RecursiveTask

public abstract class RecursiveTask extends ForkJoinTask<V>

A recursive result-bearing ForkJoinTask.

For a classic example, here is a task computing Fibonacci numbers:

 class Fibonacci extends RecursiveTask<Integer> {
   final int n;
   Fibonacci(int n) { this.n = n; }
   protected Integer compute() {
     if (n <= 1)
       return n;
     Fibonacci f1 = new Fibonacci(n - 1);
     f1.fork();
     Fibonacci f2 = new Fibonacci(n - 2);
     return f2.compute() + f1.join();
   }
 }
However, besides being a dumb way to compute Fibonacci functions (there is a simple fast linear algorithm that you'd use in practice), this is likely to perform poorly because the smallest subtasks are too small to be worthwhile splitting up. Instead, as is the case for nearly all fork/join applications, you'd pick some minimum granularity size (for example 10 here) for which you always sequentially solve rather than subdividing.

Public Constructor Summary

Public Method Summary

final V
getRawResult()
Returns the result that would be returned by join(), even if this task completed abnormally, or null if this task is not known to have been completed.

Protected Method Summary

abstract V
compute()
The main computation performed by this task.
final boolean
exec()
Implements execution conventions for RecursiveTask.
final void
setRawResult(V value)
Forces the given value to be returned as a result.

Inherited Method Summary