RFR: 8304065: HttpServer.stop should terminate immediately if no exchanges are in progress [v4]

[Daniel Fuchs]

On Fri, 23 May 2025 09:49:09 GMT, Daniel Fuchs <dfuchs at openjdk.org> wrote:

>> the internal state representation of the server could do with a rethink and overhaul, and representing part of that state in a synchronisation primitive obscures/obfuscates the server state's semantics. I don't think it's "clean code"
>
> I agree that the semantic of `finished` `finishing`  is a bit obfuscated. On the other hand I don't think we should go so far as overhauling / rethinking the states in this PR. If you recall there have been lots of fixes in this area (we had some `assert` firing at some point, and it took some time to find the root cause and fix).
> That said having both a boolean *and* a countdown latch would be duplicate info, and potentially harder to manage consistency. 
> If we don't want the countdown latch we might go back to looping with Thread.sleep in stop, or use wait/notify, and I am not sure it would be much better.

I have a suggestion. Let's do this:


    public final boolean finished() {
        // we're finished when the latch reaches 0
        return finishedLatch.getCount() == 0;
    }
    
    public final boolean isFinishing() {
        return finished();
    }


Then replace things like `if (finished ...` with `if (finished() ...`
That should minimize the changes and make them look less awkward.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25333#discussion_r2109317990