From: Matt Birkholz <puck@birchwood-abbey.net>
Date: Sat, 20 Dec 2014 21:34:56 +0000 (-0700)
Subject: smp: share: uxfs.o
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=d4b4a9b877c4c58984d215e7796d420014f1654f;p=mit-scheme.git

smp: share: uxfs.o
---

diff --git a/README.txt b/README.txt
index b6ededa62..5690b41df 100644
--- a/README.txt
+++ b/README.txt
@@ -683,8 +683,12 @@ command line.  The remaining 12 belong to the 7 microcode modules and
   uxfile.o:
 
   uxfs.o:
-  00000000 b directory_pointers
-  00000004 b n_directory_pointers
+  00000000 b directory_pointers		locked
+  00000004 b n_directory_pointers	locked
+
+	OK.  The directory_pointers table is managed much like the
+	channel_table and is locked up in the same way.  (Just the
+	writers are required to serialize.)
 
   uxio.o:
   00000004 C OS_channel_table_size
diff --git a/src/microcode/uxfs.c b/src/microcode/uxfs.c
index 2f03cfd69..e56a67dc2 100644
--- a/src/microcode/uxfs.c
+++ b/src/microcode/uxfs.c
@@ -24,7 +24,7 @@ USA.
 
 */
 
-#include "scheme.h"
+#include "prims.h"
 #include "ux.h"
 #include "osfs.h"
 #include "osfile.h"
@@ -122,6 +122,13 @@ USA.
 #ifndef FILE_TOUCH_OPEN_TRIES
 #  define FILE_TOUCH_OPEN_TRIES 5
 #endif
+
+#ifdef ENABLE_SMP
+static pthread_mutex_t mutex = MUTEX_INITIALIZER;
+#  ifdef ENABLE_DEBUGGING_TOOLS
+static bool locked_p = false;
+#  endif
+#endif
 
 #define STAT_SYSTEM_CALL(name, expression, if_failure)	\
   do {							\
@@ -548,6 +555,7 @@ UX_initialize_directory_reader (void)
 static unsigned int
 allocate_directory_pointer (DIR * pointer)
 {
+  LOCK ();
   if (n_directory_pointers == 0)
     {
       DIR ** pointers = ((DIR **) (UX_malloc ((sizeof (DIR *)) * 4)));
@@ -562,6 +570,7 @@ allocate_directory_pointer (DIR * pointer)
 	while (scan < end)
 	  (*scan++) = 0;
       }
+      UNLOCK();
       return (0);
     }
   {
@@ -571,6 +580,7 @@ allocate_directory_pointer (DIR * pointer)
       if ((*scan++) == 0)
 	{
 	  (*--scan) = pointer;
+	  UNLOCK();
 	  return (scan - directory_pointers);
 	}
   }
@@ -582,7 +592,10 @@ allocate_directory_pointer (DIR * pointer)
        (UX_realloc (((void *) directory_pointers),
 		    ((sizeof (DIR *)) * n_pointers))));
     if (pointers == 0)
-      error_system_call (ENOMEM, syscall_realloc);
+      {
+	UNLOCK();
+	error_system_call (ENOMEM, syscall_realloc);
+      }
     {
       DIR ** scan = (pointers + result);
       DIR ** end = (pointers + n_pointers);
@@ -592,6 +605,7 @@ allocate_directory_pointer (DIR * pointer)
     }
     directory_pointers = pointers;
     n_directory_pointers = n_pointers;
+    UNLOCK();
     return (result);
   }
 }
@@ -643,6 +657,8 @@ OS_directory_read_matching (unsigned int index, const char * prefix)
 void
 OS_directory_close (unsigned int index)
 {
+  LOCK();
   closedir (REFERENCE_DIRECTORY (index));
   DEALLOCATE_DIRECTORY (index);
+  UNLOCK();
 }