1 /* tuples.c -- management of `tuples' (car and two values)
2 
3    Copyright (C) 1993, 1994, 2000 John Harper <john@dcs.warwick.ac.uk>
4 
5    $Id$
6 
7    This file is part of librep.
8 
9    librep is free software; you can redistribute it and/or modify it
10    under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 2, or (at your option)
12    any later version.
13 
14    librep is distributed in the hope that it will be useful, but
15    WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with librep; see the file COPYING.  If not, write to
21    the Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
22 
23 #define _GNU_SOURCE
24 
25 #include "repint.h"
26 
27 #define rep_TUPLEBLK_SIZE	680		/* ~8k */
28 
29 /* Symbol allocation blocks */
30 typedef struct rep_tuple_block_struct rep_tuple_block;
31 struct rep_tuple_block_struct {
32     rep_tuple_block *next;
33     rep_ALIGN_CELL(rep_tuple tuples[rep_TUPLEBLK_SIZE]);
34 };
35 
36 static rep_tuple_block *tuple_block_chain;
37 static rep_tuple *tuple_freelist;
38 int rep_allocated_tuples, rep_used_tuples;
39 
40 repv
rep_make_tuple(repv car,repv a,repv b)41 rep_make_tuple (repv car, repv a, repv b)
42 {
43     rep_tuple *t;
44     if (tuple_freelist == 0)
45     {
46 	rep_tuple_block *sb = rep_ALLOC_CELL (sizeof (rep_tuple_block));
47 	if (sb != 0)
48 	{
49 	    int i;
50 	    rep_allocated_tuples += rep_TUPLEBLK_SIZE;
51 	    sb->next = tuple_block_chain;
52 	    tuple_block_chain = sb;
53 	    for (i = 0; i < (rep_TUPLEBLK_SIZE - 1); i++)
54 	    {
55 		sb->tuples[i].a = rep_VAL (&sb->tuples[i + 1]);
56 		sb->tuples[i].car = 0;
57 	    }
58 	    sb->tuples[i].a = rep_VAL (tuple_freelist);
59 	    sb->tuples[i].car = 0;
60 	    tuple_freelist = sb->tuples;
61 	}
62 	else
63 	    abort ();
64     }
65     t = tuple_freelist;
66     tuple_freelist = rep_TUPLE (t->a);
67     t->car = car;
68     t->a = a;
69     t->b = b;
70     rep_used_tuples++;
71     rep_data_after_gc += sizeof (rep_tuple);
72     return rep_VAL (t);
73 }
74 
75 void
rep_mark_tuple(repv t)76 rep_mark_tuple (repv t)
77 {
78     rep_MARKVAL (rep_TUPLE (t)->a);
79     rep_MARKVAL (rep_TUPLE (t)->b);
80 }
81 
82 void
rep_sweep_tuples(void)83 rep_sweep_tuples (void)
84 {
85     rep_tuple_block *sb;
86     rep_tuple *tem_freelist = 0;
87     int tem_used = 0;
88     for (sb = tuple_block_chain; sb != 0; sb = sb->next)
89     {
90 	rep_tuple *this = sb->tuples;
91 	rep_tuple *last = &(sb->tuples[rep_TUPLEBLK_SIZE]);
92 	while (this < last)
93 	{
94 	    if (!rep_GC_CELL_MARKEDP (rep_VAL (this)))
95 	    {
96 		this->a = rep_VAL (tem_freelist);
97 		tem_freelist = this;
98 	    }
99 	    else
100 	    {
101 		rep_GC_CLR_CELL (rep_VAL (this));
102 		tem_used++;
103 	    }
104 	    this++;
105 	}
106     }
107     tuple_freelist = tem_freelist;
108     rep_used_tuples = tem_used;
109 }
110 
111 void
rep_tuples_kill(void)112 rep_tuples_kill(void)
113 {
114     rep_tuple_block *sb = tuple_block_chain;
115     while (sb != 0)
116     {
117 	rep_tuple_block *nxt = sb->next;
118 	rep_FREE_CELL (sb);
119 	sb = nxt;
120     }
121     tuple_block_chain = NULL;
122 }
123