我已经下载了 release 并在和java8-ea之间进行了快速比较。Array.sortArrays.parallelSort
结果是这样的：
我可以理解 praralleSort 至少应该像 Plain old 一样执行sort，如果不是更快的话..但这不是发生的事情。
根据以下规格进行的比较：
HP ProBook Intel Core i5with 4G RAMon Ubuntu 13.04 Linuxwith JDK 的版本：Java HotSpot(TM) 64-Bit Server VM (build 25.0-b23, mixed mode)
我通过这种方式创建了三个字段的自定义对象数组（按保留顺序添加对象）：
package com.cmd;
import java.util.Arrays;
public class Main {
public static void main(String[] args) {
for (int i=100; i <= 10_000_000; i*=10){
runTest(i);
}
}
private static void runTest(final int size){
// Fist obtain two Arrays of same data
Employee[] empArrForSort = createVeryLargeEmpArray(size);
Employee[] empArrForSortCopy = Arrays.copyOf(empArrForSort, empArrForSort.length);
long start = System.currentTimeMillis();
Arrays.sort(empArrForSort, (e1, e2) -> new Integer(e1.getId()).compareTo(e2.getId()));
logStart(size + ": sort", start);
start = System.currentTimeMillis();
Arrays.parallelSort(empArrForSortCopy, (e1, e2) -> new Integer(e1.getId()).compareTo(e2.getId()));
logStart(size + ": parallel sort", start);
}
private static void logStart(String label, long startTimeMillis) {
System.out.println("End " + label + " the array. It took: " + (System.currentTimeMillis() - startTimeMillis) + " ms");
}
private static Employee[] createVeryLargeEmpArray(final int size) {
Employee[] ret = new Employee[size];
for (int i = 0; i < ret.length; i++) {
ret[i] = Employee.createEmployee(ret.length - i, "Mohammad" + i, "");
}
return ret;
}
static class Employee {
private int id;
private String name;
private String email;
private Employee(int id, String name, String email) {
this.id = id;
this.name = name;
this.email = email;
}
public static Employee createEmployee(int id, String name, String email) {
return new Employee(id, name, email);
}
public int getId() {
return id;
}
}
}
并且，另一个运行表明，Parallel 仅在列表包含 10,000,000 时执行 pad，在所有其他情况下看起来更好。
>java -Xmx2000m com.cmd.Main
End 100: sort the array. It took: 110 ms
End 100: parallel sort the array. It took: 6 ms
End 1000: sort the array. It took: 2 ms
End 1000: parallel sort the array. It took: 3 ms
End 10000: sort the array. It took: 11 ms
End 10000: parallel sort the array. It took: 11 ms
End 100000: sort the array. It took: 15 ms
End 100000: parallel sort the array. It took: 37 ms
End 1000000: sort the array. It took: 553 ms
End 1000000: parallel sort the array. It took: 187 ms
End 10000000: sort the array. It took: 640 ms
End 10000000: parallel sort the array. It took: 1099 ms