- Boost-users - lists.preview.boost.org

asio::io_service as a thread-pool executor
by aiooua 08 Sep '11

08 Sep '11

I'm trying to use boost::asio::io_service as a thread pool executor. Here's my attempt: ---- using std::vector; using boost::bind; using boost::thread; using boost::shared_ptr; using boost::asio::io_service; class executor { public: executor(size_t n): service_(n), work_(service_) { for (size_t i = 0; i < n; i++) { shared_ptr<thread> worker(new thread(bind(&io_service::run, &service_))); pool_.push_back(worker); } } ~executor() { service_.stop(); for (auto i = pool_.begin(); i != pool_.end(); ++i) { (*i)->join(); } } template<typename F> void submit(F task) { service_.post(task); } private: io_service service_; io_service::work work_; vector<shared_ptr<thread> > pool_; }; void work() {} void other_work(const char *c) {} struct functor_work { void operator()() {} }; auto lambda = [] {}; int main() { executor e(4); e.submit(work); e.submit(boost::bind(other_work, "input")); e.submit(functor_work()); e.submit(lambda); } ---- Is this usage correct or am I missing anything here? The bit I'm not sure about in particular is this: Is it guaranteed that the io_service::run will wait for the completion of the posted jobs (via io_service::post) after I have called io_service::stop? In other words, do I have to explicitly ensure that my executor instance lives at least as long as the last submitted job has finished? Or can I assume that io_service::run will only return after all its posted jobs have had a chance to finish? Thanks!

1 0

[Units] defining a derived dimension
by Michael Powell 08 Sep '11

08 Sep '11

I want to define a dimension stroke_rate, or flow_rate, for that matter. Not too out of the ordinary for our application. So I am starting with something like this for my dimensions. #include <boost/units/derived_dimension.hpp> #include <boost/units/physical_dimensions/length.hpp> #include <boost/units/physical_dimensions/time.hpp> typedef boost::units::derived_dimension<boost::units::dimensionless_type,1,boost::units::time_base_dimension,-1>::type stroke_rate_dimension; typedef boost::units::derived_dimension<boost::units::length_dimension,3,boost::units::time_dimension,-1>::type flow_rate_dimension; typedef boost::units::unit<ourns::units::stroke_rate_dimension,boost::units::si::system> stroke_rate; typedef boost::units::unit<ourns::units::flow_rate_dimension,boost::units::si::system> flow_rate; However, I am receiving compiler errors when I try and include the units, Error 1 error C2039: 'value' : is not a member of 'boost::units::detail::dimension_list_tag' C:\Source\Simulations\tools\boost-msvc90-pro\boost\mpl\aux_\preprocessed\plain\less.hpp 20 CS.Calculations.Managed Error 2 error C2065: 'value' : undeclared identifier C:\Source\Simulations\tools\boost-msvc90-pro\boost\mpl\aux_\preprocessed\plain\less.hpp 21 CS.Calculations.Managed Error 3 error C2039: 'value' : is not a member of 'boost::units::detail::dimension_list_tag' C:\Source\Simulations\tools\boost-msvc90-pro\boost\mpl\aux_\preprocessed\plain\less.hpp 21 CS.Calculations.Managed Error 4 error C2065: 'value' : undeclared identifier C:\Source\Simulations\tools\boost-msvc90-pro\boost\mpl\aux_\preprocessed\plain\less.hpp 22 CS.Calculations.Managed And so on along these lines. What am I doing wrong with the units and/or dimensions? This is quite similar to energy_density_dimension, for example. typedef derived_dimension<length_base_dimension,-1,mass_base_dimension,1,time_base_dimension,-2>::type energy_density_dimension; However, I am failing to see any appreciable difference. Any thoughts? Thanks, Michael

2 4

units length operator * / area
by Michael Powell 08 Sep '11

08 Sep '11

Units users, How do I define an operator* which takes a quantity<length>,quantity<length> and returns a quantity<area>? This doesn't seem to be defined in the boost::units, which somewhat surprises me. How do we make something like that part of the core definition? Thanks, Michael

