Support IO_URING transport

[franz1981]

I'm implementing support for https://github.com/netty/netty-incubator-transport-io_uring on Vert-x Transport, see https://github.com/franz1981/vert.x/tree/4.2.1_iouring for some initial experiment.

[franz1981]

There are some test failures related missing sendFile support that I'm working around by forcing supportsFileRegion to return false with IoUring on ConnectionBase::sendFile:

  public final ChannelFuture sendFile(RandomAccessFile raf, long offset, long length) throws IOException {
    // Write the content.
    ChannelPromise writeFuture = chctx.newPromise();
    if (!supportsFileRegion()) {
      // Cannot use zero-copy
      writeToChannel(new ChunkedFile(raf, offset, length, 8192), writeFuture);
    } else {
      // No encryption - use zero-copy.
      sendFileRegion(raf, offset, length, writeFuture);
    }
    if (writeFuture != null) {
      writeFuture.addListener(fut -> raf.close());
    } else {
      raf.close();
    }
    return writeFuture;
  }

The downside is that writeToChannel too doesn't seems to work correctly and I'm investigating what's going on.

[franz1981]

I've fixed #4163 (comment) with franz1981@4eafe9f

[franz1981]

Just FYI this is the last run:

Results :

Failed tests: 
  Http1xTest>HttpTest.testListenDomainSocketAddress:144->HttpTestBase.startServer:93->HttpTestBase.startServer:118->AsyncTestBase.awaitLatch:598->AsyncTestBase.awaitLatch:602->AsyncTestBase.assertTrue:378 null
  Http2ClientTest.lambda$testNetSocketConnect$198:1428->AsyncTestBase.assertEquals:241 expected:<2> but was:<1>
  Http2ServerTest.lambda$testNetSocketConnect$250:2251->AsyncTestBase.assertEquals:241 expected:<2> but was:<1>
  Http2Test>HttpTest.testListenDomainSocketAddress:144->HttpTestBase.startServer:93->HttpTestBase.startServer:118->AsyncTestBase.awaitLatch:598->AsyncTestBase.awaitLatch:602->AsyncTestBase.assertTrue:378 null
  Http2Test>HttpTest.lambda$testServerConnectionHandlerClose$573:3625->AsyncTestBase.fail:414 null
  NetTest.testListenDomainSocketAddress:1896->startServer:3843->startServer:3855->AsyncTestBase.awaitLatch:598->AsyncTestBase.awaitLatch:602->AsyncTestBase.assertTrue:378 null
  NetTest.access$2400:77->AsyncTestBase.assertEquals:360 expected:<true> but was:<false>
Tests in error: 
  DatagramTest.testPauseResume:209->AsyncTestBase.await:121->AsyncTestBase.await:133 » IllegalState
  Http1xTest>AsyncTestBase.after:83->HttpTestBase.tearDown:69->VertxTestBase.tearDown:87->AsyncTestBase.close:662->AsyncTestBase.awaitLatch:598->AsyncTestBase.awaitLatch:602->AsyncTestBase.assertTrue:380->AsyncTestBase.handleThrowable:183 » IllegalState
  Http2MetricsTest.testPushPromise:99->AsyncTestBase.await:121->AsyncTestBase.await:133 » IllegalState
  Http2MetricsTest>AsyncTestBase.after:83->HttpMetricsTestBase.tearDown:54->HttpTestBase.tearDown:69->VertxTestBase.tearDown:87->AsyncTestBase.close:662->AsyncTestBase.awaitLatch:598->AsyncTestBase.awaitLatch:602->AsyncTestBase.assertTrue:380->AsyncTestBase.handleThrowable:183 » IllegalState
  Http2MetricsTest>AsyncTestBase.after:83->HttpMetricsTestBase.tearDown:54->HttpTestBase.tearDown:69->VertxTestBase.tearDown:87->AsyncTestBase.close:662->AsyncTestBase.awaitLatch:598->AsyncTestBase.awaitLatch:602->AsyncTestBase.assertTrue:380->AsyncTestBase.handleThrowable:183 » IllegalState
  Http2ServerTest.testUpgradeToClearTextGet:2546->testUpgradeToClearText:2607->AsyncTestBase.await:121->AsyncTestBase.await:133 » IllegalState
  Http2Test>AsyncTestBase.after:83->HttpTestBase.tearDown:69->VertxTestBase.tearDown:87->AsyncTestBase.close:662->AsyncTestBase.awaitLatch:598->AsyncTestBase.awaitLatch:602->AsyncTestBase.assertTrue:380->AsyncTestBase.handleThrowable:183 » IllegalState
  NetTest>AsyncTestBase.after:83->tearDown:129->VertxTestBase.tearDown:87->AsyncTestBase.close:662->AsyncTestBase.awaitLatch:598->AsyncTestBase.awaitLatch:602->AsyncTestBase.assertTrue:380->AsyncTestBase.handleThrowable:183 » IllegalState
  NetTest.testStartTLSClientCertClientNotTrusted:1317->testTLS:1571->testTLS:1601->AsyncTestBase.await:121->AsyncTestBase.await:133 » IllegalState

Tests run: 4760, Failures: 7, Errors: 9, Skipped: 14

And many of these tests shouldn't run because are using domain socket, that's still not supported

I'm going to prepare a draft PR ASAP

[tsegismont]

Thank you for looking into this. It's great to have feedback and a contribution in the making!

…

[vietj]

The transport should be optional and only used when the jar is present on the classpath and native epoll is not present

[Sanne]

The transport should be optional and only used when the jar is present on the classpath and native epoll is not present

Haven't checked the latest version of the code, but that's how it was working when I tested an early preview.