June 2013 - Boost - lists.preview.boost.org

Re: [boost] [Boost-users] [thread] synchronized_value: value and move semantics
by Klaim - Joël Lamotte 08 Jun '13

08 Jun '13

I just discovered synchronized_value from reading the 1.54.0 beta documentation. On Wed, Feb 20, 2013 at 7:02 PM, Vicente J. Botet Escriba < vicente.botet(a)wanadoo.fr> wrote: > Do you see something completely wrong with this addition? > No idea yet but I'm willing to test it in production code. See below for minor details. > Has some of you had a need for this? Could you share the context? > Yes, I think so. I have some cases (which I'm still working on but will be published as OSS soon) where I do something like that: struct ThingInfo { Id<ObjectInfo> id; std::string name; URI location; }; struct ThingContent { std::vector< Id<Foo> > foo_id_list; std::vector< Id<Bar> > bar_id_list; }; // this type MUST have thread-safe interface class Thing { public: explicit Thing( ThingInfo info ); ThingInfo info() const { boost::lock_guard<boost::mutex> lg( m_info_mutex ); return m_info; } ThingContent content() const { boost::lock_guard<boost::mutex> lg( m_content_mutex ); return m_content; } // + several modifying functions that use the work queue like that: void add( std::shared<Bar> bar ) { m_work_queue.push( [this, bar]{ m_bars.emplace_back( bar ); { boost::lock_guard<boost::mutex> lg( m_content_mutex ); m_content.bar_id_list.emplace_back( bar->id() ); } }); } void rename( std::string new_name ) { m_work_queue.push( [this, new_name]{ boost::lock_guard<boost::mutex> lg( m_content_mutex ); // SILENT ERROR!!! m_info.name = new_name; }); } private: WorkQueue m_work_queue; // tasks executed later std::vector< std::shared<Foo> > m_foos; // manipulated only by code in the work queue std::vector< std::shared<Bar> > m_bars; // idem ThingInfo m_info; // should be manipulated only with m_info_mutex locked ThingContent m_content; // should be manipulated only with m_content_mutex locked boost::mutex m_info_mutex; // protect m_info boost::mutex m_content_mutex; // protect m_content }; This is not real code but just how it looks like in my work-in-progress classes in my OSS project. >From reading the documentation, using synchronized_value I would then change the Thing implementation to: // this type MUST have thread-safe interface class Thing { public: explicit Thing( ThingInfo info ); ThingInfo info() const { return *m_info; } ThingContent content() const { *return m_content; } // + several modifying functions that use the work queue like that: void add( std::shared<Bar> bar ) { m_work_queue.push( [this, bar]{ m_bars.emplace_back( bar ); m_content.synchronize()->bar_id_list.emplace_back( bar->id() ); }); } void rename( std::string new_name ) { m_work_queue.push( [this, new_name]{ m_info.synchronize()->name = new_name; // OK: CAN'T USE THE WRONG MUTEX!! }); } private: WorkQueue m_work_queue; // tasks executed later std::vector< std::shared<Foo> > m_foos; // manipulated only by code in the work queue std::vector< std::shared<Bar> > m_bars; // idem boost::sychronized_value<ThingInfo> m_info; boost::sychronized_value<ThingContent> m_content; }; This version is to me: - more explicit on reading; - shorter; - avoid some mistakes like the one pointed in the comments - which might be hard to spot; The only thing that bother me is that synchronized_value is a long name and the "_value" part is, in my opinion, too much. Also, maybe using the pointer-semantic operators is not the best idea. I guess that if std::optional does, then it's ok. Once Boost 1.54.0 is released I will have the opportunity to try it by refactoring my code. I'll report if I find issues. Joel Lamotte

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[Boost.Test] Error with "putenv" when using (1.53) release branch
by Daryle Walker 07 Jun '13

07 Jun '13

This happened to me a few months ago when trying out a Windows 8 compiling setup with Code::Blocks. I pointed to the release branch of Boost, which should be set to 1.53. I included Boost.Test, I think by #including boost/test/include/unit_test.hpp so everything comes in without linking in the library directly. There was some sort of error involving "putenv," not sure what anymore. I "fixed" it by switching to the trunk branch. Now I'm trying a new setup, with Eclipse. This time I'm adding Boost.Test by adding the files directly to the project list. (I'm experimenting with splitting my tests into 3 files.) I'm referencing the release branch again, which should still be on 1.53. I got "'putenv' was not declared in scope" error. It's at Line 95 of boost/test/utils/runtime/config.hpp. Did a hard error sneak by everyone, or is my setup incomplete? Both IDE setups use G++ on MinGW for the compiler. Is there some #define I'm missing? Should I switch to using the trunk again? Daryle W.

