public InnerRedisLock(IRedisClient redisClient, string key, TimeSpan timeOut)
{
this.redisClient = redisClient;
this.key = key;
ExecExtensions.RetryUntilTrue(() =>
{
var realSpan = timeOut == TimeSpan.Zero ? new TimeSpan(365, 0, 0, 0) : timeOut; //if nothing is passed in the timeout hold for a year
var expireTime = NetworkTime.Now.Add(realSpan);
var lockString = ((long)(expireTime.ToUnixTime() + 1)).ToString();
var nx = redisClient.SetEntryIfNotExists(key, lockString);
if (nx)
{
return(true);
}
var lockExpireString = redisClient.Get <string>(key);
long lockExpireTime;
if (!long.TryParse(lockExpireString, out lockExpireTime))
{
return(false);
}
if (lockExpireTime > NetworkTime.Now.ToUnixTime())
{
return(false);
}
return(redisClient.GetAndSetEntry(key, lockString) == lockExpireString);
}, timeOut
);
}
public RedisLock(RedisClient redisClient, string key, TimeSpan?timeOut)
{
this.redisClient = redisClient;
this.key = key;
ExecExtensions.RetryUntilTrue(
() => redisClient.SetEntryIfNotExists(key, "lock " + DateTime.UtcNow.ToUnixTime()),
timeOut
);
}
public RedisLock(RedisClient redisClient, string key, TimeSpan?timeOut)
{
this.redisClient = redisClient;
this.key = key;
ExecExtensions.RetryUntilTrue(
() =>
{
//This pattern is taken from the redis command for SETNX http://redis.io/commands/setnx
//Calculate a unix time for when the lock should expire
TimeSpan realSpan = timeOut ?? new TimeSpan(365, 0, 0, 0); //if nothing is passed in the timeout hold for a year
DateTime expireTime = DateTime.UtcNow.Add(realSpan);
string lockString = (expireTime.ToUnixTimeMs() + 1).ToString();
//Try to set the lock, if it does not exist this will succeed and the lock is obtained
var nx = redisClient.SetValueIfNotExists(key, lockString);
if (nx)
{
return(true);
}
//If we've gotten here then a key for the lock is present. This could be because the lock is
//correctly acquired or it could be because a client that had acquired the lock crashed (or didn't release it properly).
//Therefore we need to get the value of the lock to see when it should expire
redisClient.Watch(key);
string lockExpireString = redisClient.Get <string>(key);
long lockExpireTime;
if (!long.TryParse(lockExpireString, out lockExpireTime))
{
redisClient.UnWatch(); // since the client is scoped externally
return(false);
}
//If the expire time is greater than the current time then we can't let the lock go yet
if (lockExpireTime > DateTime.UtcNow.ToUnixTimeMs())
{
redisClient.UnWatch(); // since the client is scoped externally
return(false);
}
//If the expire time is less than the current time then it wasn't released properly and we can attempt to
//acquire the lock. The above call to Watch(_lockKey) enrolled the key in monitoring, so if it changes
//before we call Commit() below, the Commit will fail and return false, which means that another thread
//was able to acquire the lock before we finished processing.
using (var trans = redisClient.CreateTransaction()) // we started the "Watch" above; this tx will succeed if the value has not moved
{
trans.QueueCommand(r => r.Set(key, lockString));
return(trans.Commit()); //returns false if Transaction failed
}
},
timeOut
);
}
public RedisLock(RedisClient redisClient, string key, TimeSpan?timeOut)
{
this.redisClient = redisClient;
this.key = key;
ExecExtensions.RetryUntilTrue(
() =>
{
//This pattern is taken from the redis command for SETNX http://redis.io/commands/setnx
//Calculate a unix time for when the lock should expire
TimeSpan realSpan = timeOut ?? new TimeSpan(365, 0, 0, 0); //if nothing is passed in the timeout hold for a year
DateTime expireTime = DateTime.UtcNow.Add(realSpan);
string lockString = (expireTime.ToUnixTimeMs() + 1).ToString();
//Try to set the lock, if it does not exist this will succeed and the lock is obtained
var nx = redisClient.SetEntryIfNotExists(key, lockString);
if (nx)
{
return(true);
}
//If we've gotten here then a key for the lock is present. This could be because the lock is
//correctly acquired or it could be because a client that had acquired the lock crashed (or didn't release it properly).
