pub type DeferNotify = fn(ctx: *mut c_void, handle: HandleId);Expand description
Issue 2146 (RFC-0112 D2, Defer) – the notifier
Executor::set_defer_notifier installs: called with the host’s context and
the HandleId of a deferred callback that has just been queued.
Runs on the spinning thread, inside spin_once. It must not block, and it
has no way to reach the executor; what it is for is waking or pending the
host task that will call Executor::run_deferred or
Executor::run_deferred_handle.