May 2010 - Boost - lists.preview.boost.org

Mutexes claim a Windows event handle
by Peters, Richard 03 Jun '10

03 Jun '10

Hi! I have a problem with boost::recursive_mutex "sometimes" keeping a handle to a Windows Event. My application uses a lot of objects, each containing a recursive_mutex. The objects are accessed from different threads using a scoped_lock (see code below). In Boost 1.34 there was no problem, but after we switched to 1.39 it seems that the process collects more and more handles to Windows Events. Only when the objects that contain the recursive_mutex are destroyed, the handles are released again. The problem is that I must support 100,000 objects containg multiple mutexes, so if each mutex can cost one handle the total number of handles in use may become huge. I tried the latest Boost version (1.43) but that makes no difference. The strange thing is that not every object keeps a handle, i.e.: the number of handles collected is less than the number of objects created. When increasing the nrActions the number of handles collected comes closer to the number of objects. I could understand if a recursive_mutex costs a handle, except that in boost 1.34 they didn't so I wonder if this was an accident or a deliberate change. And most important: Is there a way to get the same behavior as in 1.34 where a mutex did not cost me one handle each? Thanks for your advice! Code example: #include <list> #include <boost/bind.hpp> #include <boost/thread.hpp> #include <boost/thread/recursive_mutex.hpp> #include <boost/enable_shared_from_this.hpp> class ActiveObject : public boost::enable_shared_from_this<ActiveObject> { private: boost::recursive_mutex mActionLock; void action() { boost::recursive_mutex::scoped_lock asyncLock(mActionLock); } public: void startAction() { boost::recursive_mutex::scoped_lock syncLock(mActionLock); boost::thread th(boost::bind(&ActiveObject::action, shared_from_this())); } }; int main() { { std::list< boost::shared_ptr<ActiveObject> > jobList; for (int nrObjects = 0; nrObjects < 1000; ++nrObjects) { boost::shared_ptr<ActiveObject> pActiveObject( new ActiveObject() ); jobList.push_back(pActiveObject); for (int nrActions = 0; nrActions < 3; ++nrActions) { pActiveObject->startAction(); } } // At this point, a lot of handles are in use. } // Here, the handles are released again. exit(0); } This message and attachment(s) are intended solely for use by the addressee and may contain information that is privileged, confidential or otherwise exempt from disclosure under applicable law. If you are not the intended recipient or agent thereof responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by telephone and with a 'reply' message. Thank you for your co-operation.

5 9

Maintaining boost.org
by Dean Michael Berris 03 Jun '10

03 Jun '10

Good day everyone! If you were at the BoostCon 2010 panel session, I suggested that maintaining boost.org can be a less painful process and that I was willing to help out in transitioning the current site from the way it is currently set up to maybe use Wordpress to host the site. There are other options that I would like to explore only after looking at many different tools and the current process of maintaining it. I tried sending mail to the Boost-docs list but I haven't gotten any responses yet so I chose to send another email to the developers mailing list. There are a couple of questions I would like to ask and would really appreciated getting an answer about: 1. Is there currently a boost.org web team? If so, who are in the team? 2. What is the current process of building the boost.org site? What is the toolchain used and how are changes managed? Before I go into the detail of a proposal of making boost.org a little more "interactive" and "inclusive" I would first like to know the state of the system and whether there are any low hanging fruit that can be taken care of before I even suggest changing it. FWIW, I volunteer to help manage boost.org to make it more inviting to the community and more dynamic than it currently is. Although the boost.org website does host the web-based library documentation, I would like to be able to see more information on it about the community, the process, and news on what's going on. Pending a "full" proposal I would definitely appreciate thoughts about the matter too. -- Dean Michael Berris deanberris.com

12 40

[boost::endian] Request for comments/interest
by Tomas Puverle 01 Jun '10

01 Jun '10

I wrote an endian library on the flight back from boostcon but it has taken a little time to clear the submission with the firm. I realize that Beman's endian swapper library is already in the review queue but I hope my approach is different and interesting enough to warrant consideration. It's located here in the vault (Utilities/endian-puverle.zip): http://www.boostpro.com/vault/index.php?action=downloadfile&filename=endian… The highlights of the library are the following: - Very simple interface: swap<machine_to_little/big>(), swap_in_place<machine_to_little/big>() - Support for built-in and user-defined data types and ranges thereof. E.g. you can swap ranges of structs containing/deriving from other structs - endian::iterator, which will iterate across a range swapping values as necessary. It works with any swappable type. The library is described/documented/tested in the file main.cpp at the root of the zip archive. Unfinished items: - Right now, the library only includes the "vanilla" swapper, meaning it doesn't take advantage of special instructions on architectures which natively support endian conversion. I didn't include this in order to prevent cluttering the code with #ifdefs. This functionality would, however, be part of the final library. - Ideally, the metafunction is_mutable_range<> should be moved out of endian::detail and become part of Boost.Range of Boost.TypeTraits. I have donned by bulletproof vest and I'm ready for any feedback you may have. :) Tom

