Hi, um, :) https://metacpan.org/pod/distribution/perl/pod/perlguts.pod#How-multiple-interpreters-and-concurrency-are-supported

So to the top add #define PERL_NO_GET_CONTEXT     /* we want efficiency */ and then 

void callback(){
dTHX;       /* fetch context */
...

[download]
and thats it?

In reply to Re^5: (SOLVED) XS: Passing an external library's function a Perl XS callback by Anonymous Monk
in thread SOLVED: XS: Passing an external library's function a Perl XS callback by stevieb

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