beginning of network stack latency analysis

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
fix: safe iteration over the HT

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
support for unique inserts

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
clarify return codes for event_in

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>