/* 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. */ #include "libguile/_scm.h" #include "libguile/vectors.h" #include "libguile/validate.h" #include "libguile/weaks.h" /* {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 {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 { 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 SCM_DEFINE (scm_make_weak_key_hash_table, "make-weak-key-hash-table", 1, 0, 0, (SCM size), "@deffnx {Scheme Procedure} make-weak-value-hash-table size\n" "@deffnx {Scheme Procedure} 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 {Scheme Procedure} weak-value-hash-table? obj\n" "@deffnx {Scheme Procedure} 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; } 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 () { #include "libguile/weaks.x" } /* Local Variables: c-file-style: "gnu" End: */