Wrong javadoc, Promise::tryComplete never throws IllegalStateException

[mxj4]

vavr/vavr/src/main/java/io/vavr/concurrent/Promise.java

Line 241 in 22ac105

* @throws IllegalStateException if this {@code Promise} has already been completed.

[nfekete]

It seems it can throw IllegalStateException, see

vavr/vavr/src/main/java/io/vavr/concurrent/FutureImpl.java

Line 250 in 1e6af93

throw new IllegalStateException("The Future is completed.");

and

vavr/vavr/src/main/java/io/vavr/concurrent/FutureImpl.java

Line 229 in 1e6af93

complete(value);

,

vavr/vavr/src/main/java/io/vavr/concurrent/Promise.java

Line 335 in 1e6af93

return future.tryComplete(value);

[mxj4]

@nfekete tryComplete call complete only when isCompleted() is false, and the isCompleted() check is synchronized so complete from another thread cannot happen concurrently with the check.

[danieldietrich]

That's right - it may throw. However, maybe it is an implementation detail and we should fix the API spec for 1.0. I will keep the ticket open.

[mxj4]

@danieldietrich can you enlighten me on how would tryComplete throw IllegalStateException? And does fix the API spec mean you plan to make it not throw in 1.0?

[danieldietrich]

@mxj4 it can't throw, otherwise the Future invariant does not hold and a bug is revealed. It never threw so far (nor it will). It should not be part of the public API and wil be removed in 1.0.

[mxj4]

@danieldietrich It's still useful in some cases. Currently I use ScheduledExecutorService with it to implement timeout for vavr Future.

[danieldietrich]

@mx4j thanks for the feedback

[danieldietrich]

Fixed that in #2093 - see also this description