1 1

Unicode support in boost?
by code 08 Sep '11

08 Sep '11

Hi, Can someone tell me how much Boost supports Uincode? Thank you

5 10

Wave Linker Error
by Alexander Feldman 08 Sep '11

08 Sep '11

Gentlemen, I'm getting the following linker error: /tmp/ccTiqxQC.o: In function `boost::wave::cpplexer::lex_input_interface<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char> >, char*> > > > >* boost::wave::cpplexer::lex_input_interface_generator<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char> >, char*> > > > >::new_lexer<boost::spirit::classic::position_iterator<boost::spirit::basic_istream_iterator<char, std::char_traits<char> >, boost::spirit::classic::file_position_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::classic::nil_t> >(boost::spirit::classic::position_iterator<boost::spirit::basic_istream_iterator<char, std::char_traits<char> >, boost::spirit::classic::file_position_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::classic::nil_t> const&, boost::spirit::classic::position_iterator<boost::spirit::basic_istream_iterator<char, std::char_traits<char> >, boost::spirit::classic::file_position_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::classic::nil_t> const&, boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char> >, char*> > > const&, boost::wave::language_support)': wave+spirit.cpp:(.text._ZN5boost4wave8cpplexer29lex_input_interface_generatorINS1_9lex_tokenINS0_4util13file_positionINS4_11flex_stringIcSt11char_traitsIcESaIcENS4_9CowStringINS4_22AllocatorStringStorageIcS9_EEPcEEEEEEEEE9new_lexerINS_6spirit7classic17position_iteratorINSK_22basic_istream_iteratorIcS8_EENSL_18file_position_baseISsEENSL_5nil_tEEEEEPNS1_19lex_input_interfaceISH_EERKT_SY_RKSG_NS0_16language_supportE[boost::wave::cpplexer::lex_input_interface<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char> >, char*> > > > >* boost::wave::cpplexer::lex_input_interface_generator<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char> >, char*> > > > >::new_lexer<boost::spirit::classic::position_iterator<boost::spirit::basic_istream_iterator<char, std::char_traits<char> >, boost::spirit::classic::file_position_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::classic::nil_t> >(boost::spirit::classic::position_iterator<boost::spirit::basic_istream_iterator<char, std::char_traits<char> >, boost::spirit::classic::file_position_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::classic::nil_t> const&, boost::spirit::classic::position_iterator<boost::spirit::basic_istream_iterator<char, std::char_traits<char> >, boost::spirit::classic::file_position_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::classic::nil_t> const&, boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char> >, char*> > > const&, boost::wave::language_support)]+0x13): undefined reference to `boost::wave::cpplexer::new_lexer_gen<boost::spirit::classic::position_iterator<boost::spirit::basic_istream_iterator<char, std::char_traits<char> >, boost::spirit::classic::file_position_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::classic::nil_t>, boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char> >, char*> > >, boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char> >, char*> > > > >::new_lexer(boost::spirit::classic::position_iterator<boost::spirit::basic_istream_iterator<char, std::char_traits<char> >, boost::spirit::classic::file_position_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::classic::nil_t> const&, boost::spirit::classic::position_iterator<boost::spirit::basic_istream_iterator<char, std::char_traits<char> >, boost::spirit::classic::file_position_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::classic::nil_t> const&, boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char> >, char*> > > const&, boost::wave::language_support)' collect2: ld returned 1 exit status -------------------------- Trying to link: std::ifstream instream(argv[1]); std::string instring; if (!instream.is_open()) { std::cerr << "Could not open input file: " << argv[1] << std::endl; return -2; } instream.unsetf(std::ios::skipws); typedef boost::spirit::classic::position_iterator<boost::spirit::istream_iterator> pos_iterator; boost::spirit::istream_iterator begin1(instream); boost::spirit::istream_iterator end1; pos_iterator begin(begin1, end1, argv[1]); pos_iterator end; typedef boost::wave::cpplexer::lex_token<> token_type; typedef boost::wave::cpplexer::lex_iterator<token_type> lex_iterator_type; typedef boost::wave::context<pos_iterator, lex_iterator_type> context_type; context_type ctx(begin, end, argv[1]); context_type::iterator_type preprocessedInputBegin = ctx.begin(); context_type::iterator_type preprocessedInputEnd = ctx.end(); --------------- Any ideas what am I missing? Thanks, -- Alex

