Correcting some mistakes below. make clean; perl Configure.pl --without-threads looks different now.
On Dec 17, 2012, at 11:27 PM, Reini Urban <rur...@x-ray.at> wrote: > On Mon, Dec 17, 2012 at 7:06 PM, James E Keenan <jk...@verizon.net> wrote: >> Am I correct in thinking that Parrot now builds with threads by default? > > Yes. > >> I.e., that if you *don't* want to build with threads you have to explicitly >> opt-out by saying: >> >> perl Configure.pl --without-threads > > No, that is not possible yet. threads support is builtin. > --without-threads will cause HAS_THREADS to be set to 0, but we > haven't tested this configuration. > >> I ask as a relatively threads-ignorant person (which I think most software >> developers probably are). For example, I have never built a threaded Perl >> 5, nor, to the best of my knowledge, have I ever run on one. And during the >> many months in which the threads branch was under development, I was mainly >> concerned with one question: Which tests were breaking? > > Unfortunately it is not easy to come up with breakage tests. > Similar to the breaking readline IO tests, which expect user-input. > >> So, I would welcome a presentation -- and perhaps inclusion in our >> documentation -- of issues such as: >> >> * Why does Parrot now build with threads by default? > > Because this is IMHO the single most important feature since 15 years > of perl development. > This is the feature which seperates perl6 from perl5. Which would get > perl6 some momentum over perl5. > The hyper operators parallelize lists automatically to saturate all > available CPU cores. > hyper - forces none-lazy list context, that ignores the order of > results (allows parallel computing) > Manual safe and fast background processing. > >> * What exactly does "building Parrot with threads" mean? > > That parrot supports threads now. > Green threads as described in pdd25_concurrency, plus native OS thread > support. > See also http://perl6advent.wordpress.com/2012/12/11/day-11-parrot-threads/ > for > a short overview and the links in the docs for more. > >> * Under what circumstances would you want to build '--without-threads'? > If you want to forbid native OS threads with our concurrency model. I.e. green threads without OS threads. > If you want to forbid the experimental minefield, which threads with > GC can cause. > However, I would not recommend --without threads. > --without-threads does not set HAS_THREADS. > However HAS_THREADS has been set for the last year, even without > threads support. > So nqp and rakudo can not rely on HAS_THREADS for previous parrot > versions. (They can now). > The best feature I came up with was #ifdef PARROT_THREAD_H_GUARD > We did never tested --without threads. > > Tasks work even --without-threads, pthreads are enabled even --without-threads The second part is wrong. pthreads are disabled when doing --without-threads. The task tests do work, but not that fast as with native threads. I was not able to break the expensive threads + GC tests which fail on darwin, when setting --without-threads. ./parrot examples/threads/chameneos.pir > I would recommend testing and enabling threads support in your application > (nqp and perl6 being the most important), > while we get the remaining GC problems with threads under stress fixed. > > parrot is stable if you don't invoke Task subs. > It is experimental if you invoke Tasks. > > All parrot tests pass, most examples pass correctly, but there are > some platforms which might fail in the GC with threaded functions. If > you stress the GC in threaded functions you might get segfaults, esp. > on darwin. > It was not possible to break threads on windows though, and it is much > harder on linux. > > A short summary of this will be in the release announcement of course. > I could not fix the GC bugs alone, we need some efforts to get it done. > I pushed some of my efforts to rurban/fix-gc-thr-gh880+gh875 > -- > Reini Urban > http://cpanel.net/ http://www.perl-compiler.org/ _______________________________________________ http://lists.parrot.org/mailman/listinfo/parrot-dev
