NPE during frees Factory class

[Dgzt]

Hi,

Set null to Factory static class like this causes NullPointerException:

Exception in thread "main" java.lang.NullPointerException: Cannot read field "native_address" because "sInstance" is null
	at jolt.core.Factory.set_sInstance(Factory.java:62)
	at com.github.dgzt.mundus.plugin.joltphysics.runtime.JoltPhysicsPlugin.dispose(JoltPhysicsPlugin.java:127)

This is in the Factory class:

[xpenatan]

Hi @Dgzt,

I've modified the parser to use Factory.NULL instead of a null instance. Previously, the code checked if the instance was null and passed a 0 pointer value to JNI. Performing this check every frame could slightly impact performance, particularly on the web. To eliminate the need for checking the parameter instance each frame, all parameter instances must now be non-null. All Jolt classes should now have a static NULL object.

[Dgzt]

Hi @Dgzt,

I've modified the parser to use Factory.NULL instead of a null instance. Previously, the code checked if the instance was null and passed a 0 pointer value to JNI. Performing this check every frame could slightly impact performance, particularly on the web. To eliminate the need for checking the parameter instance each frame, all parameter instances must now be non-null. All Jolt classes should now have a static NULL object.

Thanks the quick response! I've changed in my plugin to use Factory.NULL instead of null.

[Dgzt]

Hi @xpenatan ,

I cloned this repo and the test works with null parameter, because seems the dispose method doesn't call.

[xpenatan]

Hi @Dgzt , can you give more details about this:

because seems the dispose method doesn't call.

You mean that your calling dispose but its not really disposing ?

[Dgzt]

Hi @Dgzt , can you give more details about this:

because seems the dispose method doesn't call.

You mean that your calling dispose but its not really disposing ?

If I add a log entry (System.out.println or Gdx.app.log) into this method:

xJolt/examples/samples/core/src/main/java/jolt/example/samples/app/jolt/JoltInstance.java

Line 84 in d691071

physicsSystem.dispose();

. But the log entry doesn't show in the console if I close the test.

Edit:
And there is no NullPointerException with this null:

xJolt/examples/samples/core/src/main/java/jolt/example/samples/app/jolt/JoltInstance.java

Line 89 in d691071

Factory.set_sInstance(null);

[xpenatan]

Hi @Dgzt , can you give more details about this:

because seems the dispose method doesn't call.

You mean that your calling dispose but its not really disposing ?

If I add a log entry (System.out.println or Gdx.app.log) into this method:

xJolt/examples/samples/core/src/main/java/jolt/example/samples/app/jolt/JoltInstance.java

Line 84 in d691071

physicsSystem.dispose();
. But the log entry doesn't show in the console if I close the test.
Edit: And there is no NullPointerException with this null:

xJolt/examples/samples/core/src/main/java/jolt/example/samples/app/jolt/JoltInstance.java

Line 89 in d691071

Factory.set_sInstance(null);

This is why. Screen never calls dispose. I added the NULL instance.

[Dgzt]

Hi @Dgzt , can you give more details about this:

because seems the dispose method doesn't call.

You mean that your calling dispose but its not really disposing ?

If I add a log entry (System.out.println or Gdx.app.log) into this method:
xJolt/examples/samples/core/src/main/java/jolt/example/samples/app/jolt/JoltInstance.java
Line 84 in d691071
physicsSystem.dispose();
. But the log entry doesn't show in the console if I close the test.
Edit: And there is no NullPointerException with this null:
xJolt/examples/samples/core/src/main/java/jolt/example/samples/app/jolt/JoltInstance.java
Line 89 in d691071
Factory.set_sInstance(null);

This is why. Screen never calls dispose. I added the NULL instance.

Thanks, I think this ticket can be closed.

Maybe this issue caused this memory leak?

[xpenatan]

I'll need to retest to verify if the memory is stable.