2 2

[Serialization]Serialization of pointer to pointers
by Kangkook Jee 08 Sep '11

08 Sep '11

Hi, all I'm trying to use boost library for serialization of my program which contains many custom class definitions. However, I can't figure out how to handle a class member which is *pointer to pointers* such as 'a' from the following code snippet. class B { A** a; friend class boost::serialization::access; … template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & a: …. Above code fails to be compiled with the following error message. … /usr/include/boost/archive/detail/oserializer.hpp:148:5: instantiated from ‘void boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::archive::text_oarchive, T = A*]’ serial0.cpp:118:1: instantiated from here /usr/include/boost/serialization/access.hpp:118:9: error: request for member ‘serialize’ in ‘t’, which is of non-class type ‘A*’ Do we have a typical way to handle a such case? I spend some time to find a solution from the web and tutorials but I couldn't. I'm new to the boost library and your helps will be greatly appreciated. Thanks, Kangkook

2 1

Re: [Boost-users] [!! SPAM] Wave Preprocessor without Using a Lexer
by Hartmut Kaiser 08 Sep '11

08 Sep '11

> Does anybody know how to use the wave preprocessor *without* using the cpp > lexer? That does not work. The Wave parser depends on getting tokenized input. This is by design and probably different from any other preprocessor. Those are normally implemented on the character level. Wave is not, it's a tokenizing preprocessor. Regards Hartmut --------------- http://boost-spirit.com

1 0

Re: [Boost-users] Unicode support in boost?
by code 07 Sep '11

07 Sep '11

Hi Vicente, Thank you for the reply. When I took a look at codes under "thread', I found there are some places where BOOST_NO_ANSI_APIS is related ( for example in once.hpp ) #ifdef BOOST_NO_ANSI_APIS typedef wchar_t once_char_type #else typedef char once_char_type #endif There is no relation between both librairies that I'm aware of. If you are more explicit with the problem you have, maybe we can help you better. Best, Vicente BTW, don't top post and please send message in text only mode.

1 0

boost::xpressive Error 2668 call to amibous function
by Jens Saathoff 07 Sep '11

07 Sep '11

Hi! I get the error C2668 if i try to compile the following code(xpressive example from docs): #include <string> #include <iostream> #include <boost/xpressive/xpressive.hpp> #include <boost/xpressive/regex_actions.hpp> #include <map> using namespace boost::xpressive; int main() { std::map<std::string, int> result; std::string str("aaa=>1 bbb=>23 ccc=>456"); // Match a word and an integer, separated by =>, // and then stuff the result into a std::map<> sregex pair = ( (s1= +_w) >> "=>" >> (s2= +_d) )[ ref(result)[s1] = as<int>(s2) ]; // Match one or more word/integer pairs, separated // by whitespace. sregex rx = pair >> *(+_s >> pair); if(regex_match(str, rx)) { std::cout << result["aaa"] << '\n'; std::cout << result["bbb"] << '\n'; std::cout << result["ccc"] << '\n'; } return 0; } The complete error: D:\Projekte\xpressive-test\main.cpp:29: Fehler:C2668: 'boost::xpressive::ref' : ambiguous call to overloaded function D:\Frameworks\boost\boost_147\boost/xpressive/regex_actions.hpp(850): could be 'const boost::xpressive::reference<T> boost::xpressive::ref<std::map<_Kty,_Ty>>(T &)' with [ T=std::map<std::string,int>, _Kty=std::string, _Ty=int ] C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\INCLUDE\xrefwrap(439): or 'std::tr1::reference_wrapper<_Ty> std::tr1::ref<std::map<_Kty,int>>(_Ty &)' [found using argument-dependent lookup] with [ _Ty=std::map<std::string,int>, _Kty=std::string ] while trying to match the argument list '(std::map<_Kty,_Ty>)' with [ _Kty=std::string, _Ty=int ] What's the problem here? Thank you very much!

