i386/mach/mach_absolute_time.c

   1 /*
   2  * Copyright (c) 2000-2002 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 #if !defined(__ppc__)
  26 #include <stdint.h>
  27 #include <mach/clock.h>
  28 #include <mach/mach_time.h>
  29 #define __APPLE_API_PRIVATE
  30 #include <machine/cpu_capabilities.h>
  31 #undef  __APPLE_API_PRIVATE
  32
  33 extern mach_port_t clock_port;
  34
  35 #define COMM_PAGE_VERSION \
  36         (*((short *) _COMM_PAGE_VERSION))
  37
  38 #define COMM_PAGE_NANOTIME() \
  39         (((uint64_t (*)()) _COMM_PAGE_NANOTIME)())
  40
  41 uint64_t
  42 mach_absolute_time(void) {
  43         if (__builtin_expect(COMM_PAGE_VERSION == 1, 0)) {
  44                 mach_timespec_t now;
  45                 (void)clock_get_time(clock_port, &now);
  46                 return (uint64_t)now.tv_sec * NSEC_PER_SEC + now.tv_nsec;
  47         }
  48         return COMM_PAGE_NANOTIME();
  49 }
  50 #endif