GraalVM native image support

[sdeleuze]

GraalVM now offers an official way to detect its presence via the org.graalvm.nativeimage.imagecode system property. We use that in Spring to adapt to Graal (see GraalDetector). You could maybe add similar capabilities to Netty PlatformDependent. That's seems similar to what you are doing now depending on JDK versions and other parameters, and I think Netty + Graal native images are a pretty exciting combination.

Current area that need customization with Reactor Netty that could take advantage of a dedicated GraalVM detection mechanism are:

• ClassNotFoundException: com.jcraft.jzlib.Deflater when --report-unsupported-elements-at-runtime is not used, see ClassNotFoundException: com.jcraft.jzlib.Deflater when generating native image oracle/graal#494
• -Dio.netty.noUnsafe=true has to be specified explicitly

This blog post contains also valuable information.

[sdeleuze]

Any chance to see that one part of Netty 5 ?

[normanmaurer]

@sdeleuze this sounds like a good idea to me... would you be interested in submitting a PR against the master branch ?

[sdeleuze]

No sure to have the bandwidth for now, but if that changes I will.

[normanmaurer]

Fixed by #8963