obj-gc-test-fail.js

// run with "node --expose_gc"

var weak = require('weak')
  , util = require('util')

function MyObject () {
  var self = this;
  Object.defineProperty(this, 'color', {
    get: function() { return 'red' }
  })
  setTimeout(function () { 
    self.emit('close')
  }, 2000)
}

util.inherits(MyObject, process.EventEmitter)

var count = 0
  , countGc = 0

for (var i = 0; i < 1000; i++) {
  var o = new MyObject()
  count++
  o.on('close', function () { count--})
  countGc++
  weak(o, function () { countGc-- })
}

setInterval(function () {
  gc()
  console.log('objects: %d, garbage collected: %d', count, countGc)
}, 1000)

obj-gc-test-pass.js

// run with "node --expose_gc"

var weak = require('weak')
  , util = require('util')

function MyObject () {
  var self = this;
  this.color = 'red'
  setTimeout(function () { 
    self.emit('close')
  }, 2000)
}

util.inherits(MyObject, process.EventEmitter)

var count = 0
  , countGc = 0

for (var i = 0; i < 1000; i++) {
  var o = new MyObject()
  count++
  o.on('close', function () { count--})
  countGc++
  weak(o, function () { countGc-- })
}

setInterval(function () {
  gc()
  console.log('objects: %d, garbage collected: %d', count, countGc)
}, 1000)

output-fail.txt

objects: 1000, garbage collected: 1000
objects: 1000, garbage collected: 1000
objects: 0, garbage collected: 12
objects: 0, garbage collected: 12
objects: 0, garbage collected: 12
objects: 0, garbage collected: 12
objects: 0, garbage collected: 12
objects: 0, garbage collected: 12
objects: 0, garbage collected: 12
objects: 0, garbage collected: 12
...

output-pass.txt

objects: 1000, garbage collected: 1000
objects: 1000, garbage collected: 1000
objects: 0, garbage collected: 0
objects: 0, garbage collected: 0
objects: 0, garbage collected: 0
objects: 0, garbage collected: 0
objects: 0, garbage collected: 0
objects: 0, garbage collected: 0
objects: 0, garbage collected: 0
objects: 0, garbage collected: 0
...