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 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 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