91 lines
2.9 KiB
Java
91 lines
2.9 KiB
Java
// concurrency/ListComparisons.java
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// ©2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
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// {Args: 1 10 10} (Fast verification check during build)
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// Rough comparison of thread-safe List performance.
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import java.util.concurrent.*;
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import java.util.*;
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import onjava.*;
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abstract class ListTest extends Tester<List<Integer>> {
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ListTest(String testId, int nReaders, int nWriters) {
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super(testId, nReaders, nWriters);
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}
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class Reader extends TestTask {
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long result = 0;
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void test() {
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for(long i = 0; i < testCycles; i++)
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for(int index = 0; index < containerSize; index++)
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result += testContainer.get(index);
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}
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void putResults() {
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readResult += result;
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readTime += duration;
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}
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}
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class Writer extends TestTask {
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void test() {
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for(long i = 0; i < testCycles; i++)
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for(int index = 0; index < containerSize; index++)
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testContainer.set(index, writeData[index]);
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}
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void putResults() {
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writeTime += duration;
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}
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}
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void startReadersAndWriters() {
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for(int i = 0; i < nReaders; i++)
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exec.execute(new Reader());
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for(int i = 0; i < nWriters; i++)
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exec.execute(new Writer());
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}
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}
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class SynchronizedArrayListTest extends ListTest {
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List<Integer> containerInitializer() {
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return Collections.synchronizedList(
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new ArrayList<>(
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new CountingIntegerList(containerSize)));
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}
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SynchronizedArrayListTest(int nReaders, int nWriters) {
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super("Synched ArrayList", nReaders, nWriters);
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}
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}
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class CopyOnWriteArrayListTest extends ListTest {
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List<Integer> containerInitializer() {
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return new CopyOnWriteArrayList<>(
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new CountingIntegerList(containerSize));
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}
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CopyOnWriteArrayListTest(int nReaders, int nWriters) {
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super("CopyOnWriteArrayList", nReaders, nWriters);
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}
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}
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public class ListComparisons {
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public static void main(String[] args) {
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Tester.initMain(args);
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new SynchronizedArrayListTest(10, 0);
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new SynchronizedArrayListTest(9, 1);
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new SynchronizedArrayListTest(5, 5);
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new CopyOnWriteArrayListTest(10, 0);
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new CopyOnWriteArrayListTest(9, 1);
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new CopyOnWriteArrayListTest(5, 5);
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Tester.exec.shutdown();
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}
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}
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/* Output:
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Type Read time Write time
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Synched ArrayList 10r 0w 700989 0
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Synched ArrayList 9r 1w 2531313 60622
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readTime + writeTime = 2591935
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Synched ArrayList 5r 5w 1396291 649761
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readTime + writeTime = 2046052
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CopyOnWriteArrayList 10r 0w 551005 0
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CopyOnWriteArrayList 9r 1w 161945 123521
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readTime + writeTime = 285466
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CopyOnWriteArrayList 5r 5w 549580 4230146
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readTime + writeTime = 4779726
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*/
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