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Diffstat (limited to 'boehm-gc/include/gc_alloc.h')
-rw-r--r-- | boehm-gc/include/gc_alloc.h | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/boehm-gc/include/gc_alloc.h b/boehm-gc/include/gc_alloc.h new file mode 100644 index 0000000..1d912db --- /dev/null +++ b/boehm-gc/include/gc_alloc.h @@ -0,0 +1,380 @@ +/* + * Copyright (c) 1996-1998 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 is a C++ header file that is intended to replace the SGI STL +// alloc.h. +// +// This assumes the collector has been compiled with -DATOMIC_UNCOLLECTABLE +// and -DALL_INTERIOR_POINTERS. We also recommend +// -DREDIRECT_MALLOC=GC_uncollectable_malloc. +// +// Some of this could be faster in the explicit deallocation case. In particular, +// we spend too much time clearing objects on the free lists. That could be avoided. +// +// This uses template classes with static members, and hence does not work +// with g++ 2.7.2 and earlier. +// + +#include "gc.h" + +#ifndef GC_ALLOC_H + +#define GC_ALLOC_H +#define __ALLOC_H // Prevent inclusion of the default version. Ugly. +#define __SGI_STL_ALLOC_H +#define __SGI_STL_INTERNAL_ALLOC_H + +#ifndef __ALLOC +# define __ALLOC alloc +#endif + +#include <stddef.h> +#include <string.h> + +// The following is just replicated from the conventional SGI alloc.h: + +template<class T, class alloc> +class simple_alloc { + +public: + static T *allocate(size_t n) + { return 0 == n? 0 : (T*) alloc::allocate(n * sizeof (T)); } + static T *allocate(void) + { return (T*) alloc::allocate(sizeof (T)); } + static void deallocate(T *p, size_t n) + { if (0 != n) alloc::deallocate(p, n * sizeof (T)); } + static void deallocate(T *p) + { alloc::deallocate(p, sizeof (T)); } +}; + +#include "gc.h" + +// The following need to match collector data structures. +// We can't include gc_priv.h, since that pulls in way too much stuff. +// This should eventually be factored out into another include file. + +extern "C" { + extern void ** const GC_objfreelist_ptr; + extern void ** const GC_aobjfreelist_ptr; + extern void ** const GC_uobjfreelist_ptr; + extern void ** const GC_auobjfreelist_ptr; + + extern void GC_incr_words_allocd(size_t words); + extern void GC_incr_mem_freed(size_t words); + + extern char * GC_generic_malloc_words_small(size_t word, int kind); +} + +// Object kinds; must match PTRFREE, NORMAL, UNCOLLECTABLE, and +// AUNCOLLECTABLE in gc_priv.h. + +enum { GC_PTRFREE = 0, GC_NORMAL = 1, GC_UNCOLLECTABLE = 2, + GC_AUNCOLLECTABLE = 3 }; + +enum { GC_max_fast_bytes = 255 }; + +enum { GC_bytes_per_word = sizeof(char *) }; + +enum { GC_byte_alignment = 8 }; + +enum { GC_word_alignment = GC_byte_alignment/GC_bytes_per_word }; + +inline void * &GC_obj_link(void * p) +{ return *(void **)p; } + +// Compute a number of words >= n+1 bytes. +// The +1 allows for pointers one past the end. +inline size_t GC_round_up(size_t n) +{ + return ((n + GC_byte_alignment)/GC_byte_alignment)*GC_word_alignment; +} + +// The same but don't allow for extra byte. +inline size_t GC_round_up_uncollectable(size_t n) +{ + return ((n + GC_byte_alignment - 1)/GC_byte_alignment)*GC_word_alignment; +} + +template <int dummy> +class GC_aux_template { +public: + // File local count of allocated words. Occasionally this is + // added into the global count. A separate count is necessary since the + // real one must be updated with a procedure call. + static size_t GC_words_recently_allocd; + + // Same for uncollectable mmory. Not yet reflected in either + // GC_words_recently_allocd or GC_non_gc_bytes. + static size_t GC_uncollectable_words_recently_allocd; + + // Similar