Try using the --optimistic-types=false flag and see if that helps. Sent from my iPhone
> On Aug 19, 2019, at 4:48 PM, Ryan Berdeen <rberd...@hubspot.com> wrote: > > I've encountered what seems like bug introduced in Java 9 where variables > can be leaked by the engine across separate contexts. I've extracted this > minimal reproduction out of service I'm running in projection in Java 8. > Gist: https://gist.github.com/also/412ce859f10f0b501bbfc43d15342dfc > > Given this script > > var x; > function test() { > x = 1; > print(++test.calls); > eval(''); > } > test.calls = 0; > test(); > > Repeatedly running it with a new context in the same engine works fine in > Java 8 (it will print "1" forever), but in Java 9+, things get weird. I > tested on macOS in openjdk 12.0.2 2019-07-16 from Oracle. > > ScriptEngine engine = new > ScriptEngineManager().getEngineByName("nashorn"); > > for (int i = 0; i < 20; i++) { > SimpleScriptContext context = new SimpleScriptContext(); > Bindings bindings = engine.createBindings(); > context.setBindings(bindings, ScriptContext.ENGINE_SCOPE); > engine.eval(script, context); > } > > > This logs > 1 > 2 > 3 > 4 > ... > > If you add a second `engine.eval(script, context);` to the loop, it starts > to look like an optimization bug: > > 1 > 1 > 2 > NaN > 1 > 1 > 2 > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > NaN > 1 > 2 > 1 > 2 > 1 > 2 > 1 > > It seems to stabilize on 2, 1 after the 18th iteration. With a third call > to "engine.eval(script, context);" in the loop, it settles sooner: > > 1 > 1 > 1 > 2 > NaN > NaN > 1 > 1 > 1 > 1 > 1 > 1 > > It works as expected if you omit `context` in the calls to `engine.eval()`, > if you omit the `x = 1;` or `eval('');` lines in the `test` function, if > you call `print(++test.calls);` before `x = 1;`, or when using the > "graal.js" engine. > > I know GraalVM JS is probably the way forward here, but was hoping I'd be > able to upgrade to Java 12 before making the switch.
