Concurrent file write-access

Marco

Hi, I have a web service that logs some information to a text file; this web service is invoked asynchronously by a number of client apps, and this is causing a "The process cannot access the file because it is being used by another process" error.

This is the code I am using

FileStream fs = new FileStream(filename, FileMode.Append,
_FileAccess.Write, FileShare.Write);

writer = new StreamWriter(fs);
...
writer.Close();

No other code is accessing that file. Am I missing something?

4 Replies

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Marco18y ago
I would rather write to the Win Event Log or to a Database, but we need to have a CSV output with a specific schema and we don't have any DB instance we can use at the moment.
0
Ryan Alford18y ago
is it a requirement to write to a file? writing to the server's event log would not cause this problem.
0
Marco18y ago
Hi, I have tried the Mutex class (having a different Mutex instance referring to the same Mutex name for each Web Service instance) but that didn't help - for some reason, with concurrent Web Service requests the Mutex goes into deadlock (as well as slowing down greatly the application execution).

Is there any way to share a file for writing? I don't care about the order the data is written to the file, just that each write operation is atomic and does not stop the others.

Thanks
0
Sunny Chen18y ago
Did you have a try on the Mutex class?
```
using System.Threading;
Mutex mutex = new Mutex();
mutex.WaitOne();
// Do your job here
mutex.ReleaseMutex();
```
I don't know if this helps in your scenario, you can have a check.

Hope this helps.
0