1/* $NetBSD: gc.c,v 1.1.1.1 2016/01/14 00:11:29 christos Exp $ */ 2 3/* gc.c -- Functions to remember and garbage collect unused node contents. 4 Id: gc.c,v 1.3 2004/04/11 17:56:45 karl Exp 5 6 Copyright (C) 1993, 2004 Free Software Foundation, Inc. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2, or (at your option) 11 any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 21 22 Written by Brian Fox (bfox@ai.mit.edu). */ 23 24#include "info.h" 25 26/* Array of pointers to the contents of gc-able nodes. A pointer on this 27 list can be garbage collected when no info window contains a node whose 28 contents member match the pointer. */ 29static char **gcable_pointers = (char **)NULL; 30static int gcable_pointers_index = 0; 31static int gcable_pointers_slots = 0; 32 33/* Add POINTER to the list of garbage collectible pointers. A pointer 34 is not actually garbage collected until no info window contains a node 35 whose contents member is equal to the pointer. */ 36void 37add_gcable_pointer (char *pointer) 38{ 39 gc_pointers (); 40 add_pointer_to_array (pointer, gcable_pointers_index, gcable_pointers, 41 gcable_pointers_slots, 10, char *); 42} 43 44/* Grovel the list of info windows and gc-able pointers finding those 45 node->contents which are collectible, and free them. */ 46void 47gc_pointers (void) 48{ 49 register int i, j, k; 50 INFO_WINDOW *iw; 51 char **new = (char **)NULL; 52 int new_index = 0; 53 int new_slots = 0; 54 55 if (!info_windows || !gcable_pointers_index) 56 return; 57 58 for (i = 0; (iw = info_windows[i]); i++) 59 { 60 for (j = 0; j < iw->nodes_index; j++) 61 { 62 NODE *node = iw->nodes[j]; 63 64 /* If this node->contents appears in our list of gcable_pointers, 65 it is not gc-able, so save it. */ 66 for (k = 0; k < gcable_pointers_index; k++) 67 if (gcable_pointers[k] == node->contents) 68 { 69 add_pointer_to_array 70 (node->contents, new_index, new, new_slots, 10, char *); 71 break; 72 } 73 } 74 } 75 76 /* We have gathered all of the pointers which need to be saved. Free any 77 of the original pointers which do not appear in the new list. */ 78 for (i = 0; i < gcable_pointers_index; i++) 79 { 80 for (j = 0; j < new_index; j++) 81 if (gcable_pointers[i] == new[j]) 82 break; 83 84 /* If we got all the way through the new list, then the old pointer 85 can be garbage collected. */ 86 if (new && !new[j]) 87 free (gcable_pointers[i]); 88 } 89 90 free (gcable_pointers); 91 gcable_pointers = new; 92 gcable_pointers_slots = new_slots; 93 gcable_pointers_index = new_index; 94} 95