StructuredTaskScope.TimeoutException vs UncheckedTimeoutException

[Pavel Rappo]

If StructuredTaskScope.TimeoutException were to be replaced with
general-purpose java.util.concurrent.UncheckedTimeoutException, then
perhaps something similar could be done for
StructuredTaskScope.FailedException. I wonder if, in this hypothetical
design, it could be replaced with general-purpose
java.util.concurrent.UncheckedExecutionException, which would wrap
java.util.concurrent.ExecutionException.

One trivial downside of this unchecked-wrapper-exception design is the
length of respective stacktraces: they will become longer.


On Tue, Oct 21, 2025 at 2:37 PM Pavel Rappo <pavel.rappo at gmail.com> wrote:
>
> While symmetry might be good in itself, public
> UncheckedTimeoutException could also be used by others. By contrast,
> StructuredTaskScope.TimeoutException is highly-specific exception that
> has package access, so it cannot be instantiated outside
> java.util.concurrent.
>
> Separately, I was thinking about the possibility of a clash between
> java.util.concurrent.TimeoutException and
> java.util.concurrent.StructuredTaskScope.TimeoutException in the same
> file. Using longer names to disambiguate those is always possible, but
> it might not look pretty.
>
> -Pavel
>
> On Tue, Oct 21, 2025 at 2:15 PM Robert Engels <robaho at me.com> wrote:
> >
> > I agree that symmetry with the IOException would be better.
> >
> > > On Oct 21, 2025, at 7:51 AM, Pavel Rappo <pavel.rappo at gmail.com> wrote:
> > >
> > > As suggested in a PR thread [*], I bring this question to loom-dev:
> > >
> > > I haven't been paying much attention to the recent previews of this
> > > feature, so feel free to point me to a relevant discussion elsewhere.
> > >
> > > As I understand it, an unchecked StructuredTaskScope.TimeoutException
> > > was added in JDK 25. There's also the well-known checked
> > > java.util.TimeoutException. I assume that the namesake exception was
> > > added solely because it's unchecked. I also assume
> > > UncheckedTimeoutException was considered at some stage, because in my
> > > mind, the situation is similar to that of
> > > IOException/UncheckedIOException.
> > >
> > > Why did you choose to add a namesake instead of an unchecked wrapper
> > > exception? Was it because you consider that the likelihood of mixing
> > > the two TimeoutException's is low in the context of a single file?
> > >
> > > -Pavel
> > >
> > > [*]: https://github.com/openjdk/jdk/pull/27392#issuecomment-3426369195