From: Mark Friedman <edu/mit/csail/zurich/markf>
Date: Tue, 8 Oct 1991 21:46:43 +0000 (+0000)
Subject: Cached the current working directory to avoid needless calls to the
X-Git-Tag: 20090517-FFI~10164
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=9e0686be39cdcfc5aea3910f774dd7ad75618f47;p=mit-scheme.git

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.
---

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 *