[src/trunk]: src/usr.bin/xlint/common - keep the fd to /dev/zero open

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2ed99fc85559
branches:  trunk
changeset: 553892:2ed99fc85559
user:      christos <christos%NetBSD.org@localhost>
date:      Wed Oct 22 16:10:03 2003 +0000

description:
- keep the fd to /dev/zero open
- take advantage of MAP_ANONYMOUS

diffstat:

 usr.bin/xlint/common/mem.c |  20 +++++++++++---------
 1 files changed, 11 insertions(+), 9 deletions(-)

diffs (54 lines):

diff -r b3b2502e3e63 -r 2ed99fc85559 usr.bin/xlint/common/mem.c
--- a/usr.bin/xlint/common/mem.c        Wed Oct 22 15:57:33 2003 +0000
+++ b/usr.bin/xlint/common/mem.c        Wed Oct 22 16:10:03 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mem.c,v 1.5 2003/10/21 23:58:53 christos Exp $ */
+/*     $NetBSD: mem.c,v 1.6 2003/10/22 16:10:03 christos Exp $ */
 
 /*
  * Copyright (c) 1994, 1995 Jochen Pohl
@@ -33,7 +33,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: mem.c,v 1.5 2003/10/21 23:58:53 christos Exp $");
+__RCSID("$NetBSD: mem.c,v 1.6 2003/10/22 16:10:03 christos Exp $");
 #endif
 
 #include <sys/param.h>
@@ -94,26 +94,28 @@
        errx(1, "virtual memory exhausted");
 }
 
+#if defined(MAP_ANONYMOUS) && !defined(MAP_ANON)
+#define        MAP_ANON        MAP_ANONYMOUS
+#endif
+
 void *
 xmapalloc(size_t len)
 {
        static const int prot = PROT_READ | PROT_WRITE;
+       static int fd = -1;
        void *p;
 #ifdef MAP_ANON
        static const int flags = MAP_ANON | MAP_PRIVATE;
-       int fd = -1;
 #else
        static const int flags = MAP_PRIVATE;
-       int fd = open("/dev/zero", O_RDWR);
 
-       if (fd == -1)
-               err(1, "Cannot open `/dev/zero'");
+       if (fd == -1) {
+               if ((fd = open("/dev/zero", O_RDWR)) == -1)
+                       err(1, "Cannot open `/dev/zero'");
+       }
 #endif
        p = mmap(NULL, len, prot, flags, fd, (off_t)0);
        if (p == (void *)-1)
                err(1, "Cannot map memory for %lu bytes", (unsigned long)len);
-#ifndef MAP_ANON
-       (void)close(fd);
-#endif
        return p;
 }