From 70399a721cced0c702f6cfe8a08fb9dae45aa18f Mon Sep 17 00:00:00 2001
From: Corinna Vinschen <corinna@vinschen.de>
Date: Tue, 31 Mar 2015 11:22:50 +0200
Subject: [PATCH] Avoid excessive locking and calling tzset in time functions.

	* libc/time/lcltime_r.c (localtime_r): Call _tzset_unlocked inside
	TZ lock.
	* libc/time/mktime.c (mktime):  Ditto.
	* libc/time/strftime.c (strftime, wcsftime): Ditto.  Guard against
	calling _tzset_unlocked more than once (baring recursion).

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
---
 newlib/ChangeLog             |  8 ++++++++
 newlib/libc/time/lcltime_r.c |  2 +-
 newlib/libc/time/mktime.c    |  4 ++--
 newlib/libc/time/strftime.c  | 16 ++++++++++++++--
 4 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 420354ef6..e615421d1 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,11 @@
+2015-03-31  Corinna Vinschen  <vinschen@redhat.com>
+
+	* libc/time/lcltime_r.c (localtime_r): Call _tzset_unlocked inside
+	TZ lock.
+	* libc/time/mktime.c (mktime):  Ditto.
+	* libc/time/strftime.c (strftime, wcsftime): Ditto.  Guard against
+	calling _tzset_unlocked more than once (baring recursion).
+
 2015-03-31  Corinna Vinschen  <vinschen@redhat.com>
 
 	* libc/time/local.h (_tzset_unlocked_r): Add prototype.
diff --git a/newlib/libc/time/lcltime_r.c b/newlib/libc/time/lcltime_r.c
index 8a69e40ee..3342e9906 100644
--- a/newlib/libc/time/lcltime_r.c
+++ b/newlib/libc/time/lcltime_r.c
@@ -31,8 +31,8 @@ _DEFUN (localtime_r, (tim_p, res),
   year = res->tm_year + YEAR_BASE;
   ip = __month_lengths[isleap(year)];
 
-  tzset ();
   TZ_LOCK;
+  _tzset_unlocked ();
   if (_daylight)
     {
       if (year == tz->__tzyear || __tzcalc_limits (year))
diff --git a/newlib/libc/time/mktime.c b/newlib/libc/time/mktime.c
index 8669fbdfb..44c0257f7 100644
--- a/newlib/libc/time/mktime.c
+++ b/newlib/libc/time/mktime.c
@@ -197,10 +197,10 @@ _DEFUN(mktime, (tim_p),
   /* compute total seconds */
   tim += (days * _SEC_IN_DAY);
 
-  tzset ();
-
   TZ_LOCK;
 
+  _tzset_unlocked ();
+
   if (_daylight)
     {
       int tm_isdst;
diff --git a/newlib/libc/time/strftime.c b/newlib/libc/time/strftime.c
index 72f06d32e..9e677346e 100644
--- a/newlib/libc/time/strftime.c
+++ b/newlib/libc/time/strftime.c
@@ -703,6 +703,7 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
   CHAR alt;
   CHAR pad;
   unsigned long width;
+  int tzset_called = 0;
 
   struct lc_time_T *_CurrentTimeLocale = __get_current_time_locale ();
   for (;;)
@@ -1283,7 +1284,13 @@ recurse:
           if (tim_p->tm_isdst >= 0)
             {
 	      long offset;
-	      tzset ();
+
+	      TZ_LOCK;
+	      if (!tzset_called)
+		{
+		  _tzset_unlocked ();
+		  tzset_called = 1;
+		}
 
 #if defined (__CYGWIN__)
 	      /* Cygwin must check if the application has been built with or
@@ -1302,6 +1309,7 @@ recurse:
 		 but have to use __tzrule for daylight savings.  */
 	      offset = -tz->__tzrule[tim_p->tm_isdst > 0].offset;
 #endif
+	      TZ_UNLOCK;
 	      len = snprintf (&s[count], maxsize - count, CQ("%+03ld%.2ld"),
 			      offset / SECSPERHOUR,
 			      labs (offset / SECSPERMIN) % 60L);
@@ -1314,8 +1322,12 @@ recurse:
 	      size_t size;
 	      const char *tznam = NULL;
 
-	      tzset ();
 	      TZ_LOCK;
+	      if (!tzset_called)
+		{
+		  _tzset_unlocked ();
+		  tzset_called = 1;
+		}
 #if defined (__CYGWIN__)
 	      /* See above. */
 	      extern const char *__cygwin_gettzname (const struct tm *tmp);