15 55

[gil] Is bit_aligned_pixel_iterator a standard conformant random access iterator?
by Christian Henning 01 Jun '10

01 Jun '10

Hi there, I'm having an interesting discussion over at the MSDN forums regarding compiler errors with MSVC10 that show up when using standard algorithms and bit_aligned images. Basically the question is why MSVC10 doesn't understand that bit_aligned_pixel_iterator is a random access iterator. For some reasons it thinks it's an input iterator and though std::copy, in this case, cannot find the correct copy implementation. One of the folks over at MSDN thinks that bit_aligned_pixel_iterator isn't implemented correctly with the interator_facade. He/She also thinks that iterator isn't fully standard compliant since it doesn't give a real reference but a proxy object instead when deferencing. I'm not sure if that's correct. Anyone knows if that's true or not. Here is the full text: http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/3c9eac4f-86e… In any event it seems I need to do some adjustment in the the gil code to have it working with my gil io extension and MSVC10. Right now I have the compiler errors all over my test suite. Regards, Christian

4 8

[range_ex] proper attribution
by Eric Niebler 31 May '10

31 May '10

The history of range algorithms in Boost goes back a long way. I'd like to see http://tinyurl.com/2d778f4 reflect that. When I wrote my earlier incomplete RangeEx library, I was careful to acknowledge (http://tinyurl.com/2dwdrhg) that I had borrowed heavily from the Container Algorithms library first written by Jeremy Siek and Vladimir Prus. If, as seems likely, Boost.RangeEx owes a debt to my RangeEx library, that should be noted, as well as the debt owed to Jeremy and Vladimir. Thanks, -- Eric Niebler BoostPro Computing http://www.boostpro.com

3 2

Multicore-BGL
by Giorgio Zoppi 31 May '10

31 May '10

Hi, we're intersted in how to optimize BGL on Multicore for adding our standard Bellman-Ford algorithms for optical networks. How do the current boost work on Multicore? BGL is thread-safe? Which parts are required to optimize? Cheers, Giorgio. -- Quiero ser el rayo de sol que cada día te despierta para hacerte respirar y vivir en me. "Favola -Moda".

5 7

boost::log access violation with global objects destructors
by Philippe Vaucher 31 May '10

31 May '10

Hello, Boost.Log creates an access violation when global objects being destructed attemps to log something. The doc says that I have to keep a shared_ptr to the core, but even doing so doesn't seem to work. I created a simple testcase here: http://codepad.org/pr8fAiZ2 The access violation location changes when the code change so I'm not sure how to handle this. This happens on Windows XP with boost 1.43 and the latest boost.log source from the svn. Thanks in advance! Philippe

3 5

[multiindex] internal scope_guard has changed access from public to protected
by Thorsten Ottosen 31 May '10

31 May '10

Hi Joaquín, I'm using the scope_guard from multi_index/detail/scope_guard.hpp. It seems like a revision has made the destructor and copy-constructor protected instead of private. This is in some sense more idiomatic, but it breaks a use that I have in my upcomming auto_buffer class. Basically I'm only constructing a scope_guard object when I know the code can throw, otherwise I construct a "null" scope_guard which is simply an instance of scope_guard_impl_base. Here's the code: namespace auto_buffer_detail { typedef boost::multi_index::detail::scope_guard_impl_base null_guard; } #define BOOST_AUTO_BUFFER_CONSTRUCTOR_SCOPE_GUARD() \ boost::has_nothrow_copy<T>::value ? boost::auto_buffer_detail::null_guard() : \ boost::multi_index::detail::make_obj_guard( *this, \ &auto_buffer::deallocate, \ buffer_, members_.capacity_ ) and use it like so: boost::multi_index::detail::scope_guard guard = BOOST_AUTO_BUFFER_CONSTRUCTOR_SCOPE_GUARD(); ... guard.dismiss(); Any chance you make the two members public again? -Thorsten

6 19

Boost related events calendar
by vicente.botet 30 May '10

30 May '10

Hi, In http://www.boost.org/development/index.html, the section "Release Schedule" contains much more "Boost related events", maybe we can change the title. BTW, the release schedule for 1.44.0 is missing. Will the Bug Spring Week take place (June 5-13th)? If yes, can someone having the rights add this to the calendar? Best, _____________________ Vicente Juan Botet Escribá http://viboes.blogspot.com/

