| /* |
| * Copyright (c) International Business Machines Corp., 2001-2004 |
| * |
| * 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 of the License, 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 program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| #include <stdlib.h> |
| #include <assert.h> |
| |
| #include "cirlist.h" |
| #include "util.h" |
| |
| void init_cirlist(struct cirlist *cl) |
| { |
| cl->count = 0; |
| cl->head = NULL; |
| } |
| |
| int cl_empty(struct cirlist *cl) |
| { |
| return !(cl->count); |
| } |
| |
| void cl_insert_tail(struct cirlist *cl, cldatatype object) |
| { |
| struct cnode *new = ffsb_malloc(sizeof(struct cnode)); |
| new->obj = object; |
| if (cl->count == 0) { |
| assert(cl->head == NULL); |
| cl->head = new; |
| cl->head->next = cl->head; |
| cl->head->prev = cl->head; |
| cl->count = 1; |
| } else { |
| if (cl->count == 1) { |
| assert(cl->head->next == cl->head); |
| assert(cl->head->prev == cl->head); |
| cl->head->next = new; |
| cl->head->prev = new; |
| new->next = cl->head; |
| new->prev = cl->head; |
| } else { |
| assert(cl->head->next != cl->head); |
| assert(cl->head->prev != cl->head); |
| |
| new->next = cl->head; |
| new->prev = (cl->head)->prev; |
| cl->head->prev->next = new; |
| cl->head->prev = new; |
| } |
| cl->count++; |
| } |
| } |
| |
| cldatatype cl_remove_head(struct cirlist *cl) |
| { |
| struct cnode *oldhead = NULL; |
| struct cnode *newhead = NULL; |
| cldatatype ret = NULL; |
| |
| if (cl->count == 0) { |
| assert(cl->head == NULL); |
| return NULL; |
| } |
| if (cl->count == 1) { |
| assert(cl->head->next == cl->head); |
| assert(cl->head->prev == cl->head); |
| oldhead = cl->head; |
| cl->head = NULL; |
| cl->count = 0; |
| } else if (cl->count == 2) { |
| oldhead = cl->head; |
| newhead = oldhead->next; |
| newhead->next = newhead; |
| newhead->prev = newhead; |
| cl->head = newhead; |
| cl->count = 1; |
| } else { |
| assert(cl->head->next != cl->head); |
| assert(cl->head->prev != cl->head); |
| oldhead = cl->head; |
| newhead = oldhead->next; |
| newhead->prev = oldhead->prev; |
| newhead->prev->next = newhead; |
| cl->head = newhead; |
| cl->count--; |
| } |
| ret = oldhead->obj; |
| oldhead->obj = (void *)(-1); |
| oldhead->next = (void *)(-1); |
| oldhead->prev = (void *)(-1); |
| free(oldhead); |
| |
| return ret; |
| } |