Add metadata for Netty SelectorProviderUtil

[czp3009]

What does this PR do?

Add reflection hints for Netty SelectorProviderUtil

Netty code in io.netty.channel.socket.nio.SelectorProviderUtil:

@SuppressJava6Requirement(reason = "Usage guarded by java version check")
static Method findOpenMethod(String methodName) {
    if (PlatformDependent.javaVersion() >= 15) {
        try {
            return SelectorProvider.class.getMethod(methodName, java.net.ProtocolFamily.class);
        } catch (Throwable e) {
            logger.debug("SelectorProvider.{}(ProtocolFamily) not available, will use default", methodName, e);
        }
    }
    return null;
}

If Java version higher than or equals to 15, SelectorProviderUtil may invoke java.nio.channels.spi.SelectorProvide by reflection.

SelectorProviderUtil.findOpenMethod will be called in two Netty class: NioSocketChannel and NioServerSocketChannel corresponding to two SelectorProvider methods: openSocketChannel and openServerSocketChannel.

This PR add metadata for them.

Code sections where the PR accesses files, network, docker or some external service

None

Checklist before merging

• I have considered including reachability metadata directly in the library or the framework (see our contributing document)
• I am the original author of all content provided in the pull request, and I did not copy the content from any other source (see the tests section from our contributing document)
• For all tests where I am not the sole author, I have added a comment that proves I may publish them under the specified license (see the tests section from our contributing document)
• I have properly formatted metadata files (see our formatting guide)
• I have added thorough tests (see the tests section from our contributing document)
• I have filled all places where my pull request accesses files, network, docker, or any other external service (see the section above)

[dnestoro]

Can't you use EnabledOnJre annotation (see this) and write unit test which covers described metadata?

[dnestoro]

@czp3009 is there a plan to work on this PR? Have you tried EnaledOnJre as I mentioned in previous comment?

[nkonev]

I suppose that the better place is https://github.com/netty/netty - they already have graal-related metadata https://github.com/netty/netty/issues?q=graal

[dnestoro]

I suppose that the better place is https://github.com/netty/netty - they already have graal-related metadata https://github.com/netty/netty/issues?q=graal

That would be even better!

[czp3009]

hi @dnestoro , i was also trying to add metadata to Netty repository, but that doesn't solve the problem. please see following issue: netty/netty#13575

After discussing with the Netty repository manager, i was decided to commit the metadata to this repository.

I am very sorry for not submitting test case code for a long time, but I've been really busy lately, and I'm not familiar with test cases like this. I'm not sure when I'll have time to do this PR, at least not in the near future.

[violetagg]

@dnestoro The tests below should validate this change.

diff --git a/tests/src/io.netty/netty-common/4.1.80.Final/src/test/java/netty/NettyTests.java b/tests/src/io.netty/netty-common/4.1.80.Final/src/test/java/netty/NettyTests.java
index 5df7cc2..a38c1ba 100644
--- a/tests/src/io.netty/netty-common/4.1.80.Final/src/test/java/netty/NettyTests.java
+++ b/tests/src/io.netty/netty-common/4.1.80.Final/src/test/java/netty/NettyTests.java
@@ -7,6 +7,9 @@
 package netty;
 
 import java.io.InputStream;
+import java.net.Inet6Address;
+import java.nio.channels.UnsupportedAddressTypeException;
+import java.nio.channels.spi.SelectorProvider;
 import java.time.Duration;
 import java.util.Objects;
 import java.util.concurrent.atomic.AtomicReference;
@@ -56,8 +59,13 @@ import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
 import io.netty.util.CharsetUtil;
 import org.awaitility.Awaitility;
 import org.hamcrest.CoreMatchers;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Assumptions;
 import org.junit.jupiter.api.Test;
 
+import static io.netty.channel.socket.InternetProtocolFamily.IPv4;
+import static io.netty.util.NetUtil.LOCALHOST;
+
 public class NettyTests {
     private static final int PORT = 8080;
 
@@ -71,6 +79,36 @@ public class NettyTests {
         test(false);
     }
 
+    @Test
+    void testNioSocketChannel() {
+        Assumptions.assumeTrue(LOCALHOST instanceof Inet6Address);
+
+        EventLoopGroup group = new NioEventLoopGroup();
+        try {
+            Bootstrap b = new Bootstrap().group(group)
+                    .channelFactory(() -> new NioSocketChannel(SelectorProvider.provider(), IPv4))
+                    .handler(new LoggingHandler());
+            Assertions.assertThrows(UnsupportedAddressTypeException.class, () -> b.bind(LOCALHOST, 7777).sync().channel());
+        } finally {
+            group.shutdownGracefully();
+        }
+    }
+
+    @Test
+    void testNioServerSocketChannel() {
+        Assumptions.assumeTrue(LOCALHOST instanceof Inet6Address);
+
+        EventLoopGroup group = new NioEventLoopGroup();
+        try {
+            Bootstrap b = new Bootstrap().group(group)
+                    .channelFactory(() -> new NioServerSocketChannel(SelectorProvider.provider(), IPv4))
+                    .handler(new LoggingHandler());
+            Assertions.assertThrows(UnsupportedAddressTypeException.class, () -> b.bind(LOCALHOST, 7777).sync().channel());
+        } finally {
+            group.shutdownGracefully();
+        }
+    }
+
     private void test(boolean ssl) throws Exception {
         EventLoopGroup bossGroup = new NioEventLoopGroup(1);
         EventLoopGroup workerGroup = new NioEventLoopGroup();

[violetagg]

cc @bclozel @sdeleuze

[sdeleuze]

@czp3009 Can you please update your PR with the tests proposed by @violetagg ?

[czp3009]

@sdeleuze @dnestoro test case updated

[violetagg]

Thanks!