if (errno != ERANGE)
 	error_system_call (errno, syscall_getcwd);
-      path_size *= 2;
+      current_dir_path_size *= 2;
       {
-	char * new_path = (UX_realloc (path, path_size));
-	if (new_path == 0)
+	char * new_current_dir_path =
+	  (UX_realloc (current_dir_path, current_dir_path_size));
+	if (new_current_dir_path == 0)
 	  /* ANSI C requires `path' to be unchanged -- we may have to
 	     discard it for systems that don't behave thus. */
 	  error_system_call (ENOMEM, syscall_realloc);
-	path = new_path;
+	current_dir_path = new_current_dir_path;
       }
     }
 }
@@ -298,7 +303,22 @@ DEFUN_VOID (OS_working_dir_pathname)
 void
 DEFUN (OS_set_working_dir_pathname, (name), CONST char * name)
 {
+  size_t name_size = strlen (name);
   STD_VOID_SYSTEM_CALL (syscall_chdir, (UX_chdir (name)));
+  while (1) {
+    if (name_size < current_dir_path_size) {
+      strcpy(current_dir_path, name);
+      return;
+    } 
+    current_dir_path_size *= 2;
+    {
+      char * new_current_dir_path =
+	(UX_realloc (current_dir_path, current_dir_path_size));
+      if (new_current_dir_path == 0)
+	error_system_call (ENOMEM, syscall_realloc);
+      current_dir_path = new_current_dir_path;
+    }
+  }
 }
 
 CONST char *
-- 
2.25.1