/libs/headers/gc/gc_gcj.h

 1/* 
 2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
 3 * Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.
 4 * Copyright 1996-1999 by Silicon Graphics.  All rights reserved.
 5 * Copyright 1999 by Hewlett-Packard Company.  All rights reserved.
 6 *
 7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
 8 * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
 9 *
10 * Permission is hereby granted to use or copy this program
11 * for any purpose,  provided the above notices are retained on all copies.
12 * Permission to modify the code and to distribute modified code is granted,
13 * provided the above notices are retained, and a notice that the code was
14 * modified is included with the above copyright notice.
15 */
16
17/* This file assumes the collector has been compiled with GC_GCJ_SUPPORT */
18/* and that an ANSI C compiler is available.				 */
19
20/*
21 * We allocate objects whose first word contains a pointer to a struct
22 * describing the object type.  This struct contains a garbage collector mark
23 * descriptor at offset MARK_DESCR_OFFSET.  Alternatively, the objects
24 * may be marked by the mark procedure passed to GC_init_gcj_malloc.
25 */
26
27#ifndef GC_GCJ_H
28
29#define GC_GCJ_H
30
31#ifndef MARK_DESCR_OFFSET
32#  define MARK_DESCR_OFFSET	sizeof(word)
33#endif
34	/* Gcj keeps GC descriptor as second word of vtable.	This	*/
35	/* probably needs to be adjusted for other clients.		*/
36	/* We currently assume that this offset is such that:		*/
37	/*	- all objects of this kind are large enough to have	*/
38	/*	  a value at that offset, and				*/
39	/* 	- it is not zero.					*/
40	/* These assumptions allow objects on the free list to be 	*/
41	/* marked normally.						*/
42
43#ifndef _GC_H
44#   include "gc.h"
45#endif
46
47/* The following allocators signal an out of memory condition with	*/
48/* return GC_oom_fn(bytes);						*/
49
50/* The following function must be called before the gcj allocators	*/
51/* can be invoked.							*/
52/* mp_index and mp are the index and mark_proc (see gc_mark.h)		*/
53/* respectively for the allocated objects.  Mark_proc will be 		*/
54/* used to build the descriptor for objects allocated through the	*/
55/* debugging interface.  The mark_proc will be invoked on all such 	*/
56/* objects with an "environment" value of 1.  The client may choose	*/
57/* to use the same mark_proc for some of its generated mark descriptors.*/
58/* In that case, it should use a different "environment" value to	*/
59/* detect the presence or absence of the debug header.			*/
60/* Mp is really of type mark_proc, as defined in gc_mark.h.  We don't 	*/
61/* want to include that here for namespace pollution reasons.		*/
62extern void GC_init_gcj_malloc(int mp_index, void * /* really mark_proc */mp);
63
64/* Allocate an object, clear it, and store the pointer to the	*/
65/* type structure (vtable in gcj).				*/
66/* This adds a byte at the end of the object if GC_malloc would.*/
67extern void * GC_gcj_malloc(size_t lb, void * ptr_to_struct_containing_descr);
68/* The debug versions allocate such that the specified mark_proc	*/
69/* is always invoked.							*/
70extern void * GC_debug_gcj_malloc(size_t lb,
71				  void * ptr_to_struct_containing_descr,
72				  GC_EXTRA_PARAMS);
73
74/* Similar to GC_gcj_malloc, but assumes that a pointer to near the	*/
75/* beginning of the resulting object is always maintained.		*/
76extern void * GC_gcj_malloc_ignore_off_page(size_t lb,
77				void * ptr_to_struct_containing_descr);
78
79/* The kind numbers of normal and debug gcj objects.		*/
80/* Useful only for debug support, we hope.			*/
81extern int GC_gcj_kind;
82
83extern int GC_gcj_debug_kind;
84
85# ifdef GC_DEBUG
86#   define GC_GCJ_MALLOC(s,d) GC_debug_gcj_malloc(s,d,GC_EXTRAS)
87#   define GC_GCJ_MALLOC_IGNORE_OFF_PAGE(s,d) GC_debug_gcj_malloc(s,d,GC_EXTRAS)
88# else
89#   define GC_GCJ_MALLOC(s,d) GC_gcj_malloc(s,d)
90#   define GC_GCJ_MALLOC_IGNORE_OFF_PAGE(s,d) \
91	GC_gcj_malloc_ignore_off_page(s,d)
92# endif
93
94#endif /* GC_GCJ_H */