From 7eb159fca71758d405336f5509129896529b89e6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=AB=A5=E6=88=90?=
<13191486+tong-cheng666@user.noreply.gitee.com>
Date: Sun, 29 Oct 2023 22:01:23 +0800
Subject: [PATCH] =?UTF-8?q?=E5=88=9D=E5=A7=8B=E5=8C=96?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
---
.gitignore | 38 ++++++++++++++++++
.idea/.gitignore | 10 +++++
.idea/encodings.xml | 7 ++++
.idea/misc.xml | 14 +++++++
.idea/vcs.xml | 6 +++
pom.xml | 17 ++++++++
src/main/java/com/tong/SpinLockDemo.java | 51 ++++++++++++++++++++++++
7 files changed, 143 insertions(+)
create mode 100644 .gitignore
create mode 100644 .idea/.gitignore
create mode 100644 .idea/encodings.xml
create mode 100644 .idea/misc.xml
create mode 100644 .idea/vcs.xml
create mode 100644 pom.xml
create mode 100644 src/main/java/com/tong/SpinLockDemo.java
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5ff6309
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,38 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
\ No newline at end of file
diff --git a/.idea/.gitignore b/.idea/.gitignore
new file mode 100644
index 0000000..afa4cd3
--- /dev/null
+++ b/.idea/.gitignore
@@ -0,0 +1,10 @@
+# 默认忽略的文件
+/shelf/
+/workspace.xml
+# 基于编辑器的 HTTP 客户端请求
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
+# Zeppelin 忽略的文件
+/ZeppelinRemoteNotebooks/
diff --git a/.idea/encodings.xml b/.idea/encodings.xml
new file mode 100644
index 0000000..aa00ffa
--- /dev/null
+++ b/.idea/encodings.xml
@@ -0,0 +1,7 @@
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
new file mode 100644
index 0000000..82dbec8
--- /dev/null
+++ b/.idea/misc.xml
@@ -0,0 +1,14 @@
+
+
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..94a25f7
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
new file mode 100644
index 0000000..d6ddbf3
--- /dev/null
+++ b/pom.xml
@@ -0,0 +1,17 @@
+
+
+ 4.0.0
+
+ com.tong
+ SpinLockDemo
+ 1.0-SNAPSHOT
+
+
+ 17
+ 17
+ UTF-8
+
+
+
diff --git a/src/main/java/com/tong/SpinLockDemo.java b/src/main/java/com/tong/SpinLockDemo.java
new file mode 100644
index 0000000..3ec75f2
--- /dev/null
+++ b/src/main/java/com/tong/SpinLockDemo.java
@@ -0,0 +1,51 @@
+package com.tong;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * @author: tongCheng
+ * @Package: SpinLockDemo
+ * @ClassName: SpinLockDemo
+ * @date: 2023-10-28 13:46
+ * 实现一个自旋锁，复习CAS思想
+ * 自旋锁的好处：循环比较获取没有类似wait的阻塞
+ * 通过CAS操作完成自旋锁，A线程先进来调用myLock方法自己持有锁5秒钟，B随后进来后
+ * 发现当前线程持有锁，所有只能通过自旋等待，知道A释放锁后B随后抢到
+ */
+public class SpinLockDemo {
+
+ AtomicReference atomicReference = new AtomicReference<>();
+
+ public void lock() {
+ Thread thread = Thread.currentThread();
+ System.out.println(Thread.currentThread().getName()+"\t"+"----come in");
+ while (!atomicReference.compareAndSet(null, thread)) {
+
+ }
+ }
+
+ public void unLock() {
+ Thread thread = Thread.currentThread();
+ atomicReference.compareAndSet(thread, null);
+ System.out.println(Thread.currentThread().getName()+"\t"+"----task over,unLock...");
+ }
+
+ public static void main(String[] args) {
+ SpinLockDemo spinLockDemo = new SpinLockDemo();
+ new Thread(() -> {
+ spinLockDemo.lock();
+ //暂停几秒钟线程
+ try { TimeUnit.SECONDS.sleep(5); } catch (InterruptedException e) { e.printStackTrace(); }
+ spinLockDemo.unLock();
+ }, "A").start();
+ //暂停500毫秒，线程A先于B启动
+ try { TimeUnit.MILLISECONDS.sleep(500); } catch (InterruptedException e) { e.printStackTrace(); }
+
+ new Thread(() -> {
+ spinLockDemo.lock();
+
+ spinLockDemo.unLock();
+ }, "B").start();
+ }
+}