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
52static 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
60struct tm *
61rpl_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.  */
72struct tm *
73rpl_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
89int
90rpl_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.  */
112void
113rpl_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