November 2009 - Boost-users

Link issue with condition_variable
by Bradley W. Settlemyer 19 Mar '10

19 Mar '10

Hello, I'm using boost for the first time and I'm struggling to link my program. I've added libboost_pthread-mt to the link link (which got most of the symbols), but I still can't seem to get the symbols for the condition variables. The issue could be with the code, as I find the lock-mutex-condition_variable interactions to be very confusing, but it does appear to be a link issue. Consider the following error message emitted during link command: mpicxx <objects> -D_FILE_OFFSET_BITS=64 -L/lib64 -lfuse -lrt -ldl -lboost_thread-mt -lpthread -o aio_benchmark src/aio/thread_pool_adaptive_writer.o: In function `aio::ThreadPoolWriter::Write(aio::File*, std::vector<int, std::allocator<int> >, void*, unsigned long)': /home/bws/sandbox/aiofs/src/aio/thread_pool_writer.cc:59: undefined reference to `boost::condition_variable::notify_all()' /home/bws/sandbox/aiofs/src/aio/thread_pool_writer.cc:63: undefined reference to `boost::condition_variable::wait(boost::unique_lock<boost::mutex>&)' src/aio/thread_pool_writer.o: In function `aio::ThreadPoolWriter::threadWait()': /home/bws/sandbox/aiofs/src/aio/thread_pool_writer.cc:76: undefined reference to `boost::condition_variable::wait(boost::unique_lock<boost::mutex>&)' /home/bws/sandbox/aiofs/src/aio/thread_pool_writer.cc:110: undefined reference to `boost::condition_variable::notify_one()' Is condition variable in a different library? I am using the boost stuff distributed with Fedora 11: boost-1.37.0-7.fc11.x86_64 boost-devel-1.37.0-7.fc11.x86_64 Cheers, Brad

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Transfering the process state to another process
by Lloyd 18 Feb '10

18 Feb '10

Hi, We want to have a program which cannot be terminated by the user (even admin). I think the only way to do this is to write a watchdog process. So there will be a master and a slave process, the master will be the active process, and the slave keep on watching the master. I case if the master is terminated, the slave become master and initiates a new slave process. But we need to transfer (or share) the process state of "old master" with the "new master" (So that the new master can continue form where the old master has stopped). Is this possible with shared memory? Or is there is a better way? Thanks, Lloyd ______________________________________ Scanned and protected by Email scanner

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[1.35.0][OSX][iostreams] Exception thrown with utf8 filename
by Christophe Radondy 17 Feb '10

17 Feb '10

Hi, I try to do a cross-platform source code and I have this code. I compiled boost 1.35 in universal binaries on Mac OS 10.5.4 with intel platform (IMAC core 2 duo 3Ghz) The same code works on linux (Ubuntu 8.0.4 and debian) and windows platforms but on Mac OS 10.5 I have an exception in boost's libraries. We compile on universal binaries with -fexceptions options of g++ 4.0.1 (Apple). This is my code: <code> boost::filesystem::wpath unicode(L"abcdef\u0110"); boost::filesystem::ofstream file(unicode.string()); // throws Invalid Argument on Mac file << "abcdef" << endl; file.close(); <endcode/> If I do this, it works: <code> boost::filesystem::path utf8("abcdef\xC4\x90"); // \xC4\x90 == \u0110 boost::filesystem::ofstream file(utf8.string()); // works ok file << "abcdef" << endl; file.close(); <endcode/> When the ofstream is created, this function is executed and crashes when I use Unicode parameters : <code> unicode.external_file_string(); // throws uncaught exception of type boost::filesystem::basic_filesystem_error<boost::filesystem::basic_path<std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > - boost::filesystem::wpath::to_external conversion error: Invalid argument <endcode/> Do you have any idea? Is this a known bug? Did I miss a setting? Thanks for your help. Regards, Christophe.

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[Boost] Is this library availble for 64 bit?
by Jaiswal, Usha [OS-IE] 11 Feb '10

11 Feb '10

Is there any version of Boost for 64 bit.

