[9 + 8u] RFR - 8066612: Add a test that will call getDeclaredFields() on all classes and try to set them accessible.

[David Holmes]

Hi Daniel,

On 4/12/2014 7:05 PM, Daniel Fuchs wrote:
> On 12/4/14 4:37 AM, David Holmes wrote:
>>
>> Once clarification please ...
>>
>> On 4/12/2014 8:47 AM, Daniel Fuchs wrote:
>>> Hi,
>>>
>>> This is a review for a new test which has a different
>>> implementation for JDK 8 & JDK 9
>>>
>>> During the review of
>>> JDK-8065552: setAccessible(true) on fields of Class may throw
>>>               a SecurityException,
>>> it was remarked that such a test would be useful.
>>>
>>> So here is such a test that loads all classes from the BCL, calls
>>> getDeclaredFields() for each of them, and attempt to set
>>> each field to accessible.
>>> On JDK 8 and JDK 9 this is quite fast (~ 3.2sec when a security
>>> manager is on).
>>>
>>> The differences between 8 & 9 are limited to:
>>>
>>>     - ClassLoader:
>>>          - on 8 we use 'null' (BCL)
>>>          - on 9 we use the system class loader.
>>
>> I haven't seen anything in JEP 220, regarding modules, that indicates
>> that classes currently loaded  by the boot-loader will now be loaded
>> by the system classloader ???
>
> In [1] towards the end:
>
> [1] http://openjdk.java.net/jeps/220
>
> "The defining class loader of the types in some existing packages
>   will change. Existing code that makes assumptions about the class
>   loaders of these types might not work correctly."
>   (then there is a list of specific changes).
>
> This test looks up all class names in the image files and attempt
> to load the corresponding class. But as indicated in [1]
> some of these classes are now in the Boot CL, some in the
> Extension CL, and some in the Application CL.

Yes but that is a small set of specific types. The boot classes are 
still loaded by the boot loader.

> So the test uses the System CL to load each class - which ensures
> that the loading will be delegated to the appropriate ClassLoader.

It wasn't the use of the system loader to load the classes that I was 
concerned about but the check whether cls.getClassLoader() was the 
system loader - as it would not be for the boot classes.

David

> best regards,
>
> -- daniel
>
>>
>> Thanks,
>> David
>>
>>>     - Building the stream of class names:
>>>          - on 8 we have jars & folders in the boot class path
>>>          - on 9 we have .jimage files
>>>
>>>
>>> webrev jdk8:
>>> http://cr.openjdk.java.net/~dfuchs/webrev_8066612/webrev-jdk8.00/
>>>
>>> webrev jdk9:
>>> http://cr.openjdk.java.net/~dfuchs/webrev_8066612/webrev-jdk9.00/
>>>
>>>
>>> best regards,
>>>
>>> -- daniel
>>>
>>> PS: For the curious I have also experimented with a version of this
>>> test for JDK 7u [1] (where Streams have been replaced by Lists).
>>> On 7 you need to either increase the PermGen size or split the
>>> test into several invocations (the method I chose in [1]).
>>>
>>> [1] don't review the link below - it's just for the record
>>>      if/when someone wants to backport on 7u...
>>> http://cr.openjdk.java.net/~dfuchs/webrev_8066612/webrev-jdk7.00
>