Cannot create more than 42 Tpie instances simultaneously

[ghost]

We use tpie for external sorting in the keyvi project. And when we run it on big machines (128 core) we need to start more than 42 instance simultaneously. Unfortunately we hit the limit of tpie temporary directories created with a second.

Unable to find free name for temporary folder.

[Mortal]

I think a better solution would be to use Boost to make a random directory name: http://stackoverflow.com/a/5988737