Re: [GCJ] Performance of GUI applications on embedded systems

Hi,

> > The problem is that the program is spending almost all of the time
> > generating stack traces, millions and millions of them.
> 
> And one reason for that is pointless class lookups in
> the GTK peer code.
> 
> Look at this:
> 
> Java_gnu_java_awt_peer_gtk_FreetypeGlyphVector_getKerning
> (JNIEnv *env, jobject obj __attribute__((unused)), jint rightGlyph, jint leftGlyph, jlong fnt)
> {
>   ...
> 
>   cls = (*env)->FindClass (env, "java/awt/geom/Point2D$Double");
>   method = (*env)->GetMethodID (env, cls, "<init>", "(DD)V");
>   return (*env)->NewObjectA(env, cls, method, values);
> }
> 
> Now, this method only returns a pair of points, and it would have been
> trivial to pass a 2-element array into it, fill, with x and y, and
> return the same array.  But no, we do a class lookup on
> java/awt/geom/Point2D$Double and call its constructor with two
> double values.

Or we could cache the MIDs and FIDs, like is recommended in all good JNI
books.

/Roman

-- 
Dipl.-Inform. (FH) Roman Kennke, Software Engineer, http://kennke.org
aicas Allerton Interworks Computer Automated Systems GmbH
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