September 2009 - Boost-users

[thread] multiple producers, single consumer - bosst-specific and generic questions
by Julien Claassen 11 Sep '09

11 Sep '09

Hello everyone! Thanks for all the help I already got. And excuse my poor understanding of of multithreading. I would like to implement a "multiple producer single consumer" pattern. My current solution is working with signals, which, I think is not very efficient. And also it doesn't work properly with the code I have, (see end of this mail). But besides that problem I have a generic question. If I worked with buffers and mutex, there are two choices, it seems: 1. Use one buffer, at the cost of deletion from the middle, when one producer terminates (so consumer won't communicate with a dead thread). 2. Have a buffer per producer, but also have a synchronisation per buffer and the consumer must look in several buffers, plus I don't know, how many producers there will be. This all should lead to a user interface, with different input-methods. So what would you suggest? It must be speedy and very CPU friendly. Thanks in advance for consideration. I'd also be happy for some suggested reading. Only one thing: printed books or documents in non-plain-text form besides .doc, .pdf and .ps aren't of any use to me, for I'm blind and using Linux text based environment. Kindest regards (For code, see below) Julien *** CODE SNIPPET *** boost::mutex my_mtx; // the Mutex for passing on events/chars // assumptions: // the following variables are passed to the Input object as a reference // int& its_q_size; // condition& its_in_condition; // condition& its_out_condition; // boost::signals2::signal<void (char)>& its_sig; void Input::run() { char input; boost::unique_lock<boost::mutex> lk(my_mtx); while (input != 'q') { cin >> input; while (its_q_size != 0) { its_in_condition.wait(lk); } its_sig(input); its_q_size = 0; its_out_condition.notify_all(); } } void Controller::run() { sig_t sig; // passed as its_sig condition in_condition, out_condition; // passed respectively as // its_incondition and its_out_condition int q_size = 0; // passed as char input; boost::unique_lock<boost::mutex> lk(my_mtx); Input *ip = new Input(in_condition,out_condition,sig,q_size); ip->connect(bind(&Controller::slot1, this, _1)); ip->connect(boost::bind(&Controller::slot2, this, _1)); thread runner(boost::bind(&Input::run, ip)); // why no third param _1 // here? With one it won't compiler! while (input != 'q') { while (q_size != 1) { out_condition.wait(lk); } // Do something with data received from the slots q_size = 0; in_condition.notify_all(); } runner.join(); } *** END OF CODE *** Effects: Read once, send signal, read again print info from first read and send signal again. Only really sync, when q is pressed. I expect due to runner-thread ending. -------- Music was my first love and it will be my last (John Miles) ======== FIND MY WEB-PROJECT AT: ======== http://ltsb.sourceforge.net the Linux TextBased Studio guide ======= AND MY PERSONAL PAGES AT: ======= http://www.juliencoder.de

4 8

boost::options, boost::shared_ptr with Intel C++ Compiler 11.x
by Marat Abrarov 11 Sep '09

11 Sep '09

Hi Boost C++ Libraries developers and users! I'm using boost 1.40. I have a project at http://sourceforge.net/projects/asio-samples/ (only SVN trunk is available now) It uses MS C++ Compiler (9.0 SP1 - MS Visual Studio 2008 SP1) and boost::program_options (+ boost::asio + boost::...). When I switched that project (I mean "echo_server") to Intel C++ Compiler 11.1.038 (I tried all 11.1.x) and built debug version (Debug Win32) (with addition of option /vmg to compiler command line - stupid Intel :) it works fine except shared_ptr-to-bool cast (for example: include/ma/echo/server/session_manager.hpp: 319). This issue I found only at "Debug Win32" build mode - at "Debug x64" all is fine and the built executable (echo_server.exe) works right. When I build "Release Win32" or "Release x64", the built executable don't work at all - it fails somewhere at the boost::program_options (I think at std::vector<std::string>::operator= or std::vector<std::string> copy-constructor). Does anybody: 1) tried to use boost::shared_ptr 2) tried to use boost::prorgam_options with Intel C++ Compiler 11.1.x? P.S. - If I change boost_1_40_0\boost\smart_ptr\detail\operator_bool.hpp: 9 - add "|| defined (BOOST_INTEL)" - then shared_ptr-to-bool cast works fine (Win32/x64 Debug/Release) Regards, Marat Abrarov.

