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8073124: Tune test and document TimSort runs length stack size increase

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Reviewed-by: dholmes
This commit is contained in:
Lev Priima 2015-02-16 19:16:50 -05:00
parent 0ad8cc755b
commit a1d6f0cbcd
3 changed files with 24 additions and 8 deletions
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4
jdk/src/java.base/share/classes/java/util/ComparableTimSort.java
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@ -144,6 +144,10 @@ class ComparableTimSort {
* large) stack lengths for smaller arrays. The "magic numbers" in the
* computation below must be changed if MIN_MERGE is decreased. See
* the MIN_MERGE declaration above for more information.
* The maximum value of 49 allows for an array up to length
* Integer.MAX_VALUE-4, if array is filled by the worst case stack size
* increasing scenario. More explanations are given in section 4 of:
* http://envisage-project.eu/wp-content/uploads/2015/02/sorting.pdf
*/
int stackLen = (len < 120 ? 5 :
len < 1542 ? 10 :

4
jdk/src/java.base/share/classes/java/util/TimSort.java
View File

@ -174,6 +174,10 @@ class TimSort<T> {
* large) stack lengths for smaller arrays. The "magic numbers" in the
* computation below must be changed if MIN_MERGE is decreased. See
* the MIN_MERGE declaration above for more information.
* The maximum value of 49 allows for an array up to length
* Integer.MAX_VALUE-4, if array is filled by the worst case stack size
* increasing scenario. More explanations are given in section 4 of:
* http://envisage-project.eu/wp-content/uploads/2015/02/sorting.pdf
*/
int stackLen = (len < 120 ? 5 :
len < 1542 ? 10 :

24
jdk/test/java/util/Arrays/TimSortStackSize2.java
View File

@ -24,10 +24,10 @@
/*
* @test
* @bug 8072909
* @run main/othervm TimSortStackSize2 67108864
* @run main/othervm -Xmx385m TimSortStackSize2 67108864
* not for regular execution on all platforms:
* run main/othervm -Xmx8g TimSortStackSize2 1073741824
* run main/othervm -Xmx32g TimSortStackSize2 2147483644
* run main/othervm -Xmx16g TimSortStackSize2 2147483644
* @summary Test TimSort stack size on big arrays
*/
import java.util.ArrayList;
@ -41,22 +41,30 @@ public class TimSortStackSize2 {
int lengthOfTest = Integer.parseInt(args[0]);
boolean passed = true;
try {
Arrays.sort(new TimSortStackSize2(lengthOfTest).createArray(),
new Comparator<Object>() {
Integer [] a = new TimSortStackSize2(lengthOfTest).createArray();
long begin = System.nanoTime();
Arrays.sort(a, new Comparator<Object>() {
@SuppressWarnings("unchecked")
public int compare(Object first, Object second) {
return ((Comparable<Object>)first).compareTo(second);
}
});
System.out.println("TimSort OK");
long end = System.nanoTime();
System.out.println("TimSort: " + (end - begin));
a = null;
} catch (ArrayIndexOutOfBoundsException e){
System.out.println("TimSort broken");
System.out.println("TimSort broken:");
e.printStackTrace();
passed = false;
}
try {
Arrays.sort(new TimSortStackSize2(lengthOfTest).createArray());
System.out.println("ComparableTimSort OK");
Integer [] a = new TimSortStackSize2(lengthOfTest).createArray();
long begin = System.nanoTime();
Arrays.sort(a);
long end = System.nanoTime();
System.out.println("ComparableTimSort: " + (end - begin));
a = null;
} catch (ArrayIndexOutOfBoundsException e){
System.out.println("ComparableTimSort broken:");
e.printStackTrace();