How does "default" folder work for different users, builds and releases?

If I use the default folder, do I need to empty it on my first actions, or does that happen automatically? What happens if 2 different users execute the same build? Does it create different default folders for each instance?

Product: BuildMaster
Version: 4.0.9

The "default" folder (usually the SRC subfolder) is unique to applications and deployables, and is housed under the <bmas-tmp>\A<appid>\S<depid> folders. It is cleared during the "preparing agents" step at the start of every action, unless it's a re-execution of a failed deployment.

Only one execution within an application is permitted at the same time, so the second one created will be queued until the first completes.