1 /* gc.c -- Functions to remember and garbage collect unused node contents.
2 $Id: gc.c,v 1.1.1.3 2006/07/17 16:03:42 espie Exp $
3
4 Copyright (C) 1993, 2004 Free Software Foundation, Inc.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19
20 Written by Brian Fox (bfox@ai.mit.edu). */
21
22 #include "info.h"
23
24 /* Array of pointers to the contents of gc-able nodes. A pointer on this
25 list can be garbage collected when no info window contains a node whose
26 contents member match the pointer. */
27 static char **gcable_pointers = (char **)NULL;
28 static int gcable_pointers_index = 0;
29 static int gcable_pointers_slots = 0;
30
31 /* Add POINTER to the list of garbage collectible pointers. A pointer
32 is not actually garbage collected until no info window contains a node
33 whose contents member is equal to the pointer. */
34 void
add_gcable_pointer(char * pointer)35 add_gcable_pointer (char *pointer)
36 {
37 gc_pointers ();
38 add_pointer_to_array (pointer, gcable_pointers_index, gcable_pointers,
39 gcable_pointers_slots, 10, char *);
40 }
41
42 /* Grovel the list of info windows and gc-able pointers finding those
43 node->contents which are collectible, and free them. */
44 void
gc_pointers(void)45 gc_pointers (void)
46 {
47 register int i, j, k;
48 INFO_WINDOW *iw;
49 char **new = (char **)NULL;
50 int new_index = 0;
51 int new_slots = 0;
52
53 if (!info_windows || !gcable_pointers_index)
54 return;
55
56 for (i = 0; (iw = info_windows[i]); i++)
57 {
58 for (j = 0; j < iw->nodes_index; j++)
59 {
60 NODE *node = iw->nodes[j];
61
62 /* If this node->contents appears in our list of gcable_pointers,
63 it is not gc-able, so save it. */
64 for (k = 0; k < gcable_pointers_index; k++)
65 if (gcable_pointers[k] == node->contents)
66 {
67 add_pointer_to_array
68 (node->contents, new_index, new, new_slots, 10, char *);
69 break;
70 }
71 }
72 }
73
74 /* We have gathered all of the pointers which need to be saved. Free any
75 of the original pointers which do not appear in the new list. */
76 for (i = 0; i < gcable_pointers_index; i++)
77 {
78 for (j = 0; j < new_index; j++)
79 if (gcable_pointers[i] == new[j])
80 break;
81
82 /* If we got all the way through the new list, then the old pointer
83 can be garbage collected. */
84 if (new && !new[j])
85 free (gcable_pointers[i]);
86 }
87
88 free (gcable_pointers);
89 gcable_pointers = new;
90 gcable_pointers_slots = new_slots;
91 gcable_pointers_index = new_index;
92 }
93