===================================================================
RCS file: /home/cvs/OpenXM_contrib2/asir2000/gc/headers.c,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -p -r1.1 -r1.2
--- OpenXM_contrib2/asir2000/gc/headers.c	1999/12/03 07:39:09	1.1
+++ OpenXM_contrib2/asir2000/gc/headers.c	2000/12/01 09:26:11	1.2
@@ -50,10 +50,8 @@ ptr_t h;
  
 static ptr_t scratch_free_ptr = 0;
  
-ptr_t GC_scratch_end_ptr = 0;
-
-ptr_t GC_scratch_last_end_ptr = 0;
-		/* End point of last obtained scratch area */
+/* GC_scratch_last_end_ptr is end point of last obtained scratch area.  */
+/* GC_scratch_end_ptr is end point of current scratch area.		*/
  
 ptr_t GC_scratch_alloc(bytes)
 register word bytes;
@@ -128,6 +126,13 @@ hdr * hhdr;
     hhdr -> hb_next = (struct hblk *) hdr_free_list;
     hdr_free_list = hhdr;
 }
+
+hdr * GC_invalid_header;
+
+#ifdef USE_HDR_CACHE
+  word GC_hdr_cache_hits = 0;
+  word GC_hdr_cache_misses = 0;
+#endif
  
 void GC_init_headers()
 {
@@ -138,6 +143,8 @@ void GC_init_headers()
     for (i = 0; i < TOP_SZ; i++) {
         GC_top_index[i] = GC_all_nils;
     }
+    GC_invalid_header = alloc_hdr();
+    GC_invalidate_map(GC_invalid_header);
 }
 
 /* Make sure that there is a bottom level index block for address addr  */
@@ -191,10 +198,10 @@ word addr;
     return(TRUE);
 }
 
-/* Install a header for block h.  */
-/* The header is uninitialized.	  */
-/* Returns FALSE on failure.	  */
-GC_bool GC_install_header(h)
+/* Install a header for block h.	*/
+/* The header is uninitialized.	  	*/
+/* Returns the header or 0 on failure.	*/
+struct hblkhdr * GC_install_header(h)
 register struct hblk * h;
 {
     hdr * result;
@@ -205,7 +212,7 @@ register struct hblk * h;
 #   ifdef USE_MUNMAP
 	result -> hb_last_reclaimed = GC_gc_no;
 #   endif
-    return(result != 0);
+    return(result);
 }
 
 /* Set up forwarding counts for block h of size sz */