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Weird problem with boost::noncopyable and boost::mutex
by Daniel V 18 Mar '10

18 Mar '10

Hi, *I was doing a program in C++ where I simulate a Java's ArrayList...* * * template <class T> class Duo { public: Duo *next; T element; Duo(T el,Duo *sig) { element=el; next=sig; } ~Duo() {}; Duo* getNext() {return next;} T getElement() {return element;} void setNext(Duo *myNext) {next=myNext;} void setElement(T el){element=el;} }; template <class T> class ArrayList { public: Duo <T>*Ptr_First; Duo <T>*Ptr_Last; ArrayList(){Ptr_First = Ptr_Last = NULL;}; ~ArrayList(){} void insert(T el); std::pair<T, int> get(int index); }; template <class T> void ArrayList<T>::insert(T elem) { Duo<T> *ptr_walker = Ptr_First; Duo<T> *ptr_cache; if (Ptr_First == NULL && Ptr_Last == NULL) { Duo<T> *Ptr_temp = new Duo<T>(elem, NULL); Ptr_First = Ptr_temp; Ptr_Last = Ptr_temp; } else { while (ptr_walker->getNext() != NULL) ptr_walker = ptr_walker->getNext(); ptr_cache = ptr_walker; Duo<T> *Ptr_temp = new Duo<T>(elem, NULL); Ptr_Last = Ptr_temp; ptr_walker->setNext(Ptr_temp); } } template <class T> std::pair<T, int> ArrayList<T>::get(int index) { Duo<T> *ptr_walker; std::pair <T, int> receiver; receiver.first = ptr_walker->getElement(); receiver.second = 0; bool found = false; if ((Ptr_First == NULL) && (Ptr_Last == NULL)) return receiver; else { ptr_walker = Ptr_First; for (int i = 0; i<index; i++) { ptr_walker = ptr_walker->getNext(); } receiver.first = ptr_walker->getElement(); receiver.second = 1; return receiver; } } *The thing is that I instanciated an ArrayList object and called the "insert" method and I received an error from boost::mutex AND boost::noncopyable!! and I am not using them at all!!* *This is the code that generates the error:* ArrayList<ObjectA> myArrayListA; ObjectA myObjectA; myArrayListA.insert(myObjectA); *and the errors I got:* mkdir -p build/Debug/GNU-MacOSX rm -f build/Debug/GNU-MacOSX/main.o.d g++ -pthreads -lboost_thread -c -g -fPIC -MMD -MP -MF build/Debug/GNU-MacOSX/main.o.d -o build/Debug/GNU-MacOSX/main.o main.cpp /usr/local/include/boost/noncopyable.hpp: In copy constructor 'boost::mutex::mutex(const boost::mutex&)': In file included from main.cpp:23: /usr/local/include/boost/noncopyable.hpp:27: error: 'boost::noncopyable_::noncopyable::noncopyable(const boost::noncopyable_::noncopyable&)' is private /usr/local/include/boost/thread/pthread/mutex.hpp:31: error: within this context ObjectA.h: In copy constructor 'ObjectA::ObjectA(const ObjectA&)': ObjectA.h:18: note: synthesized method 'boost::mutex::mutex(const boost::mutex&)' first required here *Any Ideas why am I receiving this errors?* THANKS!! Dann

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[multi_index] Is replace() ok within container iteration loop?
by PB 18 Mar '10

18 Mar '10

Hello, This question is about boost:multi_index_container. Code is iterating over a multi_index_container and replacing some elements. The data being replaced has nothing to do with any keys/indices. Is this allowed by multi_index_container? Thanks, Pete

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[asio] async_read_until'smatch_condition requirements/guarantees
by Maxim Yanchenko 18 Mar '10

18 Mar '10

Hi Chris/All, I didn't find anything about this in the docs, so asking here. Why I'm asking: for some protocols matching condition can be pretty complex and will include some parsing of a partially received message. It would be great to reuse information that was already parsed, to avoid parsing same things many times. Also, when we finally received the whole message and match_condition returns true, the handler is invoked which will do mostly the same parsing that was already made by the match_condition - this is also a thing that would be great to avoid. 1) Is the same match_condition object used every time, or multiple copies can be created? 2) Does the state of the match_condition object persist between different condition checks? 3) How match_condition is used if we have several threads? Should I protect access to the state with this regard? 4) In which thread match_condition is executed? is it internal asio thread or one of the threads that called io_service.run()? 5) What if I call the handler code right in the match_condition if the condition is met? In this case I can reuse data I already extracted while checking the condition, and will also avoid waiting for my handler in the asio queue. 6) Same as 5), with one addition - what if I have only one thread that calls io_service.run()? Of course I can figure out all this stuff from the source code, but it's obviously subject to change, so I would better rely on something more stable, like docs (would be great to eventually have answers to the above questions in the docs). Thanks, Maxim

