写锁被释放，没有被关押 [英] Write lock being released without being held

问题描述

我有一种情况，即ReadWriterLockSlim抛出异常System.Threading.SynchronizationLockException - 要释放的写入锁定未经举行当我尝试执行ExitWriteLock（）。据我所知，这是不应该的，因为进入try块后续线程将块，直到他们能够获得的锁。我失去了一些东西呢？

这个问题看起来非常相似，这其中，但是没有办法解决被张贴在那里。

  // code简化的例子。

公共类i18nService {
    内部静态ReaderWriterLockSlim cacheLock =新ReaderWriterLockSlim（LockRecursionPolicy.NoRecursion）;

    私人字符串ProcessText（）
    {
        尝试 {
            cacheLock.EnterWriteLock（）;
            返回XYZ;
        }
        最后 {
            cacheLock.ExitWriteLock（）; //错误是扔在这里。
        }
    }
}
 

非常感谢您的帮助： - ）

解决方案

 尝试{
        cacheLock.EnterWriteLock（）;
        返回XYZ;
    }
    最后 {
        cacheLock.ExitWriteLock（）; //错误是扔在这里。
    }
 

问：发生什么，如果 cacheLock.EnterWriteLock（）; 失败

答：最后语句被执行

• cacheLock.ExitWriteLock（）; 被称为
• 但是，我们没有锁定

试试这个：

 私人字符串ProcessText（）
{
    cacheLock.EnterWriteLock（）;
    尝试 {
        返回XYZ;
    }
    最后 {
        cacheLock.ExitWriteLock（）; //错误是扔在这里。
    }
}
 

presumably .NET的设计以这样一种方式，如果 EnterWriteLock（）失败，锁被释放（或从未在所有举行）。

I have a situation whereby ReadWriterLockSlim is throwing the exception "System.Threading.SynchronizationLockException - The write lock is being released without being held." when I try to execute ExitWriteLock(). As far as I can tell, this shouldn't happen because subsequent threads that enter the try block will 'block' until they can obtain the lock. Am I missing something here?

The issue looks very similar to this one, however no solution was posted there.

//Code simplified for example. 

public class i18nService {
    internal static ReaderWriterLockSlim cacheLock = new ReaderWriterLockSlim(LockRecursionPolicy.NoRecursion);

    private string ProcessText()
    {
        try {
            cacheLock.EnterWriteLock();
            return "xyz";
        }
        finally {
            cacheLock.ExitWriteLock(); // Error is throwing here. 
        }
    }
}

Thanks very much for your help :-)

解决方案

    try {
        cacheLock.EnterWriteLock();
        return "xyz";
    }
    finally {
        cacheLock.ExitWriteLock(); // Error is throwing here. 
    }

Q: What happens if cacheLock.EnterWriteLock(); fails?

A: The finally statement gets executed.

• cacheLock.ExitWriteLock(); gets called
• But we don't have the lock

Try this:

private string ProcessText()
{
    cacheLock.EnterWriteLock();
    try {
        return "xyz";
    }
    finally {
        cacheLock.ExitWriteLock(); // Error is throwing here. 
    }
}

Presumably .NET is designed in such a way that if EnterWriteLock() fails, the lock is released (or never held at all).

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