-/* Copyright (C) 1995,1996,1998,2000,2001 Free Software Foundation, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this software; see the file COPYING. If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
- * Boston, MA 02111-1307 USA
- *
- * As a special exception, Free Software Foundation gives permission
- * for additional uses of the text contained in its release of this library.
- *
- * The exception is that, if you link this library with other files
- * to produce an executable, this does not by itself cause the
- * resulting executable to be covered by the GNU General Public License.
- * Your use of that executable is in no way restricted on account of
- * linking this library code into it.
- *
- * This exception does not however invalidate any other reasons why
- * the executable file might be covered by the GNU General Public License.
- *
- * This exception applies only to the code released by
- * Free Software Foundation as part of this library. If you copy
- * code from other releases distributed under the terms of the GPL into a copy of
- * this library, as the General Public License permits, the exception does
- * not apply to the code that you add in this way. To avoid misleading
- * anyone as to the status of such modified files, you must delete
- * this exception notice from such code.
- *
- * If you write modifications of your own for this library, it is your choice
- * whether to permit this exception to apply to your modifications.
- * If you do not wish that, delete this exception notice. */
-
-/* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
- gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
-
-\f
-
-#include "libguile/_scm.h"
-#include "libguile/vectors.h"
-
-#include "libguile/validate.h"
-#include "libguile/weaks.h"
-
-\f
-
-/* {Weak Vectors}
- */
-
-
-/* Allocate memory for a weak vector on behalf of the caller. The allocated
- * vector will be of the given weak vector subtype. It will contain size
- * elements which are initialized with the 'fill' object, or, if 'fill' is
- * undefined, with an unspecified object.
- */
-static SCM
-allocate_weak_vector (scm_t_bits type, SCM size, SCM fill, const char* caller)
-#define FUNC_NAME caller
-{
- if (SCM_INUMP (size))
- {
- size_t c_size;
- SCM v;
-
- SCM_ASSERT_RANGE (1, size, SCM_INUM (size) >= 0);
- c_size = SCM_INUM (size);
-
- SCM_NEWCELL2 (v);
- SCM_SET_WVECT_GC_CHAIN (v, SCM_EOL);
- SCM_SET_WVECT_TYPE (v, type);
-
- if (c_size > 0)
- {
- scm_t_bits *base;
- size_t j;
-
- if (SCM_UNBNDP (fill))
- fill = SCM_UNSPECIFIED;
-
- SCM_ASSERT_RANGE (1, size, c_size <= SCM_VECTOR_MAX_LENGTH);
- base = scm_must_malloc (c_size * sizeof (scm_t_bits), FUNC_NAME);
- for (j = 0; j != c_size; ++j)
- base[j] = SCM_UNPACK (fill);
- SCM_SET_VECTOR_BASE (v, base);
- SCM_SET_VECTOR_LENGTH (v, c_size, scm_tc7_wvect);
- scm_remember_upto_here_1 (fill);
- }
- else
- {
- SCM_SET_VECTOR_BASE (v, NULL);
- SCM_SET_VECTOR_LENGTH (v, 0, scm_tc7_wvect);
- }
-
- return v;
- }
- else if (SCM_BIGP (size))
- SCM_OUT_OF_RANGE (1, size);
- else
- SCM_WRONG_TYPE_ARG (1, size);
-}
-#undef FUNC_NAME
-
-
-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 allocate_weak_vector (0, size, fill, FUNC_NAME);
-}
-#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 primitive 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
-{
- SCM res;
- SCM *data;
- long i;
-
- /* Dirk:FIXME:: In case of multiple threads, the list might get corrupted
- while the vector is being created. */
- i = scm_ilength (l);
- SCM_ASSERT (i >= 0, l, SCM_ARG1, FUNC_NAME);
- res = scm_make_weak_vector (SCM_MAKINUM (i), SCM_UNSPECIFIED);
- data = SCM_VELTS (res);
-
- while (!SCM_NULLP (l))
- {
- *data++ = SCM_CAR (l);
- l = SCM_CDR (l);
- }
-
- return res;
-}
-#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_BOOL (SCM_WVECTP (obj) && !SCM_IS_WHVEC (obj));
-}
-#undef FUNC_NAME
-
-\f
-
-SCM_DEFINE (scm_make_weak_key_hash_table, "make-weak-key-hash-table", 1, 0, 0,
- (SCM size),
- "@deffnx primitive make-weak-value-hash-table size\n"
- "@deffnx primitive make-doubly-weak-hash-table 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_hash_table
-{
- return allocate_weak_vector (1, size, SCM_EOL, FUNC_NAME);
-}
-#undef FUNC_NAME
-
-
-SCM_DEFINE (scm_make_weak_value_hash_table, "make-weak-value-hash-table", 1, 0, 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_hash_table
-{
- return allocate_weak_vector (2, size, SCM_EOL, FUNC_NAME);
-}
-#undef FUNC_NAME
-
-
-SCM_DEFINE (scm_make_doubly_weak_hash_table, "make-doubly-weak-hash-table", 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_hash_table
-{
- return allocate_weak_vector (3, size, SCM_EOL, FUNC_NAME);
-}
-#undef FUNC_NAME
-
-
-SCM_DEFINE (scm_weak_key_hash_table_p, "weak-key-hash-table?", 1, 0, 0,
- (SCM obj),
- "@deffnx primitive weak-value-hash-table? obj\n"
- "@deffnx primitive doubly-weak-hash-table? 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_hash_table_p
-{
- return SCM_BOOL (SCM_WVECTP (obj) && SCM_IS_WHVEC (obj));
-}
-#undef FUNC_NAME
-
-
-SCM_DEFINE (scm_weak_value_hash_table_p, "weak-value-hash-table?", 1, 0, 0,
- (SCM obj),
- "Return @code{#t} if @var{obj} is a weak value hash table.")
