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  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #if !defined(__ppc__)
  24 #include <stdint.h>
  25 #include <mach/clock.h>
  26 #include <mach/mach_time.h>
  27 #define __APPLE_API_PRIVATE
  28 #include <machine/cpu_capabilities.h>
  29 #undef  __APPLE_API_PRIVATE
  30
  31 extern mach_port_t clock_port;
  32
  33 #define COMM_PAGE_VERSION \
  34         (*((short *) _COMM_PAGE_VERSION))
  35
  36 #define COMM_PAGE_NANOTIME() \
  37         (((uint64_t (*)()) _COMM_PAGE_NANOTIME)())
  38
  39 uint64_t
  40 mach_absolute_time(void) {
  41         if (__builtin_expect(COMM_PAGE_VERSION == 1, 0)) {
  42                 mach_timespec_t now;
  43                 (void)clock_get_time(clock_port, &now);
  44                 return (uint64_t)now.tv_sec * NSEC_PER_SEC + now.tv_nsec;
  45         }
  46         return COMM_PAGE_NANOTIME();
  47 }
  48 #endif