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problems with nested boost::bind and boost::asio
by Marco 03 Apr '14

03 Apr '14

Hi, I use async_read of boost::asio to receive network data. After a complete 'packet' was read (which needs 2 async read calls) I want to call a user defined handler. Therefore, I introduced a new templater parameter in my callback methods. Unfortunately, my code ends in a compile error. If I outcomment the handler call, than it compiles fine. But with the call of the handler object, I got a conversion error. At first I want to describe my code on some excerpts: ---------------------------------------------------------------------------------------- In 'startProcessing' I use perfect forwarding for the callback object. template<typename T> void startProcessing(T&& handler,bool activateNoDelay = true) { // m_socket.set_option(asio::ip::tcp::no_delay(activateNoDelay )); // startAsyncRead(std::forward<T>(handler)); } ---------------------------------------------------------------------------------------- 'startAsynRead' has two overloads. One for boost::bind objects and one for all other. The boost bind objects are encased with boost::protect to prevent an evaluation of boost::bind in the later binds. // template<typename T> void startAsyncRead(T handler) { startAsyncReadImpl(handler); } //overload for boost bind objects necessary template<typename R, typename F, typename L> void startAsyncRead(boost::_bi::bind_t<R, F, L> handler) { startAsyncReadImpl(boost::protect(handler)); } ---------------------------------------------------------------------------------------- 'startAsyncReadImpl' calls asio::async_read and uses boost::bind to commit the handler object as a third parameter. // template<typename T> void startAsyncReadImpl(T&& handler) { //at first we need to read the header information auto& buf = m_headerInBuffer.getBuffer(); boost::asio::async_read( m_socket, boost::asio::buffer(buf.begin(), buf.size()), boost::asio::transfer_exactly(buf.size()), boost::bind(&CMessageChannel::handleAsyncReadHeader<T>, this,_1, _2, std::forward<T>(handler)) ); } ---------------------------------------------------------------------------------------- 'handleAsyncReadHeader' does some stuff and than calls asio::async_read with another method. // template<typename T> void handleAsyncReadHeader(const boost::system::error_code& error, std::size_t bytes_transferred, T handler) { . . . boost::asio::async_read( m_socket, boost::asio::buffer(buf.begin(), buf.size()), boost::asio::transfer_exactly(size), boost::bind(&CMessageChannel::handleAsyncReadBody<T>, this, _1, _2,handler) ); } ---------------------------------------------------------------------------------------- Finally, 'handleAsyncReadBody' has to do the wished call of the handler. // template<typename T> inline void CMessageChannel::handleAsyncReadBody(const boost::system::error_code& error, std::size_t bytes_transferred, T handler) { ... handler(Packet(m_headerInBuffer.getShort(4), bytes_transferred, m_currReadBuffer)); } ---------------------------------------------------------------------------------------- And here a call of start process: void testPacket(Packet& packet) {} . . . conn->startProcessing(boost::bind(&CMessageServer::testPacket, this, _1)); ---------------------------------------------------------------------------------------- I use Visual Studio 2013 and got the following error message: 1>D:\libraries\cpp\boost\boost_1_55_0\boost/bind/bind.hpp(313): error C2664: 'void boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>::operator ()(T *,A1) const' : Konvertierung von Argument 2 von 'const tuc::nw::Packet' in 'tuc::nw::Packet &' nicht möglich -> can't convert argument 2 'const tuc::nw::Packet' to tuc::nw::Packet & I never use const in my call chain. It seems that boost::protect introduces the const for the parameter. And I have no idea how to fix it :( ---------------------------------------------------------------------------------------- Here is the complete error message: 1>------ Erstellen gestartet: Projekt: network, Konfiguration: Release Win32 ------ 1> MessageChannel.cpp 1> MessageServer.cpp 1>D:\libraries\cpp\boost\boost_1_55_0\boost/bind/bind.hpp(313): error C2664: 'void boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>::operator ()(T *,A1) const' : Konvertierung von Argument 2 von 'const tuc::nw::Packet' in 'tuc::nw::Packet &' nicht möglich 1> with 1> [ 1> T=tuc::nw::CMessageServer 1> , A1=tuc::nw::Packet & 1> ] 1> Durch die Konvertierung gehen Qualifizierer verloren 1> D:\libraries\cpp\boost\boost_1_55_0\boost/bind/bind_template.hpp(47): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>::operator ()<F,boost::_bi::list1<const A1 &>>(boost::_bi::type<void>,F &,A &,int)". 