Cleans up underlying resources. This object must be run() again afterwards to be valid
Registers the signal handler in the event loop
Triggers the handler in its local thread
Human-readable string describing the error
Returns the Thread that created this object.
Used to diagnose errors when run() or kill() returns false
Enqueues a signal in the event loop of the AsyncSignal owner's thread, which allows a foreign thread to trigger the callback handler safely.