Add context-specific special object table, generalizing catchstack_save and current_c...

[factor.git] / vm / contexts.hpp

diff --git a/vm/contexts.hpp b/vm/contexts.hpp
index 9ba9bb313cf520daa45a91160becc6ff2aaf50c8..e555bd4a92ec41099f6b38396abafcd2a360f868 100644 (file)
--- a/vm/contexts.hpp
+++ b/vm/contexts.hpp
@@ -1,6 +1,14 @@
 namespace factor
 {
 
+static const cell context_object_count = 10;
+
+enum context_object {
+       OBJ_NAMESTACK,
+       OBJ_CATCHSTACK,
+       OBJ_CONTEXT_ID,
+};
+
 /* Assembly code makes assumptions about the layout of this struct */
 struct context {
        /* C stack pointer on entry */
@@ -19,13 +27,16 @@ struct context {
        /* memory region holding current retain stack */
        segment *retainstack_region;
 
-       /* saved special_objects slots on entry to callback */
-       cell catchstack_save;
-       cell current_callback_save;
+       /* context-specific special objects, accessed by context-object and
+       set-context-object primitives */
+       cell context_objects[context_object_count];
 
        context *next;
 
        context(cell ds_size, cell rs_size);
+       void reset_datastack();
+       void reset_retainstack();
+       void reset_context_objects();
 
        cell peek()
        {
@@ -50,16 +61,6 @@ struct context {
                replace(tagged);
        }
 
-       void reset_datastack()
-       {
-               datastack = datastack_region->start - sizeof(cell);
-       }
-
-       void reset_retainstack()
-       {
-               retainstack = retainstack_region->start - sizeof(cell);
-       }
-
        static const cell stack_reserved = (64 * sizeof(cell));
 
        void fix_stacks()