AccessController.doPrivileged and default methods

[Sean Mullan]

On 7/6/17 10:33 AM, Sean Mullan wrote:
> On 7/5/17 4:01 PM, Adam Petcher wrote:
>>
>> Very interesting. The exception originates in the VM, so I added the 
>> hotspot-dev list to the discussion. It looks like the VM either can't 
>> find the method, or it decides that it's not the right kind of method.
> 
> Right. The check that is causing this error is in jvm.cpp [1]:
> 
> 1271  if (m.is_null() || !m->is_method() || !m()->is_public() || 
> m()->is_static()) {
> 1272    THROW_MSG_0(vmSymbols::java_lang_InternalError(), "No run method");
> 1273  }
> 
> I'll file a bug unless someone has a good explanation for this behavior.

Bug now filed: https://bugs.openjdk.java.net/browse/JDK-8183962

--Sean

> 
> Thanks,
> Sean
> 
> [1] 
> http://hg.openjdk.java.net/jdk9/jdk9/hotspot/file/1ca8f038fceb/src/share/vm/prims/jvm.cpp#l1271 
> 
> 
> 
>> On 7/4/2017 7:57 AM, Michael Rasmussen wrote:
>>> Hi
>>>
>>> I was playing around with having an easy way to have doPrivileged call
>>> void methods via lambdas/method references, and noticed that if you
>>> use AccessController.doPrivileged(PrivilegedAction), and the run
>>> method is implemented as a default method, then you get the following
>>> exception: java.lang.InternalError: No run method
>>>
>>> I failed finding anywhere in the documentation stating this should not
>>> be supported, or a bug report about it, so writing/asking here.
>>>
>>> See example code below
>>>
>>> Kind regards
>>> Michael Rasmussen
>>>
>>>
>>> //----
>>>
>>> package com.test;
>>>
>>> import java.security.AccessController;
>>> import java.security.PrivilegedAction;
>>>
>>> public class Test {
>>>    interface VoidPrivilegedAction extends PrivilegedAction<Void> {
>>>      void perform();
>>>
>>>      @Override
>>>      default Void run() {
>>>        perform();
>>>        return null;
>>>      }
>>>    }
>>>
>>>    static void doPrivileged(VoidPrivilegedAction act) {
>>>      AccessController.doPrivileged(act);
>>>    }
>>>
>>>    public static void main(String[] args) throws Exception {
>>>      doPrivileged(() -> 
>>> System.out.println(System.getProperty("java.home")));
>>>    }
>>> }
>>>
>>> //----
>>>
>>> Exception in thread "main" java.lang.InternalError: No run method
>>> at java.security.AccessController.doPrivileged(Native Method)
>>> at com.test.Test.doPrivileged(Test.java:18)
>>> at com.test.Test.main(Test.java:22)
>>