Review request for JDK-8062141: Various performance issues parsing JSON

Marcus Lagergren marcus.lagergren at
Sat Jan 31 15:40:56 UTC 2015

Stellar work, Hannes! And readable code.

Awesome numbers, Hannes. Why was the last JSON parser so slow? I guess it was just a case of clean room implement per spec to ensure correctness, right? I don’t think we’ve paid a lot of attention to the JSON code since it was first written.

Does everything compile without warnings? I notice you have explicitly added a @SuppressWarnings(“unchecked”) in JSONFunctions. Why was this the case? List<?> still too weak?

Do your ProperyHashMap changes give us benefits in performance elsewhere too? (or slowdowns for that matter)

Do you have any micro benchmarks you used to test this to check in ? 



> On 30 Jan 2015, at 17:40, Hannes Wallnoefer <hannes.wallnoefer at> wrote
> Please review JDK-8062141: Various performance issues parsing JSON:
> Thew new JSON parser is about 2-3 x faster than our old one, roughly on par with the ones in Rhino or V8.
> Hannes

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