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 "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 */ 173
