How do I pause main() until all other threads have died?
- by thechiman
In my program, I am creating several threads in the main() method. The last line in the main method is a call to System.out.println(), which I don't want to call until all the threads have died. I have tried calling Thread.join() on each thread however that blocks each thread so that they execute sequentially instead of in parallel.
Is there a way to block the main() thread until all other threads have finished executing? Here is the relevant part of my code:
public static void main(String[] args) {
//some other initialization code
//Make array of Thread objects
Thread[] racecars = new Thread[numberOfRaceCars];
//Fill array with RaceCar objects
for(int i=0; i<numberOfRaceCars; i++) {
racecars[i] = new RaceCar(laps, args[i]);
}
//Call start() on each Thread
for(int i=0; i<numberOfRaceCars; i++) {
racecars[i].start();
try {
racecars[i].join(); //This is where I tried to using join()
//It just blocks all other threads until the current
//thread finishes.
} catch(InterruptedException e) {
e.printStackTrace();
}
}
//This is the line I want to execute after all other Threads have finished
System.out.println("It's Over!");
}
Thanks for the help guys!
Eric
