Hi again,
await-event is not thread-safe.
(defn await-event
[target event]
(let [evt (promise)
remove-fn (promise)
handler (fn [e] (@remove-fn) (deliver evt e))]
(deliver remove-fn (listen target event handler))
@evt))
remove-fn should also be a promise. Otherwise the user might click the
button, after handler registration and before reset of the atom. Then we run
into a NPE when "calling" nil. Unlikely, but a race condition nevertheless.
This way the handler would block until the remove function is provided.
There is also no chance of dead-lock, because the code does nothing else
than delivering the promise as fast as possible. So the above should work in
all cases.
Sincerely
Meikel
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