3 3

[system] Heads up: Breaking changes
by Beman Dawes 30 May '10

30 May '10

Changeset 62313 brings Boost.System into closer conformance with the C++0x working paper (and FCD) with regard to the system_category and generic_category interface. Because system_category and generic_category change from constants to functions returning references, this is a breaking change. The fix is to change uses of "system_category" to "system_category()", and "generic_category" to "generic_category()". See https://svn.boost.org/trac/boost/changeset/62313 AFAIK, the only Boost library this change breaks is filesystem. The changeset includes fixes for it. Asio also uses System, but in a way that does not break AFAICT. Before committing the change, I tested system, filesystem, and asio locally on Windows and Linux. But given the possibility of unintended consequences, I thought a heads up to the list might be useful. I'll try to keep a close eye on regression tests as they cycle, but if anyone has any problems, please let me know. Thanks, --Beman

1 0

[move] problem with msvc and BOOST_MOVABLE_BUT_NOT_COPYABLE
by Oliver Kowalke 30 May '10

30 May '10

I get an linker error (private: __thiscall X::X(class X &) is unresolved symbol) with msvc-9.0 on XP. AFAIL (docu) implementing the copy-ctor isn't required and passing values from static memeber functions are allowed. What's wrong? Oliver #include "stdafx.h" #include <boost/move/move.hpp> class X { private: BOOST_MOVABLE_BUT_NOT_COPYABLE( X); public: X(); static X create(); X( BOOST_RV_REF( X) other); X & operator=( BOOST_RV_REF( X) other); }; X::X() {} X X::create() { X x; return x; // passing value form static memeber-fn } X::X( BOOST_RV_REF( X) other) {} X & X::operator=( BOOST_RV_REF( X) other) { return * this; } int _tmain(int argc, _TCHAR* argv[]) { X x( X::create() ); return 0; } -- GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01

6 29

https://svn.boost.org: SSL negociation failed
by vicente.botet 29 May '10

29 May '10

Hi, I'm getting this error while trying to commit Commit Commit failed (details follow): OPTIONS of 'https://svn.boost.org/svn/boost/sandbox/chrono/boost/chrono': SSL negotiation failed: SSL error: unknown protocol (https://svn.boost.org) I get the same error while I try to connect to https://svn.boost.org. Telling that the SSL version is is an old non secured one. Have others the same error or is just a problem in my configuration? Best, _____________________ Vicente Juan Botet Escribá http://viboes.blogspot.com/

7 8

[endian] Use in Hash algorithms
by Scott McMurray 29 May '10

29 May '10

Popular hash algorithms (MD5, SHA, ...) involve a preprocessing stage to turn bytes (or individual bits) into (32- or 64-bit) words, using a certain byte (and bit) order. For my Hash library, I ended up writing a pack function that takes an endianness and the number of bits in the input and output values, and combines or splits the input as needed. A simple example: { array<uint8_t, 8> in = {{0x67, 0x45, 0x23, 0x01, 0xEF, 0xCD, 0xAB, 0x89}}; array<uint32_t, 2> out; pack<little_octet_big_bit, 8, 32>(in, out); array<uint32_t, 2> eout = {{0x01234567, 0x89ABCDEF}}; assert(out == eout); } As a bonus, it also handles non-bytes units: { array<uint8_t, 3> in = {{31, 17, 4}}; array<uint16_t, 1> out; pack<big_bit, 5, 15>(in, out); array<uint16_t, 1> eout = {{(31 << 10) | (17 << 5) | (4 << 0)}}; assert(out == eout); } An extensive set of examples can be found here: <http://svn.boost.org/svn/boost/sandbox/hash/libs/hash/test/pack.cpp> This is used to turn the input into words, to turn the length into words for padding, for figuring out where in the word the "1" padding bit goes, and for turning the state back into octets for display. There are enough optimizations SFINAEed in that the first example just results in a memcpy on x86, but doesn't require contiguous input. (It's perfectly happy with single-pass input, though usually somewhat slower in that case.) I'm not sure how widely applicable this form of the solution would be, but I think it's a case where both the byte-swapping version and Beman's swap-on-load approach are awkward. ~ Scott McMurray

3 4

[log] unspecified error when going from win7 to xp
by Christoph Heindl 29 May '10

29 May '10

Hi, forgive me if the following error description is too vague. We are currently using boost.log (exported on 2010/05/20, compiled with msvc 9.0 sp1 on win7 against boost 1.40.0) in a large C++ project. On top of this C++ project a C-API is placed to ease integration with .NET's pInvoke technology. This C-API consists of very primitive methods. Integration with .NET (2.0 or 3.x does not matter) works fine on win7. But when the executables are moved to a windows xp (or lower) based platform (with all redistributables installed) it breaks with an AccessViolationException. We tracked down the problem (without the ability to debug :) to the usage of BOOST_LOG_FUNCTION and/or BOOST_LOG_NAMED_SCOPE. If those macros are not used, everything works fine again. I know my description is vague, but maybe someone has an idea if the problem is us or the problem could rely in those macros. Help is desperately needed. Best regards, Christoph

