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Postings from May 2010
2010/5/3 Jan Dubois <jand@activestate.com>: > On Mon, 03 May 2010, Reini Urban wrote: >> 2010/5/3 Ruslan Zakirov <ruz@bestpractical.com>: >> > While testing a simple benchmark script I noticed that threaded >> > version is 25% faster. I suspect that the code may be is not thread >> > safe, however don't know anything about perl threads. >> >> This is because threaded passes the my_perl struct on the stack, PL_op >> is just 4(%esi). > > Note that fox XS code this is only true if you > > #define PERL_NO_GET_CONTEXT > > Otherwise my_perl will actually be redefined to *Perl_get_context(), > which will fetch the actual my_perl from thread-local storage, which > will be really slow. > >> Accessing stack locals is much faster than accessing a global. > > So please make sure you define PERL_NO_GET_CONTEXT in your modules > if you are an XS author. It is not on by default for backwards > compatibility reasons only. FYI: That's why I started working on http://github.com/rurban/perl/tree/local-op to get this advantage for non-threaded and #undef PERL_NO_GET_CONTEXT also. -- Reini Urban http://phpwiki.org/ http://murbreak.at/Thread Previous | Thread Next