1 0

Re: [Boost-users] [units,typeof] meta_multiply units?
by Rupert Mazzucco 11 Sep '09

11 Sep '09

> say I have a functor F which takes an argument of type > > F::arg_type = quantity<time> > > and returns a value of type > > F::ret_type = quantity<velocity> > > Now I want to write an integration function, which should > return the correct type, something like > > template<class F> > F::ret_type*F::arg_type // only conceptually > integrate(F& f, typename F::arg_type a, typename F::arg_type b); > > so instantiating this with the above functor should produce a > return type quantity<time*velocity==length>. How can I combine > F::arg_type and F::ret_type to produce the correct return type > for the function template? Attempted to solve this with the help of boost.typeof: template<class F> BOOST_TYPEOF_TPL(F::ret_type() * F::arg_type()) integrate(F& f, typename F::arg_type a, typename F::arg_type b); but MVC9 produces a error C2064: term does not evaluate to a function taking 0 arguments for the default constructor calls in the macro argument. Any ideas welcome. Thanks -- Rupert Mazzucco <mazzucco(a)iiasa.ac.at> Research Scholar, Evolution and Ecology Program IIASA - Institute for Applied Systems Analysis Schlossplatz 1, 2361 Laxenburg, Austria Phone: +43 2236 807 522 Fax: +43 2236 713 13

2 1

[bzip2 iostreams] [serialization] How to serialize an object into a bzip2 file and vice versa.
by Sebastian Korf 11 Sep '09

11 Sep '09

Hi. I right now managed to store objects via serialization onto harddisk. Because these files are still big and i used the textstream to serialize the object i decided to shrink the files...so far the plan :) I rebuild the iostreams with bzip support (that was also quite a pain ;) and now i can decompress a simple precompressed text file easily: int main() { using namespace std; using namespace boost::iostreams; ifstream file("E:\\test.txt.bz2", ios_base::in | ios_base::binary); filtering_streambuf<input> in; in.push(bzip2_decompressor()); in.push(file); ofstream fileOutput("E:\\test2.text"); copy(in,fileOutput); } But if i try to decompress a file which i serialized, bzip just runs forever doing nothing. SO my first question is, if someone knows why the serialized compressed files can not be decompressed. My second question is, if it is possible to serialize directly into a compressed bz2 file. I really looked around in the internet but still cannot get a clue so please respond. http://www.codeproject.com/KB/stl/zipstream.aspx?fid=16084&df=90&mpp=25&sor… http://lists.boost.org/Archives/boost/2003/10/53755.php Thanks, SK

2 1

[interprocess] named_condition wait question
by Moritz 11 Sep '09

11 Sep '09

Hi, I am using boost::interprocess::named_condition to synchronize 1-to-many communication. The reading processes are waiting on a named_condition that indicates the possibility to read. Problem is now that they wait until doomsday if no one triggers notify. So they can't quit the reading process themselves. Now I am thinking about using timed_wait instead of wait. That means checking some other exit-condition periodically. The question is now if the reader can miss the notify while he is checking that exit-condition? This is crucial to me because the readers have to notice new data in a shared memory segment. Thanks in advance. Problematic code: named_upgradable_mutex mtx; named_condition cond; { sharable_lock<named_upgradable_mutex> lock(mtx); while(true) { read(); cond.wait(lock); } } Possible solution?: named_upgradable_mutex mtx; named_condition cond; { sharable_lock<named_upgradable_mutex> lock(mtx); while(true) { read(); while (true) { if (cond.timed_wait(lock, 1 second)) break; else check_for_thread_interruption() } } }

