/* $OpenBSD: mem2.c,v 1.2 1996/06/26 05:44:25 deraadt Exp $ */ /* $NetBSD: mem2.c,v 1.3 1995/10/02 17:27:11 jpo Exp $ */ /* * Copyright (c) 1994, 1995 Jochen Pohl * All Rights Reserved. * * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Jochen Pohl for * The NetBSD Project. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. */ #ifndef lint static char rcsid[] = "$OpenBSD: mem2.c,v 1.2 1996/06/26 05:44:25 deraadt Exp $"; #endif #include #include #include #include #include #include #include "lint2.h" /* length of new allocated memory blocks */ static size_t mblklen; /* offset of next free byte in mbuf */ static size_t nxtfree; /* current buffer to server memory requests from */ static void *mbuf; void initmem() { int pgsz; pgsz = getpagesize(); mblklen = ((MBLKSIZ + pgsz - 1) / pgsz) * pgsz; nxtfree = mblklen; } /* * Allocate memory in large chunks to avoid space and time overhead of * malloc(). This is possible because memory allocated by xalloc() * need never to be freed. */ void * xalloc(sz) size_t sz; { void *ptr; int prot, flags; sz = ALIGN(sz); if (nxtfree + sz > mblklen) { /* use mmap() instead of malloc() to avoid malloc overhead. */ prot = PROT_READ | PROT_WRITE; flags = MAP_ANON | MAP_PRIVATE; mbuf = mmap(NULL, mblklen, prot, flags, -1, (off_t)0); if (mbuf == (void *)-1) err(1, "can't map memory"); if (ALIGN((u_long)mbuf) != (u_long)mbuf) errx(1, "mapped address is not aligned"); (void)memset(mbuf, 0, mblklen); nxtfree = 0; } ptr = (char *)mbuf + nxtfree; nxtfree += sz; return (ptr); }