From 03a7312e23097677664dfc3e89b51b335b0e8d12 Mon Sep 17 00:00:00 2001
From: Looly <loolly@aliyun.com>
Date: Thu, 21 Aug 2025 11:37:30 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8D`AbstrachCache.get`=E5=8F=AF?=
 =?UTF-8?q?=E8=83=BD=E9=80=A0=E6=88=90=E7=9A=84=E6=AD=BB=E9=94=81=E9=97=AE?=
 =?UTF-8?q?=E9=A2=98=EF=BC=88issue#4022@Github=EF=BC=89?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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---
 CHANGELOG.md                                  |  1 +
 .../cn/hutool/cache/impl/AbstractCache.java   | 22 +++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 315c658b5..3b4a589e8 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@
 * 【extra  】      修复`QLExpressEngine`allowClassSet无效问题（issue#3994@Github）
 * 【core   】      修复`StrBuilder`insert插入计算错误问题（issue#ICTSRZ@Gitee）
 * 【cron   】      修复`CronPatternUtil.nextDateAfter`计算下一个匹配表达式的日期时，计算错误问题（issue#4006@Github）
+* 【cach   】      修复`AbstrachCache.get`可能造成的死锁问题（issue#4022@Github）
 
 -------------------------------------------------------------------------------------------------------------
 # 5.8.39(2025-06-20)
diff --git a/hutool-cache/src/main/java/cn/hutool/cache/impl/AbstractCache.java b/hutool-cache/src/main/java/cn/hutool/cache/impl/AbstractCache.java
index 5ff371789..337b682c6 100755
--- a/hutool-cache/src/main/java/cn/hutool/cache/impl/AbstractCache.java
+++ b/hutool-cache/src/main/java/cn/hutool/cache/impl/AbstractCache.java
@@ -7,6 +7,7 @@ import cn.hutool.core.lang.mutable.Mutable;
 import cn.hutool.core.lang.mutable.MutableObj;
 import cn.hutool.core.map.SafeConcurrentHashMap;
 
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
@@ -65,6 +66,11 @@ public abstract class AbstractCache<K, V> implements Cache<K, V> {
 	 */
 	protected CacheListener<K, V> listener;
 
+	/**
+	 * 相同线程key缓存，用于检查key循环引用导致的死锁
+	 */
+	private final ThreadLocal<Set<K>> loadingKeys = ThreadLocal.withInitial(HashSet::new);
+
 	// ---------------------------------------------------------------- put start
 	@Override
 	public void put(K key, V object) {
@@ -126,6 +132,12 @@ public abstract class AbstractCache<K, V> implements Cache<K, V> {
 	public V get(K key, boolean isUpdateLastAccess, long timeout, Func0<V> supplier) {
 		V v = get(key, isUpdateLastAccess);
 		if (null == v && null != supplier) {
+			// 在尝试加锁前，检查当前线程是否已经在加载这个 key，见：issue#4022
+			// 如果是，则说明发生了循环依赖。
+			if (loadingKeys.get().contains(key)) {
+				throw new IllegalStateException("Circular dependency detected for key: " + key);
+			}
+
 			//每个key单独获取一把锁，降低锁的粒度提高并发能力，see pr#1385@Github
 			final Lock keyLock = keyLockMap.computeIfAbsent(key, k -> new ReentrantLock());
 			keyLock.lock();
@@ -135,9 +147,15 @@ public abstract class AbstractCache<K, V> implements Cache<K, V> {
 				// 因此此处需要使用带全局锁的get获取值
 				v = get(key, isUpdateLastAccess);
 				if (null == v) {
+					loadingKeys.get().add(key);
 					// supplier的创建是一个耗时过程，此处创建与全局锁无关，而与key锁相关，这样就保证每个key只创建一个value，且互斥
-					v = supplier.callWithRuntimeException();
-					put(key, v, timeout);
+					try {
+						v = supplier.callWithRuntimeException();
+						put(key, v, timeout);
+					} finally {
+						// 无论 supplier 执行成功还是失败，都必须在 finally 块中移除标记
+						loadingKeys.get().remove(key);
+					}
 				}
 			} finally {
 				keyLock.unlock();