Some information related to your questions:

- I think I explained a few times in the forum how task_scheduler_init works, and that initializing TBB for a second time in a thread has low overhead. Thus the solution Peter suggested is what we recommend.

- in the next version of TBB, there will be support for automatic initialization. So you will not need to create task_scheduler_init on each call for sake of threads that did not yet initialize TBB explicitly. Still I would recommend to keep a global init object that covers DLL lifetime, to ensure TBB worker threads remain alive.

- if two independent user threads (we call them "masters") use TBB concurrently, they will share the TBB workers. Whatever master publishes its tasks first, will get the workers; but once a worker completed the piece of work stolen earlier, it will seek for another piece to steal, and the second master will be considered. The masters will most of the time work on their own tasks; but if the task pool becomes empty while stolen pieces of job are not yet completed, a master will also go and steal, possibly from another master. There is no direct way to influence stealing.

- for hooks, learn task_scheduler_observer.

- I am not sure what do you want to achieve with the above mentioned wrappers over TBB parallel algorithms. Could you elaborate a little?