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diff --git a/gc/nursery.h b/gc/nursery.h
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+
+/* 
+ * Copyright (c) 1999 by Silicon Graphics.  All rights reserved.
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program
+ * for any purpose,  provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
+ */
+
+/*
+ * THIS IMPLEMENTATION FOR THIS INTERFACE IS INCOMPLETE.
+ * NONE OF THIS HAS BEEN TESTED.  DO NOT USE.
+ *
+ * Comments on the interface are appreciated, especially from
+ * potential users of the interface.
+ *
+ * This is a Bartlett style copying collector for young objects.
+ * We assume for now that all objects allocated through this
+ * mechanism have pointers only in the first BITMAP_BITS words.
+ * (On a 32-bit machine, BITMAP_BITS is 30.)
+ * Objects allocated in this manner should be rarely referenced
+ * by objects not allocated either through this interface, or through
+ * the typed allocation interface.
+ * If this interface is used, we assume that type information provided
+ * through either this or the typed allocation interface is valid
+ * in a stronger sense:
+ *
+ * 1) No pointers are stored in fields not marked as such.
+ *    (Otherwise it is only necessary that objects referenced by
+ *    fields marked as nonpointers are also reachable via another
+ *    path.)
+ * 2) Values stored in pointer fields are either not addresses in
+ *    the heap, or they really are pointers.  In the latter case, it
+ *    is acceptable to move the object they refer to, and to update
+ *    the pointer.
+ *
+ * GC_free may not be invoked on objects allocated with GC_copying_malloc.
+ *
+ * No extra space is added to the end of objects allocated through this
+ * interface.  If the client needs to maintain pointers past the
+ * end, the size should be explicitly padded.
+ * 
+ * We assume that calls to this will usually be compiler generated.
+ * Hence the interface is allowed to be a bit ugly in return for speed.
+ */
+
+#include "gc_copy_descr.h"
+
+/* GC_copy_descr.h must define						*/
+/* GC_SIZE_FROM_DESCRIPTOR(descr) and					*/
+/* GC_BIT_MAP_FROM_DESCRIPTOR(descr).					*/
+/* It may either be the GC supplied version of the header file, or a	*/
+/* client specific one that derives the information from a client-	*/
+/* specific type descriptor.						*/
+
+typedef GC_PTR GC_copy_alloc_state;
+				/* Current allocator state.	*/
+				/* Multiple allocation states	*/
+				/* may be used for concurrent	*/
+				/* allocation, or to enhance	*/
+				/* locality.			*/
+				/* Should be treated as opaque.	*/
+
+/* Allocate a memory block of size given in the descriptor, and with	*/
+/* pointer layout given by the descriptor.  The resulting block may not	*/
+/* be cleared, and should immediately be initialized by the client.	*/
+/* (A concurrent GC may see an uninitialized pointer field.  If it	*/
+/* points outside the nursery, that's fine.  If it points inside, it	*/
+/* may retain an object, and be relocated.  But that's also fine, since	*/
+/* the new value will be immediately overwritten.			*/
+/* This variant acquires the allocation lock, and uses a default 	*/
+/* global allocation state.						*/
+GC_PTR GC_copying_malloc(GC_copy_descriptor);
+
+/* A variant of the above that does no locking on the fast path,	*/
+/* and passes an explicit pointer to an allocation state.		*/
+/* The allocation state is updated.					*/
+/* There will eventually need to be a macro or inline function version	*/
+/* of this.								*/
+GC_PTR GC_copying_malloc2(GC_copy_descriptor, GC_copy_alloc_state *);
+
+/* Initialize an allocation state so that it can be used for 	*/
+/* allocation.  This implicitly reserves a small section of the	*/
+/* nursery for use with this allocator.				*/
+void GC_init_copy_alloc_state(GC_copy_alloc_state *);