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Serialization of a unordered_map
by Basti Korf 08 Feb '10

08 Feb '10

Hallo, I just wondered, why there is no possibility to serialize a unordered map. Since the STL map is serialized, i take the file for it and changed all maps to boost::unordered_map (multimap). Or is there a better way, i just did not see? Here is the code: #ifndef BOOST_SERIALIZATION_UNORDEREDMAP_HPP #define BOOST_SERIALIZATION_UNORDEREDMAP_HPP // MS compatible compilers support #pragma once #if defined(_MSC_VER) && (_MSC_VER >= 1020) # pragma once #endif /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8 // serialization/map.hpp: // serialization for stl map templates // (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . // Use, modification and distribution is subject to the Boost Software // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) // See http://www.boost.org for updates, documentation, and revision history. #include <boost/unordered_map.hpp> #include <boost/config.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/collections_save_imp.hpp> #include <boost/serialization/collections_load_imp.hpp> #include <boost/serialization/split_free.hpp> namespace boost { namespace serialization { template<class Archive, class Type, class Key, class Compare, class Allocator > inline void save( Archive & ar, const boost::unordered_map<Key, Type, Compare, Allocator> &t, const unsigned int /* file_version */ ){ boost::serialization::stl::save_collection< Archive, boost::unordered_map<Key, Type, Compare, Allocator> >(ar, t); } template<class Archive, class Type, class Key, class Compare, class Allocator > inline void load( Archive & ar, boost::unordered_map<Key, Type, Compare, Allocator> &t, const unsigned int /* file_version */ ){ boost::serialization::stl::load_collection< Archive, boost::unordered_map<Key, Type, Compare, Allocator>, boost::serialization::stl::archive_input_map< Archive, boost::unordered_map<Key, Type, Compare, Allocator> >, boost::serialization::stl::no_reserve_imp<boost::unordered_map< Key, Type, Compare, Allocator > > >(ar, t); } // split non-intrusive serialization function member into separate // non intrusive save/load member functions template<class Archive, class Type, class Key, class Compare, class Allocator > inline void serialize( Archive & ar, boost::unordered_map<Key, Type, Compare, Allocator> &t, const unsigned int file_version ){ boost::serialization::split_free(ar, t, file_version); } // multimap template<class Archive, class Type, class Key, class Compare, class Allocator > inline void save( Archive & ar, const boost::unordered_multimap<Key, Type, Compare, Allocator> &t, const unsigned int /* file_version */ ){ boost::serialization::stl::save_collection< Archive, boost::unordered_multimap<Key, Type, Compare, Allocator> >(ar, t); } template<class Archive, class Type, class Key, class Compare, class Allocator > inline void load( Archive & ar, boost::unordered_multimap<Key, Type, Compare, Allocator> &t, const unsigned int /* file_version */ ){ boost::serialization::stl::load_collection< Archive, boost::unordered_multimap<Key, Type, Compare, Allocator>, boost::serialization::stl::archive_input_multimap< Archive, boost::unordered_multimap<Key, Type, Compare, Allocator> >, boost::serialization::stl::no_reserve_imp< boost::unordered_multimap<Key, Type, Compare, Allocator> > >(ar, t); } // split non-intrusive serialization function member into separate // non intrusive save/load member functions template<class Archive, class Type, class Key, class Compare, class Allocator > inline void serialize( Archive & ar, boost::unordered_multimap<Key, Type, Compare, Allocator> &t, const unsigned int file_version ){ boost::serialization::split_free(ar, t, file_version); } } // serialization } // namespace boost #endif // BOOST_SERIALIZATION_UNORDEREDMAP_HPP Best regards, SK -- GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01

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multi_index_container assertion after crash
by Eli Zakashansky 26 Jan '10

26 Jan '10

Hi, I have an application which uses a persistent multi_index_container (I am using bip::managed_mapped_file && after openning the file I do "container = mappedFile->find_or_construct(...)"). I have an interesting behavior when my process crashes/stopped during massive use of the multi_index_container after the process restarts I don't experience any problems reading or inserting new elements to the container but if I try to erase elements or call mutli_index_container::clear (Debug mode only BOOST_MULTI_INDEX_ENABLE_SAFE_MODE is defined) an assertion pops up (safe_mode::Check_same_owner / safe_mode::Check_valid_iterator). At first I thought that this kind of assertion fails due to concurrency issue, but it is not the case (I verified that this data structure is not accessed from more than one thread at a time, during this time the container is locked). Does anyone has any idea what can cause this situation? Or has a resolution ? Thanks a lot in advance, Eli.