2 6

Is there any interest in Boost.Conversion?
by vicente.botet 29 May '10

29 May '10

Hi, The Boost.Conversion library (Generic explicit conversion between unrelated types) has not revealed too much interest for the Boost community since v0.4 was released on 10/09. For those that don't know it yet you can get the documentation and download links from https://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Conv… I have added on the sandbox some pending issues that Jeffrey Hellrung related to conversions that need extra information. If B1 is covertible to A1 using convert_to, now we can conver vectors of conversible types. B1 b10, b11, b12, b13; std::vector<B1> vb2; vb2[0]=b10; vb2[1]=b11; vb2[2]=b12; vb2[3]=b13; std::vector<A1> va2(boost::convert_to<std::vector<A1> >(vb2)) std::vector<A1,std::allocator<A1> > va6( boost::convert_to<std::vector<A1,std::allocator<A1> > >(pack(vb2, std::allocator<A1>()))); Note that when the Target constructor has some arguments (as is the case for vector with a specific allocator) we pack the Source and the Target arguments in a pack. The first argument is the Source. boost::conversion::pack(vb2, std::allocator<A1>()) The function 'pack' is currently a little bit rudimentary, but is usable already for vector conversions using a specific allocator. Currently accepts only two parameters, I plan to go up to 5 parameters. Any suggestion for better namming 'boost::conversion::pack'. I have no solution for the ambiguity problem of a user getting two different overloads of the same conversion on different namespaces, other than suggesting that convert_to overloadings should be done on the namespace of the Source, for example. Jeffrey does this answer to your attends? I will release the pack function and vector conversion (v.0.5) on the Vault once I will update the documentation. Comments are welcome :) Best, _____________________ Vicente Juan Botet Escribá http://viboes.blogspot.com/

4 8

[svn] https://svn.boost.org SSL negotiation failed, ssl_error_ssl2_disabled
by Niels Dekker - address until 2010-10-10 29 May '10

29 May '10

TortoiseSVN tells me, when I try to update: > > Command: Update > Error: OPTIONS of 'https://svn.boost.org/svn/boost': SSL negotiation failed: SSL > Error: error: unknown protocol (https://svn.boost.org) > Finished!: And when I try to open https://svn.boost.org in Firefox (running on Windows XP), it tells me: > > Secure Connection Failed > An error occurred during a connection to svn.boost.org. > > Can't connect securely because the site uses an older, insecure version of the SSL protocol. > > (Error code: ssl_error_ssl2_disabled) Is the server down? Thanks in advance, Niels -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center

