/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
* Copyright 1996 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.
*/
/*
* Some simple primitives for allocation with explicit type information.
* Facilities for dynamic type inference may be added later.
* Should be used only for extremely performance critical applications,
* or if conservative collector leakage is otherwise a problem (unlikely).
* Note that this is implemented completely separately from the rest
* of the collector, and is not linked in unless referenced.
* This does not currently support GC_DEBUG in any interesting way.
*/
/* Boehm, May 19, 1994 2:13 pm PDT */
#ifndef _GC_TYPED_H
# define _GC_TYPED_H
# ifndef _GC_H
# include "gc.h"
# endif
typedef GC_word * GC_bitmap;
/* The least significant bit of the first word is one if */
/* the first word in the object may be a pointer. */
# define GC_get_bit(bm, index) \
(((bm)[divWORDSZ(index)] >> modWORDSZ(index)) & 1)
# define GC_set_bit(bm, index) \
(bm)[divWORDSZ(index)] |= (word)1 << modWORDSZ(index)
typedef GC_word GC_descr;
GC_API GC_descr GC_make_descriptor GC_PROTO((GC_bitmap bm, size_t len));
/* Return a type descriptor for the object whose layout */
/* is described by the argument. */
/* The least significant bit of the first word is one */
/* if the first word in the object may be a pointer. */
/* The second argument specifies the number of */
/* meaningful bits in the bitmap. The actual object */
/* may be larger (but not smaller). Any additional */
/* words in the object are assumed not to contain */
/* pointers. */
/* Returns a conservative approximation in the */
/* (unlikely) case of insufficient memory to build */
/* the descriptor. Calls to GC_make_descriptor */
/* may consume some amount of a finite resource. This */
/* is intended to be called once per type, not once */
/* per allocation. */
GC_API GC_PTR GC_malloc_explicitly_typed
GC_PROTO((size_t size_in_bytes, GC_descr d));
/* Allocate an object whose layout is described by d. */
/* The resulting object MAY NOT BE PASSED TO REALLOC. */
/* The returned object is cleared. */
GC_API GC_PTR GC_malloc_explicitly_typed_ignore_off_page
GC_PROTO((size_t size_in_bytes, GC_descr d));
GC_API GC_PTR GC_calloc_explicitly_typed
GC_PROTO((size_t nelements,
size_t element_size_in_bytes,
GC_descr d));
/* Allocate an array of nelements elements, each of the */
/* given size, and with the given descriptor. */
/* The elemnt size must be a multiple of the byte */
/* alignment required for pointers. E.g. on a 32-bit */
/* machine with 16-bit aligned pointers, size_in_bytes */
/* must be a multiple of 2. */
/* Returned object is cleared. */
#ifdef GC_DEBUG
# define GC_MALLOC_EXPLICTLY_TYPED(bytes, d) GC_MALLOC(bytes)
# define GC_CALLOC_EXPLICTLY_TYPED(n, bytes, d) GC_MALLOC(n*bytes)
#else
# define GC_MALLOC_EXPLICTLY_TYPED(bytes, d) \
GC_malloc_explicitly_typed(bytes, d)
# define GC_CALLOC_EXPLICTLY_TYPED(n, bytes, d) \
GC_calloc_explicitly_typed(n, bytes, d)
#endif /* !GC_DEBUG */
#endif /* _GC_TYPED_H */
