From f74e47bfefcbfbfc4aa179b40a81627eeb5f340a Mon Sep 17 00:00:00 2001
From: liangjinglin <liangjinglin@hc-smart.com>
Date: Sun, 2 Feb 2025 13:12:57 +0800
Subject: [PATCH] =?UTF-8?q?20250201=20jvm=E8=B0=83=E4=BC=98?=
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---
 src/java/jvm/JVM.java    | 23 ++++++++++++++
 src/java/jvm/heapGc.java | 66 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 89 insertions(+)
 create mode 100644 src/java/jvm/JVM.java
 create mode 100644 src/java/jvm/heapGc.java

diff --git a/src/java/jvm/JVM.java b/src/java/jvm/JVM.java
new file mode 100644
index 0000000..2544495
--- /dev/null
+++ b/src/java/jvm/JVM.java
@@ -0,0 +1,23 @@
+package jvm;
+
+public class JVM {
+
+    private int a;
+
+    private int b;
+
+    public JVM(int a, int b) {
+        this.a = a;
+        this.b = b;
+    }
+
+    public int add() {
+        return a + b;
+    }
+
+    public static void main(String[] args) {
+        JVM jvm = new JVM(1, 2);
+        int result = jvm.add();
+        System.out.println(result);
+    }
+}
diff --git a/src/java/jvm/heapGc.java b/src/java/jvm/heapGc.java
new file mode 100644
index 0000000..0f542d6
--- /dev/null
+++ b/src/java/jvm/heapGc.java
@@ -0,0 +1,66 @@
+package jvm;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Observable;
+
+public class heapGc {
+
+    private byte[] bytes = new byte[1024 * 100]; // 1M
+
+    //cmd jvisualvm可以看到jvm的内存、线程等使用情况
+    //arthas调优,https://alibaba.github.io/arthas
+    public static void main(String[] args) {
+        heapGc heapGc = new heapGc();
+        heapGc.deadLock();
+    }
+
+    private void gc()  throws InterruptedException{
+        List<heapGc> list = new ArrayList<>();
+        while (true) {
+            list.add(new heapGc());
+            Thread.sleep(5);
+        }
+    }
+
+    private void cpuHigh(){
+        new Thread(() -> {
+            while (true) {
+
+            }
+        }).start();
+    }
+
+    private void deadLock(){
+        Object a = new Object();
+        Object b = new Object();
+        Thread threadA = new Thread(() -> {
+            synchronized (a) {
+                try {
+                    Thread.sleep(1000);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+                synchronized (b) {
+                    System.out.println("get b");
+                }
+            }
+        });
+
+        Thread threadB = new Thread(() -> {
+            synchronized (b) {
+                try {
+                    Thread.sleep(1000);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+                synchronized (a) {
+                    System.out.println("get a");
+                }
+            }
+        });
+
+        threadA.start();
+        threadB.start();
+    }
+}