How can I wait for set of asynchronous callback functions?

Question

I have code that looks something like this in javascript:

forloop {
    //async call, returns an array to its callback
}

After ALL of those

Answer 1

You can emulate it like this:

  countDownLatch = {
     count: 0,
     check: function() {
         this.count--;
         if (this.count == 0) this.calculate();
     },
     calculate: function() {...}
  };

then each async call does this:

countDownLatch.count++;

while in each asynch call back at the end of the method you add this line:

countDownLatch.check();

In other words, you emulate a count-down-latch functionality.