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[lockfree] Faster ring-buffer queue implementation
by Alexander Krizhanovsky 16 Jan '14

16 Jan '14

Hello, some time ago I've implemented lock-free multi-producer multi-consumer queue on ring buffer and recently I've compared it's performance with current (Boost 1.55.0) boost::lockfree::queue - it shows 50% better performance. I've made just a quick glance on the Boost implementation and noticed that it uses CAS operations which is basically slower than simple RMW (atomic increment in our case) on modern x86-64 hardware. Maybe I've made some mistake in boost::lockfree::queue usage. If so then I'll be obliged for pointing me out the problem in my benchmark. Otherwise I'm wondering if it has sense to integrate the queue implementation into boost::lockfree? The algorithm description is available at http://www.linuxjournal.com/content/lock-free-multi-producer-multi-consumer… The source code of the queue with the benchmark for boost::lockfree::queue: https://github.com/krizhanovsky/NatSys-Lab/blob/master/lockfree_rb_q.cc And the benchmark results are available here: http://natsys-lab.blogspot.ru/2014/01/natsys-lock-free-queue-in-comparison.… Thanks! -- Alexander Krizhanovsky NatSys Lab. (http://natsys-lab.com) tel: +7 (916) 717-3899, +7 (499) 747-6304 e-mail: ak(a)natsys-lab.com

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[Fibers] asio handler not respecting scheduler
by Eugene Yakubovich 16 Jan '14

16 Jan '14

While working on factoring out the scheduling algorithm, I noticed that when fibers are used with asio, the completion handler manually invokes the fiber: boost-fiber/include/boost/fiber/asio/detail/yield.hpp: In yield_handler<T>: void operator()( T t) { * ec_ = boost::system::error_code(); * value_ = t; fiber_->set_ready(); boost::fibers::detail::scheduler::instance()->spawn( fiber_); boost::fibers::detail::scheduler::instance()->run(); } Why does it call spawn? Shouldn't the scheduler (run method that follows) decide which fiber to run next? What happens if there's another fiber with a higher priority that's ready? A similar issue also comes up when launching a new fiber. The documentation supports the implementation in that the control immediately is transferred to the new fiber. However, shouldn't the scheduling algorithm decide when the new fiber should run? As an unrelated issue, I think this maybe a bug -- it's setting the active fiber to ready instead of waiting: void round_robin::yield() { <snip> // set active fiber to state_waiting active_fiber_->set_ready(); <snip> } Same issue in round_robin_ws and asio/round_robin. Regards, Eugene

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[Boost.Sync] no master branch?
by Eric Niebler 16 Jan '14

16 Jan '14

What is Boost.Sync and why doesn't its repository have a master branch? -- Eric Niebler Boost.org http://www.boost.org

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1.56 release schedule?
by Tim Blechmann 15 Jan '14

15 Jan '14

hi all, according to the website, the 1.56 beta was scheduled on dec 31st and the release date is feb 3rd ... maybe the release managers could update the release schedule? shifting the dates by a month could be realistic, or what do other people think? cheers, tim

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Re: [boost] [Fibers] Performance
by Brian Wood 15 Jan '14

15 Jan '14

Oliver Kowalke wrote: 2014/1/13 Hartmut Kaiser <hartmut.kaiser(a)gmail.com> >> >> Ping? Any news? I'd make my vote depend on the outcome of the performance >> tests. >> > > I'll add performance tests but I doubt that I could finish to implement the > tests till Wednesday. > I've to look through the tests provided by the HPX-project, select some and > try to understand > what they are doing. Maybe a few weeks could be given to Oliver to do the testing. -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

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[graph][BGL][PBGL] Proposed patches
by bminano 15 Jan '14

15 Jan '14

Hi, I found two problems using the graph library, concretely using it in parallel. Swimming into the code I think I found possible solutions to that. I proposed two patches in boost Trac at tickets #9549 and #8250, but I had no response. I am afraid the tickets were not revised, so I think publishing here would be a good idea. Maybe the maintainers of the library want to apply that patches for future releases. I hope so, as I am working in a project that will select boost graph as a masterpiece of graph simulations. I the responsible wants to ask me about the bugs I'll be glad to answer. -- View this message in context: http://boost.2283326.n4.nabble.com/graph-BGL-PBGL-Proposed-patches-tp465789… Sent from the Boost - Dev mailing list archive at Nabble.com.