//Therefore we need to get the value of the lock to see when it should expire
string lockExpireString = redisClient.Get <string>(key);
long lockExpireTime;
if (!long.TryParse(lockExpireString, out lockExpireTime))
{
return(false);
}
//If the expire time is greater than the current time then we can't let the lock go yet
if (lockExpireTime > DateTime.UtcNow.ToUnixTimeMs())
{
return(false);
}
//If the expire time is less than the current time then it wasn't released properly and we can attempt to
//acquire the lock. This is done by setting the lock to our timeout string AND checking to make sure
//that what is returned is the old timeout string in order to account for a possible race condition.
return(redisClient.GetAndSetEntry(key, lockString) == lockExpireString);
},
timeOut
);
}
public virtual void Lock(object key)
{
log.DebugFormat("acquiring cache lock : {0}", key);
try
{
var globalKey = CacheNamespace.GlobalKey(key, RedisNamespace.NumTagsForLockKey);
using (var client = this.clientManager.GetClient())
{
// Derived from ServiceStack's RedisLock.
ExecExtensions.RetryUntilTrue(() =>
{
var wasSet = true; //client.SetEntryIfNotExists(globalKey, "lock " + DateTime.UtcNow.ToUnixTime());
if (wasSet)
{
acquiredLocks[key] = globalKey;
}
return(wasSet);
}, lockTimeout);
}
}
catch (Exception e)
{
log.ErrorFormat("could not acquire cache lock : ", key);
var evtArg = new RedisCacheExceptionEventArgs(e);
OnException(evtArg);
if (evtArg.Throw)
{
throw;
}
}
}
public virtual void WaitForWorkersToStop(TimeSpan?timeout = null)
{
ExecExtensions.RetryUntilTrue(
() => Interlocked.CompareExchange(ref status, 0, 0) == WorkerStatus.Stopped,
timeout);
}
public override LockResult TryGetDistributedLock(TimeSpan?getlockTimeOut, TimeSpan?taskrunTimeOut)
{
if (lockresult == LockResult.Success)
{
throw new Exception("检测到当前锁已获取");
}
try
{
using (var redisClient = DistributedLockConfig.GetRedisPoolClient())
{
//内部的函数返回true，这个方法才会结束
ExecExtensions.RetryUntilTrue(
() =>
{
//SETNX 语法规则详见： http://redis.io/commands/setnx
//计算lock的 unix time 过期时间
//TimeSpan realSpan = taskrunTimeOut ?? TimeSpan.FromMilliseconds(DistributedLockConfig.MaxLockTaskRunTime);
TimeSpan realSpan = taskrunTimeOut.Value;
DateTime expireTime = DateTime.UtcNow.Add(realSpan);
string lockString = (expireTime.ToUnixTimeMs() + 1).ToString();
//SetEntryIfNotExists：尝试 set 锁，如果锁不存在则 set 到 redis 里，并返回true
var nx = redisClient.SetEntryIfNotExists(key, lockString);
if (nx)
{
lockresult = LockResult.Success;
return(true);
}
//如果锁已经存在，有可能是正确的获取，也可能是进程异常，没有正确释放锁，
//因此我们要检测 lock 的值（unix time），判断 lock 何时过期，否则会引起死锁
//监视 lock 的 key，如果在事务执行之前这个(或这些) key 被其他命令所改动，那么事务将被打断。
redisClient.Watch(key);
string lockExpireString = redisClient.Get <string>(key);
long lockExpireTime;
//如果 lock 的 value 不能正确转换为过期时间，则 lock 不正确，
//有可能是因为 lock 被其他进程改动了
if (!long.TryParse(lockExpireString, out lockExpireTime))
{
redisClient.UnWatch();
lockresult = LockResult.GetLockTimeOutFailure;
return(false);
}
//如果过期时间大于当前时间，则锁还未过期，当前进程不能继续执行
if (lockExpireTime > DateTime.UtcNow.ToUnixTimeMs())
{
redisClient.UnWatch();
lockresult = LockResult.GetLockTimeOutFailure;
return(false);
}
//如果过期时间小于当前时间，则锁没有被正常释放，之前的线程可能出现了异常
//在这之前用watch监视了lock的key，如果lock的值没有被改动，则当前事务将正常执行
using (var trans = redisClient.CreateTransaction())
