engine-pseudocode.js

type Operation = {
  behavior: Function,
  timeAdded: integer,
  msDelay: integer,
};

class OperationQueue {
  operations: Operation[] = [];
  
  operationsForTime(time) {
    return this.operations.filter(operation => {
      return (operation.timeAdded + (operation.msDelay || 0)) <= time;
    });
  }
  
  push(operation) {
    this.operations.push(operation);
  }
}

JavascriptEngine.operationQueue = new OperationQueue();

// JavascriptEngine.operationQueue.push can be called by
// things like setTimeout and events firing

while (true) {
  // start of tick
  operationQueue.operationsForTime(new Date().getTime()).forEach(operation => {
    operation.behavior();
  });
  // end of tick
};