基于redis的分布式锁

  1 using System;
  2 using System.Diagnostics;  3 using System.Text;  4 using System.Threading;  5 using BookSleeve;  6  7 namespace ViewAlloc.Threading  8 {  9 public class RedisBillLockHandler  10  {  11 private const int DEFAULT_SINGLE_EXPIRE_TIME = 10;  12 private static readonly DateTime DEFAULT_DATETIME = new DateTime(1970, 1, 1);  13 private const int DEFAULT_DB = 0;  14  15 private readonly RedisConnection client;  16  17 /// <summary>  18 /// 构造  19 /// </summary>  20 /// <param name="client"></param>  21 public RedisBillLockHandler(RedisConnection client)  22  {  23 this.client = client;  24  }  25  26 /// <summary>  27 /// 获取锁  28 /// 如果锁可用立即返回true,否则返回false  29 /// </summary>  30 /// <param name="key"></param>  31 /// <returns></returns>  32 public bool TryLock(String key)  33  {  34 return TryLock(key, 0L);  35  }  36  37 /// <summary>  38 /// 锁在给定的等待时间内空闲，则获取锁成功 返回true， 否则返回false  39 /// </summary>  40 /// <param name="key"></param>  41 /// <param name="timeout"></param>  42 /// <returns></returns>  43 public bool TryLock(String key, long timeout)  44  {  45 try  46  {  47 Stopwatch watch = Stopwatch.StartNew();  48 do  49  {  50 long tt = (long)(DateTime.Now - DEFAULT_DATETIME).TotalSeconds;  51 long timestamp = tt + DEFAULT_SINGLE_EXPIRE_TIME + 1;  52  53 var tran = client.CreateTransaction();  54 var taskSetIfNotExists = tran.Strings.SetIfNotExists(DEFAULT_DB, key, Encoding.UTF8.GetBytes(timestamp.ToString()));  55 var taskGet = tran.Strings.Get(DEFAULT_DB, key);  56  tran.Execute().Wait();  57  tran.Dispose();  58 if (taskSetIfNotExists.Result == true)  59  {  60 return true;  61  }  62 else  63  {  64  65 long ex = long.Parse(Encoding.UTF8.GetString(taskGet.Result));  66 if (tt > ex)  67  {  68 var taskGetSet = client.Strings.GetSet(DEFAULT_DB, key, Encoding.UTF8.GetBytes(timestamp.ToString()));  69 long old = long.Parse(Encoding.UTF8.GetString(taskGetSet.Result)); 70 71 if (ex == old) 72 { 73 return true; 74 } 75 } 76 } 77 if (timeout == 0) 78 { 79 break; 80 } 81 Thread.Sleep(300); 82 } while (watch.ElapsedMilliseconds < timeout * 1000); 83 return false; 84 } 85 catch (Exception exc) 86 { 87 throw new RedisBillLockException(exc.Message, exc); 88 } 89 } 90 91 /// <summary> 92 /// 如果锁空闲立即返回 93 /// 获取失败一直等待 94 /// </summary> 95 /// <param name="key"></param> 96 public void Lock(String key) 97 { 98 try 99 { 100 do 101 { 102 long tt = (long)(DateTime.Now - DEFAULT_DATETIME).TotalSeconds; 103 long timestamp = tt + DEFAULT_SINGLE_EXPIRE_TIME + 1; 104 105 var tran = client.CreateTransaction(); 106 var taskSetIfNotExists = tran.Strings.SetIfNotExists(DEFAULT_DB, key, Encoding.UTF8.GetBytes(timestamp.ToString())); 107 var taskGet = tran.Strings.Get(DEFAULT_DB, key); 108 tran.Execute().Wait(); 109 tran.Dispose(); 110 if (taskSetIfNotExists.Result == true) 111 { 112 break; 113 } 114 else 115 { 116 117 long ex = long.Parse(Encoding.UTF8.GetString(taskGet.Result)); 118 if (tt > ex) 119 { 120 var taskGetSet = client.Strings.GetSet(DEFAULT_DB, key, Encoding.UTF8.GetBytes(timestamp.ToString())); 121 long old = long.Parse(Encoding.UTF8.GetString(taskGetSet.Result)); 122 if (ex == old) 123 { 124 break; 125 } 126 } 127 } 128 129 Thread.Sleep(300); 130 } while (true); 131 } 132 catch (Exception exc) 133 { 134 throw new RedisBillLockException(exc.Message, exc); 135 } 136 } 137 138 /// <summary> 139 /// 释放锁 140 /// </summary> 141 /// <param name="keys"></param> 142 public void UnLock(String key) 143 { 144 try 145 { 146 long tt = (long)(DateTime.Now - DEFAULT_DATETIME).TotalSeconds; 147 var taskGet = client.Strings.Get(DEFAULT_DB, key); 148 long ex = long.Parse(Encoding.UTF8.GetString(taskGet.Result)); 149 if (tt < ex) 150 { 151 var taskRemove = client.Keys.Remove(DEFAULT_DB, key); 152 taskRemove.Wait(); 153 } 154 } 155 catch (Exception exc) 156 { 157 throw new RedisBillLockException(exc.Message, exc); 158 } 159 } 160 } 161 162 }

