hello, Using fibers in the threadpool in order to enable fork/join comes with some difficulties. My idea is to use recursive sub-task invokation as default and fiber only in some special cases. 1.) parent-task locks a mutex and sub-task has also to lock the mutex -> using recursive_mutex 2.) sub-task waits for signal of parent-task (condition variable) the recursive invokation of sub-task do not work. In this case I would suggest that the sub-task should be executed in a fiber. task< R >::get() - does recursive invokation of sub-task task< R >::get( new_context() ) - does execute the sub-task in a new fiber What do you think about this? regards, Oliver -- Ist Ihr Browser Vista-kompatibel? Jetzt die neuesten Browser-Versionen downloaden: http://www.gmx.net/de/go/browser