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[boost-users] [assign] std::vector initialisation by boost::assign::list_of
by Andrey Torba 18 Mar '10

18 Mar '10

The code is compilable on msvc but is not on gcc-4.3: #include <boost/assign/list_of.hpp> #include <vector> int main() { //OK std::vector<int> v = boost::assign::list_of(1)(2); // error std::vector<int> v(boost::assign::list_of(1)(2)); return 0; } I can initialise std::vector in a first way. But the problem occurs when i try to initialise std::vector in a class initialization list: class sss { std::vector<int> v; sss() : v(boost::assign::list_of(1)(2)) {} }; -- Regards, Andrey

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custom allocators, pool_alloc, more questions
by B Hart 18 Mar '10

18 Mar '10

I asked for explanation about custom allocators, but unfortunately the answers I got led to more questions which didn't get answered. Supposing a code block: { std::set<unsigned int, std::less<unsigned int>, boost::pool_allocator<unsigned int>> v; const int K = 10485750; for(int i=0; i<K; i++) { v.insert(i); } } //Does memory get released automatically here? or after the line: boost::singleton_pool<boost::pool_allocator_tag, sizeof(unsigned int)>::release_memory(); //what is release_memory() doing besides just setting the node type to a default? Why does that matter? Last, is the life of the singleton instance for the duration of program execution, or just the codeblock?

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Spirit question
by philip tucker 17 Mar '10

17 Mar '10

Please see attached code. Why does line A compile while line B doesn't? Thanks.

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program option library segfaults for exception
by Neetu Garg 17 Mar '10

17 Mar '10

Sorry for the duplicate post, I think my message posted under different conversation. Hi, I have application that is using boost program option library. If I provide unknown option via CLI it should throw exception. The library is statically linked on windows and Linux environment. It works fine on windows platform I do get exception for unknown CLI option. On Linux platform I get "segfault" in place of exception for unknown CLI option. It is s a multi-threaded application and it also uses boost thread library. Application does throw exception on Linux also if I link dynamically. I am using following flags to link the library statically: LDFLAGS= -fexceptions -static-libgcc -Wl,-static -L/usr/lib -lboost_program_options-gcc41-mt -lboost_filesystem-gcc41-mt -lboost_thread-gcc41-mt -lboost_system-gcc41-mt -lnet7ssh -lbotan -ltar -lz -lrt -lpthread I am using following version of gcc: # g++ --version g++ (GCC) 4.1.1 Copyright (C) 2006 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Here is the core dump for the segfault: (gdb) backtrace #0 __gnu_internal::get_global () at /usr/software/src/gcc-4.1.1/libstdc++-v3/libsupc++/eh_globals.cc:58 #1 0x082c0f67 in __cxa_get_globals () at /usr/software/src/gcc-4.1.1/libstdc++-v3/libsupc++/eh_globals.cc:71 #2 0x082c0b3f in __cxa_allocate_exception (thrown_size=32) at /usr/software/src/gcc-4.1.1/libstdc++-v3/libsupc++/eh_alloc.cc:154 #3 0x080a71f8 in boost::program_options::detail::cmdline::finish_option () #4 0x080a77eb in boost::program_options::detail::cmdline::run () #5 0x0806f3aa in boost::program_options::basic_command_line_parser<char>::run () #6 0x080660e9 in CLIHandler::collectCLIOptions () #7 0x0808a0d1 in perfstat::runPerfstat () #8 0x0808af3d in main () Current language: auto; currently c++ Appreciate your help Regards, NG

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Signal code: Address not mapped (1) eroor
by alev mutlu 17 Mar '10

