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Diffstat (limited to 'gc/include/gc_typed.h')
| -rw-r--r-- | gc/include/gc_typed.h | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/gc/include/gc_typed.h b/gc/include/gc_typed.h new file mode 100644 index 0000000..e4a6b94 --- /dev/null +++ b/gc/include/gc_typed.h @@ -0,0 +1,91 @@ +/* + * 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. */ + +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. */ + +#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 */ + |