node/lib/v8.js

// Copyright (c) 2014, StrongLoop Inc.
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

'use strict';

var EventEmitter = require('events');
var v8binding = process.binding('v8');

var v8 = module.exports = new EventEmitter();
v8.getHeapStatistics = v8binding.getHeapStatistics;
v8.setFlagsFromString = v8binding.setFlagsFromString;


function emitGC(before, after) {
  v8.emit('gc', before, after);
}


v8.on('newListener', function(name) {
  if (name === 'gc' && EventEmitter.listenerCount(this, name) === 0) {
    v8binding.startGarbageCollectionTracking(emitGC);
  }
});


v8.on('removeListener', function(name) {
  if (name === 'gc' && EventEmitter.listenerCount(this, name) === 0) {
    v8binding.stopGarbageCollectionTracking();
  }
});