Question

I need to build a unique filename in a multithreaded application which is serializing some data on the disk.
What approach could I use to ensure a unique name.
The app was not multithreaded before and was using Ticks. When using multiple threads, it failed much faster than I expected.
I now added the CurrentThreadId to the filename, and that should do it

string.Format("file_{0}_{1}.xml", DateTime.Now.Ticks, Thread.CurrentThread.ManagedThreadId)

Is there any “smarter” way of doing this?

Answer 1

What about Guid.NewGuid() instead of the thread id?

string.Format("file_{0}_{1:N}.xml", DateTime.Now.Ticks, Guid.NewGuid()) 

By keeping the ticks as part of the name, the names will still be in approximate date order if ordering is important.

The {1:N} gets rid of the curly braces and dashes in the guid.

Also, consider using DateTime.UtcNow.Ticks, so as to guarantee incremental ticks when daylight saving time kicks in.