using System;

namespace ViewAlloc.Threading
{
    /// <summary> /// 分布式锁属性 /// </summary> [AttributeUsage(AttributeTargets.Method | AttributeTargets.Property)] public class RedisBillLockAttribute : Attribute { public string Scheme { set; get; } public string Key { set; get; } public RedisBillLockAttribute(string scheme, string key) { this.Scheme = scheme; this.Key = key; } } }

using System;
using System.Reflection;
using System.Runtime.Remoting; using System.Runtime.Remoting.Messaging; namespace ViewAlloc.Threading { /// <summary> /// 装饰类，不需要对每一个类进行封装了，性能可能会有一细细的影响 /// </summary> public class RedisBillLockWrapper { public static T Wrap<T>(T target) where T : MarshalByRefObject { return new MyProxy(typeof(T), target).GetTransparentProxy() as T; } private class MyProxy : System.Runtime.Remoting.Proxies.RealProxy { public MyProxy(Type t, MarshalByRefObject target) : base(t) { this.target = target; } public override IMessage Invoke(IMessage msg) { MethodBase method = (msg as IMethodMessage).MethodBase; object[] atts = method.GetCustomAttributes(typeof(RedisBillLockAttribute), false); bool locking = atts.Length == 1; IMessage result = null; if (locking) { RedisBillLockAttribute redisBillLockAttribute = atts[0] as RedisBillLockAttribute; BookSleeve.RedisConnection client = new BookSleeve.RedisConnection(redisBillLockAttribute.Scheme); client.Open(); try { RedisBillLockHandler lockHandler = new RedisBillLockHandler(client); lockHandler.Lock(redisBillLockAttribute.Key); try { result = RemotingServices.ExecuteMessage(target, msg as IMethodCallMessage); } finally { lockHandler.UnLock(redisBillLockAttribute.Key); } } finally { client.Close(false); } } else { result = RemotingServices.ExecuteMessage(target, msg as IMethodCallMessage); } return result; } private MarshalByRefObject target; } } }

class TestLock
    {
        public void Run()
        {
            Console.WriteLine("{0:yyyyMMddHHmmssfff}获取了锁", DateTime.Now); Thread.Sleep(1000); } }

class TestLock : MarshalByRefObject
    {
        [RedisBillLock("127.0.0.1", "viewalloc_lock_service_key_test")] public void Run() { Console.WriteLine("{0:yyyyMMddHHmmssfff}获取了锁", DateTime.Now); Thread.Sleep(1000); } }

 TestLock testLock = RedisBillLockWrapper.Wrap<TestLock>(new TestLock());

                testLock.Run();