可以记录到ASP.net WEb服务器中的文本文件导致锁定

Question

Can logging to text file in ASP.net WEb server cause locks

Thi is my code:

var outStream = new FileStream(Server.MapPath("~\\bin\\error.txt"), FileMode.Append, FileAccess.Write, FileShare.ReadWrite);

As you see FileShare is both read and write.

So far I have not seen any issues. Are you aware of possible issues using this method. (I do not want to log error to windows event)

Answer 1

Not 100% sure I understand what you are asking, but any time something writes to a file, the file is locked by that application for the period of time that it takes to complete the write. If there is another application writing to the same file at times, there will be the potential for conflict. If both applications are coded to handle conflicts of this nature, then all will be fine. So if you are coding to handle this situation, you would put the write method in a TRY block within a WHILE block. If an error occurs writing, then it would stay in the while block and pause for a second or something and then try again. Once the write is successful, break out of the while block. You may also want to put in a counter and limit the number of tries.

Just be aware that if you do this that the thread will sit here until the write is successful, so if you don't want this to hold up your application it needs to be done with another thread.

Answer 2

I think you would just want to do a lock on a static object that wraps the File I/O. This static object would ensure the file updates are thread safe.

With respect to Mr. Hinkle, I had always heard one would not want to have multiple try/catch fails inside a while loop as pure design -- unless I'm missing something. I can see where practically this would work, but I always thought exceptions should not become part of the "main flow" in this way.