X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=hs-boehmgc.git;a=blobdiff_plain;f=gc-7.2%2Finclude%2Fgc_typed.h;fp=gc-7.2%2Finclude%2Fgc_typed.h;h=a794fbbe4101550c4ad7a37e09e3f29454cd282c;hp=0000000000000000000000000000000000000000;hb=324587ba93dc77f37406d41fd2a20d0e0d94fb1d;hpb=2a4ea609491b225a1ceb06da70396e93916f137a diff --git a/gc-7.2/include/gc_typed.h b/gc-7.2/include/gc_typed.h new file mode 100644 index 0000000..a794fbb --- /dev/null +++ b/gc-7.2/include/gc_typed.h @@ -0,0 +1,114 @@ +/* + * 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. + */ + +#ifndef GC_TYPED_H +#define GC_TYPED_H + +#ifndef GC_H +# include "gc.h" +#endif + +#ifdef __cplusplus + extern "C" { +#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_WORDSZ (8 * sizeof(GC_word)) +#define GC_get_bit(bm, index) \ + (((bm)[(index) / GC_WORDSZ] >> ((index) % GC_WORDSZ)) & 1) +#define GC_set_bit(bm, index) \ + ((bm)[(index) / GC_WORDSZ] |= (GC_word)1 << ((index) % GC_WORDSZ)) +#define GC_WORD_OFFSET(t, f) (offsetof(t,f) / sizeof(GC_word)) +#define GC_WORD_LEN(t) (sizeof(t) / sizeof(GC_word)) +#define GC_BITMAP_SIZE(t) ((GC_WORD_LEN(t) + GC_WORDSZ - 1) / GC_WORDSZ) + +typedef GC_word GC_descr; + +GC_API GC_descr GC_CALL GC_make_descriptor(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. */ + +/* It is possible to generate a descriptor for a C type T with */ +/* word aligned pointer fields f1, f2, ... as follows: */ +/* */ +/* GC_descr T_descr; */ +/* GC_word T_bitmap[GC_BITMAP_SIZE(T)] = {0}; */ +/* GC_set_bit(T_bitmap, GC_WORD_OFFSET(T,f1)); */ +/* GC_set_bit(T_bitmap, GC_WORD_OFFSET(T,f2)); */ +/* ... */ +/* T_descr = GC_make_descriptor(T_bitmap, GC_WORD_LEN(T)); */ + +GC_API void * GC_CALL GC_malloc_explicitly_typed(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 void * GC_CALL GC_malloc_explicitly_typed_ignore_off_page( + size_t /* size_in_bytes */, + GC_descr /* d */); + +GC_API void * GC_CALL GC_calloc_explicitly_typed(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 element 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_EXPLICITLY_TYPED(bytes, d) GC_MALLOC(bytes) +# define GC_CALLOC_EXPLICITLY_TYPED(n, bytes, d) GC_MALLOC((n) * (bytes)) +#else +# define GC_MALLOC_EXPLICITLY_TYPED(bytes, d) \ + GC_malloc_explicitly_typed(bytes, d) +# define GC_CALLOC_EXPLICITLY_TYPED(n, bytes, d) \ + GC_calloc_explicitly_typed(n, bytes, d) +#endif + +#ifdef __cplusplus + } /* matches extern "C" */ +#endif + +#endif /* GC_TYPED_H */