Subj : Re: Solaris real-time thread capabilities
To   : comp.unix.solaris,comp.programming.threads
From : capnwhit
Date : Tue Sep 06 2005 05:51 pm

Hello Eric,

Here's a quick hack... that shows the max diff between successive
invocations of gethrtime(). I may try the histogram approach suggested
by Chris Friesen.

BEGIN SAMPLE CODE
============================================

#include <iostream>
#include <sys/time.h>

int
main(int argc, char* argv[])
{
    const int ARG_SECONDS   =  1;
    const int ARG_NUMBER    =  2;

    if(argc != ARG_NUMBER)
    {
        std::cout << "Usage: "
                  << argv[0] << " number_of_seconds"
                  << std::endl;
        exit(1);
    }

    long CONVERT_SECONDS_TO_NS = 1000000000;

    int numberOfSecondsForTest = atoi(argv[ARG_SECONDS]);

    hrtime_t startTime = gethrtime();
    hrtime_t endTime = startTime + numberOfSecondsForTest *
CONVERT_SECONDS_TO_NS;

    hrtime_t t1 = 0;
    hrtime_t t2 = 0;

    hrtime_t diff = 0;
    hrtime_t cummulativeDiff = 0;
    hrtime_t averageDiff = 0;
    hrtime_t maxDiff = 0;

    long numCyclesInsideSpinLoop = 0;

    hrtime_t currentTime = gethrtime();
    while(currentTime < endTime)
    {
        numCyclesInsideSpinLoop += 1;

        t1 = gethrtime();
        t2 = gethrtime();

        diff = t2 - t1;
        cummulativeDiff += diff;

        averageDiff = cummulativeDiff / numCyclesInsideSpinLoop;

        if(diff > maxDiff)
        {
            maxDiff = diff;
            std::cout << "NEW MAXIMUM VALUE: maxDiff = " << maxDiff
                      << ", averageDiff = " << averageDiff
                      << std::endl;
        }

        currentTime = gethrtime();
    }
}
============================================
END SAMPLE CODE

.