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Diffstat (limited to 'lib/gettimeofday.c')
-rw-r--r-- | lib/gettimeofday.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/lib/gettimeofday.c b/lib/gettimeofday.c new file mode 100644 index 0000000000..5d35060950 --- /dev/null +++ b/lib/gettimeofday.c @@ -0,0 +1,154 @@ +/* Provide gettimeofday for systems that don't have it or for which it's broken. + + Copyright (C) 2001-2003, 2005-2007, 2009-2012 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, see <http://www.gnu.org/licenses/>. */ + +/* written by Jim Meyering */ + +#include <config.h> + +/* Specification. */ +#include <sys/time.h> + +#include <time.h> + +#if HAVE_SYS_TIMEB_H +# include <sys/timeb.h> +#endif + +#if GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME + +/* Work around the bug in some systems whereby gettimeofday clobbers + the static buffer that localtime uses for its return value. The + gettimeofday function from Mac OS X 10.0.4 (i.e., Darwin 1.3.7) has + this problem. The tzset replacement is necessary for at least + Solaris 2.5, 2.5.1, and 2.6. */ + +static struct tm tm_zero_buffer; +static struct tm *localtime_buffer_addr = &tm_zero_buffer; + +# undef localtime +extern struct tm *localtime (time_t const *); + +# undef gmtime +extern struct tm *gmtime (time_t const *); + +/* This is a wrapper for localtime. It is used only on systems for which + gettimeofday clobbers the static buffer used for localtime's result. + + On the first call, record the address of the static buffer that + localtime uses for its result. */ + +struct tm * +rpl_localtime (time_t const *timep) +{ + struct tm *tm = localtime (timep); + + if (localtime_buffer_addr == &tm_zero_buffer) + localtime_buffer_addr = tm; + + return tm; +} + +/* Same as above, since gmtime and localtime use the same buffer. */ +struct tm * +rpl_gmtime (time_t const *timep) +{ + struct tm *tm = gmtime (timep); + + if (localtime_buffer_addr == &tm_zero_buffer) + localtime_buffer_addr = tm; + + return tm; +} + +#endif /* GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME */ + +#if TZSET_CLOBBERS_LOCALTIME + +# undef tzset +extern void tzset (void); + +/* This is a wrapper for tzset, for systems on which tzset may clobber + the static buffer used for localtime's result. */ +void +rpl_tzset (void) +{ + /* Save and restore the contents of the buffer used for localtime's + result around the call to tzset. */ + struct tm save = *localtime_buffer_addr; + tzset (); + *localtime_buffer_addr = save; +} +#endif + +/* This is a wrapper for gettimeofday. It is used only on systems + that lack this function, or whose implementation of this function + causes problems. */ + +int +gettimeofday (struct timeval *restrict tv, void *restrict tz) +{ +#undef gettimeofday +#if HAVE_GETTIMEOFDAY +# if GETTIMEOFDAY_CLOBBERS_LOCALTIME + /* Save and restore the contents of the buffer used for localtime's + result around the call to gettimeofday. */ + struct tm save = *localtime_buffer_addr; +# endif + +# if defined timeval /* 'struct timeval' overridden by gnulib? */ +# undef timeval + struct timeval otv; + int result = gettimeofday (&otv, (struct timezone *) tz); + if (result == 0) + { + tv->tv_sec = otv.tv_sec; + tv->tv_usec = otv.tv_usec; + } +# else + int result = gettimeofday (tv, (struct timezone *) tz); +# endif + +# if GETTIMEOFDAY_CLOBBERS_LOCALTIME + *localtime_buffer_addr = save; +# endif + + return result; + +#else + +# if HAVE__FTIME + + struct _timeb timebuf; + _ftime (&timebuf); + tv->tv_sec = timebuf.time; + tv->tv_usec = timebuf.millitm * 1000; + +# else + +# if !defined OK_TO_USE_1S_CLOCK +# error "Only 1-second nominal clock resolution found. Is that intended?" \ + "If so, compile with the -DOK_TO_USE_1S_CLOCK option." +# endif + tv->tv_sec = time (NULL); + tv->tv_usec = 0; + +# endif + + return 0; + +#endif +} |