/usr.bin/xlint/lint2/mem2.c
https://bitbucket.org/freebsd/freebsd-head/ · C · 97 lines · 42 code · 14 blank · 41 comment · 4 complexity · 0ae361d2df3f811d859fc71ce2161cfd MD5 · raw file
- /* $NetBSD: mem2.c,v 1.6 2002/01/21 19:49:52 tv 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.
- */
- #include <sys/cdefs.h>
- #if defined(__RCSID) && !defined(lint)
- __RCSID("$NetBSD: mem2.c,v 1.6 2002/01/21 19:49:52 tv Exp $");
- #endif
- __FBSDID("$FreeBSD$");
- #include <sys/param.h>
- #include <sys/types.h>
- #include <sys/mman.h>
- #include <err.h>
- #include <unistd.h>
- #include <string.h>
- #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(void)
- {
- 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(size_t sz)
- {
- void *ptr;
- int prot, flags;
- /* Align to at least 8 bytes. */
- sz = (sz + 7) & ~7L;
- 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 *)MAP_FAILED)
- err(1, "can't map memory");
- (void)memset(mbuf, 0, mblklen);
- nxtfree = 0;
- }
- ptr = (char *)mbuf + nxtfree;
- nxtfree += sz;
- return (ptr);
- }