Make sure Vertx is closed

[dsgrieve]

The issue is that the JVM won't exit. Closing Vertx fixes that.

[karianna]

But why?

[ghost]

I am concerned that this is a race condition in cases where there is more than 1 channel setup. I've not seen Censum not shutdown because of this.

[dsgrieve]

Run the sample in the gctoolkit repository from the main branch. The app should exit when main exits. It does not. One should not have to explicitly call System.exit().

[zheng-kai]

I would like to know if this issue has been resolved yet. I have downloaded the source code for version 3.0.4 and ran the sample program, but the program still does not end even after the Main function has finished executing.
Here are the results of my execution:

Jun 13, 2023 12:45:51 PM io.netty.util.internal.PlatformDependent <clinit>
INFO: Your platform does not provide complete low-level API for accessing direct buffers reliably. Unless explicitly requested, heap buffer will always be preferred to avoid potential system instability.
Jun 13, 2023 12:45:51 PM io.vertx.core.impl.DeploymentManager
SEVERE: Undeploy failed
java.lang.IllegalStateException: Already undeployed
	at io.vertx.core@4.4.0/io.vertx.core.impl.DeploymentManager$DeploymentImpl.doUndeploy(DeploymentManager.java:322)
	at io.vertx.core@4.4.0/io.vertx.core.impl.DeploymentManager.undeployVerticle(DeploymentManager.java:82)
	at io.vertx.core@4.4.0/io.vertx.core.impl.DeploymentManager.undeployAll(DeploymentManager.java:109)
	at io.vertx.core@4.4.0/io.vertx.core.impl.VertxImpl.lambda$close$15(VertxImpl.java:629)
	at io.vertx.core@4.4.0/io.vertx.core.impl.future.FutureImpl$3.onSuccess(FutureImpl.java:141)
	at io.vertx.core@4.4.0/io.vertx.core.impl.future.FutureBase.emitSuccess(FutureBase.java:60)
	at io.vertx.core@4.4.0/io.vertx.core.impl.future.FutureImpl.addListener(FutureImpl.java:196)
	at io.vertx.core@4.4.0/io.vertx.core.impl.future.PromiseImpl.addListener(PromiseImpl.java:23)
	at io.vertx.core@4.4.0/io.vertx.core.impl.future.FutureImpl.onComplete(FutureImpl.java:164)
	at io.vertx.core@4.4.0/io.vertx.core.impl.future.PromiseImpl.onComplete(PromiseImpl.java:23)
	at io.vertx.core@4.4.0/io.vertx.core.impl.VertxImpl.close(VertxImpl.java:628)
	at com.microsoft.gctoolkit.vertx@3.0.4/com.microsoft.gctoolkit.vertx.VertxChannel.close(VertxChannel.java:36)
	at com.microsoft.gctoolkit.vertx@3.0.4/com.microsoft.gctoolkit.vertx.VertxDataSourceChannel.close(VertxDataSourceChannel.java:39)
	at com.microsoft.gctoolkit.api@3.0.4/com.microsoft.gctoolkit.jvm.AbstractJavaVirtualMachine.analyze(AbstractJavaVirtualMachine.java:199)
	at com.microsoft.gctoolkit.api@3.0.4/com.microsoft.gctoolkit.GCToolKit.analyze(GCToolKit.java:308)
	at Cases/main.Main.main(Main.java:31)

The XYDataSet for G1GCYoungInitialMark contains 10 items.
G1GCYoungInitialMark not managed
The XYDataSet for G1GCRemark contains 10 items.
G1GCRemark not managed
The XYDataSet for G1GCCleanup contains 10 items.
G1GCCleanup not managed
ConcurrentCleanupForNextMark : 10
ConcurrentClearClaimedMarks : 10
ConcurrentMark : 10
ConcurrentRootRegionScan : 10
G1GCYoungInitialMark : 10
G1GCCleanup : 10
G1GCRemark : 10
G1GCConcurrentCleanup : 10
Total pause time  : 0.0243
Total run time    : 0.0243
Percent pause time: 2.84

The version of Java I am using is as follows:

> ./jdk-11.0.19_hotspot/bin/java -version
java version "11.0.19" 2023-04-18 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.19+9-LTS-224)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.19+9-LTS-224, mixed mode)

Is there any solution to this now, or is it a problem with my configuration?

[dsgrieve]

@zheng-kai PR #291 should fix the problem. At least, it works on my machine.

The the IllegalStateException is not a problem (still, I'll create an issue for it).

[kcpeppe]

Hi @zheng-kai, I believe there should be code in to prevent your app from hanging. I'll take a look to see where that is.