sys/gettimeofday.c

   1 /*
   2  * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
  27  *
  28  *      File:   libc/sys/gettimeofday.c
  29  */
  30
  31 #include <time.h>
  32 #include <tzfile.h>
  33 #include <sys/time.h>
  34 #include <errno.h>
  35 #include <sys/syscall.h>
  36 #include <unistd.h>
  37
  38 #define __APPLE_API_PRIVATE
  39 #include <machine/cpu_capabilities.h>
  40 #undef  __APPLE_API_PRIVATE
  41
  42
  43 int gettimeofday (struct timeval *tp, struct timezone *tzp)
  44 {
  45         static int validtz = 0;
  46         static struct timezone cached_tz = {0};
  47         struct timeval localtv;
  48
  49         if (tp == NULL) {
  50             if (tzp == NULL)
  51                 return  (0);
  52             tp = &localtv;
  53         }
  54
  55 #if defined(__ppc__) || defined(__ppc64__)
  56         {
  57             extern int __ppc_gettimeofday(struct timeval *, struct timezone *);
  58             extern int __commpage_gettimeofday(struct timeval *);
  59
  60             if (__commpage_gettimeofday(tp)) {          /* first try commpage */
  61                 if (__ppc_gettimeofday(tp,tzp)) {       /* if it fails, use syscall */
  62                     return (-1);
  63                 }
  64             }
  65         }
  66 #else
  67         if (syscall (SYS_gettimeofday, tp, tzp) < 0) {
  68                 return (-1);
  69         }
  70 #endif
  71         if (tzp) {
  72             if (validtz == 0)  {
  73                 struct tm *localtm = localtime ((time_t *)&tp->tv_sec);
  74                 cached_tz.tz_dsttime = localtm->tm_isdst;
  75                 cached_tz.tz_minuteswest =
  76                     (-localtm->tm_gmtoff / SECSPERMIN) +
  77                     (localtm->tm_isdst * MINSPERHOUR);
  78                 validtz = 1;
  79             }
  80             tzp->tz_dsttime = cached_tz.tz_dsttime;
  81             tzp->tz_minuteswest = cached_tz.tz_minuteswest;
  82         }
  83         return (0);
  84 }