2 2

iostreams or sockets?
by pedro chaparro 11 Sep '09

11 Sep '09

hi, in the asio examples there are two daytime examples , one use iostreams and the other one sockets, what criteria do i have to follows to choose one or the other? i've not really clear this concept? thanks -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

2 1

help needed with bzip2/zlib with boost
by ChristinaDRS 11 Sep '09

11 Sep '09

Hello, I am trying to get the code below to compile in Visual Studios without luck. I downloaded and built the seperate zlib and bzip2 libraries and renamed them to: libboost_zlib-vc90-mt-gd-1_39.lib libboost_bzip2-vc90-mt-gd-1_39.lib because I was getting linking errors that I was missing thes elibs. but I get a bunch of unresolved linking errors now.. any idea what I might be doing wrong? I am guessing they must be needed to be built actually by boost? Is there any instructions on how to do this? Thanks!!! 1>------ Build started: Project: BoostCompression, Configuration: Debug Win32 ------ 1>Linking... 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::zlib::default_compression" (?default_compression@zlib@iostreams@boost@@3HB) 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::zlib::deflated" (?deflated@zlib@iostreams@boost@@3HB) 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::zlib::default_strategy" (?default_strategy@zlib@iostreams@boost@@3HB) 1>main.obj : error LNK2019: unresolved external symbol "int __cdecl test_main(int,char * * const)" (?test_main@@YAHHQAPAD@Z) referenced in function "public: int __thiscall boost::minimal_test::caller::operator()(void)" (??Rcaller@minimal_test@boost@@QAEHXZ) 1>main.obj : error LNK2019: unresolved external symbol "protected: __thiscall boost::iostreams::detail::bzip2_base::~bzip2_base(void)" (??1bzip2_base@detail@iostreams@boost@@IAE@XZ) referenced in function "public: __thiscall boost::iostreams::detail::bzip2_compressor_impl<class std::allocator<char> >::~bzip2_compressor_impl<class std::allocator<char> >(void)" (??1?$bzip2_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE@XZ) 1>main.obj : error LNK2019: unresolved external symbol "protected: __thiscall boost::iostreams::detail::zlib_base::~zlib_base(void)" (??1zlib_base@detail@iostreams@boost@@IAE@XZ) referenced in function __unwindfunclet$??0?$zlib_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE@ABUzlib_params@23@@Z$0 1>main.obj : error LNK2019: unresolved external symbol "protected: __thiscall boost::iostreams::detail::zlib_base::zlib_base(void)" (??0zlib_base@detail@iostreams@boost@@IAE@XZ) referenced in function "public: __thiscall boost::iostreams::detail::zlib_compressor_impl<class std::allocator<char> >::zlib_compressor_impl<class std::allocator<char> >(struct boost::iostreams::zlib_params const &)" (??0?$zlib_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE@ABUzlib_params@23@@Z) 1>main.obj : error LNK2019: unresolved external symbol "protected: void __thiscall boost::iostreams::detail::zlib_base::reset(bool,bool)" (?reset@zlib_base@detail@iostreams@boost@@IAEX_N0@Z) referenced in function "public: __thiscall boost::iostreams::detail::zlib_compressor_impl<class std::allocator<char> >::~zlib_compressor_impl<class std::allocator<char> >(void)" (??1?$zlib_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE@XZ) 1>main.obj : error LNK2019: unresolved external symbol "protected: __thiscall boost::iostreams::detail::bzip2_base::bzip2_base(struct boost::iostreams::bzip2_params const &)" (??0bzip2_base@detail@iostreams@boost@@IAE@ABUbzip2_params@23@@Z) referenced in function "public: __thiscall boost::iostreams::detail::bzip2_compressor_impl<class std::allocator<char> >::bzip2_compressor_impl<class std::allocator<char> >(struct boost::iostreams::bzip2_params const &)" (??0?$bzip2_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE@ABUbzip2_params@23@@Z) 1>main.obj : error LNK2019: unresolved external symbol "private: void __thiscall boost::iostreams::detail::zlib_base::do_init(struct boost::iostreams::zlib_params const &,bool,void * (__cdecl*)(void *,unsigned int,unsigned int),void (__cdecl*)(void *,void *),void *)" (?do_init@zlib_base@detail@iostreams@boost@@AAEXABUzlib_params@34@_NP6APAXPAXII@ZP6AX22@Z2@Z) referenced in function "protected: void __thiscall boost::iostreams::detail::zlib_base::init<class std::allocator<char> >(struct boost::iostreams::zlib_params const &,bool,struct boost::iostreams::detail::zlib_allocator<class std::allocator<char>,class std::allocator<char> > &)" (??