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 52PR_BEGIN_EXTERN_C 53 54/**********************************************************************/ 55/************************* TYPES AND CONSTANTS ************************/ 56/**********************************************************************/ 57 58typedef 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***********************************************************************/ 105NSPR_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***********************************************************************/ 123NSPR_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***********************************************************************/ 142NSPR_API(PRIntervalTime) PR_SecondsToInterval(PRUint32 seconds); 143NSPR_API(PRIntervalTime) PR_MillisecondsToInterval(PRUint32 milli); 144NSPR_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***********************************************************************/ 163NSPR_API(PRUint32) PR_IntervalToSeconds(PRIntervalTime ticks); 164NSPR_API(PRUint32) PR_IntervalToMilliseconds(PRIntervalTime ticks); 165NSPR_API(PRUint32) PR_IntervalToMicroseconds(PRIntervalTime ticks); 166 167PR_END_EXTERN_C 168 169 170#endif /* !defined(prinrval_h) */ 171 172/* prinrval.h */ 173