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Re: [boost] GSoC 2014
by Christopher Kormanyos 15 Jan '14

15 Jan '14

> hi sir, > i m deepak, i want to apply for GSOC 2014 . i am good in c++, mathematics > and having proficient knowledge of algorithms. > i have a special interest for following boost libraries > - Boost.Math Generalized Hypergeometric Functions Well, that's a cool one for sure :-) Thank you for your interest, deepak. It's still a bit early in the game because we have not yet found an organization administrator. Nor have we formally applied as an organization for GSoC 2014. So keep an eye on the progress and base your actions accordingly. > Boost.Multiprecision > new data structures and algorithms I do not believe that we will be working on Multiprecision in this year's GSoC. Some of the things are already done, and others, quite honestly have too much novel research character for GSoC. This is an area for independent research at the moment. > i want to know if i could start early or work with boost trac or you tell me what to do As I mentioned, keep an eye on our progress. If Boost applies, and if Boost gets nominated for GSoC, then you may apply. It is a worldwide competition, so it always helps to apply early, ask questions on the board, write a good proposal, and generally do your best. Good luck. Chris. On Tuesday, January 14, 2014 8:45 PM, deepak goel <deepakgoel7514(a)gmail.com> wrote: On Monday, January 13, 2014 2:08:39 AM UTC+5:30, Christopher Kormanyos wrote: >> I have just added a page for GSoC 2014 here >> https://svn.boost.org/trac/ boost/wiki/SoC2014 > >Thank you Vicente. > >I have added "Boost.Math Generalized Hypergeometric Functions". > >Sincerely, Chris. > > > > > >On Sunday, January 12, 2014 6:45 PM, Vicente J. Botet Escriba <vicent...(a)wanadoo.fr> wrote: > >Le 12/01/14 18:20, Christopher Kormanyos a écrit : > >>> Deadline for registering as a mentoring organization for GSoC 2014 is 14 >>> Feb 2014. >>> Should we start collecting ideas? >> I believe we have several good ideas. We need to get moving. >> >> Does anyone know how to put up the skeleton of this kind >> of page? (Or can anyone point me in the right direction on >> how to do it?) >> >> https://svn.boost.org/trac/ boost/wiki/SoC2013 >> >> The hard part, I believe, will be finding one or more org admins. >> The guys did a great job last year, and set the bar pretty high. >> >> * I can probably mentor a student. >> * I can help collecting and writing the ideas on SVN trac. >> * I could also help writing the GSoC 2014 proposal and with recruiting. >> >> But org admin would potentially be too much of a commitment for me. >> >> Is anyone interested in being org admin for GSoC 2014? >> >Hi, > >I have just added a page for GSoC 2014 here >https://svn.boost.org/trac/ boost/wiki/SoC2014. > >Be free to add your projects and ideas. >Vicente > > hi sir, i m deepak, i want to apply for GSOC 2014 . i am good in c++, mathematics and having proficient knowledge of algorithms. i have a special interest for following boost libraries - Boost.Math Generalized Hypergeometric Functions Boost.Multiprecision new data structures and algorithms i want to know if i could start early or work with boost trac or you tell me what to do ______________________________ _________________ >Unsubscribe & other changes: http://lists.boost.org/ mailman/listinfo.cgi/boost > > >______________________________ _________________ >Unsubscribe & other changes: http://lists.boost.org/ mailman/listinfo.cgi/boost >

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Regression test results starting to become available
by Beman Dawes 15 Jan '14

15 Jan '14

http://beta.boost.org/development/tests/master/developer/summary.html http://beta.boost.org/development/tests/develop/developer/summary.html Only a few of the testers have cycled. Some testers are only reporting results for 15 or so libraries. That's an artifact of getting started; these testers cycle the full tests will appear. --Beman

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[git] annotated SVN synchronization for boost.test (example only)
by Peter A. Bigot 15 Jan '14

