When, in the process of running a Swing program, is the
UI thread (event-dispatch thread, EDT) first spawned?
Presumably any given JVM could do whatever it wants
(for example, always spawning the EDT at start-up, whether
or not it’s ever used), but as a practical matter when
is the EDT typically created?
Does it get created when SwingUtilities.invokeLater()
is first called? When a JPanel is first instantiated?
And if the event pump is started separately from creating
the EDT, when does that typically happen?