v/thirdparty/libgc/include/gc/gc_inline.h

209 lines
8.8 KiB
C

/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
* Copyright (c) 2005 Hewlett-Packard Development Company, L.P.
*
* 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.
*/
#ifndef GC_INLINE_H
#define GC_INLINE_H
/* WARNING: */
/* Note that for these routines, it is the clients responsibility to */
/* add the extra byte at the end to deal with one-past-the-end pointers.*/
/* In the standard collector configuration, the collector assumes that */
/* such a byte has been added, and hence does not trace the last word */
/* in the resulting object. */
/* This is not an issue if the collector is compiled with */
/* DONT_ADD_BYTE_AT_END, or if GC_all_interior_pointers is not set. */
/* This interface is most useful for compilers that generate C. */
/* It is also used internally for thread-local allocation. */
/* Manual use is hereby discouraged. */
#include "gc.h"
#include "gc_tiny_fl.h"
#if GC_GNUC_PREREQ(3, 0)
# define GC_EXPECT(expr, outcome) __builtin_expect(expr,outcome)
/* Equivalent to (expr), but predict that usually (expr)==outcome. */
#else
# define GC_EXPECT(expr, outcome) (expr)
#endif
#ifndef GC_ASSERT
# ifdef NDEBUG
# define GC_ASSERT(expr) /* empty */
# else
# include <assert.h>
# define GC_ASSERT(expr) assert(expr)
# endif
#endif
#ifdef __cplusplus
extern "C" {
#endif
#ifndef GC_PREFETCH_FOR_WRITE
# if GC_GNUC_PREREQ(3, 0) && !defined(GC_NO_PREFETCH_FOR_WRITE)
# define GC_PREFETCH_FOR_WRITE(x) __builtin_prefetch((x), 1)
# else
# define GC_PREFETCH_FOR_WRITE(x) (void)0
# endif
#endif
/* Object kinds; must match PTRFREE, NORMAL in gc_priv.h. */
#define GC_I_PTRFREE 0
#define GC_I_NORMAL 1
/* Store a pointer to a list of newly allocated objects of kind k and */
/* size lb in *result. The caller must make sure that *result is */
/* traced even if objects are ptrfree. */
GC_API void GC_CALL GC_generic_malloc_many(size_t /* lb */, int /* k */,
void ** /* result */);
/* Generalized version of GC_malloc and GC_malloc_atomic. */
/* Uses appropriately the thread-local (if available) or the global */
/* free-list of the specified kind. */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_malloc_kind(size_t /* lb */, int /* k */);
#ifdef GC_THREADS
/* Same as above but uses only the global free-list. */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_malloc_kind_global(size_t /* lb */, int /* k */);
#else
# define GC_malloc_kind_global GC_malloc_kind
#endif
/* An internal macro to update the free list pointer atomically (if */
/* the AO primitives are available) to avoid race with the marker. */
#if defined(GC_THREADS) && defined(AO_HAVE_store)
# define GC_FAST_M_AO_STORE(my_fl, next) \
AO_store((volatile AO_t *)(my_fl), (AO_t)(next))
#else
# define GC_FAST_M_AO_STORE(my_fl, next) (void)(*(my_fl) = (next))
#endif
/* The ultimately general inline allocation macro. Allocate an object */
/* of size granules, putting the resulting pointer in result. Tiny_fl */
/* is a "tiny" free list array, which will be used first, if the size */
/* is appropriate. If granules is too large, we allocate with */
/* default_expr instead. If we need to refill the free list, we use */
/* GC_generic_malloc_many with the indicated kind. */
/* Tiny_fl should be an array of GC_TINY_FREELISTS void * pointers. */
/* If num_direct is nonzero, and the individual free list pointers */
