Re: [lsp4e-dev] Request timeouts

[Mickael Istria <mistria@xxxxxxxxxx>]

On 12/07/2016 08:22 PM, Vlad Dumitrescu wrote:

Hi!

Hi Vlad,

I see that the timeouts for the different requests are diverse and feel a bit "random". Should there be a policy for how to choose the values? It's possible that different severs would have different response times.

I fully agree about timeouts, and to be honest you're not far from the truth with the random approach ;) So far, timeouts were set in a way that maximized the chances of getting a result without causing an annoying freeze, and all that only in the context of development and demos, not in the context of real usage... It's not really what we can call a "policy" ;)
Do you think a single timeout value for all operations would fit? Or maybe one per language server? Or does this have to be specific to each operation...?

It would be much nicer if one could get intermediate results as they become available (but probably quite difficult to handle).

Indeed. However, there are not many places in the IDE where a stream-based approach is useful. Most interactions (commands, content-assist, hovers...) expect all data to be there synchronously before presenting them. Introducing asynchronous support is something that requires some changes in Platform, and there are ongoing changes such as https://git.eclipse.org/r/#/c/85343/ . But still, such change expect full results before showing up and do not consider streaming.

More importantly, probably, what do we do if a request times out? An async solution would be to run all of these in separate threads/jobs, use a relatively large timeout value and if there is a timeout, cancel the request. Eclipse already may or may not run operations in jobs/threads, so this needs to be investigated for each case, but I think auto-cancelling requests on timeout could be added as an utility and used instead of CompletableFuture.get, What do you think?

We can discuss this on https://bugs.eclipse.org/bugs/show_bug.cgi?id=508457 and related bugs. Much work is actually to happen on Platform side.

Cheers,

--
Mickael Istria
Eclipse developer for Red Hat Developers
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