nextTick.js

nextTick.js

/*
  2012-04-22 jorge@jorgechamorro.com

  MacBookPro5,4 core2duo @ 2.53GHz, node v0.7.5:
  loopsPerSecond: 103412616.3, nextTicksPerSecond: 671885.8, ratio: 153.9x times faster

  beagleboard beaglebone @ 500Mhz:
  loopsPerSecond: 6781040.2, nextTicksPerSecond: 27472.4, ratio: 246.8x times faster
*/

(function (ctr,t,kLoops,displayPeriod,i) {
  
  function inc () { ctr++ }
  function ƒ () { inc(), process.nextTick(ƒ) }

  function display (ntps,ntpsStr,i,lps,lpsStr,ratioStr) {
    ntps= ctr*1e3/(Date.now()-t); //nextTicks per second
    ntpsStr= ", nextTicksPerSecond: "+ ntps.toFixed(1);
    
    setTimeout(display, displayPeriod);
  
    ctr= 0, i= kLoops, t= Date.now();
    while (i--) { inc() }
    lps= ctr*1e3/(Date.now()-t); //loops per second
    lpsStr= "loopsPerSecond: "+ lps.toFixed(1);
  
    ratioStr= ", ratio: "+ (lps/ntps).toFixed(1)+ "x times faster";
    console.log( lpsStr+ ntpsStr+ ratioStr );
  
    ctr= 0, t= Date.now();
  }
  
  
  displayPeriod= 2e3;
  
  process.stdout.write('Calibrating loop');
  kLoops= 2e6;
  do {
    ctr= 0, i= kLoops, t= Date.now();
    while (i--) inc();
    t= (Date.now()- t) || 1;
    var ratio= (displayPeriod/2)/t;
    kLoops= Math.floor(kLoops* ratio);
    process.stdout.write('.');
  } while ((ratio < 0.9) || (ratio > 1.1));
  console.log('DONE. kLoops -> '+ kLoops);
  
  setTimeout(display, displayPeriod);
  ctr= 0, t= Date.now();
  ƒ();
  
})()