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Diffstat (limited to 'usr.bin/xlint/lint2/mem2.c')
-rw-r--r-- | usr.bin/xlint/lint2/mem2.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/usr.bin/xlint/lint2/mem2.c b/usr.bin/xlint/lint2/mem2.c new file mode 100644 index 0000000..48e759e --- /dev/null +++ b/usr.bin/xlint/lint2/mem2.c @@ -0,0 +1,97 @@ +/* $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); +} |