2 2

[boost.thread?][1.46.1] "memory clobbered before allocated block"
by Igor Gorbunov 07 Sep '11

07 Sep '11

Hello, I've ran across a strange bug. GCCs mcheck reports "memory clobbered before allocated block". Reproducible (not every run) with the following test program when executed from gdb: ----- #include <boost/thread.hpp> void proc_func(){ std::vector<int> v1(1024); } int main() { std::vector<int> v2(1024); boost::thread t1(proc_func); t1.join(); } ----- The same test program runs fine (or I'm not been able to trigger this bug) when recompiled with std.thread. I'm in doubt that there is a bug in boost.thread, so maybe build system misconfiguration or gdb bug? stack trace: /home/gie/work/tests/memd1/debug/test [18157] [cores: 0] Thread [2] 18160 [core: 0] (Suspended : Signal : SIGABRT:Aborted) *__GI_raise() at raise.c:64 0x7ffff70d0405 *__GI_abort() at abort.c:92 0x7ffff70d3680 __libc_message() at libc_fatal.c:189 0x7ffff7106dbb *__GI___libc_fatal() at libc_fatal.c:200 0x7ffff7106e9e mabort() at mcheck.c:366 0x7ffff7117aea checkhdr() at mcheck.c:117 0x7ffff71172eb freehook() at mcheck.c:190 0x7ffff71175dc __nptl_deallocate_tsd() at pthread_create.c:155 0x7ffff6e88129 start_thread() at pthread_create.c:311 0x7ffff6e88b4e clone() at clone.S:112 0x7ffff717336d 0x0 Thread [1] 18157 [core: 0] (Suspended : Container) pthread_join() at pthread_join.c:89 0x7ffff6e89e65 boost::thread::join() at thread.cpp:234 0x7ffff7bd2bba main() at main.cpp:12 0x409212 build log: /usr/bin/make all /usr/bin/cmake -H/home/gie/work/tests/memd1/src -B/home/gie/work/tests/memd1/debug --check-build-system CMakeFiles/Makefile.cmake 0 /usr/bin/cmake -E cmake_progress_start /home/gie/work/tests/memd1/debug/CMakeFiles /home/gie/work/tests/memd1/debug/CMakeFiles/progress.marks /usr/bin/make -f CMakeFiles/Makefile2 all make[1]: Entering directory `/home/gie/work/tests/memd1/debug' /usr/bin/make -f CMakeFiles/test.dir/build.make CMakeFiles/test.dir/depend make[2]: Entering directory `/home/gie/work/tests/memd1/debug' cd /home/gie/work/tests/memd1/debug && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/gie/work/tests/memd1/src /home/gie/work/tests/memd1/src /home/gie/work/tests/memd1/debug /home/gie/work/tests/memd1/debug /home/gie/work/tests/memd1/debug/CMakeFiles/test.dir/DependInfo.cmake --color= make[2]: Leaving directory `/home/gie/work/tests/memd1/debug' /usr/bin/make -f CMakeFiles/test.dir/build.make CMakeFiles/test.dir/build make[2]: Entering directory `/home/gie/work/tests/memd1/debug' /usr/bin/cmake -E cmake_progress_report /home/gie/work/tests/memd1/debug/CMakeFiles 1 [100%] Building CXX object CMakeFiles/test.dir/main.cpp.o /usr/bin/c++ -g -I/home/gie/work/tests/memd1/debug -std=c++0x -Wall -Wextra -pedantic -o CMakeFiles/test.dir/main.cpp.o -c /home/gie/work/tests/memd1/src/main.cpp Linking CXX executable test /usr/bin/cmake -E cmake_link_script CMakeFiles/test.dir/link.txt --verbose=1 /usr/bin/c++ -g CMakeFiles/test.dir/main.cpp.o -o test -rdynamic -lmcheck -lboost_thread-mt make[2]: Leaving directory `/home/gie/work/tests/memd1/debug' /usr/bin/cmake -E cmake_progress_report /home/gie/work/tests/memd1/debug/CMakeFiles 1 [100%] Built target test make[1]: Leaving directory `/home/gie/work/tests/memd1/debug' /usr/bin/cmake -E cmake_progress_start /home/gie/work/tests/memd1/debug/CMakeFiles 0 -- With best regards, Igor.

1 0