1/* Provide gettimeofday for systems that don't have it or for which it's broken. 2 3 Copyright (C) 2001, 2002, 2003, 2005, 2006, 2007 Free Software 4 Foundation, Inc. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software Foundation, 18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ 19 20/* written by Jim Meyering */ 21 22#include <config.h> 23 24/* Specification. */ 25#include <sys/time.h> 26 27#include <time.h> 28 29#if HAVE_SYS_TIMEB_H 30# include <sys/timeb.h> 31#endif 32 33#if GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME 34 35/* Work around the bug in some systems whereby gettimeofday clobbers 36 the static buffer that localtime uses for its return value. The 37 gettimeofday function from Mac OS X 10.0.4 (i.e., Darwin 1.3.7) has 38 this problem. The tzset replacement is necessary for at least 39 Solaris 2.5, 2.5.1, and 2.6. */ 40 41static struct tm tm_zero_buffer; 42static struct tm *localtime_buffer_addr = &tm_zero_buffer; 43 44/* This is a wrapper for localtime. It is used only on systems for which 45 gettimeofday clobbers the static buffer used for localtime's result. 46 47 On the first call, record the address of the static buffer that 48 localtime uses for its result. */ 49 50struct tm * 51localtime (time_t const *timep) 52{ 53#undef localtime 54 extern struct tm *localtime (time_t const *); 55 struct tm *tm = localtime (timep); 56 57 if (localtime_buffer_addr == &tm_zero_buffer) 58 localtime_buffer_addr = tm; 59 60 return tm; 61} 62 63/* Same as above, since gmtime and localtime use the same buffer. */ 64struct tm * 65gmtime (time_t const *timep) 66{ 67#undef gmtime 68 extern struct tm *gmtime (time_t const *); 69 struct tm *tm = gmtime (timep); 70 71 if (localtime_buffer_addr == &tm_zero_buffer) 72 localtime_buffer_addr = tm; 73 74 return tm; 75} 76 77#endif /* GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME */ 78 79#if TZSET_CLOBBERS_LOCALTIME 80/* This is a wrapper for tzset, for systems on which tzset may clobber 81 the static buffer used for localtime's result. */ 82void 83tzset (void) 84{ 85#undef tzset 86 extern void tzset (void); 87 88 /* Save and restore the contents of the buffer used for localtime's 89 result around the call to tzset. */ 90 struct tm save = *localtime_buffer_addr; 91 tzset (); 92 *localtime_buffer_addr = save; 93} 94#endif 95 96/* This is a wrapper for gettimeofday. It is used only on systems 97 that lack this function, or whose implementation of this function 98 causes problems. */ 99 100int 101rpl_gettimeofday (struct timeval *restrict tv, void *restrict tz) 102{ 103#undef gettimeofday 104#if HAVE_GETTIMEOFDAY 105# if GETTIMEOFDAY_CLOBBERS_LOCALTIME 106 /* Save and restore the contents of the buffer used for localtime's 107 result around the call to gettimeofday. */ 108 struct tm save = *localtime_buffer_addr; 109# endif 110 111 int result = gettimeofday (tv, tz); 112 113# if GETTIMEOFDAY_CLOBBERS_LOCALTIME 114 *localtime_buffer_addr = save; 115# endif 116 117 return result; 118 119#else 120 121# if HAVE__FTIME 122 123 struct _timeb timebuf; 124 _ftime (&timebuf); 125 tv->tv_sec = timebuf.time; 126 tv->tv_usec = timebuf.millitm * 1000; 127 128# else 129 130# if !defined OK_TO_USE_1S_CLOCK 131# error "Only 1-second nominal clock resolution found. Is that intended?" \ 132 "If so, compile with the -DOK_TO_USE_1S_CLOCK option." 133# endif 134 tv->tv_sec = time (NULL); 135 tv->tv_usec = 0; 136 137# endif 138 139 return 0; 140 141#endif 142} 143