Transplant jmh test Skynet.java from Loom

[youyou0805]

Main changes

1.Create a standalone Maven project to meet the needs of JMH 2.To make it compatible with KonaJDK8, replace the keyword var with the corresponding type when declaring variables.

Detailed diff output

diff --git a/Skynet.java b/Skynet.java
index a9255dd..b64ef58 100644
--- a/Skynet.java
+++ b/Skynet.java
@@ -20,7 +20,8 @@
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
-package org.openjdk.bench.loom;
+package com.example;

 import org.openjdk.jmh.annotations.Benchmark;
 import org.openjdk.jmh.annotations.BenchmarkMode;
@@ -46,7 +47,7 @@ import java.util.concurrent.TimeUnit;
 @SuppressWarnings("preview")
 public class Skynet {

-    @Param({"1000000"})
+    /*
+    * The original default value of 1,000,000 for this parameter would cause excessive computational
+    * overhead and memory usage during training, resulting in a program that cannot run successfully.
+    * To maintain stability and ensure successful execution, we set a smaller default value of 100,000 instead.
+    */
+    @Param({"100000"}) 
     public int num;

     static class Channel<T> {
@@ -89,9 +90,9 @@ public class Skynet {

     static void skynet(Channel<Long> result, int num, int size, int div) {
         if (size == 1) {
             result.send((long) num);
         } else {
-            var chan = new Channel<Long>();
+            Channel<Long> chan = new Channel<>();
             for (int i = 0; i < div; i++) {
                 int subNum = num + i * (size / div);
                 Thread.startVirtualThread(() -> skynet(chan, subNum, size / div, div));
@@ -106,7 +107,7 @@ public class Skynet {

     @Benchmark
     public long skynet() {
-        var chan = new Channel<Long>();
+        Channel<Long> chan = new Channel<>();
         Thread.startVirtualThread(() -> skynet(chan, 0, num, 10));
         return chan.receive();
     }

[tencent-adm]

All committers have signed the CLA.

[miao-zheng]

1. 在comment里列出来，这个文件和loom的原始文件的git diff结果；
2. 上次讨论过，num是100万的时候，可能会出现out of memory的问题，后续进展如何？

[youyou0805]

1. 在comment里列出来，这个文件和loom的原始文件的git diff结果；
2. 上次讨论过，num是100万的时候，可能会出现out of memory的问题，后续进展如何？

1. git diff结果已列出
2. 之后我尝试了在不同的设备上运行程序，但是问题仍然无法得到解决，所以测试时不得不降低Param值。正如老师您上次开会时所说的那样，loom不会有这样的问题，num可以达到100万。

[miao-zheng]

可以把这个num改小一点

[youyou0805]

可以把这个num改小一点

好的

[miao-zheng]

文件目录改为demo/fiber/loom/Skynet