From owner-svn-src-head@FreeBSD.ORG  Mon Dec 21 19:43:23 2009
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 DC1C6106566C;
	Mon, 21 Dec 2009 19:43:23 +0000 (UTC) (envelope-from jhb@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id CB1108FC18;
	Mon, 21 Dec 2009 19:43:23 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id nBLJhNor038427;
	Mon, 21 Dec 2009 19:43:23 GMT (envelope-from jhb@svn.freebsd.org)
Received: (from jhb@localhost)
	by svn.freebsd.org (8.14.3/8.14.3/Submit) id nBLJhNUU038425;
	Mon, 21 Dec 2009 19:43:23 GMT (envelope-from jhb@svn.freebsd.org)
Message-Id: <200912211943.nBLJhNUU038425@svn.freebsd.org>
From: John Baldwin <jhb@FreeBSD.org>
Date: Mon, 21 Dec 2009 19:43:23 +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: r200797 - head/lib/libc/stdtime
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: Mon, 21 Dec 2009 19:43:24 -0000

Author: jhb
Date: Mon Dec 21 19:43:23 2009
New Revision: 200797
URL: http://svn.freebsd.org/changeset/base/200797

Log:
  Use _once() to initialize the pthread key for thread-local storage to hold
  the results of localtime() instead of using a pthread mutex directly.
  
  MFC after:	1 week

Modified:
  head/lib/libc/stdtime/localtime.c

Modified: head/lib/libc/stdtime/localtime.c
==============================================================================
--- head/lib/libc/stdtime/localtime.c	Mon Dec 21 19:39:10 2009	(r200796)
+++ head/lib/libc/stdtime/localtime.c	Mon Dec 21 19:43:23 2009	(r200797)
@@ -237,6 +237,9 @@ static char		lcl_TZname[TZ_STRLEN_MAX + 
 static int		lcl_is_set;
 static pthread_once_t	gmt_once = PTHREAD_ONCE_INIT;
 static pthread_rwlock_t	lcl_rwlock = PTHREAD_RWLOCK_INITIALIZER;
+static pthread_once_t	localtime_once = PTHREAD_ONCE_INIT;
+static pthread_key_t	localtime_key;
+static int		localtime_key_error;
 
 char *			tzname[2] = {
 	wildabbr,
@@ -1406,27 +1409,24 @@ struct tm * const	tmp;
 	return result;
 }
 
+static void
+localtime_key_init(void)
+{
+
+	localtime_key_error = _pthread_key_create(&localtime_key, free);
+}
+
 struct tm *
 localtime(timep)
 const time_t * const	timep;
 {
-	static pthread_mutex_t localtime_mutex = PTHREAD_MUTEX_INITIALIZER;
-	static pthread_key_t localtime_key = -1;
 	struct tm *p_tm;
-	int r;
 
 	if (__isthreaded != 0) {
-		if (localtime_key < 0) {
-			_pthread_mutex_lock(&localtime_mutex);
-			if (localtime_key < 0) {
-				if ((r = _pthread_key_create(&localtime_key,
-				    free)) != 0) {
-					_pthread_mutex_unlock(&localtime_mutex);
-					errno = r;
-					return(NULL);
-				}
-			}
-			_pthread_mutex_unlock(&localtime_mutex);
+		_once(&localtime_once, localtime_key_init);
+		if (localtime_key_error != 0) {
+			errno = localtime_key_error;
+			return(NULL);
 		}
 		p_tm = _pthread_getspecific(localtime_key);
 		if (p_tm == NULL) {