Storing Exceptions in flat file -

In any application, we can log the error using the flat file system.

How are we the exception when there are more than one user who are logged in the same flat file?

Many thanks.

You can create a thread to read exceptions, to read exceptions. Exceptions in the original exception handling code queue will write. Since there is only one thread for writing the file, so everything is sorted. Of course, you need to implement thread-safe queue, but your language or structure probably provides one.