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Diffstat (limited to 'libguile/weaks.c')
-rw-r--r-- | libguile/weaks.c | 294 |
1 files changed, 0 insertions, 294 deletions
diff --git a/libguile/weaks.c b/libguile/weaks.c deleted file mode 100644 index 92d351e51..000000000 --- a/libguile/weaks.c +++ /dev/null @@ -1,294 +0,0 @@ -/* Copyright (C) 1995,1996,1998,2000,2001, 2003, 2006, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public License - * as published by the Free Software Foundation; either version 3 of - * the License, or (at your option) any later version. - * - * This library is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - * 02110-1301 USA - */ - - - -#ifdef HAVE_CONFIG_H -# include <config.h> -#endif - -#include <stdio.h> - -#include "libguile/_scm.h" -#include "libguile/vectors.h" -#include "libguile/hashtab.h" - -#include "libguile/validate.h" -#include "libguile/weaks.h" - -#include "libguile/bdw-gc.h" -#include <gc/gc_typed.h> - - - -/* Weak pairs for use in weak alist vectors and weak hash tables. - - We have weal-car pairs, weak-cdr pairs, and doubly weak pairs. In weak - pairs, the weak component(s) are not scanned for pointers and are - registered as disapperaring links; therefore, the weak component may be - set to NULL by the garbage collector when no other reference to that word - exist. Thus, users should only access weak pairs via the - `SCM_WEAK_PAIR_C[AD]R ()' macros. See also `scm_fixup_weak_alist ()' in - `hashtab.c'. */ - -/* Type descriptors for weak-c[ad]r pairs. */ -static GC_descr wcar_pair_descr, wcdr_pair_descr; - - -SCM -scm_weak_car_pair (SCM car, SCM cdr) -{ - scm_t_cell *cell; - - cell = (scm_t_cell *)GC_malloc_explicitly_typed (sizeof (*cell), - wcar_pair_descr); - - cell->word_0 = car; - cell->word_1 = cdr; - - if (SCM_NIMP (car)) - /* Weak car cells make sense iff the car is non-immediate. */ - SCM_I_REGISTER_DISAPPEARING_LINK ((GC_PTR) &cell->word_0, - (GC_PTR) SCM2PTR (car)); - - return (SCM_PACK (cell)); -} - -SCM -scm_weak_cdr_pair (SCM car, SCM cdr) -{ - scm_t_cell *cell; - - cell = (scm_t_cell *)GC_malloc_explicitly_typed (sizeof (*cell), - wcdr_pair_descr); - - cell->word_0 = car; - cell->word_1 = cdr; - - if (SCM_NIMP (cdr)) - /* Weak cdr cells make sense iff the cdr is non-immediate. */ - SCM_I_REGISTER_DISAPPEARING_LINK ((GC_PTR) &cell->word_1, - (GC_PTR) SCM2PTR (cdr)); - - return (SCM_PACK (cell)); -} - -SCM -scm_doubly_weak_pair (SCM car, SCM cdr) -{ - /* Doubly weak cells shall not be scanned at all for pointers. */ - scm_t_cell *cell = (scm_t_cell *)scm_gc_malloc_pointerless (sizeof (*cell), - "weak cell"); - - cell->word_0 = car; - cell->word_1 = cdr; - - if (SCM_NIMP (car)) - SCM_I_REGISTER_DISAPPEARING_LINK ((GC_PTR) &cell->word_0, - (GC_PTR) SCM2PTR (car)); - if (SCM_NIMP (cdr)) - SCM_I_REGISTER_DISAPPEARING_LINK ((GC_PTR) &cell->word_1, - (GC_PTR) SCM2PTR (cdr)); - - return (SCM_PACK (cell)); -} - - - - -/* 1. The current hash table implementation in hashtab.c uses weak alist - * vectors (formerly called weak hash tables) internally. - * - * 2. All hash table operations still work on alist vectors. - * - * 3. The weak vector and alist vector Scheme API is accessed through - * the module (ice-9 weak-vector). - */ - - -/* {Weak Vectors} - */ - - -SCM_DEFINE (scm_make_weak_vector, "make-weak-vector", 1, 1, 0, - (SCM size, SCM fill), - "Return a weak vector with @var{size} elements. If the optional\n" - "argument @var{fill} is given, all entries in the vector will be\n" - "set to @var{fill}. The default value for @var{fill} is the\n" - "empty list.") -#define FUNC_NAME s_scm_make_weak_vector -{ - return scm_i_make_weak_vector (0, size, fill); -} -#undef FUNC_NAME - - -SCM_REGISTER_PROC(s_list_to_weak_vector, "list->weak-vector", 1, 0, 0, scm_weak_vector); - -SCM_DEFINE (scm_weak_vector, "weak-vector", 0, 0, 1, - (SCM l), - "@deffnx {Scheme Procedure} list->weak-vector l\n" - "Construct a weak vector from a list: @code{weak-vector} uses\n" - "the list of its arguments while @code{list->weak-vector} uses\n" - "its only argument @var{l} (a list) to construct a weak vector\n" - "the same way @code{list->vector} would.") -#define FUNC_NAME s_scm_weak_vector -{ - return