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authortron <tron@NetBSD.org>2010-10-24 17:53:27 +0000
committertron <tron@NetBSD.org>2010-10-24 17:53:27 +0000
commit1dc4fb4ea1158e8a25af80ccb351aff4d2930d60 (patch)
tree1daa6b52daea14ab34df492bf51bfb131fccae70 /lib/libc/stdlib
parent410614d6b381263ea08b0add3db883dc3f922ba5 (diff)
Double the size of the allocate environment vector when we resize it.
This should speed up extending the environment via setenv(3).
Diffstat (limited to 'lib/libc/stdlib')
-rw-r--r--lib/libc/stdlib/getenv.c37
1 files changed, 23 insertions, 14 deletions
diff --git a/lib/libc/stdlib/getenv.c b/lib/libc/stdlib/getenv.c
index a6b5222680c..f7c393c1fc9 100644
--- a/lib/libc/stdlib/getenv.c
+++ b/lib/libc/stdlib/getenv.c
@@ -1,4 +1,4 @@
-/* $NetBSD: getenv.c,v 1.25 2010/10/02 10:51:07 tron Exp $ */
+/* $NetBSD: getenv.c,v 1.26 2010/10/24 17:53:27 tron Exp $ */
/*
* Copyright (c) 1987, 1993
@@ -34,7 +34,7 @@
#if 0
static char sccsid[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93";
#else
-__RCSID("$NetBSD: getenv.c,v 1.25 2010/10/02 10:51:07 tron Exp $");
+__RCSID("$NetBSD: getenv.c,v 1.26 2010/10/24 17:53:27 tron Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
@@ -105,7 +105,7 @@ int
__allocenv(int offset)
{
char **p;
- size_t nl;
+ size_t required_len, new_len;
if (offset == -1 || saveenv != environ) {
char **ptr;
@@ -113,33 +113,42 @@ __allocenv(int offset)
offset++;
}
- nl = offset + 2; /* one for potentially new entry one for NULL */
- if (nl <= environ_malloced_len && saveenv == environ)
+ /* one for potentially new entry one for NULL */
+ required_len = offset + 2;
+
+ if (required_len <= environ_malloced_len && saveenv == environ)
return 0;
+ /* Make sure we at least double the size of the arrays. */
+ new_len = (environ_malloced_len >= 16) ?
+ (environ_malloced_len << 1) : 16;
+ while (new_len < required_len)
+ new_len = new_len << 1;
+
if (saveenv == environ) { /* just increase size */
- if ((p = realloc(saveenv, nl * sizeof(*p))) == NULL)
+ if ((p = realloc(saveenv, new_len * sizeof(*p))) == NULL)
return -1;
(void)memset(&p[environ_malloced_len], 0,
- (nl - environ_malloced_len) * sizeof(*p));
+ (new_len - environ_malloced_len) * sizeof(*p));
saveenv = p;
} else { /* get new space */
free(saveenv);
- if ((saveenv = malloc(nl * sizeof(*saveenv))) == NULL)
+ if ((saveenv = malloc(new_len * sizeof(*saveenv))) == NULL)
return -1;
- (void)memcpy(saveenv, environ, (nl - 2) * sizeof(*saveenv));
- saveenv[nl - 2] = NULL;
- saveenv[nl - 1] = NULL;
+ (void)memcpy(saveenv, environ,
+ (required_len - 2) * sizeof(*saveenv));
+ (void)memset(&saveenv[required_len - 2], 0,
+ (new_len - (required_len - 2)) * sizeof(*saveenv));
}
environ = saveenv;
- p = realloc(__environ_malloced, nl * sizeof(*p));
+ p = realloc(__environ_malloced, new_len * sizeof(*p));
if (p == NULL)
return -1;
(void)memset(&p[environ_malloced_len], 0,
- (nl - environ_malloced_len) * sizeof(*p));
- environ_malloced_len = nl;
+ (new_len - environ_malloced_len) * sizeof(*p));
+ environ_malloced_len = new_len;
__environ_malloced = p;
return 0;