Some parallel methods in the standard libraries

• ​ In Java 8, java.util.Arrays includes parallelSort method that implements a parallel merge sort

  • ​ API documentation

  • ​ source code

  • ​ source code of the helper classes

• ​ In addition, java.util.Arrays provides

  • ​ parallelPrefix for computing all the cumulative prefixes of the array w.r.t.an associative binary operator, and

  • ​ parallelSetAll that sets the values of an array according to some function

• ​ The scala parallel collections library also provides parallel ways for computing folds, maximum elements etc. They are quite good in general, try using them if

  • ​ the computer has many cores available,

  • ​ the applied operations are independent and thus parallelize, and

  • ​ the size of the collections is large or the applied operations take non-negligible amount of time