scm_i_make_weak_vector_from_list (0, l); -} -#undef FUNC_NAME - - -SCM_DEFINE (scm_weak_vector_p, "weak-vector?", 1, 0, 0, - (SCM obj), - "Return @code{#t} if @var{obj} is a weak vector. Note that all\n" - "weak hashes are also weak vectors.") -#define FUNC_NAME s_scm_weak_vector_p -{ - return scm_from_bool (SCM_I_WVECTP (obj) && !SCM_IS_WHVEC (obj)); -} -#undef FUNC_NAME - - -/* Weak alist vectors, i.e., vectors of alists. - - The alist vector themselves are _not_ weak. The `car' (or `cdr', or both) - of the pairs within it are weak. See `hashtab.c' for details. */ - - -/* FIXME: We used to have two implementations of weak hash tables: the one in - here and the one in `hashtab.c'. The difference is that weak alist - vectors could be used as vectors while (weak) hash tables can't. We need - to unify that. */ - -SCM_DEFINE (scm_make_weak_key_alist_vector, "make-weak-key-alist-vector", 0, 1, 0, - (SCM size), - "@deffnx {Scheme Procedure} make-weak-value-alist-vector size\n" - "@deffnx {Scheme Procedure} make-doubly-weak-alist-vector size\n" - "Return a weak hash table with @var{size} buckets. As with any\n" - "hash table, choosing a good size for the table requires some\n" - "caution.\n" - "\n" - "You can modify weak hash tables in exactly the same way you\n" - "would modify regular hash tables. (@pxref{Hash Tables})") -#define FUNC_NAME s_scm_make_weak_key_alist_vector -{ - return scm_make_weak_key_hash_table (size); -} -#undef FUNC_NAME - - -SCM_DEFINE (scm_make_weak_value_alist_vector, "make-weak-value-alist-vector", 0, 1, 0, - (SCM size), - "Return a hash table with weak values with @var{size} buckets.\n" - "(@pxref{Hash Tables})") -#define FUNC_NAME s_scm_make_weak_value_alist_vector -{ - return scm_make_weak_value_hash_table (size); -} -#undef FUNC_NAME - - -SCM_DEFINE (scm_make_doubly_weak_alist_vector, "make-doubly-weak-alist-vector", 1, 0, 0, - (SCM size), - "Return a hash table with weak keys and values with @var{size}\n" - "buckets. (@pxref{Hash Tables})") -#define FUNC_NAME s_scm_make_doubly_weak_alist_vector -{ - return scm_make_doubly_weak_hash_table (size); -} -#undef FUNC_NAME - - -SCM_DEFINE (scm_weak_key_alist_vector_p, "weak-key-alist-vector?", 1, 0, 0, - (SCM obj), - "@deffnx {Scheme Procedure} weak-value-alist-vector? obj\n" - "@deffnx {Scheme Procedure} doubly-weak-alist-vector? obj\n" - "Return @code{#t} if @var{obj} is the specified weak hash\n" - "table. Note that a doubly weak hash table is neither a weak key\n" - "nor a weak value hash table.") -#define FUNC_NAME s_scm_weak_key_alist_vector_p -{ - return scm_from_bool (SCM_I_WVECTP (obj) && SCM_IS_WHVEC (obj)); -} -#undef FUNC_NAME - - -SCM_DEFINE (scm_weak_value_alist_vector_p, "weak-value-alist-vector?", 1, 0, 0, - (SCM obj), - "Return @code{#t} if @var{obj} is a weak value hash table.") -#define FUNC_NAME s_scm_weak_value_alist_vector_p -{ - return scm_from_bool (SCM_I_WVECTP (obj) && SCM_IS_WHVEC_V (obj)); -} -#undef FUNC_NAME - - -SCM_DEFINE (scm_doubly_weak_alist_vector_p, "doubly-weak-alist-vector?", 1, 0, 0, - (SCM obj), - "Return @code{#t} if @var{obj} is a doubly weak hash table.") -#define FUNC_NAME s_scm_doubly_weak_alist_vector_p -{ - return scm_from_bool (SCM_I_WVECTP (obj) && SCM_IS_WHVEC_B (obj)); -} -#undef FUNC_NAME - - - - -SCM -scm_init_weaks_builtins () -{ -#include "libguile/weaks.x" - return SCM_UNSPECIFIED; -} - -void -scm_weaks_prehistory () -{ - /* Initialize weak pairs. */ - GC_word wcar_pair_bitmap[GC_BITMAP_SIZE (scm_t_cell)] = { 0 }; - GC_word wcdr_pair_bitmap[GC_BITMAP_SIZE (scm_t_cell)] = { 0 }; - - /* In a weak-car pair, only the second word must be scanned for - pointers. */ - GC_set_bit (wcar_pair_bitmap, GC_WORD_OFFSET (scm_t_cell, word_1)); - wcar_pair_descr = GC_make_descriptor (wcar_pair_bitmap, - GC_WORD_LEN (scm_t_cell)); - - /* Conversely, in a weak-cdr pair, only the first word must be scanned for - pointers. */ - GC_set_bit (wcdr_pair_bitmap, GC_WORD_OFFSET (scm_t_cell, word_0)); - wcdr_pair_descr = GC_make_descriptor (wcdr_pair_bitmap, - GC_WORD_LEN (scm_t_cell)); - -} - -void -scm_init_weaks () -{ - scm_c_define_gsubr ("%init-weaks-builtins", 0, 0, 0, - scm_init_weaks_builtins); -} - - -/* - Local Variables: - c-file-style: "gnu" - End: -*/ |