From 4555ef2b378fbeb5d08dbc1164e1260ed65cb3d5 Mon Sep 17 00:00:00 2001
From: witskeeper <witskeeper@gmail.com>
Date: Sat, 3 Aug 2024 13:02:04 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E5=B9=B6=E5=8F=91=E6=8E=A7?=
 =?UTF-8?q?=E5=88=B6=E6=96=87=E6=A1=A3?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/content/concurrency/redis-lock.md        | 67 +++++++++++++++++++
 .../{domain => concurrency}/row-version.md    |  0
 docs/mkdocs.yml                               |  3 +
 3 files changed, 70 insertions(+)
 create mode 100644 docs/content/concurrency/redis-lock.md
 rename docs/content/{domain => concurrency}/row-version.md (100%)

diff --git a/docs/content/concurrency/redis-lock.md b/docs/content/concurrency/redis-lock.md
new file mode 100644
index 00000000..56d670f2
--- /dev/null
+++ b/docs/content/concurrency/redis-lock.md
@@ -0,0 +1,67 @@
+# 悲观锁-Redis锁
+
+## 什么是Redis锁？
+
+`Redis锁`是一种用于解决并发问题的机制，基于Redis的`悲观锁`实现。在并发环境中，多个用户可能同时变更同一资源，如果不加以限制，不同用户之间的操作可能相互覆盖，导致数据不一致的问题。`Redis锁`就是为了解决这个问题而设计的。
+
+## Redis锁的实现原理
+
+`Redis锁`的实现原理是通过在Redis中设置一个唯一的键来表示锁，当一个线程获取锁时，其他线程无法获取锁，直到该线程释放锁。具体步骤如下：
+1. 线程A尝试获取锁，在Redis中设置一个唯一键，如果设置成功功，则获取锁。
+2. 线程A执行完操作后，删除该唯一键，释放锁。
+3. 线程B尝试获取锁，如果Redis中不存在该唯一键，则获取锁，否则等待或重试。
+
+## Redis锁的使用场景
+
+`Redis锁`主要用于解决高并发问题，例如在订单系统中，当多个用户同时下单时，可能会导致超卖的问题，此时可以使用`Redis锁`使得扣除库存的操作每次只能有一个线程执行，确保数据的一致性。
+
+## 注册Redis锁
+
+在Program.cs注册`IDistributedLock`：
+```csharp
+using NetCorePal.Extensions.DistributedLocks;
+using NetCorePal.Extensions.DistributedLocks.Redis;
+using StackExchange.Redis;
+
+var redis = ConnectionMultiplexer.Connect(builder.Configuration.GetConnectionString("Redis")!);
+builder.Services.AddSingleton<IConnectionMultiplexer>(p => redis);
+builder.Services.AddRedisLocks();
+```
+
+## 使用Redis锁
+
+在需要使用锁的地方注入`IDistributedLock`：
+```csharp
+using NetCorePal.Extensions.DistributedLocks;
+namespace DistributedLocksSample
+{
+    public class RedisLockSample
+    {
+        private readonly IDistributedLock _lock;
+        public RedisLockSample(IDistributedLock @lock)
+        {
+            _lock = @lock;
+        }
+
+        public async Task LockSample()
+        {
+            using (var l = await _lock.Acquire("lock-key", TimeSpan.FromSeconds(10)))
+            {
+                // do something
+            }
+        }
+        
+        public async Task TryLockSample()
+        {
+            var lockerHandler = await _lock.TryAcquire("lock-key", TimeSpan.FromSeconds(10)))
+            if (lockerHandler != null)
+            {
+                using (lockerHandler)
+                {
+                    // do something
+                }
+            }
+        }
+    }
+}
+```
\ No newline at end of file
diff --git a/docs/content/domain/row-version.md b/docs/content/concurrency/row-version.md
similarity index 100%
rename from docs/content/domain/row-version.md
rename to docs/content/concurrency/row-version.md
diff --git a/docs/mkdocs.yml b/docs/mkdocs.yml
index 2215af7f..2350e114 100644
--- a/docs/mkdocs.yml
+++ b/docs/mkdocs.yml
@@ -65,6 +65,9 @@ nav:
     - 上下文访问器: context/context-accessor.md
     - AspNetCore: context/aspnetcore-context-processor.md
     - CAP: context/cap-context-processor.md
+  - 并发控制:
+    - 乐观锁-行版本号: concurrency/row-version.md
+    - 悲观锁-Redis锁: concurrency/redis-lock.md
   - 多环境:
     - 环境上下文: env/env-context.md
     - 环境服务选择器: env/env-service-selector.md