very slow jni code callbacks

Andrew Haley aph@redhat.com
Mon Sep 28 20:13:00 GMT 2009


Herman ten Brugge wrote:

> I did try some older gcc releases because I once had good
> results for callbacks.
> The 4.1.2 release shows some different results.
> 
> #                       open jdk        gcj
> # no_jni                 1.48              12.12        (  8 times slower)
> # jni                   66.70             200.93        (  3 times slower)
> 
> So there must be a change some time ago that made this
> much slower.

It depends only on the number of active ClassLoaders, and how much
processing they do.  The fix for this is to remove the classname
lookups at runtime.

Andrew.



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