1 0

[log] Condition variable has not been initialized
by Jorge Moraleda 29 May '10

29 May '10

When testing boost.log for race conditions using valgrind drd, some non initialized condition variables are reported at initialization time. I am using Valgrind-3.6.0.SVN and gcc version 4.4.4 (Debian 4.4.4-1). These are the valgrind error messages: ==27651== condition variable has not been initialized: cond 0x6174420 ==27651== at 0x4C267B9: pthread_cond_broadcast@* (drd_pthread_intercepts.c:756) ==27651== by 0x66DBCD2: ??? (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x6719E85: ??? (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x66C4BD2: ??? (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x7FF000561: ??? ==27651== by 0x722F63762F656771: ??? ==27651== by 0x2F6E69622F657068: ??? ==27651== by 0x722F726576726572: ??? ==27651== by 0x767265732D657068: ??? ==27651== by 0x2D2D00772D007264: ??? ==27651== by 0x72635F776F6C6C60: ??? ==27651== by 0x62645F65746164: ??? ==27651== ==27651== condition variable has not been initialized: cond 0x6174420 ==27651== at 0x4C267B9: pthread_cond_broadcast@* (drd_pthread_intercepts.c:756) ==27651== by 0x66D7F1A: boost::log_mt_posix::basic_core<char>::get() (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0xB5087C: boost::log_mt_posix::sources::basic_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex> >::basic_logger() (basic_logger.hpp:122) ==27651== by 0xB4F166: boost::log_mt_posix::sources::basic_severity_logger<boost::log_mt_posix::sources::basic_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex> >, util::logging::severity_level>::basic_severity_logger() (severity_feature.hpp:169) ==27651== by 0xB4DA3D: boost::log_mt_posix::sources::basic_composite_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex>, boost::mpl::vector1<boost::log_mt_posix::sources::severity<util::logging::severity_level> > >::basic_composite_logger() (basic_logger.hpp:391) ==27651== by 0xB4C771: boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>::severity_logger_mt() (severity_logger.hpp:77) ==27651== by 0xB4BA3C: __static_initialization_and_destruction_0(int, int) (Logging.cpp:35) ==27651== by 0xB4BAC6: global constructors keyed to _ZN4util7logging3aux9theLoggerE (Logging.cpp:215) ==27651== by 0xB58095: ??? (in /home/jorge/vc/ripe/bin/server/ripe-server) ==27651== by 0x9D3732: ??? (in /home/jorge/vc/ripe/bin/server/ripe-server) ==27651== ==27651== condition variable has not been initialized: cond 0x6174420 ==27651== at 0x4C267B9: pthread_cond_broadcast@* (drd_pthread_intercepts.c:756) ==27651== by 0x5F6AD14: ??? (in /usr/local/lib/libboost_thread.so.1.42.0) ==27651== by 0x5F6AD48: boost::detail::get_current_thread_data() (in /usr/local/lib/libboost_thread.so.1.42.0) ==27651== by 0x5F6AD68: boost::detail::find_tss_data(void const*) (in /usr/local/lib/libboost_thread.so.1.42.0) ==27651== by 0x5F6ADD8: boost::detail::get_tss_data(void const*) (in /usr/local/lib/libboost_thread.so.1.42.0) ==27651== by 0x66D6FAB: boost::log_mt_posix::basic_core<char>::implementation::init_thread_data() (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x66D7619: boost::log_mt_posix::basic_core<char>::open_record(boost::log_mt_posix::basic_attribute_set<char> const&) (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x9F5432: boost::log_mt_posix::basic_record<char> boost::log_mt_posix::sources::basic_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex> >::open_record_unlocked<boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> >(boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> const&) (basic_logger.hpp:269) ==27651== by 0x9F3EDE: boost::log_mt_posix::basic_record<char> boost::log_mt_posix::sources::basic_severity_logger<boost::log_mt_posix::sources::basic_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex> >, util::logging::severity_level>::open_record_unlocked<boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> >(boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> const&) (severity_feature.hpp:226) ==27651== by 0x9F2511: boost::log_mt_posix::basic_record<char> boost::log_mt_posix::sources::basic_composite_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex>, boost::mpl::vector1<boost::log_mt_posix::sources::severity<util::logging::severity_level> > >::open_record<boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> >(boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> const&) (basic_logger.hpp:509) ==27651== by 0xB4B5DF: util::logging::init(util::logging::severity_level, std::string const&) (Logging.cpp:190) ==27651== by 0xB49DA0: util::logging::init(std::string const&, std::string const&) (Logging.cpp:96) ==27651== ==27651== condition variable has not been initialized: cond 0x6174420 ==27651== at 0x4C267B9: pthread_cond_broadcast@* (drd_pthread_intercepts.c:756) ==27651== by 0x66D8D1A: ??? (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x66D9F43: boost::log_mt_posix::aux::stream_provider<char>::allocate_compound(boost::log_mt_posix::basic_record<char> const&) (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x9F3F72: boost::log_mt_posix::aux::record_pump<boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level> >::record_pump(boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>&, boost::log_mt_posix::basic_record<char> const&) (record_ostream.hpp:293) ==27651== by 0xB4B5FC: util::logging::init(util::logging::severity_level, std::string const&) (record_ostream.hpp:330) ==27651== by 0xB49DA0: util::logging::init(std::string const&, std::string const&) (Logging.cpp:96) ==27651== by 0x9DB05C: util::Configuration::parseCommandLine(int, char**) (Configuration.hpp:176) ==27651== by 0x9D6C5C: ripe_server::Configuration::Configuration(int, char**) (Configuration.cpp:70) ==27651== by 0xA48A86: main (posix_main.cpp:94) ==27651==

