Graalvm Isolate thread blocking

[geek29]

I am trying out native-netty-plot demo which is about running java code in native-image isolates. I made some changes in the demo after which example is blocking. HTTP Client making requests to netty server is blocking waiting for response. On further investigation, I found out code is blocking on Isolates.tearDownIsolate(renderingContext); call.

Below is the original code which I modified - mainly using logger library logback and making network call using Apach Http clients. I would like to know under what circumstances tearDownIsolate call will block? and How to investigate it further.

@CEntryPoint
    private static ObjectHandle plotAsSVG(@CEntryPoint.IsolateThreadContext IsolateThread renderingContext, IsolateThread nettyContext, ObjectHandle functionHandle, double xmin, double xmax) {
        //long initialMemory = printMemoryUsage("Rendering isolate initial memory usage: ", 0);

        / * Resolve and delete the functionHandle, now that execution is in the rendering isolate. * /
        String function = ObjectHandles.getGlobal().get(functionHandle);
        ObjectHandles.getGlobal().destroy(functionHandle);

        //byte[] svgBytes = ImageSingletons.lookup(Graphics2DPlotter.class).plotAsSVG(function, xmin, xmax);
        byte[] svgBytes = ImageSingletons.lookup(XYZRunner.class).run(function, xmin, xmax);

        ObjectHandle byteBufferHandle;
        try (PinnedObject pin = PinnedObject.create(svgBytes)) {
            byteBufferHandle = createByteBuffer(nettyContext, pin.addressOfArrayElement(0), svgBytes.length);
        }

        //printMemoryUsage("Rendering isolate final memory usage: ", initialMemory);

        return byteBufferHandle;
    }

[geek29]

Network connection being open caused isolate teardown block. Closing this issue.