As we know, Java have join method in multi-threading, I want to achieve the same in NodeJs. Is these any equivalent to join method of java in NodeJs?

**Below is my requirement:** 
I have 3 methods(m1(),m2(),m3()) which calculates huge data and returns a number. Then i have one Sum() method which adds all three numbers returned by these three(m1(),m2(),m3()) methods. As these three methods are taking approx. 10 min each to calculate the data, my sum() method have to wait for approx. 30 mins to start executing. So i want to execute these three(m1(),m2(),m3()) methods parallelly. But my condition here is, The Sum method should start execute only when all three methods complete their execution and add the data returned by three methods.