pub fn install()Expand description
Install SIGINT/SIGTERM handlers that flip the shared shutdown flag.
Idempotent on the signal-hook side: re-registering the same
signal layers another handler on top, but the cost is a few bytes
and the observable behaviour is unchanged, so callers can invoke
this more than once without harm.
On non-Unix targets this is a no-op (Windows signal semantics differ; the CLI does not currently ship on Windows).