From a21e8a31e8ee43f5f22f023e9bee8a58d1109500 Mon Sep 17 00:00:00 2001
From: Matt Birkholz <puck@birchwood-abbey.net>
Date: Fri, 5 Dec 2014 18:00:34 -0700
Subject: [PATCH] smp: share: uxenv.o

---
 README.txt            | 14 ++++++++------
 src/microcode/uxenv.c | 45 ++++++++++++++++++++++++++++++++++---------
 2 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/README.txt b/README.txt
index 935db9c81..b6ededa62 100644
--- a/README.txt
+++ b/README.txt
@@ -671,12 +671,14 @@ command line.  The remaining 12 belong to the 7 microcode modules and
 	simultaneous threads can cause a ruckus, but otherwise... OK.
 
   uxenv.o:
-  00000010 b current_dir_path
-  0000000c b current_dir_path_size
-  00000000 b initial_process_clock
-  00000004 b initial_rtc
-  00000000 d utc_epoch_minus_unix_epoch
-  00000020 b zero_tx.8640
+  00000010 b current_dir_path		locked
+  0000000c b current_dir_path_size	locked
+  00000000 b initial_process_clock	read-only, initialize_process_clock
+  00000004 b initial_rtc		read-only, initialize_real_time_clock
+  00000000 d utc_epoch_minus_unix_epoch	read-only
+  00000020 b zero_tx.8640		read-only
+
+	OK.
 
   uxfile.o:
 
diff --git a/src/microcode/uxenv.c b/src/microcode/uxenv.c
index 5ef35e0d3..d0c546fde 100644
--- a/src/microcode/uxenv.c
+++ b/src/microcode/uxenv.c
@@ -24,7 +24,6 @@ USA.
 
 */
 
-#include "scheme.h"
 #include "prims.h"
 #include "ux.h"
 #include "osenv.h"
@@ -622,25 +621,45 @@ UX_initialize_environment (void)
 static size_t current_dir_path_size = 0;
 static char * current_dir_path = 0;
 
+#ifdef ENABLE_SMP
+static pthread_mutex_t mutex = MUTEX_INITIALIZER;
+#  ifdef ENABLE_DEBUGGING_TOOLS
+static bool locked_p = false;
+#  endif
+#endif
+
 const char *
 OS_working_dir_pathname (void)
 {
-  if (current_dir_path) {
-    return (current_dir_path);
-  }
+  LOCK();
+  if (current_dir_path)
+    {
+      char *p = current_dir_path;
+      UNLOCK();
+      return (p);
+    }
   if (current_dir_path_size == 0)
     {
       current_dir_path = (UX_malloc (1024));
       if (current_dir_path == 0)
-	error_system_call (ENOMEM, syscall_malloc);
+	{
+	  UNLOCK();
+	  error_system_call (ENOMEM, syscall_malloc);
+	}
       current_dir_path_size = 1024;
     }
   while (1)
     {
       if ((UX_getcwd (current_dir_path, current_dir_path_size)) != 0)
-	return (current_dir_path);
+	{
+	  UNLOCK();
+	  return (current_dir_path);
+	}
       if (errno != ERANGE)
-	error_system_call (errno, syscall_getcwd);
+	{
+	  UNLOCK();
+	  error_system_call (errno, syscall_getcwd);
+	}
       current_dir_path_size *= 2;
       {
 	char * new_current_dir_path =
@@ -648,7 +667,10 @@ OS_working_dir_pathname (void)
 	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);
+	  {
+	    UNLOCK();
+	    error_system_call (ENOMEM, syscall_realloc);
+	  }
 	current_dir_path = new_current_dir_path;
       }
     }
@@ -658,10 +680,12 @@ void
 OS_set_working_dir_pathname (const char * name)
 {
   size_t name_size = strlen (name);
+  LOCK();
   STD_VOID_SYSTEM_CALL (syscall_chdir, (UX_chdir (name)));
   while (1) {
     if (name_size < current_dir_path_size) {
       strcpy(current_dir_path, name);
+      UNLOCK();
       return;
     }
     current_dir_path_size *= 2;
@@ -669,7 +693,10 @@ OS_set_working_dir_pathname (const char * name)
       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);
+	{
+	  UNLOCK();
+	  error_system_call (ENOMEM, syscall_realloc);
+	}
       current_dir_path = new_current_dir_path;
     }
   }
-- 
2.25.1