15 Jan '14

Below is an annotated sequence of (bash) command-line git operations that I used in a local copy of Boost.Test to understand what was happening in it, with no intention of proposing this be what the maintainers actually do with the module. Boost.Test is particularly interesting because master has been essentially unchanged for four years, while there are significant modifications pending in develop. A few of the changes on master make the SVN synchronization step tricky. People who want to hone their git-fu might find it workwhile to follow these steps in a local workspace to see how they work. I make no claim that they're the only way the same goal could be reached. I also have not used this for further development, so there the resulting structure may be flawed or contrary to strict git-flow expectations. WARNING: DO NOT paste the entire sequence into a shell window: at a couple of places you must manually do what the comment says (e.g., edit the contents of files to resolve conflicts) in order to reach a successful state. # Revert to a clean state where local branches match the origin, and the # working branches from any previous run of the script have been # removed. git fetch origin git checkout master git reset --hard origin/master git checkout develop git reset --hard origin/develop git branch -D synch/master synch/develop basis # git-merge-base identifies the commit to be used when merging things. # We're looking for something better, so no need to go beyond that one. MERGE_BASE=$(git merge-base develop master) # 635b1e38dd643af264c2ea8f0ba08dfb58337e37 echo ${MERGE_BASE} # Examine the history along master and develop, finding the most recent # SVN revision merged from develop into master. This only works if all # previous SVN revisions were also merged; if only select ones were # merged, it's probably best to skip them and keep looking. For # example, master on Boost.Test merged 81913, 63640, 62426, and a couple # others, but the last version that incorporated most prior fixes was # 57993 merged in ${MST_MP_SHA1}. git log ${MERGE_BASE}..master MST_MP_SHA1=2e4f64197956ccb94b24be4ed32abf25ee4b9dd1 # Now find the develop commit that most recently preceded that one in # SVN history. Basically, this is reviewing the log of differences # for the last commit with a SVN revision less than the one selected in # the previous step. BEWARE: If the revision you picked above doesn't # correspond to a develop branch change (e.g., if you picked 81913 which # didn't go into develop until 82756) you will create pain for yourself. git log ${MERGE_BASE}..develop # Here it's commit 57864 in ${DEV_MP_SHA1} DEV_MP_SHA1=fd8d9b3e4e4ab9656b0d880e8c519eabd134638a # Now take a look at what's different between those versions. That's # what'll get lost in a "-s ours" merge if it subsequently appeared in # develop. git diff ${DEV_MP_SHA1}..${MST_MP_SHA1} # There's some whitespace differences, some casts and error messages, # file permission changes, and two small changes from r81913 that we'll # talk about later. # Here's where my technique differs: You could do an "-s ours" merge # from the selected develop commit into master's HEAD as recommended at # https://svn.boost.org/trac/boost/wiki/StartModMaint#Firstpost-svnconversion… # but if you do you might lose cherry-pick commits on master that are # also on develop. Instead, we'll create a new merge point on master at # the synchronization point, and merge from develop. git checkout -b basis ${MST_MP_SHA1} git merge -s ours -m 'SVN merge basis preserving master' ${DEV_MP_SHA1} # Verify that the differences are the ones we accepted earlier: git diff basis..${DEV_MP_SHA1} # Now, let's do some cleanup, and get master and develop branches that # actually fork at the merge point, rather than simply assume the merge # point is identical. This indirectly helps manage the differences that # we threw away with "-s ours". git checkout -b synch/master master git rebase basis # This should show no differences, because we just inserted a commit # that records parentage but changes no content. git diff master synch/master # Do the same at develop. Here we're going to have to resolve any # conflicts between the selected merge point git checkout -b synch/develop develop git rebase basis # 66 patches in we hit one of the differences: git stat # (MANUAL STEP) There's whitespace at the end of build/Jamfile.v2. Edit # the file to remove the diff markers, stage the changes, and tell # rebase to continue. git add -u git rebase --continue # After 204 patches there's another. git stat # (MANUAL STEP) Here you'll see everything is clean except # include/boost/test/impl/framework.ipp. Search for <<<<<< and edit to # keep the one with the upper-case TUT_SUITE. git add -u git rebase --continue # And we're done. Now let's see what changed: git diff develop synch/develop # Some of the differences between master and develop at the SVN merge # point have gone away; these are the ones I suspect but have not # confirmed would have been lost had we merged to master's HEAD instead # of to the base version. A few changes remain that were in master but # not in develop. # You have a choice at this point. If the repository wasn't already # public, I'd reset master (develop) to synch/master (synch/develop) and # move on. But since they were public, merge them; keeps history, # and makes future actions cleaner. git checkout master git merge -m 'Merge in rebased master' synch/master git checkout develop git merge -m 'Merge in rebased develop' synch/develop # Finally, what would happen if we merged develop into master now? git checkout -b test master git merge develop # Very nearly a clean merge. See what's not staged: git stat -u | grep '^.[^ ]' # ## test # UU include/boost/test/utils/runtime/cla/parameter.hpp # UU include/boost/test/utils/runtime/env/variable.hpp # # Again, open the files and look for the diff markers: one uses m!=0 and # the other !!m. Which is right? Use git-blame: git blame origin/master include/boost/test/utils/runtime/cla/parameter.hpp # The master change came in 954d3ab6 which was SVN commit r81913 by # Vicente J. Botet Escriba. Show the change: git log -p 954d3ab6^! git blame origin/develop include/boost/test/utils/runtime/cla/parameter.hpp # The develop change came in 4f7fc06c which was SVN commit r82756 by # Gennadiy Rozental. Show the change: git log -p 4f7fc06c^! # Note that if, back when selecting the SVN merge point, we'd gone with # r81913 things would be completely bolluxed at this point since the # corresponding change didn't come from the develop branch. # (MANUAL STEP) It's Rozental's project, so pick the develop solution # (!!m). Then stage the changes and commit, editing the message to # indicate how you resolved the conflict. git add -u git commit

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[any] Equality
by Bjorn Reese 15 Jan '14

15 Jan '14

I noticed that boost::any does not have an operator== for comparing two boost::any objects. Is this a deliberate choice? Currently I have to (1) compare the types, and (2) convert the values with any_cast (and probably catch bad_any_cast exceptions) and compare them.

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