From owner-svn-src-head@FreeBSD.ORG  Wed Oct  3 04:46:59 2012
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 7AE39106564A;
	Wed,  3 Oct 2012 04:46:59 +0000 (UTC)
	(envelope-from ache@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id 2A7F78FC12;
	Wed,  3 Oct 2012 04:46:59 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.4/8.14.4) with ESMTP id q934kwko064504;
	Wed, 3 Oct 2012 04:46:58 GMT (envelope-from ache@svn.freebsd.org)
Received: (from ache@localhost)
	by svn.freebsd.org (8.14.4/8.14.4/Submit) id q934kwKO064502;
	Wed, 3 Oct 2012 04:46:58 GMT (envelope-from ache@svn.freebsd.org)
Message-Id: <201210030446.q934kwKO064502@svn.freebsd.org>
From: "Andrey A. Chernov" <ache@FreeBSD.org>
Date: Wed, 3 Oct 2012 04:46:58 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-head@freebsd.org
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r241154 - head/lib/libc/stdlib
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
	<svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 03 Oct 2012 04:46:59 -0000

Author: ache
Date: Wed Oct  3 04:46:58 2012
New Revision: 241154
URL: http://svn.freebsd.org/changeset/base/241154

Log:
  Optimize prev. commit for speed.
  1) Don't iterate the loop from the environment array beginning each time,
  iterate it under the last place we deactivate instead.
  2) Call __rebuild_environ() not on each iteration but once, only at the end
  of whole loop (of course, only in case if something is changed).
  
  MFC after:      1 week

Modified:
  head/lib/libc/stdlib/getenv.c

Modified: head/lib/libc/stdlib/getenv.c
==============================================================================
--- head/lib/libc/stdlib/getenv.c	Wed Oct  3 04:22:39 2012	(r241153)
+++ head/lib/libc/stdlib/getenv.c	Wed Oct  3 04:46:58 2012	(r241154)
@@ -662,6 +662,7 @@ unsetenv(const char *name)
 {
 	int envNdx;
 	size_t nameLen;
+	int newEnvActive;
 
 	/* Check for malformed name. */
 	if (name == NULL || (nameLen = __strleneq(name)) == 0) {
@@ -674,15 +675,18 @@ unsetenv(const char *name)
 		return (-1);
 
 	/* Deactivate specified variable. */
-	envNdx = envVarsTotal - 1;
 	/* Remove all occurrences. */
+	envNdx = envVarsTotal - 1;
+	newEnvActive = envActive;
 	while (__findenv(name, nameLen, &envNdx, true) != NULL) {
 		envVars[envNdx].active = false;
 		if (envVars[envNdx].putenv)
 			__remove_putenv(envNdx);
-		__rebuild_environ(envActive - 1);
-		envNdx = envVarsTotal - 1;
+		envNdx--;
+		newEnvActive--;
 	}
+	if (newEnvActive != envActive)
+		__rebuild_environ(newEnvActive);
 
 	return (0);
 }