17 Mar '10

Hi, I am getting the following run time errors for the code below. Any suggestions? _alev [ceng34:00724] *** Process received signal *** [ceng34:00724] Signal: Segmentation fault (11) [ceng34:00724] Signal code: Address not mapped (1) [ceng34:00724] Failing at address: 0xfffffffffffffff8 [ceng34:00724] [ 0] /lib64/libpthread.so.0 [0x315880de80] [ceng34:00724] [ 1] /usr/lib64/libstdc++.so.6(_ZN9__gnu_cxx18__exchange_and_addEPVii+0x2) [0x385dab7672] [ceng34:00724] [ 2] /usr/lib64/libstdc++.so.6(_ZNSs6assignERKSs+0x9b) [0x385da9ca4b] [ceng34:00724] [ 3] test-boost(_ZN5fieldaSERKS_+0x47) [0x42197f] [ceng34:00724] [ 4] test-boost(_ZNSt6__copyILb0ESt26random_access_iterator_tagE4copyIPK5fieldPS3_EET0_T_S8_S7_+0x3c) [0x4221be] [ceng34:00724] [ 5] test-boost(_ZSt10__copy_auxIPK5fieldPS0_ET0_T_S5_S4_+0x29) [0x422203] [ceng34:00724] [ 6] test-boost(_ZNSt13__copy_normalILb0ELb0EE6copy_nIPK5fieldPS2_EET0_T_S7_S6_+0x25) [0x42222b] [ceng34:00724] [ 7] test-boost(_ZSt4copyIPK5fieldPS0_ET0_T_S5_S4_+0x2d) [0x42225b] [ceng34:00724] [ 8] test-boost(_ZN5boost3mpi6detail12scatter_implI5fieldEEvRKNS0_12communicatorEPKT_PS7_iiN4mpl_5bool_ILb0EEE+0x90) [0x42a630] [ceng34:00724] [ 9] test-boost(_ZN5boost3mpi7scatterI5fieldEEvRKNS0_12communicatorEPKT_PS6_ii+0x50) [0x42b162] [ceng34:00724] [10] test-boost(_ZN5boost3mpi7scatterI5fieldEEvRKNS0_12communicatorERKSt6vectorIT_SaIS7_EEPS7_ii+0x55) [0x42b1db] [ceng34:00724] [11] test-boost(main+0x20e) [0x420880] [ceng34:00724] [12] /lib64/libc.so.6(__libc_start_main+0xf4) [0x3157c1d8b4] [ceng34:00724] [13] test-boost(__gxx_personality_v0+0x169) [0x420489] [ceng34:00724] *** End of error message *** mpirun noticed that job rank 0 with PID 724 on node ceng34-ib exited on signal 11 (Segmentation fault). #include <boost/mpi/environment.hpp> #include <boost/mpi/communicator.hpp> #include <boost/mpi/collectives.hpp> #include <boost/thread/barrier.hpp> #include <boost/thread/mutex.hpp> #include <boost/config.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/access.hpp> #include <boost/serialization/string.hpp> #include <boost/mpi/skeleton_and_content.hpp> #include <boost/mpi/datatype.hpp> #include <boost/mpi/allocator.hpp> #include <boost/archive/tmpdir.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/base_object.hpp> #include <boost/mpi.hpp> #include <boost/tokenizer.hpp> #include <boost/archive/tmpdir.hpp> #include <boost/archive/binary_oarchive.hpp> #include <boost/serialization/export.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/hash_map.hpp> #include <boost/serialization/map.hpp> #include <string> #include <iostream> #include <vector> #include <fstream> #define MASTER 0 int arraySize = 7; using namespace std; namespace mpi = boost::mpi; struct field { string field_name; string field_type; string field_ref; string field_colType; }; namespace boost { namespace serialization{ template<class Archive> void serialize(Archive & ar, struct field & f, unsigned int version){ ar & f.field_name; ar & f.field_type; ar & f.field_ref; ar & f.field_colType; } } } int main(int argc, char* argv[]) { mpi::environment env(argc, argv); mpi::communicator world; int m_mySize, w_mySize, kk,i; struct field *relAllValues; struct field *relMyValues; vector<struct field> C; struct field c; w_mySize = arraySize / world.size(); cout << "w_mySize = " << w_mySize << endl; if (world.rank() == MASTER){ for(int i = 0; i < arraySize; i++){ c.field_name = "field_name=" ; c.field_type = "field_type="; c.field_ref = "field_ref="; c.field_colType = "field_colType="; C.push_back(c); } m_mySize = arraySize / world.size() + arraySize % world.size(); relMyValues = (struct field *) malloc(sizeof(struct field) * w_mySize); relAllValues = (struct field *) malloc(sizeof(struct field) * arraySize); } else{ relMyValues = (struct field *) malloc(sizeof(struct field) * w_mySize); } if (world.rank() == MASTER){ scatter(world, C, relMyValues, w_mySize, 0); } else{ scatter(world, C, relMyValues, w_mySize, 0); } if (world.rank() == 1){ cout << "MY RANK IS " << world.rank() << endl; } }

