WG: missing TZ_LOCK

Becker, Andreas becker@se-elektronic.de
Tue Jun 28 00:26:00 GMT 2011


Hi Folks,

We are using the localtime, mktime -  functions really heavy. Sometimes a miscalculation happened. 
With hard investigations, we could verify that the problem is a missing lock around the global __tzinfo_type *tz structure.  
This structure is returned by __gettzinfo() and changed by __tz_calc_limits(year) .
Operations on this structure should be protected by TZ_LOCK() and TZ_UNLOCK(). 
This is correctly done in (newlib/time/) mktm_r.c, tzset_r.c and strftime.c but missing in mktime.c

--- a/newlib/libc/time/mktime.c Mon Jun 28 11:00:35 2010 +0200
+++ b/newlib/libc/time/mktime.c Mon Jun 27 10:18:58 2011 +0200
@@ -204,6 +204,8 @@

   isdst = tim_p->tm_isdst;

+  TZ_LOCK;
+    
   if (_daylight)
     {
       int y = tim_p->tm_year + YEAR_BASE;
@@ -251,6 +253,8 @@
   else /* otherwise assume std time */
     tim += (time_t) tz->__tzrule[0].offset;

+  TZ_UNLOCK;
+  
   /* reset isdst flag to what we have calculated */
   tim_p->tm_isdst = isdst;


Best regards,
Andi.

Mit freundlichen Grüßen

i.A. Andreas Becker 
Entwicklung Embedded 
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