/* are initialized to (void *)1, then we allocate num_direct granules */
/* directly using generic_malloc before putting multiple objects into */
/* the tiny_fl entry. If num_direct is zero, then the free lists may */
/* also be initialized to (void *)0. */
/* Note that we use the zeroth free list to hold objects 1 granule in */
/* size that are used to satisfy size 0 allocation requests. */
/* We rely on much of this hopefully getting optimized away in the */
/* num_direct = 0 case. */
/* Particularly if granules is constant, this should generate a small */
/* amount of code. */
# define GC_FAST_MALLOC_GRANS(result,granules,tiny_fl,num_direct, \
kind,default_expr,init) \
do { \
if (GC_EXPECT((granules) >= GC_TINY_FREELISTS,0)) { \
result = (default_expr); \
} else { \
void **my_fl = (tiny_fl) + (granules); \
void *my_entry=*my_fl; \
void *next; \
\
for (;;) { \
if (GC_EXPECT((GC_word)my_entry \
> (num_direct) + GC_TINY_FREELISTS + 1, 1)) { \
next = *(void **)(my_entry); \
result = (void *)my_entry; \
GC_FAST_M_AO_STORE(my_fl, next); \
init; \
GC_PREFETCH_FOR_WRITE(next); \
if ((kind) != GC_I_PTRFREE) { \
GC_end_stubborn_change(my_fl); \
GC_reachable_here(next); \
} \
GC_ASSERT(GC_size(result) >= (granules)*GC_GRANULE_BYTES); \
GC_ASSERT((kind) == GC_I_PTRFREE \
|| ((GC_word *)result)[1] == 0); \
break; \
} \
/* Entry contains counter or NULL */ \
if ((GC_signed_word)my_entry - (GC_signed_word)(num_direct) <= 0 \
/* (GC_word)my_entry <= (num_direct) */ \
&& my_entry != 0 /* NULL */) { \
/* Small counter value, not NULL */ \
GC_FAST_M_AO_STORE(my_fl, (char *)my_entry \
+ (granules) + 1); \
result = (default_expr); \
break; \
} else { \
/* Large counter or NULL */ \
GC_generic_malloc_many(((granules) == 0? GC_GRANULE_BYTES : \
GC_RAW_BYTES_FROM_INDEX(granules)), \
kind, my_fl); \
my_entry = *my_fl; \
if (my_entry == 0) { \
result = (*GC_get_oom_fn())((granules)*GC_GRANULE_BYTES); \
break; \
} \
} \
} \
} \
} while (0)
# define GC_WORDS_TO_WHOLE_GRANULES(n) \
GC_WORDS_TO_GRANULES((n) + GC_GRANULE_WORDS - 1)
/* Allocate n words (NOT BYTES). X is made to point to the result. */
/* This should really only be used if GC_all_interior_pointers is */
/* not set, or DONT_ADD_BYTE_AT_END is set. See above. */
/* Does not acquire lock. The caller is responsible for supplying */
/* a cleared tiny_fl free list array. For single-threaded */
/* applications, this may be a global array. */
# define GC_MALLOC_WORDS_KIND(result,n,tiny_fl,kind,init) \
do { \
size_t granules = GC_WORDS_TO_WHOLE_GRANULES(n); \
GC_FAST_MALLOC_GRANS(result, granules, tiny_fl, 0, kind, \
GC_malloc_kind(granules*GC_GRANULE_BYTES, kind), \
init); \
} while (0)
# define GC_MALLOC_WORDS(result,n,tiny_fl) \
GC_MALLOC_WORDS_KIND(result, n, tiny_fl, GC_I_NORMAL, \
*(void **)(result) = 0)
# define GC_MALLOC_ATOMIC_WORDS(result,n,tiny_fl) \
GC_MALLOC_WORDS_KIND(result, n, tiny_fl, GC_I_PTRFREE, (void)0)
/* And once more for two word initialized objects: */
# define GC_CONS(result, first, second, tiny_fl) \
do { \
void *l = (void *)(first); \
void *r = (void *)(second); \
GC_MALLOC_WORDS_KIND(result, 2, tiny_fl, GC_I_NORMAL, (void)0); \
if ((result) != 0 /* NULL */) { \
*(void **)(result) = l; \
GC_PTR_STORE_AND_DIRTY((void **)(result) + 1, r); \
GC_reachable_here(l); \
} \
} while (0)
GC_API void GC_CALL GC_print_free_list(int /* kind */,
size_t /* sz_in_granules */);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* !GC_INLINE_H */