$init@V?$allocator@D@std@@@zlib_base@detail@iostreams@boost@@IAEXABUzlib_params@23@_NAAU?$zlib_allocator@V?$allocator@D@std@@V12@@123@@Z) 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::zlib::stream_end" (?stream_end@zlib@iostreams@boost@@3HB) 1>main.obj : error LNK2019: unresolved external symbol "public: static void __cdecl boost::iostreams::zlib_error::check(int)" (?check@zlib_error@iostreams@boost@@SAXH@Z) referenced in function "public: bool __thiscall boost::iostreams::detail::zlib_compressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$zlib_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2019: unresolved external symbol "protected: void __thiscall boost::iostreams::detail::zlib_base::after(char const * &,char * &,bool)" (?after@zlib_base@detail@iostreams@boost@@IAEXAAPBDAAPAD_N@Z) referenced in function "public: bool __thiscall boost::iostreams::detail::zlib_compressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$zlib_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2019: unresolved external symbol "protected: int __thiscall boost::iostreams::detail::zlib_base::deflate(int)" (?deflate@zlib_base@detail@iostreams@boost@@IAEHH@Z) referenced in function "public: bool __thiscall boost::iostreams::detail::zlib_compressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$zlib_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::zlib::no_flush" (?no_flush@zlib@iostreams@boost@@3HB) 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::zlib::finish" (?finish@zlib@iostreams@boost@@3HB) 1>main.obj : error LNK2019: unresolved external symbol "protected: void __thiscall boost::iostreams::detail::zlib_base::before(char const * &,char const *,char * &,char *)" (?before@zlib_base@detail@iostreams@boost@@IAEXAAPBDPBDAAPADPAD@Z) referenced in function "public: bool __thiscall boost::iostreams::detail::zlib_compressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$zlib_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::bzip2::stream_end" (?stream_end@bzip2@iostreams@boost@@3HB) 1>main.obj : error LNK2019: unresolved external symbol "public: static void __cdecl boost::iostreams::bzip2_error::check(int)" (?check@bzip2_error@iostreams@boost@@SAXH@Z) referenced in function "public: bool __thiscall boost::iostreams::detail::bzip2_compressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$bzip2_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2019: unresolved external symbol "protected: void __thiscall boost::iostreams::detail::bzip2_base::after(char const * &,char * &)" (?after@bzip2_base@detail@iostreams@boost@@IAEXAAPBDAAPAD@Z) referenced in function "public: bool __thiscall boost::iostreams::detail::bzip2_compressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$bzip2_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2019: unresolved external symbol "protected: int __thiscall boost::iostreams::detail::bzip2_base::compress(int)" (?compress@bzip2_base@detail@iostreams@boost@@IAEHH@Z) referenced in function "public: bool __thiscall boost::iostreams::detail::bzip2_compressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$bzip2_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::bzip2::run" (?run@bzip2@iostreams@boost@@3HB) 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::bzip2::finish" (?finish@bzip2@iostreams@boost@@3HB) 1>main.obj : error LNK2019: unresolved external symbol "protected: void __thiscall boost::iostreams::detail::bzip2_base::before(char const * &,char const *,char * &,char *)" (?before@bzip2_base@detail@iostreams@boost@@IAEXAAPBDPBDAAPADPAD@Z) referenced in function "public: bool __thiscall boost::iostreams::detail::bzip2_compressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$bzip2_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2019: unresolved external symbol "protected: int __thiscall boost::iostreams::detail::zlib_base::inflate(int)" (?inflate@zlib_base@detail@iostreams@boost@@IAEHH@Z) referenced in function "public: bool __thiscall boost::iostreams::detail::zlib_decompressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$zlib_decompressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2001: unresolved external symbol "int const boost::iostreams::zlib::sync_flush" (?sync_flush@zlib@iostreams@boost@@3HB) 1>main.obj : error LNK2019: unresolved external symbol "protected: int __thiscall boost::iostreams::detail::bzip2_base::decompress(void)" (?decompress@bzip2_base@detail@iostreams@boost@@IAEHXZ) referenced in function "public: bool __thiscall boost::iostreams::detail::bzip2_decompressor_impl<class std::allocator<char> >::filter(char const * &,char const *,char * &,char *,bool)" (?filter@?