RFR:8153978:New test to verify the modules info as returned by the JVMTI

Thu Jul 21 17:14:12 UTC 2016

Christian, Sergey, 

I've modified the test per your findings. Now it is one java file and one C file only. 

Please, find the updated review at: 

Webrev: http://cr.openjdk.java.net/~akulyakh/8153978_6/ 

Thank you very much for your help. 

Best regards, 
Alexander 

----- Original Message ----- 
From: serguei.spitsyn at oracle.com 
To: christian.tornqvist at oracle.com, alexander.kulyakhtin at oracle.com 
Cc: serviceability-dev at openjdk.java.net 
Sent: Thursday, July 21, 2016 6:39:21 PM GMT +03:00 Iraq 
Subject: Re: RFR:8153978:New test to verify the modules info as returned by the JVMTI 

On 7/21/16 08:29, Christian Tornqvist wrote: 

Hi Alexander, 

>The JVMTI always reports 3 unnamed modules: the boot module, the system module and the application module. 

>The Java API does not report any unnamed modules. 

I’ll leave this up to you if this is something that we need to verify or not, the code for doing this is also overcomplicated and can be reduced to a simple assertGTE. 
The rule is that there is one unnamed module per a class loader. 
The options are: to test this rule or remove the check. 
For simplicity is better to remove this check as unclear. 

Thanks, 
Serguei 

>This should be doable without using JAR's and custom loaders by using Layer.defineModules(), see the examples in jdk/test/java/lang/reflect/Layer/BasicLayerTest.java 

>The test has been written from the user perspective. The user loads a new module in the form of jar using the ModuleLoader.loadModule() API. Then the test checks that JVMTI does return the info about that loaded module. 

>Probably, defining the module using Layer.defineModules would not be the same as loading the module using ModuleLoader.loadModule(), since the JVMTI GetAllModules() returns the info about all the currently loaded modules. 

>As the JVMTI spec says: "GetAllModules: Return an array of all modules loaded in the virtual machine.", it does not mention defining modules. 

There are several ways to get modules loaded/defined, the Layer.defineModules is part of the official Java API and is one of them. It doesn’t matter to JVMTI if they come from JAR files on disk or if they’re defined using a Java API, so I suggest you go with Layer.defineModules. 

Thanks, 

Christian 

From: Alexander Kulyakhtin [ mailto:alexander.kulyakhtin at oracle.com ] 
Sent: Thursday, July 21, 2016 10:04 AM 
To: Serguei Vladimirovich Spitsyn <serguei.spitsyn at oracle.com> ; christian.tornqvist at oracle.com 
Cc: serviceability-dev at openjdk.java.net 
Subject: Re: RFR:8153978:New test to verify the modules info as returned by the JVMTI 

Christian, 

Thank you very much for your comments. I have some concerns about the proposed changes: 

@45 & @67 

Why is this check needed? Why are there least 3 unnamed modules? 
The JVMTI always reports 3 unnamed modules: the boot module, the system module and the application module. 
The Java API does not report any unnamed modules. 

@54 

This should be doable without using JAR's and custom loaders by using Layer.defineModules(), see the examples in jdk/test/java/lang/reflect/Layer/BasicLayerTest.java 
The test has been written from the user perspective. The user loads a new module in the form of jar using the ModuleLoader.loadModule() API. Then the test checks that JVMTI does return the info about that loaded module. 
Probably, defining the module using Layer.defineModules would not be the same as loading the module using ModuleLoader.loadModule(), since the JVMTI GetAllModules() returns the info about all the currently loaded modules. 
As the JVMTI spec says: "GetAllModules: Return an array of all modules loaded in the virtual machine.", it does not mention defining modules. 

Could you, please, clarify these points for me so I fix the test appropriately? 

Best regards, 
Alexander 

----- Original Message ----- 
From: christian.tornqvist at oracle.com 
To: alexander.kulyakhtin at oracle.com , serviceability-dev at openjdk.java.net 
Sent: Wednesday, July 20, 2016 8:11:14 PM GMT +03:00 Iraq 
Subject: RE: RFR:8153978:New test to verify the modules info as returned by the JVMTI 

Hi Alexander, 

This test is unnecessarily complicated, it could be simplified a lot. 

JvmtiGetAllModulesTest.java 

Move getModulesNative() into JvmtiGetAllModulesTest.java and have it return a Set<Module> to be able to use equals later 

@27 * @compile JvmtiGetAllModulesTest.java 

No need for this, jtreg will compile it for you 

@45 & @67 

Why is this check needed? Why are there least 3 unnamed modules? 

@50 

Change this to: assertTrue(Layer.boot().equals(getModulesNative())); 

@54 

This should be doable without using JAR's and custom loaders by using Layer.defineModules(), see the examples in jdk/test/java/lang/reflect/Layer/BasicLayerTest.java 

@65 

Change this to an assertTrue using the layer containing the new module, similar to the change @50 

@73 

No need for this method 

@81 

Change this method to use the Layer.defineModules() method to define a module instead, this eliminates the need for external JAR's 

@98 

No need for this method 

If you use Layer.defineModules(), the following files can be removed: 

JarBuilder.java 

JavaModulesInfo.java 

JvmtiModulesInfo.java 

ModuleLoader.java 

ModulesInfo.java 

module-info.java 

Thanks, 

Christian 

From: serviceability-dev [ mailto:serviceability-dev-bounces at openjdk.java.net ] On Behalf Of serguei.spitsyn at oracle.com 
Sent: Monday, May 2, 2016 6:06 PM 
To: Alexander Kulyakhtin < alexander.kulyakhtin at oracle.com >; Serviceability-Dev < serviceability-dev at openjdk.java.net > 
Subject: Re: RFR:8153978:New test to verify the modules info as returned by the JVMTI 

Hi Alexander, 

Could you, fix a couple of minor issues? 

test/serviceability/jvmti/GetModulesInfo/JvmtiGetAllModulesTest.java 58         for(Module mod : my.modules()) { 59             if(!jvmtiModules.contains(mod)) { A space is missed after the 'for' and 'if' keywords. 

test/serviceability/jvmti/GetModulesInfo/ModulesInfo.java. 31     boolean compareExcludingUnnamed(ModulesInfo other) { I'd suggest to call it compareNamed. 

Otherwise, the new test looks great. 
Thanks a lot for taking care about it! 

Thanks, 
Serguei 

On 4/29/16 06:12, Alexander Kulyakhtin wrote: 

Hi, Could you, please, review these test-only changes (adding a new test). CR: https://bugs.openjdk.java.net/browse/JDK-8153978 "New test to verify the modules info as returned by the JVMTI" Webrev: http://cr.openjdk.java.net/~akulyakh/8153978_01/ The new test verifies that JVMTI returns the correct info about the modules loaded at the application startup. It also verifies that the returned info is consistent with the same info returned by the Java API. It then loads a new named module and checks the correctness of the JVMTI info again. Due to a tools issue https://bugs.openjdk.java.net/browse/CODETOOLS-7901662 the test can only be pushed in when the updated jtreg is released. The test passes fine with the nightly jtreg build, containing the CODETOOLS-7901662 fix. Best regards, Alexander 

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