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[iterators][range][rangeex] range concatenation
by Dmitry Vinogradov 12 Jan '10

12 Jan '10

Is it possible with Boost (or RangeEx) to concatenate ranges? Sample usage: template <class Range> void process_range(Range const &); std::vector<foo> v = ...; std::list<foo> l = ...; process_range(concat(v, l));

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[Math/Statistical Distributions+Random] Random number generation
by Marco Guazzone 07 Jan '10

07 Jan '10

Hi all! I'm a "boost newbie" so sorry for too trivial questions. Just trying to use boost for some statistical experiments, involving statistical distribution fitting, quantile generation (for goodness-of-fit tests), random variate generation, and so on. . The "Math/Statistical Distribution" library is great and almost complete. But I'm just curious why the random number generation (provided by the "Random" lib) and this library have not been integrated. For instance, the boost::random::exponential_distribution and the boost::math::exponential_distribution are two different worlds. I think a function like this below would be very helpful: --- [snip] --- template <typename Generator, typename RealType, typename Policy> inline RealType rand(Generator& rng, const exponential_distribution<RealType, Policy>& dist) { return -1.0 / dist.lambda() * std::log(1.0-rng()); } --- [snip] --- or something similar (e.g., rand implemented as a class method) In this case only two objects are needed: * boost::random::mersenne_twister * boost::math::exponential_distribution Instead, actually I have to keep different objects. For instance, for the exponential distribution: * boost::random::exponential_distribution * boost::random::mersenne_twister * boost::random::variate_generator * boost::math::exponential_distribution Unluckely I can't use boost::math::exponential_distribution in place of boost::random::exponential_distribution since boost::random::variate_generator expects a specific interface for the distribution. Well, what is the rationale behind the choice of this separation? Do you think would be useful to provide this kind of integration? Thank you very much in advance!! Cheers -- Marco

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Re: [Boost-users] [unit_test_framework] checkpoints for BOOST_CHECK*?
by rozelak＠volny.cz 04 Jan '10

04 Jan '10

> > rozelak(a)volny.cz wrote: > >> rozelak(a)volny.cz wrote: > >> > >>> Is there a way how to achieve what I am looking > >>> for? > >>> >>> > >> Use BOOST_TEST_MESSAGE and set log level to message > >> >> > > > > Yes, I have read about this option and it works - > > thank you. I consider > > > it as not perfect, but working solution. > > > > However, I want to ask, if the idea of checkpoints > > could be generalised > > > and used during check failure printing as well (as > > has been suggested > > > in the example in my first post). > > I don't know boost source in depth, but it seems > > that BOOST_TEST_CHECKPOINT > > > just calls boost::unit_test::unit_test_log.set_checkpoint(...), > > > > > > > > which > > > stores the checkpoint info in unit_test_log (which > > is supposed to be > > > singleton). > > Would, therefore, be possible to print the checkpoint > > stored also when > > > test failure is printed? May I be helpfull somehow > > to do this? > > > > > Or is it against the idea of the checkpoints? > > > > I think the issue is that BOOST_CHECK and friends set > a checkpoint. > I see, you are right. It is set by BOOST_TEST_PASSPOINT() macro. Well, do you think, that it would be beneficial to define new macro, e.g. BOOST_TEST_FAILRECORD (please suggest a better name, if you have one)? The macro would be implemented in the way very similar to BOOST_TEST_CHECKPOINT, but the data "recorded" by the macro would be printed only when a testcase fails or an unexpected exception occurs. It also has the advantage, that when not used, it does not affect the current behaviour of boost. Is there a change to accept it in the boost test framework, if I try to implement it? Thank you for suggestions/comments, Dan

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[test] Unexpected Exceptions
by Florian Winter 03 Jan '10

03 Jan '10

Hi, What is the intended behavior of Boost.Test if an unexpected exception is thrown? Example: void do_not_throw() throw() { throw "unexpected"; } Some of my applications using Boost.Test seem exit with an error code of 0 (successful) if an unexpected exception is thrown. Is this the intended behavior? Best regards, fw

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