2 1

[proposal] The boost.org Maintenance Effort
by Dean Michael Berris 28 May '10

28 May '10

Hi Everyone, [First of all, this is a warning -- this is a long post, and I would really appreciate it if you read through the whole thing first before posting a comment on any specific thing I say. What follows is more supposed to be read as a document, so please bear with me. :D] A couple of days ago I posted a question about who is managing the boost.org website and the current process by which the website is being generated/hosted. That discussion led to a few realizations for me that I am including in this proposal to address the relative "pain" required to maintain the current site and move forward. This post is a proposal is designed to address three key areas of the boost.org maintenance effort: * The toolchain requirements for building/generating the boost.org site. * Addressing the non-interactivity of the boost.org website and the related pages. * Per-library community/documentation management. First, a preamble: The boost.org website is meant to be the face of the Boost C++ Libraries. It should be the facade that communicates the quality and the high standard the the Boost development community hold dear as the differentiating factors that make Boost what it is. As the face of the community, the website should encourage: participation, collaboration, community building, and open communication. The website shall host all community-developed and enforced policies, all official communications from the Boost community to the world, and serve as an umbrella that shelters the libraries and communities that do become part of the Boost C++ Library effort. Next, let me outline a few broad things with specific points: Communication * We should make it easy for the whole boost community (boost.org) and individual library maintainers/community to communicate messages to the world at large in an easy, unobtrusive manner. * We should make communication a two-way process by encouraging participation (see Participation below). * We should strive to communicate more, instead of communicating less -- to do this we should make it part of the goal of those in the Boost community (not necessarily developers) to promote the libraries and the website itself. Participation * Let's encourage participation in the form of comments to blog posts, feedback on documentation pages, and discussions on specific topics/threads. * Let's make it easier for non-developers to contribute to the effort in the form of community building, providing support, and advocate the library. * We should use the boost.org website as a means of reaching out to and being one of the ways the open source community and industry at large can get in touch with: individual developers, library maintainers, or the Boost community (including users) at large. Collaboration * Let's add the boost.org website as an additional channel through which collaboration can occur as a complement to the boost-developers and boost-users mailing lists. * Let's foster a more community-driven way of solving problems without having to require everyone to be part of a central list. * Let's allow communities around Boost libraries to grow and get things done on the boost.org website. After all the "marketing" stuff above, I'll outline below the concrete steps I propose people allow me to do. Ultimately though there should be a means of measuring whether the steps I take would lead to an agreeable measure of success, so I point out some measures by which you may hold me accountable to getting done. I invite everyone to please comment on and discuss whether the steps/proposal makes sense and whether there is a better way you think I can achieve this in case you agree to my above statements. Step 1: Move static and not-so-static content over to Wordpress MU [0] The current boost.org website is composed of mostly static content that says things about the submission-review process, the guidelines for libraries, what the goal of the project is, and the like. These pages can be ported to Wordpress MU manually either by copy-pasting the content into the WYSIWYG editor or typing the content in (and editing it in the process). This step will include the establishment of who would be the administrators and the eventual maintainers of the boost.org facade. All the information regarding the Boost Community and the maintaining of the content that's specific to the boost.org website would be written, article submissions curated, and copy-edited by the administrators. I have personally volunteered to be one of these administrators who would basically act as an editor for the site. I would take on the responsibility of achieving the following (measurable) goals: 1. Establishing a "Feedback" button that allows anybody visiting the site to post feedback on whatever they think. I would prefer to use a service called Get Satisfaction [1] to gather and manage the feedback, as well as responding to feedback posted through that service. 2. Incorporating a DisQus [2] discussion system to manage comments on pages. There is already a Wordpress plugin for this and comment moderation would mostly be handled initially by me and other administrators interested in helping out in this effort. 3. Integrating and publishing regularly the Google Analytics and Wordpress MU stats on the whole site. Regularly can mean either monthly or weekly depending on who often the community wants information about the site. [0] http://mu.wordpress.org/ [1] http://getsatisfaction.com/ [2] http://disqus.com/ Step 2: Make it easy to jump from Wordpress MU to Trac for the Wiki, Tickets, and Source Viewer This would mean adding links to the appropriate pages in Trac, and in these pages a way to jump back to the boost.org website. This will require some changes in the Trac site which should be easy to pull off. The measurable outcome for this would be to see the actual integration done in a satisfactory manner. Satisfactory of course means, that it works. ;) Step 3: Set up blogs for individual libraries (who want it, or at least for library maintainers/volunteers who want to manage it) Ideally this should be done for all the libraries. Each sub-site would include (at the minimum): * A blog -- where only the maintainers and those nominated by the maintainers to have blog posting access can communicate what's happening, what's coming, whether they need help, or whether there are any nasty bugs that need attention (as well as just some general updates or cool findings regarding the library). * Static Pages -- typically there would be pages like "About", "History", "Examples", and "FAQs" which generally are mostly static. These can be edited by the maintainers and those nominated by the maintainers who would have access to these pages. * Support Information -- this would be a special static page which would point to Trac, or other places where the development and support system of the library is hosted. I am not excluding the possibility of having libraries developed in github/gitorious/sourceforge. Links to things like the mailing list on which the discussion happens, whether there's a web-based forum, or whether there's a number/company to call for support would generally go here too. * Online documentation -- as an absolute minimum there should be a page on documentation for each library in Boost accessible from the boost.org website. It would be a good thing to integrate the generated library documentation into the wordpress system itself, but at the minimum links to the generated library docs that are statically served (just like now) would be acceptable. My personal vision for boost.org would be to become the hub over which the Boost C++ community and the surrounding ecosystem of companies can join in on the action. I would even go so far as say that we should encourage and allow industry players that offer support for Boost libraries or who use Boost libraries to place advertising on the site to help with shouldering the cost of BoostCon, or other things that the Free Software Conservancy would deem necessary to spend money on. I also would like to see it be the face of the Boost community, and really a means to get users to start using boost, get excited about it, and eventually contribute back to the cause. Users who are already passionate about providing support for a wider audience of Boost users could also contribute to the cause not as library developers but people who publicize and liberally put links to the boost.org site on their blogs, on their email correspondence, and in stackoverflow.com answers. Ultimately I would personally want to see boost.org be able to handle the growth of the Boost C++ Library, and allow for more communities (not just one community) to through the site. I don't want it to replace the mailing list for Internet old timers like me who like this feel of email conversation, but for things like announcements and communicating to the wider audience I think the website should do that job superbly. Thanks for reading this far, comments, suggestions, reactions, and pledges to help would be greatly appreciated. Have a great day everyone and I hope to hear from you soon! -- Dean Michael Berris deanberris.com

