The Leader/Followers pattern provides a concurrency model where multiple
threads can efficiently de-multiplex events and dispatch event handlers
that process I/O handles shared by the threads.
## Class diagram
## Applicability
Use Leader-Followers pattern when
* multiple threads take turns sharing a set of event sources in order to detect, de-multiplex, dispatch and process service requests that occur on the event sources.
## Real world examples
* [ACE Thread Pool Reactor framework](https://www.dre.vanderbilt.edu/~schmidt/PDF/HPL.pdf)