$bzip2_decompressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAE_NAAPBDPBDAAPADPAD_N@Z) 1>main.obj : error LNK2019: unresolved external symbol "protected: void __thiscall boost::iostreams::detail::bzip2_base::end(bool)" (?end@bzip2_base@detail@iostreams@boost@@IAEX_N@Z) referenced in function "public: void __thiscall boost::iostreams::detail::bzip2_compressor_impl<class std::allocator<char> >::close(void)" (?close@?$bzip2_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QAEXXZ) 1>main.obj : error LNK2019: unresolved external symbol "private: void __thiscall boost::iostreams::detail::bzip2_base::do_init(bool,void * (__cdecl*)(void *,int,int),void (__cdecl*)(void *,void *),void *)" (?do_init@bzip2_base@detail@iostreams@boost@@AAEX_NP6APAXPAXHH@ZP6AX11@Z1@Z) referenced in function "protected: void __thiscall boost::iostreams::detail::bzip2_base::init<class std::allocator<char> >(bool,struct boost::iostreams::detail::bzip2_allocator<class std::allocator<char>,class std::allocator<char> > &)" (??$init@V?$allocator@D@std@@@bzip2_base@detail@iostreams@boost@@IAEX_NAAU?$bzip2_allocator@V?$allocator@D@std@@V12@@123@@Z) 1>D:\Debug\BoostCompression.exe : fatal error LNK1120: 29 unresolved externals [main.cpp] -------------------------------------------------------------------------------- #include <iostream> #include <sstream> #include <boost/assign/list_of.hpp> #include <boost/date_time/posix_time/posix_time.hpp> #include <boost/foreach.hpp> #include <boost/format.hpp> #include <boost/lexical_cast.hpp> #include <boost/numeric/conversion/cast.hpp> #include <boost/test/minimal.hpp> #include <boost/iostreams/copy.hpp> #include <boost/iostreams/device/back_inserter.hpp> #include <boost/iostreams/filter/bzip2.hpp> #include <boost/iostreams/filter/zlib.hpp> #include <boost/iostreams/filtering_stream.hpp> enum CompressionScheme { NO_COMPRESSION, ZLIB_COMPRESSION, BZIP2_COMPRESSION }; typedef boost::posix_time::ptime TimeType; //---------------------------------------------------------------------------- void add_compressor ( boost::iostreams::filtering_streambuf<boost::iostreams::output>& out, CompressionScheme scheme ) { switch (scheme) { case ZLIB_COMPRESSION: { out.push(boost::iostreams::zlib_compressor()); break; } case BZIP2_COMPRESSION: { out.push(boost::iostreams::bzip2_compressor()); break; } default: { break; } } } //---------------------------------------------------------------------------- void add_decompressor ( boost::iostreams::filtering_streambuf<boost::iostreams::input>& in, CompressionScheme scheme ) { switch (scheme) { case ZLIB_COMPRESSION: { in.push(boost::iostreams::zlib_decompressor()); break; } case BZIP2_COMPRESSION: { in.push(boost::iostreams::bzip2_decompressor()); break; } default: { break; } } } //---------------------------------------------------------------------------- std::string compress ( const std::string& data ) { std::stringstream compressed; std::stringstream decompressed; decompressed << data; boost::iostreams::filtering_streambuf<boost::iostreams::input> out; out.push(boost::iostreams::zlib_compressor()); out.push(decompressed); boost::iostreams::copy(out, compressed); return compressed.str(); } //---------------------------------------------------------------------------- std::string compress1 ( const std::string& data, CompressionScheme scheme ) { std::string compressed; boost::iostreams::filtering_streambuf<boost::iostreams::output> out; add_compressor(out, scheme); out.push(boost::iostreams::back_inserter(compressed)); boost::iostreams::copy(boost::make_iterator_range(data), out); return compressed; } //---------------------------------------------------------------------------- void compress2 ( const std::string& data, std::string& buffer, CompressionScheme scheme ) { buffer.clear(); boost::iostreams::filtering_streambuf<boost::iostreams::output> out; add_compressor(out, scheme); out.push(boost::iostreams::back_inserter(buffer)); boost::iostreams::copy(boost::make_iterator_range(data), out); } //---------------------------------------------------------------------------- std::string decompress ( const std::string& data ) { std::stringstream compressed; std::stringstream decompressed; compressed << data; boost::iostreams::filtering_streambuf<boost::iostreams::input> in; in.push(boost::iostreams::zlib_decompressor()); in.push(compressed); boost::iostreams::copy(in, decompressed); return decompressed.str(); } //---------------------------------------------------------------------------- std::string decompress1 ( const std::string& data, CompressionScheme scheme ) { boost::iostreams::filtering_streambuf<boost::iostreams::input> in; add_decompressor(in, scheme); in.push(boost::make_iterator_range(data)); std::string decompressed; boost::iostreams::copy(in, boost::iostreams::back_inserter(decompressed)); return decompressed; } //---------------------------------------------------------------------------- void decompress2 ( const std::string& buffer, std::string& data, CompressionScheme scheme ) { boost::iostreams::filtering_streambuf<boost::iostreams::input> in; add_decompressor(in, scheme); in.push(boost::make_iterator_range(buffer)); data.clear(); boost::iostreams::copy(in, boost::iostreams::back_inserter(data)); } //---------------------------------------------------------------------------- TimeType current_time ( ) { return boost::posix_time::microsec_clock::local_time(); } //---------------------------------------------------------------------------- double elapsed_seconds ( const TimeType& start_time ) { static const double MSEC_PER_SEC = 1000.0; TimeType end_time = current_time(); boost::posix_time::time_duration elapsed = end_time - start_time; return boost::numeric_cast<double>(elapsed.total_milliseconds()) / MSEC_PER_SEC; } //---------------------------------------------------------------------------- int test_main ( int /*argc*/, char* /*argv*/[] ) { const int NUM_ITERATIONS = 10000; const std::string send_data = "boo! how are you?"; const std::string base_statement = "ALGO %|1$-3s|: %2% cycles took %|3$0.3f| seconds"; double t0; // Try original algorithm { const std::string time_statement = base_statement + " (Original)\n"; TimeType start_time = current_time(); std::string received_data; for (int i = 0; i < NUM_ITERATIONS; ++i) { const std::string buffer = compress(send_data); received_data = decompress(buffer); } BOOST_CHECK(send_data == received_data); t0 = elapsed_seconds(start_time); std::cout << (boost::format(time_statement) % 0 % NUM_ITERATIONS % t0); } const std::string improvement_statement = base_statement + " (Improvement %|4$5.2f| %%)\n"; typedef std::vector<CompressionScheme> SchemeVectorType; const SchemeVectorType schemes = boost::assign::list_of(NO_COMPRESSION)(ZLIB_COMPRESSION)(BZIP2_COMPRESSION); // Try new algorithm 1 BOOST_FOREACH(CompressionScheme scheme, schemes) { TimeType start_time = current_time(); std::string received_data; for (int i = 0; i < NUM_ITERATIONS; ++i) { const std::string buffer = compress1(send_data, scheme); received_data = decompress1(buffer, scheme); } BOOST_CHECK(send_data == received_data); const std::string algo = std::string("1,") + boost::lexical_cast<std::string>(scheme); const double e = elapsed_seconds(start_time); const double improvement = ((t0 - e) / t0) * 100.0; std::cout << (boost::format(improvement_statement) % algo % NUM_ITERATIONS % e % improvement); } // Try new algorithm 2 BOOST_FOREACH(CompressionScheme scheme, schemes) { TimeType start_time = current_time(); std::string received_data; for (int i = 0; i < NUM_ITERATIONS; ++i) { std::string buffer; compress2(send_data, buffer, scheme); decompress2(buffer, received_data, scheme); } BOOST_CHECK(send_data == received_data); const std::string algo = std::string("2,") + boost::lexical_cast<std::string>(scheme); const double e = elapsed_seconds(start_time); const double improvement = ((t0 - e) / t0) * 100.0; std::cout << (boost::format(improvement_statement) % algo % NUM_ITERATIONS % e % improvement); } return 0; } -- View this message in context: http://www.nabble.com/help-needed-with-bzip2-zlib-with-boost-tp25401084p254… Sent from the Boost - Users mailing list archive at Nabble.com.