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BoostCon 2011 Dates and Hotel Discount (this week only!)
by David Abrahams 28 May '10

28 May '10

Hi All, BoostCon #4 was a resounding success, with 95 registrants—attendance holding steady in the face of a poor economy—and nothing but smiles all ’round. One participant was heard to say “after last year, I thought about not coming because I was sure nothing could possibly be cooler that experience, but this is even better.” I'll have more to say about the event soon, but for now a couple important details about next year: 1. Next year, BoostCon is scheduled a week later: May 15-20, 2011 which avoids a conflict with Mother's Day, a perennial issue for some attendees… and is a bit less likely to bring us snow ;-) 2. Because BoostCon has been an excellent regular customer, the Aspen Meadows is offering a $20/night discount for any Boost participant who books on or before **this Friday**, May 21 2010. After taxes, etc., that's more than a $100 savings. Use the following link to make your reservation: https://resweb.passkey.com/Resweb.do?mode=welcome_ei_new&eventID=2547965&fr… Lastly, the Meadows wants you to know that your companies or universities are welcome back for other meetings, and requests that, if you had a good hotel experience this year, you please post positive feedback on http://tripadvisor.com. See you next year, if not before! Cheers, -- Dave Abrahams Meet me at BoostCon: http://www.boostcon.com BoostPro Computing http://www.boostpro.com

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[concept] "not" and "or" concept constraints (N2081)
by Lorenzo Caminiti 28 May '10

28 May '10

Hello all, How can I use Boost.ConceptCheck to implement "not" and "or" concept constraints as they are defined in N2081? (If this is obvious from the documentation, please just point me to the link.) For example, how can I program the following code from N2081 using Boost.ConceptCheck: // "not" `!` concept constraint for some concept C (not C++ code). template<Regular T> where !C<T> void f(T x) { ... } // "or" `||` concept constraint (not C++ code). template<Regular T> where Integral<T> || Floating<T> T cos(T x) { ... } If I understand it right, I can program the "and" concept constraints in Boost.ConceptCheck just by specifying multiple concepts as in: // "and" `&&` concept constraint. template<typename T> BOOST_CONCEPT_REQUIRES( ((boost::Integral<T>)) ((boost:: Arithmetic<T>)), T) f(T x) { ... } But how do I use BOOST_CONCEPT_REQUIRES(), etc to program "not" and "or" concept constraints? Thank you very much. -- Lorenzo

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Re: [boost] [boost::endian] Request for comments/interest
by Dave Handley 28 May '10

28 May '10

"Scott McMurray" wrote: > On 28 May 2010 13:44, Cliff Green <cliffg(a)codewrangler.net<mailto:cliffg@codewrangler.net>> wrote: > > > > Studies have been performed comparing "receiver makes right" designs (where > > swapping is only performed by the receiver, if needed) with others. The > > costs of swapping on modern processors is pretty minimal compared with the > > design overhead and complexity, so "receiver makes right" many times is not > > justified. > > > > I understood it more as "we use little-endian for our network format, > since most of our machines are little-endian, but still want to allow > things to work on the couple of big-endian machines", not as "receiver > makes right". I need to reiterate that I was not talking about a "receiver makes right" design. I don't like these at all for complexity reasons. But in this day and age when a significant percentage of computers being sold are little-endian, deciding to make an internal protocol little-endian and almost completely eliminating endian swaps can make a lot of sense. If you are processing data off multiple 10Gb Ethernet feeds simultaneously, removing a single copy can make all the difference. Especially when you consider memory bandwidth constraints on a multi-threaded process. If you consider the hoops that C++0x has tried to jump through to make move semantics work, removing unnecessary copies, especially in a low level process, seems to be important to a lot of people. Dave

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Re: [boost] [boost::endian] Request for comments/interest
by Dave Handley 28 May '10

