com.bluegosling.collections.sorting

Class ParallelSort2

java.lang.Object

com.bluegosling.collections.sorting.ParallelSort2

public class ParallelSort2
extends Object

A utility for sorting large lists using multiple CPUs/cores. This is a bit more sophisticated than ParallelSort in that it performs merge operations concurrently, not just the sorting of chunks.

The merge step is parallelized by merging two adjacent chunks in a single thread. So if there are eight chunks, up to four threads can be utilized to merge them. In this example, once the eight chunks are merged into four, up to two threads can be utilized to merge those. The final step can only be done in one thread and it merges the last two chunks into the final sorted list.

See Also:

ParallelSort, SlowParallelSort

Constructor Summary

Constructors

Constructor and Description
ParallelSort2()

Method Summary

Modifier and Type	Method and Description
static <T> void	sort(List<T> list, Comparator<? super T> comparator, int requestedNumThreads) Sorts the specified list using the specified executor for running concurrent sub-tasks.
static <T extends Comparable<T>> void	sort(List<T> list, int requestedNumThreads) Sorts the specified list using the specified executor for running concurrent sub-tasks.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ParallelSort2

public ParallelSort2()

Method Detail

sort

public static <T extends Comparable<T>> void sort(List<T> list,
                                                  int requestedNumThreads)

Sorts the specified list using the specified executor for running concurrent sub-tasks.

Type Parameters:

T - the type of element in the list

Parameters:

list - the list to sort

requestedNumThreads - the number of threads to use

Throws:

NullPointerException - if any of the reference arguments are null or if the specified list contains any null elements

IllegalArgumentException - if the specified number of threads is zero or negative

RuntimeException - if this thread is interrupted while waiting on parallel operations to complete

sort

public static <T> void sort(List<T> list,
                            Comparator<? super T> comparator,
                            int requestedNumThreads)

Sorts the specified list using the specified executor for running concurrent sub-tasks.

Type Parameters:

T - the type of element in the list

Parameters:

list - the list to sort

comparator - the comparator to use for ordering items relative to one another

requestedNumThreads - the number of threads to use

Throws:

NullPointerException - if any of the reference arguments are null or if the specified list contains any null elements

IllegalArgumentException - if the specified number of threads is zero or negative

RuntimeException - if this thread is interrupted while waiting on parallel operations to complete