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[Phoenix] : Using phoenix with zip_iterator
by Manjunath Kudlur 17 Mar '10

17 Mar '10

I have the following program where I make_zip_iterator on 2 vector<int>::iterator's and am trying to pass a Phoenix expression to std::for_each on the iterator. I wrote a lazy version of tuple.get<N> for that purpose. I get a compile error because the phoenix functor only accepts references, whereas the tuple element seems to get passed by value. What am I doing wrong? Manjunath #include <iostream> #include <vector> #include <algorithm> #include <boost/iterator/zip_iterator.hpp> #include <boost/tuple/tuple.hpp> #include <boost/spirit/include/phoenix_core.hpp> #include <boost/spirit/include/phoenix_operator.hpp> #include <boost/spirit/include/phoenix_statement.hpp> #include <boost/spirit/include/phoenix_scope.hpp> #include <boost/spirit/home/phoenix/function/function.hpp> using namespace boost::phoenix; using namespace boost::phoenix::arg_names; using namespace boost::phoenix::local_names; using namespace std; namespace fusion = boost::fusion; struct print_tuple { void operator()(const boost::tuple<int&, int&>& t) const { cout << t.get<0>() << " " << t.get<1>() << "\n"; } }; struct get0_ { template<typename Arg> struct result { typedef int type; }; template<typename Arg> int operator()(Arg a1) const { return a1.get<0>(); } }; function<get0_> get0; int main() { vector<int> a(10), b(10); for(unsigned i=0, e=a.size(); i!=e; ++i) { a[i] = i; b[i] = i; } std::for_each(a.begin(), a.end(), cout << arg1); std::for_each(boost::make_zip_iterator(boost::make_tuple(a.begin(), b.begin())), boost::make_zip_iterator(boost::make_tuple(a.end(), b.end())), cout << get0(arg1)); }

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[iostreams][serialization] compressed UTF-8 XML archive
by Paul 17 Mar '10

17 Mar '10

(Was: Re: [Boost-users] Filesystem, serialization, character encoding and portable software) On 14 August 2008 00:44, Robert Ramey <ramey(a)rrsd.com> wrote: > Daniel Krügler wrote: > > Robert Ramey wrote: > >> the wide character xml archives use UTF8. > >> > >> the narrow character xml archives use the currently set locale. > >> > >> Robert Ramey > > > > Sorry for asking offhand: > > > > What is the reasoning behind this different behaviour? > > I assumed that most programs built with narrow characters used > the locale concept to deal with this. > > Wide character systems lend themselves to UTF coding so I > used that for wide char archives. In order to do this, I used > Ron Garcia's UTF code conversion facet for streams. > > It would be quite easy to generate UTF coding for narrow > character archives. Just do the following: > > a) Build the UTF code conversion facet for narrow character > input (its templated on character type). > > b) When the stream is opened, attach this facet to the stream. > > Note the the output char format is not really a property of the > serialization > library, but rather an artifact of the way it has been used. That is, the > serialization library depends on the standard stream library for this > property. > > I understand that to get a UTF-8 XML file, I need to use a wide-character stream, but I can't seem to understand how I can compress a serialized UTF-8 xml archive... it seems I can either do: namespace bio = boost::iostreams; namespace fs = boost::filesystem; fs::wofstream ofs(path,ios::binary); bio::filtering_stream<bio::output,wchar_t> out; out.push(bio::gzip_compressor()); // PROBLEM: gzip_compressor only accepts char out.push(ofs); boost::archive::xml_woarchive oa(out); --- OR --- fs::ofstream ofs(path,ios::binary); bio::filtering_stream<bio::output> out; out.push(bio::gzip_compressor()); out.push(ofs); boost::archive::xml_woarchive oa(out); // PROBLEM: only accepts wostream I've googled but haven't found anything relevant... either people use an ifstream with gzip_compressor, or they don't use gzip_compressor at all. thanks, Paul

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