AccessController.doPrivileged and default methods

[Sean Mullan]

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.

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)
>