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All talks for Meeting C++ 2013 are online!
by Jens Weller 06 Jun '13

06 Jun '13

Hi boost & C++ Community, to keep this short, all talks are online now, the schedule comes next week: http://meetingcpp.com/index.php/talks.html kind regards, Jens Weller

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merge of bugfixes still possible
by Oliver Kowalke 06 Jun '13

06 Jun '13

Hi, I got a bug-report two days before - I'd like to merge the bugfix into the release. Do I get the permission? Oliver

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[GIL] Can image::recreate reuse the memory?
by TONGARI 06 Jun '13

06 Jun '13

Hi, I'd expect image::recreate to reuse the memory much like std::vector::resize, but looked into the code shows that it creates a new one and swaps... So, is there a way to 'resize' the image without reallocating if the internal memory is sufficient? Thanks

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server and client chat via boost::asio
by Nguyễn Trường Lâm 06 Jun '13

06 Jun '13

Hello everyone. I want to write a program using socket, a client and a server to communicate between each other. But i dont know how write a message to server and display in a IDE terminal. Thank you for your help

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Migrating svn.boost.org
by DongInn Kim 06 Jun '13

06 Jun '13

Hi, This time I would like to setup a schedule to migrate svn.boost.org to the new server (wowbagger.crest.iu.edu) This migration may need some downtime on the subversion, trac, and svnmanager services because we do not want to have any inconsistencies in SVN and or trac database. I have already rsynched the 1) boost SVN repository including its hook script, 2) trac db, and 3) SVNManager and its database. Do you have any hidden processes to manage the subversion repository, trac, or SVNManager? I implemented some simple testings with some SVN activities on the new server and it seems to work fine. Can anyone volunteer to play with the migrated SVN repository, trac, and SVNManager on the new server? I can test the very basic stuff and I may miss some functionalities of the current services. If anyone who actually work on the boost project can check this out, it would be much appreciated. I would feel much safer. 1. The downtime that we may have while migrating svn.boost.org I expect that TTL value be changed to 1hour or so. While the new DNS entries are populated, the current server will NOT service svn.boost.org and the new server will instead. - Date: Wednesday June 5th, 2013 - Time: 11:00am-12:00pm Pacific US time 12:00pm-1:00pm Mountain US time 1:00pm-2:00pm Central US time 2:00pm-3:00pm Eastern US time 6:00pm-7:00pm GMT 2. The unavailable services hosted on svn.boost.org : - Subversion - trac - SVNManager 3. The DNS entries to update: - Make svn.boost.org and wiki.boost.org point to 129.79.13.33 Please let me know if you have any questions or concerns about this migration. Regards, -- - DongInn

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Re: [boost] [circular_buffer] New version of documentation
by Paul A. Bristow 06 Jun '13

06 Jun '13

> -----Original Message----- > From: Boost [mailto:boost-bounces@lists.boost.org] On Behalf Of Marshall Clow > Sent: Thursday, May 23, 2013 8:01 PM > To: boost(a)lists.boost.org > Subject: Re: [boost] [circular_buffer] Volunteer(s) needed After more work than I bargained for (see below for excuses) I have produced a Quickbook, Doxygen, Autoindex version from the existing documentation for Boost.Circular_Buffer at https://svn.boost.org/svn/boost/trunk/libs/circular_buffer/doc/circular_buf… I have made few substantive changes to the text, mainly adding more hyperlinks, (and correcting some that were wrong of missing - using the inspect tool is a really, really good idea!) So that users can comment on this new version, I have put html and pdf versions in my Dropbox. The pdf version is at https://dl.dropboxusercontent.com/u/43940943/circular_buffer.pdf which can of course be viewed by any PDF reader (I have recently moved to using Foxit instead of Adobe Reader). The html Quickbook version is from folder (libs/circular_buffer/doc/html) the at https://dl.dropboxusercontent.com/u/43940943/html/index.html (Sadly some of the icon .png files are inaccessible from the Dropbox version, which mars its beauty but you'll get the idea). This library uses the full automatic indexing of C++ names and hyperlinking to and from the text. The header files have the classes and functions fully documented in Doxygen format, and this is used to create the C++ reference sections: https://dl.dropboxusercontent.com/u/43940943/html/boost_circular_buffer_c__… to that you can see what the classes do and the parameters, template parameters, returns etc for the functions. I believe that these details are essential for Really Useful documentation. The original Doxygen standalone (whose format some users prefer) is at https://dl.dropboxusercontent.com/u/43940943/doxygen/html/index.html So you can see the pros and cons of the same information displayed side by side. The PDF and HTML versions also has an index at the end (this could be improved as it only gives C++ functions etc at present). Enjoy! (?) Comments welcome - praise preferred ;-) Paul PS Implementation notes: To get all the links correct proved *very* tiresome. Much of the trouble was inconsistent layout of existing documentation and files. IMO we need to use the GITMOD project to impose much more order on the file structure. I fear that the modularization changes will invalidate many links in documentation, so much revision will be needed :-( We must be able to predict where index.html etc will be to be able to write links without the current hassle. The Boost inspect tool proved invaluable, and all links are now reported correct. (Lots were wrong - in Doxygen comments in the header files, and in the Quickbook stuff :-( ) Despite this, there are still some sections in red where the html layout is wrong :-( I hope to find all of these in a later revision. --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

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Ticket spam
by Hartmut Kaiser 06 Jun '13

06 Jun '13

This ticket got some (harmless) spam added: https://svn.boost.org/trac/boost/ticket/6126#comment:21. What can I do to remove that comment? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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[community] request for revision: generic programming
by Steve Lorimer 06 Jun '13

06 Jun '13

In the light of C++11, the page on generic programming techniques http://www.boost.org/community/generic_programming.html is somewhat outdated. Any chance of a revision?

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