1> with 1> [ 1> T=tuc::nw::CMessageServer * 1> , F=boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &> 1> , A1=tuc::nw::Packet 1> , A=boost::_bi::list1<const tuc::nw::Packet &> 1> ] 1> D:\libraries\cpp\boost\boost_1_55_0\boost/bind/bind_template.hpp(47): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>::operator ()<F,boost::_bi::list1<const A1 &>>(boost::_bi::type<void>,F &,A &,int)". 1> with 1> [ 1> T=tuc::nw::CMessageServer * 1> , F=boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &> 1> , A1=tuc::nw::Packet 1> , A=boost::_bi::list1<const tuc::nw::Packet &> 1> ] 1> D:\libraries\cpp\boost\boost_1_55_0\boost/bind/protect.hpp(60): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>>::operator ()<A1>(const A1 &)". 1> with 1> [ 1> T=tuc::nw::CMessageServer * 1> , A1=tuc::nw::Packet 1> ] 1> D:\libraries\cpp\boost\boost_1_55_0\boost/bind/protect.hpp(60): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>>::operator ()<A1>(const A1 &)". 1> with 1> [ 1> T=tuc::nw::CMessageServer * 1> , A1=tuc::nw::Packet 1> ] 1> G:\Quellcode\nc-programming\nc-libs\nc-libs/network/MessageChannel.h(196): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void boost::_bi::protected_bind_t<boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>>>::operator ()<tuc::nw::Packet>(const A1 &)". 1> with 1> [ 1> T=tuc::nw::CMessageServer * 1> , A1=tuc::nw::Packet 1> ] 1> G:\Quellcode\nc-programming\nc-libs\nc-libs/network/MessageChannel.h(196): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void boost::_bi::protected_bind_t<boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>>>::operator ()<tuc::nw::Packet>(const A1 &)". 1> with 1> [ 1> T=tuc::nw::CMessageServer * 1> , A1=tuc::nw::Packet 1> ] 1> G:\Quellcode\nc-programming\nc-libs\nc-libs/network/MessageChannel.h(179): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void tuc::nw::CMessageChannel::handleAsyncReadBody<T>(const boost::system::error_code &,size_t,T)". 1> with 1> [ 1> T=boost::_bi::protected_bind_t<boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<tuc::nw::CMessageServer *>,boost::arg<1>>>> 1> ] 1> G:\Quellcode\nc-programming\nc-libs\nc-libs/network/MessageChannel.h(127): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void tuc::nw::CMessageChannel::handleAsyncReadHeader<T>(const boost::system::error_code &,size_t,T)". 1> with 1> [ 1> T=boost::_bi::protected_bind_t<boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<tuc::nw::CMessageServer *>,boost::arg<1>>>> 1> ] 1> G:\Quellcode\nc-programming\nc-libs\nc-libs/network/MessageChannel.h(117): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void tuc::nw::CMessageChannel::startAsyncReadImpl<boost::_bi::protected_bind_t<boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>>>>(boost::_bi::protected_bind_t<boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>>> &&)". 1> with 1> [ 1> T=tuc::nw::CMessageServer * 1> ] 1> G:\Quellcode\nc-programming\nc-libs\nc-libs/network/MessageChannel.h(76): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void tuc::nw::CMessageChannel::startAsyncRead<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>>(boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>>)". 1> with 1> [ 1> T=tuc::nw::CMessageServer * 1> ] 1> MessageServer.cpp(43): Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "void tuc::nw::CMessageChannel::startProcessing<boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>>>(boost::_bi::bind_t<void,boost::_mfi::mf1<void,tuc::nw::CMessageServer,tuc::nw::Packet &>,boost::_bi::list2<boost::_bi::value<T>,boost::arg<1>>> &&,bool)". 1> with 1> [ 1> T=tuc::nw::CMessageServer * 1> ] ========== Erstellen: 0 erfolgreich, 1 fehlerhaft, 0 aktuell, 0 übersprungen ==========