counter for explicitly deallocated memory. + static size_t GC_mem_recently_freed; + + // Again for uncollectable memory. + static size_t GC_uncollectable_mem_recently_freed; + + static void * GC_out_of_line_malloc(size_t nwords, int kind); +}; + +template <int dummy> +size_t GC_aux_template<dummy>::GC_words_recently_allocd = 0; + +template <int dummy> +size_t GC_aux_template<dummy>::GC_uncollectable_words_recently_allocd = 0; + +template <int dummy> +size_t GC_aux_template<dummy>::GC_mem_recently_freed = 0; + +template <int dummy> +size_t GC_aux_template<dummy>::GC_uncollectable_mem_recently_freed = 0; + +template <int dummy> +void * GC_aux_template<dummy>::GC_out_of_line_malloc(size_t nwords, int kind) +{ + GC_words_recently_allocd += GC_uncollectable_words_recently_allocd; + GC_non_gc_bytes += + GC_bytes_per_word * GC_uncollectable_words_recently_allocd; + GC_uncollectable_words_recently_allocd = 0; + + GC_mem_recently_freed += GC_uncollectable_mem_recently_freed; + GC_non_gc_bytes -= + GC_bytes_per_word * GC_uncollectable_mem_recently_freed; + GC_uncollectable_mem_recently_freed = 0; + + GC_incr_words_allocd(GC_words_recently_allocd); + GC_words_recently_allocd = 0; + + GC_incr_mem_freed(GC_mem_recently_freed); + GC_mem_recently_freed = 0; + + return GC_generic_malloc_words_small(nwords, kind); +} + +typedef GC_aux_template<0> GC_aux; + +// A fast, single-threaded, garbage-collected allocator +// We assume the first word will be immediately overwritten. +// In this version, deallocation is not a noop, and explicit +// deallocation is likely to help performance. +template <int dummy> +class single_client_gc_alloc_template { + public: + static void * allocate(size_t n) + { + size_t nwords = GC_round_up(n); + void ** flh; + void * op; + + if (n > GC_max_fast_bytes) return GC_malloc(n); + flh = GC_objfreelist_ptr + nwords; + if (0 == (op = *flh)) { + return GC_aux::GC_out_of_line_malloc(nwords, GC_NORMAL); + } + *flh = GC_obj_link(op); + GC_aux::GC_words_recently_allocd += nwords; + return op; + } + static void * ptr_free_allocate(size_t n) + { + size_t nwords = GC_round_up(n); + void ** flh; + void * op; + + if (n > GC_max_fast_bytes) return GC_malloc_atomic(n); + flh = GC_aobjfreelist_ptr + nwords; + if (0 == (op = *flh)) { + return GC_aux::GC_out_of_line_malloc(nwords, GC_PTRFREE); + } + *flh = GC_obj_link(op); + GC_aux::GC_words_recently_allocd += nwords; + return op; + } + static void deallocate(void *p, size_t n) + { + size_t nwords = GC_round_up(n); + void ** flh; + + if (n > GC_max_fast_bytes) { + GC_free(p); + } else { + flh = GC_objfreelist_ptr + nwords; + GC_obj_link(p) = *flh; + memset((char *)p + GC_bytes_per_word, 0, + GC_bytes_per_word * (nwords - 1)); + *flh = p; + GC_aux::GC_mem_recently_freed += nwords; + } + } + static void ptr_free_deallocate(void *p, size_t n) + { + size_t nwords = GC_round_up(n); + void ** flh; + + if (n > GC_max_fast_bytes) { + GC_free(p); + } else { + flh = GC_aobjfreelist_ptr + nwords; + GC_obj_link(p) = *flh; + *flh = p; + GC_aux::GC_mem_recently_freed += nwords; + } + } +}; + +typedef single_client_gc_alloc_template<0> single_client_gc_alloc; + +// Once more, for uncollectable objects. +template <int dummy> +class single_client_alloc_template { + public: + static void * allocate(size_t n) + { + size_t nwords = GC_round_up_uncollectable(n); + void ** flh; + void * op; + + if (n > GC_max_fast_bytes) return GC_malloc_uncollectable(n); + flh = GC_uobjfreelist_ptr + nwords; + if (0 == (op = *flh)) { + return GC_aux::GC_out_of_line_malloc(nwords, GC_UNCOLLECTABLE); + } + *flh = GC_obj_link(op); + GC_aux::GC_uncollectable_words_recently_allocd += nwords; + return op; + } + static void * ptr_free_allocate(size_t n) + { + size_t nwords = GC_round_up_uncollectable(n); + void ** flh; + void * op; + + if (n > GC_max_fast_bytes) return GC_malloc_atomic_uncollectable(n); + flh = GC_auobjfreelist_ptr + nwords; + if (0 == (op = *flh)) { + return GC_aux::GC_out_of_line_malloc(nwords, GC_AUNCOLLECTABLE); + } + *flh = GC_obj_link(op); + GC_aux::GC_uncollectable_words_recently_allocd += nwords; + return op; + } + static void deallocate(void *p, size_t n) + { + size_t nwords = GC_round_up_uncollectable(n); + void ** flh; + + if (n > GC_max_fast_bytes) { + GC_free(p); + } else { + flh = GC_uobjfreelist_ptr + nwords; + GC_obj_link(p) = *flh; + *flh = p; + GC_aux::GC_uncollectable_mem_recently_freed += nwords; + } + } + static void ptr_free_deallocate(void *p, size_t n) + { + size_t nwords = GC_round_up_uncollectable(n); + void ** flh; + + if (n > GC_max_fast_bytes) { + GC_free(p); + } else { + flh = GC_auobjfreelist_ptr + nwords; + GC_obj_link(p) = *flh; + *flh = p; + GC_aux::GC_uncollectable_mem_recently_freed += nwords; + } + } +}; + +typedef single_client_alloc_template<0> single_client_alloc; + +template < int dummy > +class gc_alloc_template { + public: + static void * allocate(size_t n) { return GC_malloc(n); } + static void * ptr_free_allocate(size_t n) + { return GC_malloc_atomic(n); } + static void deallocate(void *, size_t) { } + static void ptr_free_deallocate(void *, size_t) { } +}; + +typedef gc_alloc_template < 0 > gc_alloc; + +template < int dummy > +class alloc_template { + public: + static void * allocate(size_t n) { return GC_malloc_uncollectable(n); } + static void * ptr_free_allocate(size_t n) + { return GC_malloc_atomic_uncollectable(n); } + static void deallocate(void *p, size_t) { GC_free(p); } + static void ptr_free_deallocate(void *p, size_t) { GC_free(p); } +}; + +typedef alloc_template < 0 > alloc; + +#ifdef _SGI_SOURCE + +// We want to specialize simple_alloc so that it does the right thing +// for all pointerfree types. At the moment there is no portable way to +// even approximate that. The following approximation should work for +// SGI compilers, and perhaps some others. + +# define __GC_SPECIALIZE(T,alloc) \ +class simple_alloc<T, alloc> { \ +public: \ + static T *allocate(size_t n) \ + { return 0 == n? 0 : \ + (T*) alloc::ptr_free_allocate(n * sizeof (T)); } \ + static T *allocate(void) \ + { return (T*) alloc::ptr_free_allocate(sizeof (T)); } \ + static void deallocate(T *p, size_t n) \ + { if (0 != n) alloc::ptr_free_deallocate(p, n * sizeof (T)); } \ + static void deallocate(T *p) \ + { alloc::ptr_free_deallocate(p, sizeof (T)); } \ +}; + +__GC_SPECIALIZE(char, gc_alloc) +__GC_SPECIALIZE(int, gc_alloc) +__GC_SPECIALIZE(unsigned, gc_alloc) +__GC_SPECIALIZE(float, gc_alloc) +__GC_SPECIALIZE(double, gc_alloc) + +__GC_SPECIALIZE(char, alloc) +__GC_SPECIALIZE(int, alloc) +__GC_SPECIALIZE(unsigned, alloc) +__GC_SPECIALIZE(float, alloc) +__GC_SPECIALIZE(double, alloc) + +__GC_SPECIALIZE(char, single_client_gc_alloc) +__GC_SPECIALIZE(int, single_client_gc_alloc) +__GC_SPECIALIZE(unsigned, single_client_gc_alloc) +__GC_SPECIALIZE(float, single_client_gc_alloc) +__GC_SPECIALIZE(double, single_client_gc_alloc) + +__GC_SPECIALIZE(char, single_client_alloc) +__GC_SPECIALIZE(int, single_client_alloc) +__GC_SPECIALIZE(unsigned, single_client_alloc) +__GC_SPECIALIZE(float, single_client_alloc) +__GC_SPECIALIZE(double, single_client_alloc) + +#ifdef __STL_USE_STD_ALLOCATORS + +???copy stuff from stl_alloc.h or remove it to a different file ??? + +#endif /* __STL_USE_STD_ALLOCATORS */ + +#endif /* _SGI_SOURCE */ + +#endif /* GC_ALLOC_H */ |