28 May '10

"Cliff Green" wrote: > In most general marshalling / serialization designs where portable binary > values are required, the transform step (from "wire" to "object / memory" > model) requires a copy anyway. The low-level endian facilities should not > require an extra copy, but trying to minimize all copying and constraining > the endian library design might be misguided. In the sort of code I write, an endian swapper that had copies that weren't necessarily required, especially in the "do nothing" case where network and machine have the same endianness would not be fit for purpose. " " wrote: > This is not completly true, as your implementation will at least visit the instance. I disagree. If you look in more detail at the code that Tom has submitted, the "do nothing" case does exactly that - nothing. Specifically line 147-154 has the template specialisations that get invoked when a no-op is required, and they have no code in them. Only in the case where an endian swap is required does the implementation walk through the whole data structure. Dave

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Review of a safer memory management approach for C++?
by Bartlett, Roscoe A 28 May '10

28 May '10

Hello Boost developers, I am interested in finding one or more individuals who are knowledgeable about memory management in C++ (and especially of the reference-counting approach taken by boost::shared_ptr and boost::weak_ptr) to review an idea for a comprehensive approach to safer memory management in C++ that encapsulates all raw C++ pointers in high-level code. The technical report for the approach is: Teuchos C++ Memory Management Classes, Idioms, and Related Topics The Complete Reference A Comprehensive Strategy for Safe and Efficient Memory Management in C++ for High Performance Computing and can be found at: http://www.cs.sandia.gov/~rabartl/TeuchosMemoryManagementSAND.pdf If someone would be willing to at least go through the abbreviated table of contents laid out in the Preface and provide some feedback, I would be greatly appreciative. If there is a better mail list to send this too, please let me know. Thanks, - Ross P.S. Please make sure and respond to me personally (rabartl(a)sandia.gov<mailto:rabartl@sandia.gov>) or a spam filter will likely kill it. ----------------------------------------------------------------------- Dr. Roscoe A. Bartlett Sandia National Laboratories Department of Optimization and Uncertainty Estimation Trilinos Software Engineering Technologies and Integration Lead (505) 844-5097

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[concept] concept-based overloading (N2081)
by Lorenzo Caminiti 28 May '10

28 May '10

Hello all, How do I use Boost.ConceptCheck and/or Bosot.EnableIf to implement concept-based overloading (as discussed in N2081)? For example, from N2081, the following functions are selected based on `Iter` matching one of the two specified concepts: template<InputIterator Iter> // proposed concept syntax (not C++) void advance(Iter& x, Iter::distance_type n) { while (n > 0) { ++x; --n; } } template<BidirectionalIterator Iter> // proposed concept syntax (not C++) void advance(Iter& x, Iter::distance_type n) { if (n > 0) while (n > 0) { ++x; --n; } else while (n < 0) { --x; ++n; } } How do I program this in C++ using Boost libraries? N2081 briefly mentions this can be done in C++ using SFINAE, etc. I think I could use `enable_if` if I had some sort of `is_input_iterator` metafunction... Please just point me to the documentation if this has already been addressed there. Thank you very much. -- Lorenzo

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[iterator] issues with Boost.Iterator and Boost.MultiArray
by Thomas Klimpel 28 May '10

28 May '10

Hi, The issues reporteted in <http://lists.boost.org/Archives/boost/2010/05/165798.php> are still open. Even so I wrote: > But from my point of view, the only responsibility I may > have with respect to these issues is to notify the authors > of the affected libraries, which I have done now. it seems that I wasn't yet successful in my attemps to notify the authors. The only one that has answered so far was Thomas Witt <http://lists.boost.org/Archives/boost/2010/05/165837.php>, claiming that the bug is in Boost.MultiArray. However, my personal belief is that the bug is in <http://svn.boost.org/svn/boost/trunk/boost/iterator/detail/facade_iterator_…>. But there is definitively a "quasi unrelated" bug in Boost.MultiArray on trunk (and Thomas Witt might refer to this bug), as the "resize" regression test fails on nearly all compilers on trunk but passes on release <http://lists.boost.org/Archives/boost/2010/05/165810.php> (the link contains a patch that fixes the failures). I would be most happy, if 1) Ron (or somebody else that is allowed to apply patches to Boost.MultiArray) would simply fix the failure of the "resize" regression test on trunk (either by applying the provided patch or by fixing it in some other way). 2) Dave (or somebody else that has deep knowledge about Boost.Iterator) would confirm that the failures of Boost.MultiArray on MSVC-10 are caused by an issue in Boost.Iterator (and are probably related to Jeremy Siek's patch <https://svn.boost.org/trac/boost/changeset/21683>). I guess the result if somebody will answer at all is that I will be asked to enter a track ticket for Boost.Iterator. So if this mail should stay without useful feedback, I will enter two track tickets for Boost.MultiArray and one track ticket for Boost.Iterator, in anticipation that the feedback would probably have suggested that I should do that. Regards, Thomas

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