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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/*
** File: prinrval.h
** Description: API to interval timing functions of NSPR.
**
**
** NSPR provides interval times that are independent of network time
** of day values. Interval times are (in theory) accurate regardless
** of host processing requirements and also very cheap to acquire. It
** is expected that getting an interval time while in a synchronized
** function (holding one's lock).
**/
#if !defined(prinrval_h)
#define prinrval_h
#include "prtypes.h"
PR_BEGIN_EXTERN_C
/**********************************************************************/
/************************* TYPES AND CONSTANTS ************************/
/**********************************************************************/
typedef PRUint32 PRIntervalTime;
/***********************************************************************
** DEFINES: PR_INTERVAL_MIN
** PR_INTERVAL_MAX
** DESCRIPTION:
** These two constants define the range (in ticks / second) of the
** platform dependent type, PRIntervalTime. These constants bound both
** the period and the resolution of a PRIntervalTime.
***********************************************************************/
#define PR_INTERVAL_MIN 1000UL
#define PR_INTERVAL_MAX 100000UL
/***********************************************************************
** DEFINES: PR_INTERVAL_NO_WAIT
** PR_INTERVAL_NO_TIMEOUT
** DESCRIPTION:
** Two reserved constants are defined in the PRIntervalTime namespace.
** They are used to indicate that the process should wait no time (return
** immediately) or wait forever (never time out), respectively.
** Note: PR_INTERVAL_NO_TIMEOUT passed as input to PR_Connect is
** interpreted as use the OS's connect timeout.
**
***********************************************************************/
#define PR_INTERVAL_NO_WAIT 0UL
#define PR_INTERVAL_NO_TIMEOUT 0xffffffffUL
/**********************************************************************/
/****************************** FUNCTIONS *****************************/
/**********************************************************************/
/***********************************************************************
** FUNCTION: PR_IntervalNow
** DESCRIPTION:
** Return the value of NSPR's free running interval timer. That timer
** can be used to establish epochs and determine intervals (be computing
** the difference between two times).
** INPUTS: void
** OUTPUTS: void
** RETURN: PRIntervalTime
**
** SIDE EFFECTS:
** None
** RESTRICTIONS:
** The units of PRIntervalTime are platform dependent. They are chosen
** such that they are appropriate for the host OS, yet provide sufficient
** resolution and period to be useful to clients.
** MEMORY: N/A
** ALGORITHM: Platform dependent
***********************************************************************/
NSPR_API(PRIntervalTime) PR_IntervalNow(void);
/***********************************************************************
** FUNCTION: PR_TicksPerSecond
** DESCRIPTION:
** Return the number of ticks per second for PR_IntervalNow's clock.
** The value will be in the range [PR_INTERVAL_MIN..PR_INTERVAL_MAX].
** INPUTS: void
** OUTPUTS: void
** RETURN: PRUint32
**
** SIDE EFFECTS:
** None
** RESTRICTIONS:
** None
** MEMORY: N/A
** ALGORITHM: N/A
***********************************************************************/
NSPR_API(PRUint32) PR_TicksPerSecond(void);
/***********************************************************************
** FUNCTION: PR_SecondsToInterval
** PR_MillisecondsToInterval
** PR_MicrosecondsToInterval
** DESCRIPTION:
** Convert standard clock units to platform dependent intervals.
** INPUTS: PRUint32
** OUTPUTS: void
** RETURN: PRIntervalTime
**
** SIDE EFFECTS:
** None
** RESTRICTIONS:
** Conversion may cause overflow, which is not reported.
** MEMORY: N/A
** ALGORITHM: N/A
***********************************************************************/
NSPR_API(PRIntervalTime) PR_SecondsToInterval(PRUint32 seconds);
NSPR_API(PRIntervalTime) PR_MillisecondsToInterval(PRUint32 milli);
NSPR_API(PRIntervalTime) PR_MicrosecondsToInterval(PRUint32 micro);
/***********************************************************************
** FUNCTION: PR_IntervalToSeconds
** PR_IntervalToMilliseconds
** PR_IntervalToMicroseconds
** DESCRIPTION:
** Convert platform dependent intervals to standard clock units.
** INPUTS: PRIntervalTime
** OUTPUTS: void
** RETURN: PRUint32
**
** SIDE EFFECTS:
** None
** RESTRICTIONS:
** Conversion may cause overflow, which is not reported.
** MEMORY: N/A
** ALGORITHM: N/A
***********************************************************************/
NSPR_API(PRUint32) PR_IntervalToSeconds(PRIntervalTime ticks);
NSPR_API(PRUint32) PR_IntervalToMilliseconds(PRIntervalTime ticks);
NSPR_API(PRUint32) PR_IntervalToMicroseconds(PRIntervalTime ticks);
PR_END_EXTERN_C
#endif /* !defined(prinrval_h) */
/* prinrval.h */