{
trans.QueueCommand(r => r.Set(key, lockString)); //lockString在循环的开始会重新计算
var t = trans.Commit();
lockresult = t == false ? LockResult.GetLockTimeOutFailure : LockResult.Success;
return(t);
}
},
getlockTimeOut
);
}
}
catch (Exception exp)
{
LogManager.DefaultLogger.Error(exp, "redis分布式尝试锁系统级别严重异常");
lockresult = LockResult.LockSystemExceptionFailure;
}
return(lockresult);
}
public override LockResult TryGetDistributedLock(TimeSpan?getlockTimeOut, TimeSpan?taskrunTimeOut)
{
if (lockresult == LockResult.Success)
{
throw new DistributedLockException("检测到当前锁已获取");
}
try
{
using (var redisClient = DistributedLockConfig.GetRedisPoolClient(redisserver).GetClient())
{
ExecExtensions.RetryUntilTrue(
() =>
{
//This pattern is taken from the redis command for SETNX http://redis.io/commands/setnx
//Calculate a unix time for when the lock should expire
TimeSpan realSpan = taskrunTimeOut ?? TimeSpan.FromMilliseconds(DistributedLockConfig.MaxLockTaskRunTime); //new TimeSpan(365, 0, 0, 0); //if nothing is passed in the timeout hold for a year
DateTime expireTime = DateTime.UtcNow.Add(realSpan);
string lockString = (expireTime.ToUnixTimeMs() + 1).ToString();
//Try to set the lock, if it does not exist this will succeed and the lock is obtained
var nx = redisClient.SetEntryIfNotExists(key, lockString);
if (nx)
{
lockresult = LockResult.Success;
return(true);
}
//If we've gotten here then a key for the lock is present. This could be because the lock is
//correctly acquired or it could be because a client that had acquired the lock crashed (or didn't release it properly).
//Therefore we need to get the value of the lock to see when it should expire
redisClient.Watch(key);
string lockExpireString = redisClient.Get <string>(key);
long lockExpireTime;
if (!long.TryParse(lockExpireString, out lockExpireTime))
{
redisClient.UnWatch(); // since the client is scoped externally
lockresult = LockResult.GetLockTimeOutFailure;
return(false);
}
//If the expire time is greater than the current time then we can't let the lock go yet
if (lockExpireTime > DateTime.UtcNow.ToUnixTimeMs())
{
redisClient.UnWatch(); // since the client is scoped externally
lockresult = LockResult.GetLockTimeOutFailure;
return(false);
}
//If the expire time is less than the current time then it wasn't released properly and we can attempt to
//acquire the lock. The above call to Watch(_lockKey) enrolled the key in monitoring, so if it changes
//before we call Commit() below, the Commit will fail and return false, which means that another thread
//was able to acquire the lock before we finished processing.
using (var trans = redisClient.CreateTransaction()) // we started the "Watch" above; this tx will succeed if the value has not moved
{
trans.QueueCommand(r => r.Set(key, lockString));
//return trans.Commit(); //returns false if Transaction failed
var t = trans.Commit();
if (t == false)
{
lockresult = LockResult.GetLockTimeOutFailure;
}
else
{
lockresult = LockResult.Success;
}
return(t);
}
},
getlockTimeOut
);
}
}
catch (Exception exp)
{
XXF.Log.ErrorLog.Write(string.Format("redis分布式尝试锁系统级别严重异常,redisserver:{0}", redisserver.NullToEmpty()), exp);
lockresult = LockResult.LockSystemExceptionFailure;
}
return(lockresult);
}