test node's timers

timers.js

// 2011-09-15 jorge@jorgechamorro.com
// http://groups.google.com/group/nodejs-dev/msg/cf392e131b5fcd3a
// http://groups.google.com/group/nodejs-dev/browse_thread/thread/922a30cf88a1b784

var ms= 5;
var ctr= 0;
var RUN= 1;

function f () {
  if (RUN) {
    ctr++;
    setTimeout(f, ms);
  }
}

f();
var t0= Date.now();
setTimeout(function next () {
  
  t0= Date.now()- t0;
  var is= Math.floor((ctr/t0)*1e3);
  var shouldBe= Math.floor(1e3/ms);
  console.log([ms+ ' ms', ctr+ ' counts', t0+ ' ms elapsed time', is+ ' Hz', 'SHOULD BE: '+ (ms ? shouldBe : 'flat-out ') + ' Hz'].join(', '));
  
  if (ms--) {
    ctr= 0;
    t0= Date.now();
    setTimeout(next, 2e3);
  }
  else {
    RUN= 0;
    setTimeout(f, 666);
  }
}, 2e3);