/* $MirBSD: alloc.c,v 1.3 2004/05/23 12:47:00 tg Exp $ */ /* $OpenBSD: alloc.c,v 1.7 2004/02/19 18:51:17 deraadt Exp $ */ /* * Copyright (c) 2002 Marc Espie. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBSD * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * area-based allocation built on malloc/free */ #include "sh.h" struct link { struct link *prev; struct link *next; }; Area * ainit(Area *ap) { ap->freelist = NULL; return ap; } void afreeall(Area *ap) { struct link *l, *l2; for (l = ap->freelist; l != NULL; l = l2) { l2 = l->next; free(l); } ap->freelist = NULL; } #define L2P(l) ( (void *)(((char *)(l)) + sizeof(struct link)) ) #define P2L(p) ( (struct link *)(((char *)(p)) - sizeof(struct link)) ) void * alloc(size_t size, Area *ap) { struct link *l; l = malloc(sizeof(struct link) + size); if (l == NULL) internal_errorf(1, "unable to allocate memory"); l->next = ap->freelist; l->prev = NULL; if (ap->freelist) ap->freelist->prev = l; ap->freelist = l; return L2P(l); } void * aresize(void *ptr, size_t size, Area *ap) { struct link *l, *l2, *lprev, *lnext; if (ptr == NULL) return alloc(size, ap); l = P2L(ptr); lprev = l->prev; lnext = l->next; l2 = realloc(l, sizeof(struct link) + size); if (l2 == NULL) internal_errorf(1, "unable to allocate memory"); if (lprev) lprev->next = l2; else ap->freelist = l2; if (lnext) lnext->prev = l2; return L2P(l2); } void afree(void *ptr, Area *ap) { struct link *l; if (!ptr) return; l = P2L(ptr); if (l->prev) l->prev->next = l->next; else ap->freelist = l->next; if (l->next) l->next->prev = l->prev; free(l); }