Re: [Aegisvm-devel] Small JNI patch for AegisVM

[Philip F. <pw...@us...>]

Hi Gildas,

I just committed your JNI code with the following log:

 New feature: Implementation of JNI functions Throw, ThrowNew,
 ExceptionOccurred, AllocObject, and NewObjectV.  Based on a patch 
 contributed by Gildas Bazin <gb...@al...>.

I modified your patch a bit:
- I like the way you reuse primitive JNI functions to implement
  higher level JNI functions.  I push your idea as much as I could.
  That is why some of the low level calls in ThrowNew & NewObjectV
  are eliminated.  The most noticable one is the elimination for the
  need to create yet another method invocation function.
- As for accessibility, I am as lost as you are.  The JNI spec does
  not prescribe any accessibility tests at the sites you pointed out.
  The general philosophy is that JNI should be allowed to by-pass
  accessibility checks.  This is actually how some of the built-in
  classes are implemented.  My guess is that we don't really need
  anything at those two spots.
- ThrowNew: The local reference allocated for the string should
    be released before returning.
- ExceptionOccurred: The exception object should be wrapped by
    a local reference.

The rest are basically the same as your patch.  Attached is the 
diff I actually committed.

Philip

PS: Please let me know if you need ae_invoke_method_v for other
    purpose.  I'll then add it back.

On Sun, 22 Sep 2002, Gildas Bazin wrote:

> Hi,
> 
> I implemented another few JNI functions:
> 
> jint ae_jni_Throw(JNIEnv *env, jthrowable obj)
> jint ae_jni_ThrowNew(JNIEnv *env, jclass clazz, const char *message)
> jthrowable ae_jni_ExceptionOccurred(JNIEnv *env)
> jobject ae_jni_AllocObject(JNIEnv *env, jclass clazz)
> jobject ae_jni_NewObjectV(JNIEnv *env, jclass clazz, jmethodID methodID, 
> va_list args)
> 
> ae_jni_AllocObject, ae_jni_NewObjectV are not complete. They are missing an 
> accessibility check at the beginning, but to be honest I don't really know 
> how to do that and I'm kind of hoping you'll add it yourself ;-)
> 
> Regards,
> 
> --
> Gildas

--
Philip W. L. Fong            pw...@us...
The Aegis VM Project         http://aegisvm.sourceforge.net

The Aegis VM Project is an on-going effort to implement a lightweight,
secure JVM.  It will eventually feature a modular architecture, Proof
Linking, that supports pluggable verification modules.