gistfile1.js

import Ember from 'ember';

export default Ember.Mixin.create({
  currentRequest: 0,
  majax: function (ajax, success, fail) {
    var _this = this;
    var cr = this.get('currentRequest');
    this.set('currentRequest', ++cr);
    ajax.then(function (payload) {
      if (_this.get('currentRequest') === cr) {
        _this.set('currentRequest', 0);
        success(payload);
      }
    }, function (payload) {
      if (_this.get('currentRequest') === cr) {
        _this.set('currentRequest', 0);
        fail(payload);
      }
    });
  }
});