module/spl/spl-time.c

   1 /*****************************************************************************\
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *  For details, see <http://github.com/behlendorf/spl/>.
  10  *
  11  *  The SPL is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License as published by the
  13  *  Free Software Foundation; either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  23  *****************************************************************************
  24  *  Solaris Porting Layer (SPL) Time Implementation.
  25 \*****************************************************************************/
  26
  27 #include <sys/sysmacros.h>
  28 #include <sys/time.h>
  29
  30 #ifdef HAVE_MONOTONIC_CLOCK
  31 extern unsigned long long monotonic_clock(void);
  32 #endif
  33
  34 #ifdef DEBUG_SUBSYSTEM
  35 #undef DEBUG_SUBSYSTEM
  36 #endif
  37
  38 #define DEBUG_SUBSYSTEM S_TIME
  39
  40 void
  41 __gethrestime(timestruc_t *ts)
  42 {
  43         struct timeval tv;
  44
  45         do_gettimeofday(&tv);
  46         ts->tv_sec = tv.tv_sec;
  47         ts->tv_nsec = tv.tv_usec * NSEC_PER_USEC;
  48 }
  49 EXPORT_SYMBOL(__gethrestime);
  50
  51 /* Use monotonic_clock() by default. It's faster and is available on older
  52  * kernels, but few architectures have them, so we must fallback to
  53  * do_posix_clock_monotonic_gettime().
  54  */
  55 hrtime_t
  56 __gethrtime(void) {
  57 #ifdef HAVE_MONOTONIC_CLOCK
  58         unsigned long long res = monotonic_clock();
  59
  60         /* Deal with signed/unsigned mismatch */
  61         return (hrtime_t)(res & ~(1ULL << 63));
  62 #else
  63         struct timespec ts;
  64
  65         do_posix_clock_monotonic_gettime(&ts);
  66         return (((hrtime_t)ts.tv_sec * NSEC_PER_SEC) + ts.tv_nsec);
  67 #endif
  68 }
  69 EXPORT_SYMBOL(__gethrtime);
  70
  71 /* set_normalized_timespec() API changes
  72  * 2.6.0  - 2.6.15: Inline function provided by linux/time.h
  73  * 2.6.16 - 2.6.25: Function prototype defined but not exported
  74  * 2.6.26 - 2.6.x:  Function defined and exported
  75  */
  76 #if !defined(HAVE_SET_NORMALIZED_TIMESPEC_INLINE) && \
  77     !defined(HAVE_SET_NORMALIZED_TIMESPEC_EXPORT)
  78 void
  79 set_normalized_timespec(struct timespec *ts, time_t sec, long nsec)
  80 {
  81         while (nsec >= NSEC_PER_SEC) {
  82                 nsec -= NSEC_PER_SEC;
  83                 ++sec;
  84         }
  85         while (nsec < 0) {
  86                 nsec += NSEC_PER_SEC;
  87                 --sec;
  88         }
  89         ts->tv_sec = sec;
  90         ts->tv_nsec = nsec;
  91 }
  92 EXPORT_SYMBOL(set_normalized_timespec);
  93 #endif