-#define FUNC_NAME s_scm_weak_value_hash_table_p
-{
- return SCM_BOOL (SCM_WVECTP (obj) && SCM_IS_WHVEC_V (obj));
-}
-#undef FUNC_NAME
-
-
-SCM_DEFINE (scm_doubly_weak_hash_table_p, "doubly-weak-hash-table?", 1, 0, 0,
- (SCM obj),
- "Return @code{#t} if @var{obj} is a doubly weak hash table.")
-#define FUNC_NAME s_scm_doubly_weak_hash_table_p
-{
- return SCM_BOOL (SCM_WVECTP (obj) && SCM_IS_WHVEC_B (obj));
-}
-#undef FUNC_NAME
-
-
-static void *
-scm_weak_vector_gc_init (void *dummy1 SCM_UNUSED,
- void *dummy2 SCM_UNUSED,
- void *dummy3 SCM_UNUSED)
-{
- scm_weak_vectors = SCM_EOL;
-
- return 0;
-}
-
-
-static void *
-scm_mark_weak_vector_spines (void *dummy1 SCM_UNUSED,
- void *dummy2 SCM_UNUSED,
- void *dummy3 SCM_UNUSED)
-{
- SCM w;
-
- for (w = scm_weak_vectors; !SCM_NULLP (w); w = SCM_WVECT_GC_CHAIN (w))
- {
- if (SCM_IS_WHVEC_ANY (w))
- {
- SCM *ptr;
- SCM obj;
- long j;
- long n;
-
- obj = w;
- ptr = SCM_VELTS (w);
- n = SCM_VECTOR_LENGTH (w);
- for (j = 0; j < n; ++j)
- {
- SCM alist;
-
- alist = ptr[j];
- while ( SCM_CONSP (alist)
- && !SCM_GCMARKP (alist)
- && SCM_CONSP (SCM_CAR (alist)))
- {
- SCM_SETGCMARK (alist);
- SCM_SETGCMARK (SCM_CAR (alist));
- alist = SCM_CDR (alist);
- }
- }
- }
- }
-
- return 0;
-}
-
-
-static void *
-scm_scan_weak_vectors (void *dummy1 SCM_UNUSED,
- void *dummy2 SCM_UNUSED,
- void *dummy3 SCM_UNUSED)
-{
- SCM *ptr, w;
- for (w = scm_weak_vectors; !SCM_NULLP (w); w = SCM_WVECT_GC_CHAIN (w))
- {
- if (!SCM_IS_WHVEC_ANY (w))
- {
- register long j, n;
-
- ptr = SCM_VELTS (w);
- n = SCM_VECTOR_LENGTH (w);
- for (j = 0; j < n; ++j)
- if (SCM_FREE_CELL_P (ptr[j]))
- ptr[j] = SCM_BOOL_F;
- }
- else /* if (SCM_IS_WHVEC_ANY (scm_weak_vectors[i])) */
- {
- SCM obj = w;
- register long n = SCM_VECTOR_LENGTH (w);
- register long j;
- int weak_keys = SCM_IS_WHVEC (obj) || SCM_IS_WHVEC_B (obj);
- int weak_values = SCM_IS_WHVEC_V (obj) || SCM_IS_WHVEC_B (obj);
-
- ptr = SCM_VELTS (w);
-
- for (j = 0; j < n; ++j)
- {
- SCM * fixup;
- SCM alist;
-
- fixup = ptr + j;
- alist = *fixup;
-
- while ( SCM_CONSP (alist)
- && SCM_CONSP (SCM_CAR (alist)))
- {
- SCM key;
- SCM value;
-
- key = SCM_CAAR (alist);
- value = SCM_CDAR (alist);
- if ( (weak_keys && SCM_FREE_CELL_P (key))
- || (weak_values && SCM_FREE_CELL_P (value)))
- {
- *fixup = SCM_CDR (alist);
- }
- else
- fixup = SCM_CDRLOC (alist);
- alist = SCM_CDR (alist);
- }
- }
- }
- }
-
- return 0;
-}
-
-\f
-
-void
-scm_weaks_prehistory ()
-{
- scm_c_hook_add (&scm_before_mark_c_hook, scm_weak_vector_gc_init, 0, 0);
- scm_c_hook_add (&scm_before_sweep_c_hook, scm_mark_weak_vector_spines, 0, 0);
- scm_c_hook_add (&scm_after_sweep_c_hook, scm_scan_weak_vectors, 0, 0);
-}
-
-
-void
-scm_init_weaks ()
-{
-#ifndef SCM_MAGIC_SNARFER
-#include "libguile/weaks.x"
-#endif
-}
-
-
-/*
- Local Variables:
- c-file-style: "gnu"
- End:
-*/
+/* Copyright (C) 1995, 1996, 1998, 2000, 2001, 2003, 2006, 2008, 2009, 2010,
+ * 2011, 2012 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
+ */
+
+
+\f
+#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>
+
+
+\f
+/* 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 ((void **) &cell->word_0, 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 ((void **) &cell->word_1, 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 ((void **) &cell->word_0, SCM2PTR (car));
+ if (SCM_NIMP (cdr))
+ SCM_I_REGISTER_DISAPPEARING_LINK ((void **) &cell->word_1, SCM2PTR (cdr));
+
+ return (SCM_PACK (cell));
+}
+
+
+\f
+
+/* 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
+
+\f
+/* 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
+
+
+
+\f
+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:
+*/
HCoop / bpt / guile.git / blobdiff