RFR: 8342075: HttpClient: improve HTTP/2 flow control checks [v2]

[Jaikiran Pai]

On Mon, 21 Oct 2024 11:19:08 GMT, Daniel Fuchs <dfuchs at openjdk.org> wrote:

>> Please find here a fix that improves flow control in the HTTP/2 implementation.
>> 
>> The change makes sure that flow control issues are reported to the server as FLOW_CONTROL_ERROR.
>> It also clarify how some system properties that allow to initialize flow control windows are handled, by documenting the full range of valid values (when applicable) and explaining what happens if the property points to a value that is out of range.
>> 
>> Bad flow control values in the SETTINGS frame will also cause a FLOW_CONTROL_ERROR to be reported.
>
> Daniel Fuchs has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Apply suggestions from code review
>   
>   Co-authored-by: Andrey Turbanov <turbanoff at gmail.com>

src/java.net.http/share/classes/jdk/internal/net/http/WindowUpdateSender.java line 127:

> 125:     // corrective actions and return true.
> 126:     private boolean checkWindowSizeExceeded(int len) {
> 127:         int rcv = Math.addExact(received.get(), len);

`Math.addExact` throws an `ArithmeticException` if there is an overflow. I think we should catch it here (and take some action) instead of letting it propagate.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21567#discussion_r1810806457