root-project
Make `ROOT::EnableThreadSafety();` the default?
Using threads in conjunction with the ROOT library is now very much common place and more than once users have run into problem 'just because' they forgot to call ROOT::EnableThreadSafety();.
After verifying that the cause on a single thread application is low enough (to not harm 'too much' existing users running large single thread workloads), we probably should make ROOT::EnableThreadSafety(); the default.
Note: this is related to https://github.com/root-project/root/issues/11955 which is one example where changing the default would not only affect performance but also have a functional effect (gDirectory having different values before and after).
This is a matter to be discussed widely in the team. However, I am also of the opinion that the option should be enabled by default.
