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      1 /* Work around the bug in some systems whereby gettimeofday clobbers the
      2    static buffer that localtime uses for it's return value.  The gettimeofday
      3    function from Mac OS X 10.0.4, i.e. Darwin 1.3.7 has this problem.
      4    The tzset replacement is necessary for at least Solaris 2.5, 2.5.1, and 2.6.
      5    Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
      6 
      7    This program is free software; you can redistribute it and/or modify
      8    it under the terms of the GNU General Public License as published by
      9    the Free Software Foundation; either version 2, or (at your option)
     10    any later version.
     11 
     12    This program is distributed in the hope that it will be useful,
     13    but WITHOUT ANY WARRANTY; without even the implied warranty of
     14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     15    GNU General Public License for more details.
     16 
     17    You should have received a copy of the GNU General Public License
     18    along with this program; if not, write to the Free Software Foundation,
     19    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
     20 #include <sys/cdefs.h>
     21 __RCSID("$NetBSD: gettimeofday.c,v 1.2 2016/05/17 14:00:09 christos Exp $");
     22 
     23 
     24 /* written by Jim Meyering */
     25 
     26 #ifdef HAVE_CONFIG_H
     27 # include <config.h>
     28 #endif
     29 
     30 /* Disable the definitions of these functions (from config.h)
     31    so we can use the library versions here.  */
     32 #undef gettimeofday
     33 #undef gmtime
     34 #undef localtime
     35 #undef tzset
     36 
     37 #include <sys/types.h>
     38 
     39 #if TIME_WITH_SYS_TIME
     40 # include <sys/time.h>
     41 # include <time.h>
     42 #else
     43 # if HAVE_SYS_TIME_H
     44 #  include <sys/time.h>
     45 # else
     46 #  include <time.h>
     47 # endif
     48 #endif
     49 
     50 #include <stdlib.h>
     51 
     52 static struct tm *localtime_buffer_addr;
     53 
     54 /* This is a wrapper for localtime.  It is used only on systems for which
     55    gettimeofday clobbers the static buffer used for localtime's result.
     56 
     57    On the first call, record the address of the static buffer that
     58    localtime uses for its result.  */
     59 
     60 struct tm *
     61 rpl_localtime (const time_t *timep)
     62 {
     63   struct tm *tm = localtime (timep);
     64 
     65   if (! localtime_buffer_addr)
     66     localtime_buffer_addr = tm;
     67 
     68   return tm;
     69 }
     70 
     71 /* Same as above, since gmtime and localtime use the same buffer.  */
     72 struct tm *
     73 rpl_gmtime (const time_t *timep)
     74 {
     75   struct tm *tm = gmtime (timep);
     76 
     77   if (! localtime_buffer_addr)
     78     localtime_buffer_addr = tm;
     79 
     80   return tm;
     81 }
     82 
     83 /* This is a wrapper for gettimeofday.  It is used only on systems for which
     84    gettimeofday clobbers the static buffer used for localtime's result.
     85 
     86    Save and restore the contents of the buffer used for localtime's result
     87    around the call to gettimeofday.  */
     88 
     89 int
     90 rpl_gettimeofday (struct timeval *tv, struct timezone *tz)
     91 {
     92   struct tm save;
     93   int result;
     94 
     95   if (! localtime_buffer_addr)
     96     {
     97       time_t t = 0;
     98       localtime_buffer_addr = localtime (&t);
     99     }
    100 
    101   save = *localtime_buffer_addr;
    102   result = gettimeofday (tv, tz);
    103   *localtime_buffer_addr = save;
    104 
    105   return result;
    106 }
    107 
    108 /* This is a wrapper for tzset. It is used only on systems for which
    109    tzset may clobber the static buffer used for localtime's result.
    110    Save and restore the contents of the buffer used for localtime's
    111    result around the call to tzset.  */
    112 void
    113 rpl_tzset (void)
    114 {
    115   struct tm save;
    116 
    117   if (! localtime_buffer_addr)
    118     {
    119       time_t t = 0;
    120       localtime_buffer_addr = localtime (&t);
    121     }
    122 
    123   save = *localtime_buffer_addr;
    124   tzset ();
    125   *localtime_buffer_addr = save;
    126 }
    127