OSX/libsecurity_asn1/lib/prinrval.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /*
   3  * The contents of this file are subject to the Mozilla Public
   4  * License Version 1.1 (the "License"); you may not use this file
   5  * except in compliance with the License. You may obtain a copy of
   6  * the License at http://www.mozilla.org/MPL/
   7  *
   8  * Software distributed under the License is distributed on an "AS
   9  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
  10  * implied. See the License for the specific language governing
  11  * rights and limitations under the License.
  12  *
  13  * The Original Code is the Netscape Portable Runtime (NSPR).
  14  *
  15  * The Initial Developer of the Original Code is Netscape
  16  * Communications Corporation.  Portions created by Netscape are
  17  * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
  18  * Rights Reserved.
  19  *
  20  * Contributor(s):
  21  *
  22  * Alternatively, the contents of this file may be used under the
  23  * terms of the GNU General Public License Version 2 or later (the
  24  * "GPL"), in which case the provisions of the GPL are applicable
  25  * instead of those above.  If you wish to allow use of your
  26  * version of this file only under the terms of the GPL and not to
  27  * allow others to use your version of this file under the MPL,
  28  * indicate your decision by deleting the provisions above and
  29  * replace them with the notice and other provisions required by
  30  * the GPL.  If you do not delete the provisions above, a recipient
  31  * may use your version of this file under either the MPL or the
  32  * GPL.
  33  */
  34
  35 /*
  36 ** File:                prinrval.h
  37 ** Description: API to interval timing functions of NSPR.
  38 **
  39 **
  40 ** NSPR provides interval times that are independent of network time
  41 ** of day values. Interval times are (in theory) accurate regardless
  42 ** of host processing requirements and also very cheap to acquire. It
  43 ** is expected that getting an interval time while in a synchronized
  44 ** function (holding one's lock).
  45 **/
  46
  47 #if !defined(prinrval_h)
  48 #define prinrval_h
  49
  50 #include <security_asn1/prtypes.h>
  51
  52 PR_BEGIN_EXTERN_C
  53
  54 /**********************************************************************/
  55 /************************* TYPES AND CONSTANTS ************************/
  56 /**********************************************************************/
  57
  58 typedef PRUint32 PRIntervalTime;
  59
  60 /***********************************************************************
  61 ** DEFINES:     PR_INTERVAL_MIN
  62 **              PR_INTERVAL_MAX
  63 ** DESCRIPTION:
  64 **  These two constants define the range (in ticks / second) of the
  65 **  platform dependent type, PRIntervalTime. These constants bound both
  66 **  the period and the resolution of a PRIntervalTime.
  67 ***********************************************************************/
  68 #define PR_INTERVAL_MIN 1000UL
  69 #define PR_INTERVAL_MAX 100000UL
  70
  71 /***********************************************************************
  72 ** DEFINES:     PR_INTERVAL_NO_WAIT
  73 **              PR_INTERVAL_NO_TIMEOUT
  74 ** DESCRIPTION:
  75 **  Two reserved constants are defined in the PRIntervalTime namespace.
  76 **  They are used to indicate that the process should wait no time (return
  77 **  immediately) or wait forever (never time out), respectively.
  78 ***********************************************************************/
  79 #define PR_INTERVAL_NO_WAIT 0UL
  80 #define PR_INTERVAL_NO_TIMEOUT 0xffffffffUL
  81
  82 /**********************************************************************/
  83 /****************************** FUNCTIONS *****************************/
  84 /**********************************************************************/
  85
  86 /***********************************************************************
  87 ** FUNCTION:    PR_IntervalNow
  88 ** DESCRIPTION:
  89 **  Return the value of NSPR's free running interval timer. That timer
  90 **  can be used to establish epochs and determine intervals (be computing
  91 **  the difference between two times).
  92 ** INPUTS:      void
  93 ** OUTPUTS:     void
  94 ** RETURN:      PRIntervalTime
  95 **
  96 ** SIDE EFFECTS:
  97 **  None
  98 ** RESTRICTIONS:
  99 **  The units of PRIntervalTime are platform dependent. They are chosen
 100 **  such that they are appropriate for the host OS, yet provide sufficient
 101 **  resolution and period to be useful to clients.
 102 ** MEMORY:      N/A
 103 ** ALGORITHM:   Platform dependent
 104 ***********************************************************************/
 105 NSPR_API(PRIntervalTime) PR_IntervalNow(void);
 106
 107 /***********************************************************************
 108 ** FUNCTION:    PR_TicksPerSecond
 109 ** DESCRIPTION:
 110 **  Return the number of ticks per second for PR_IntervalNow's clock.
 111 **  The value will be in the range [PR_INTERVAL_MIN..PR_INTERVAL_MAX].
 112 ** INPUTS:      void
 113 ** OUTPUTS:     void
 114 ** RETURN:      PRUint32
 115 **
 116 ** SIDE EFFECTS:
 117 **  None
 118 ** RESTRICTIONS:
 119 **  None
 120 ** MEMORY:      N/A
 121 ** ALGORITHM:   N/A
 122 ***********************************************************************/
 123 NSPR_API(PRUint32) PR_TicksPerSecond(void);
 124
 125 /***********************************************************************
 126 ** FUNCTION:    PR_SecondsToInterval
 127 **              PR_MillisecondsToInterval
 128 **              PR_MicrosecondsToInterval
 129 ** DESCRIPTION:
 130 **  Convert standard clock units to platform dependent intervals.
 131 ** INPUTS:      PRUint32
 132 ** OUTPUTS:     void
 133 ** RETURN:      PRIntervalTime
 134 **
 135 ** SIDE EFFECTS:
 136 **  None
 137 ** RESTRICTIONS:
 138 **  Conversion may cause overflow, which is not reported.
 139 ** MEMORY:      N/A
 140 ** ALGORITHM:   N/A
 141 ***********************************************************************/
 142 NSPR_API(PRIntervalTime) PR_SecondsToInterval(PRUint32 seconds);
 143 NSPR_API(PRIntervalTime) PR_MillisecondsToInterval(PRUint32 milli);
 144 NSPR_API(PRIntervalTime) PR_MicrosecondsToInterval(PRUint32 micro);
 145
 146 /***********************************************************************
 147 ** FUNCTION:    PR_IntervalToSeconds
 148 **              PR_IntervalToMilliseconds
 149 **              PR_IntervalToMicroseconds
 150 ** DESCRIPTION:
 151 **  Convert platform dependent intervals to standard clock units.
 152 ** INPUTS:      PRIntervalTime
 153 ** OUTPUTS:     void
 154 ** RETURN:      PRUint32
 155 **
 156 ** SIDE EFFECTS:
 157 **  None
 158 ** RESTRICTIONS:
 159 **  Conversion may cause overflow, which is not reported.
 160 ** MEMORY:      N/A
 161 ** ALGORITHM:   N/A
 162 ***********************************************************************/
 163 NSPR_API(PRUint32) PR_IntervalToSeconds(PRIntervalTime ticks);
 164 NSPR_API(PRUint32) PR_IntervalToMilliseconds(PRIntervalTime ticks);
 165 NSPR_API(PRUint32) PR_IntervalToMicroseconds(PRIntervalTime ticks);
 166
 167 PR_END_EXTERN_C
 168
 169
 170 #endif /* !defined(prinrval_h) */
 171
 172 /* prinrval.h */