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timeconv.inl
by Dan Smithers 11 Sep '09

11 Sep '09

I am porting some inherited code to MSVS 2008 This is also bringing along an upgrade from boost 1.32 to a newer version (probably 1.37). I have found a thread wrapper class in the code that uses time_to directly. This is defined in lib/thread/src/timeconv.inl and doesn't look like its meant to be used directly. The original code base has timeconv.inl in the boost include directory. Was timeconv.inl moved at some point in the past? Is this as bad as I think it is? thanks dan

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Heterogeneous Bundled Properties (boost::detail::error_property_not_found)
by Mathieu Malaterre 11 Sep '09

11 Sep '09

Hi there, I am reading the following documentation: http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/bundles.html I found the following test: libs/graph/test/bundled_properties.cpp, but I still do not understand how I can define a graph with heterogeneous vertex type. Could someone please let me know how to do that ? I tried the following two approaches: typedef adjacency_list < listS, vecS, directedS, boost::any >graph_type; and struct Fruit { virtual ~Fruit() {} }; typedef adjacency_list < listS, vecS, directedS, Fruit* >graph_type; But I when retrieving the vertex I always get a boost::detail::error_property_not_found Thanks -- Mathieu

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Incorrect graph cut?
by David Doria 11 Sep '09

11 Sep '09

I made this simple graph: http://rpi.edu/~doriad/graph.png <http://rpi.edu/%7Edoriad/graph.png> The min cut between node 0 and node 3 should be 11, right? But it is returning 7. My code is below: #include <iostream> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/kolmogorov_max_flow.hpp> using namespace boost; typedef adjacency_list_traits < vecS, vecS, directedS > Traits; typedef adjacency_list < vecS, vecS, directedS, property < vertex_name_t, std::string, property < vertex_index_t, long, property < vertex_color_t, boost::default_color_type, property < vertex_distance_t, long, property < vertex_predecessor_t, Traits::edge_descriptor > > > > >, property < edge_capacity_t, double, property < edge_residual_capacity_t, double, property < edge_reverse_t, Traits::edge_descriptor > > > > Graph; Traits::edge_descriptor AddEdge(Traits::vertex_descriptor &v1, Traits::vertex_descriptor &v2, property_map < Graph, edge_reverse_t >::type &rev, const double capacity, Graph &g); int main(int, char*[]) { Graph g; //a graph with 0 vertices property_map < Graph, edge_reverse_t >::type rev = get(edge_reverse, g); //add a source and sink node, and store them in s and t, respectively Traits::vertex_descriptor v0 = add_vertex(g); Traits::vertex_descriptor v1 = add_vertex(g); Traits::vertex_descriptor v2 = add_vertex(g); Traits::vertex_descriptor v3 = add_vertex(g); AddEdge(v0, v1, rev, 6.0, g); AddEdge(v0, v2, rev, 5.0, g); AddEdge(v1, v2, rev, 8.0, g); AddEdge(v2, v3, rev, 7.0, g); //find min cut double flow = kolmogorov_max_flow(g, v0, v3); // a list of sources will be returned in s, and a list of sinks will be returned in t std::cout << "Max flow is: " << flow << std::endl; property_map<Graph, edge_capacity_t>::type capacity = get(edge_capacity, g); property_map<Graph, edge_residual_capacity_t>::type residual_capacity = get(edge_residual_capacity, g); graph_traits<Graph>::vertex_iterator u_iter, u_end; graph_traits<Graph>::out_edge_iterator ei, e_end; for (tie(u_iter, u_end) = vertices(g); u_iter != u_end; ++u_iter) for (tie(ei, e_end) = out_edges(*u_iter, g); ei != e_end; ++ei) if (capacity[*ei] > 0) std::cout << "Source: " << *u_iter << " destination: " << target(*ei, g) << " capacity: " << capacity[*ei] << "residual cap: " << residual_capacity[*ei] << " diff: " << (capacity[*ei] - residual_capacity[*ei]) << std::endl; return 0; } Traits::edge_descriptor AddEdge(Traits::vertex_descriptor &v1, Traits::vertex_descriptor &v2, property_map < Graph, edge_reverse_t >::type &rev, const double capacity, Graph &g) { Traits::edge_descriptor e1 = add_edge(v1, v2, g).first; Traits::edge_descriptor e2 = add_edge(v2, v1, g).first; put(edge_capacity, g, e1, capacity); put(edge_capacity, g, e2, capacity); rev[e1] = e2; rev[e2] = e1; } The output is: Max flow is: 7 Source: 0 destination: 1 capacity: 6residual cap: 4 diff: 2 Source: 0 destination: 2 capacity: 5residual cap: 0 diff: 5 Source: 1 destination: 0 capacity: 6residual cap: 8 diff: -2 Source: 1 destination: 2 capacity: 8residual cap: 6 diff: 2 Source: 2 destination: 0 capacity: 5residual cap: 5 diff: 0 Source: 2 destination: 1 capacity: 8residual cap: 10 diff: -2 Source: 2 destination: 3 capacity: 7residual cap: 0 diff: 7 Source: 3 destination: 2 capacity: 7residual cap: 9 diff: -2 Here are my questions: 1) Why is the max flow wrong? 2) I'm confused what that output is showing - for example, there is a Source 1 Destination 2 edge that is not a real edge. It is also missing the edge from node 3 to node 1. 3) What is the best way to determine which nodes are on the source side of the cut, and which are on the sink side? The goal is to partition the graph into two sets. 4) Is it possible to pass a list of sources and a list of sinks to kolmogorov_max_flow instead of just a single source node and a single sink node? (Or can a different boost maxflow algorithm handle that?) These are just additional constraints on where the cut should be allowed to be placed. Maybe this is not the type of thing BGL is intended for? If it is, I really think the answers to these questions should be added to the documentation! Thanks, David

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