libcfs/include/libcfs/libcfs_time.h

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 /*
  27  * This file is part of Lustre, http://www.lustre.org/
  28  * Lustre is a trademark of Sun Microsystems, Inc.
  29  *
  30  * libcfs/include/libcfs/libcfs_time.h
  31  *
  32  * Time functions.
  33  *
  34  */
  35
  36 #ifndef __LIBCFS_TIME_H__
  37 #define __LIBCFS_TIME_H__
  38
  39 /*
  40  * generic time manipulation functions.
  41  */
  42
  43 static inline cfs_time_t cfs_time_add(cfs_time_t t, cfs_duration_t d)
  44 {
  45         return (cfs_time_t)(t + d);
  46 }
  47
  48 static inline cfs_duration_t cfs_time_sub(cfs_time_t t1, cfs_time_t t2)
  49 {
  50         return (cfs_time_t)(t1 - t2);
  51 }
  52
  53 static inline int cfs_time_after(cfs_time_t t1, cfs_time_t t2)
  54 {
  55         return cfs_time_before(t2, t1);
  56 }
  57
  58 static inline int cfs_time_aftereq(cfs_time_t t1, cfs_time_t t2)
  59 {
  60         return cfs_time_beforeq(t2, t1);
  61 }
  62
  63
  64 static inline cfs_time_t cfs_time_shift(int seconds)
  65 {
  66         return cfs_time_add(cfs_time_current(), cfs_time_seconds(seconds));
  67 }
  68
  69 static inline long cfs_timeval_sub(struct timeval *large, struct timeval *small,
  70                                    struct timeval *result)
  71 {
  72         long r = (long) (
  73                 (large->tv_sec - small->tv_sec) * ONE_MILLION +
  74                 (large->tv_usec - small->tv_usec));
  75         if (result != NULL) {
  76                 result->tv_usec = r % ONE_MILLION;
  77                 result->tv_sec = r / ONE_MILLION;
  78         }
  79         return r;
  80 }
  81
  82 #define CFS_RATELIMIT(seconds)                                  \
  83 ({                                                              \
  84         /*                                                      \
  85          * XXX nikita: non-portable initializer                 \
  86          */                                                     \
  87         static time_t __next_message = 0;                       \
  88         int result;                                             \
  89                                                                 \
  90         if (cfs_time_after(cfs_time_current(), __next_message)) \
  91                 result = 1;                                     \
  92         else {                                                  \
  93                 __next_message = cfs_time_shift(seconds);       \
  94                 result = 0;                                     \
  95         }                                                       \
  96         result;                                                 \
  97 })
  98
  99 #define CFS_TICK        1
 100
 101 /*
 102  * return valid time-out based on user supplied one. Currently we only check
 103  * that time-out is not shorted than allowed.
 104  */
 105 static inline cfs_duration_t cfs_timeout_cap(cfs_duration_t timeout)
 106 {
 107         if (timeout < CFS_TICK)
 108                 timeout = CFS_TICK;
 109         return timeout;
 110 }
 111
 112 #endif