pub type BackendSignalFn = fn(pid: u32, terminate: bool) -> bool;Expand description
v7.39 (round 318, V51) — host-provided connection control. terminate
false = cancel the target’s running statement (PG pg_cancel_backend,
MySQL KILL QUERY); true = also close the connection (PG
pg_terminate_backend, MySQL KILL CONNECTION). Returns whether a
connection with that id exists — the engine has no registry of its own,
so the answer has to come from the host that accepted the sockets.
None (embedded, no connections) ⇒ nothing to signal.