* Currently, whenever a new signal stream is created we attempt to
register a global pipe with the event loop to drive events.
* We also (correctly) swallow any descriptor-already-registered errors
since the same pipe is always used
* However, we currently *deregister* the same global pipe *any time* a
Signal stream is dropped.
* This means that if 2 or more of Signal instances exist simultaneously
(even if listening for different signals) and one of them is dropped,
the remainder will starve (until any new signal is created again).
* Cargo runs each integration-style-test in its own process. Since the
tests use global data structures specific to the process, we should run
them in an isolated manner to avoid having cross-test interactions
* Fixesalexcrichton/tokio-signal#39
Run multiple loops (both in parallel and sequentially) to make sure
broadcasting to multiple of them works and we work even after the
initial loop has gone away.
Add the driver task, connecting the signal handler wakeups to the
wakeups of of the streams.
It is a prototype-quality code, a lot of cleanups and similar is needed.
Ivan Petkov