2 1

installing boost getting error "ld: symbol(s) not found for architecture x86_64" on OSX 10.9.2
by Corentin Hamel 02 Apr '14

02 Apr '14

Hi everyone, I hope this is the right place to ask my question. I'm trying to build boost 1.55.0 for python on OSX 10.9.2 but i'm encountering the following error "ld: symbol(s) not found for architecture x86_64" and I'm really blocked. I read it might be related to the standard c++ library which changed with maverick to be libc++ by default. But even adding cxxflags="-stdlib=libstdc++" when executing ./b2 didn't help. Here is what I did following the boost tutorial: download boost_1_55_0.tar ./bootstrap.sh --with-libraries=python toolset=darwin ./b2 include="/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7/" And I get the following error: link.jam: No such file or directory Building the Boost C++ Libraries. error: No best alternative for /python_for_extensions next alternative: required properties: <python>2.7 <target-os>darwin matched next alternative: required properties: <python>2.7 <target-os>darwin matched error: No best alternative for /python_for_extensions next alternative: required properties: <python>2.7 <target-os>darwin matched next alternative: required properties: <python>2.7 <target-os>darwin matched Component configuration: - python : building darwin.link.dll bin.v2/libs/python/build/darwin-4.2.1/release/threading- multi/libboost_python.dylib Undefined symbols for architecture x86_64: "_PyFile_FromString", referenced from: boost::python::exec_file(boost::python::str, boost::python::api::object, boost::python::api::object) in exec.o "_PyFile_AsFile", referenced from: boost::python::exec_file(boost::python::str, boost::python::api::object, boost::python::api::object) in exec.o "_PyEval_GetGlobals", referenced from: boost::python::eval(boost::python::str, boost::python::api::object, boost::python::api::object) in exec.o boost::python::exec(boost::python::str, boost::python::api::object, boost::python::api::object) in exec.o boost::python::exec_statement(boost::python::str, boost::python::api::object, boost::python::api::object) in exec.o boost::python::exec_file(boost::python::str, boost::python::api::object, boost::python::api::object) in exec.o "_PyRun_StringFlags", referenced from: ........ "_PyExc_StopIteration", referenced from: boost::python::objects::stop_iteration_error() in iterator.o "_PyNumber_InPlaceAdd", referenced from: boost::python::api::operator+=(boost::python::api::object&, boost::python::api::object const&) in object_operators.o "_PyUnicodeUCS2_FromEncodedObject", referenced from: _encode_string_unaryfunc in builtin_converters.o "_PyErr_NoMemory", referenced from: boost::python::handle_exception_impl(boost::function0<void>) in errors.o "_PyDict_New", referenced from: boost::python::detail::dict_base::dict_base() in dict.o boost::python::detail::dict_base::dict_base() in dict.o _instance_get_dict in class.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation) "g++" -dynamiclib -Wl,-single_module -install_name "libboost_python.dylib" -o "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/libboost_python.dylib" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/numeric.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/list.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/long.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/dict.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/tuple.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/str.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/slice.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/converter/from_python.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/converter/registry.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/converter/type_id.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object/enum.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object/class.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object/function.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object/inheritance.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object/life_support.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object/pickle_support.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/errors.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/module.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/converter/builtin_converters.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/converter/arg_to_python_base.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object/iterator.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object/stl_iterator.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object_protocol.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object_operators.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/wrapper.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/import.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/exec.o" "bin.v2/libs/python/build/darwin-4.2.1/release/threading-multi/object/function_doc_signature.o" -headerpad_max_install_names -Wl,-dead_strip -no_dead_strip_inits_and_terms ...failed darwin.link.dll bin.v2/libs/python/build/darwin-4.2.1/release/threading- multi/libboost_python.dylib... ...skipped <pstage/lib>libboost_python.dylib for lack of <pbin.v2/libs/python/build/darwin- 4.2.1/release/threading-multi>libboost_python.dylib... ...failed updating 1 target... ...skipped 1 target... Thanks for your help! Corentin Hamel Software Engineer Rocketboots Level 11, 189 Kent Street Sydney NSW 2000

2 5

boost asio synchronous vs asynchronous operations performance
by Donald Alan 31 Mar '14

31 Mar '14

Hi, I'm trying to compare the performance of boost::asio asynchronous vs synchronous IO operations for a single client. Below, I've sample synchronous and asynchronous server applications, which send 25 byte message to the client in a loop continuously. On the client side, I'm checking at what rate it is able to receive the messages. The sample setup is pretty simple. In synchronous server case, it spawns a new thread per client connection and the thread keeps sending the 25-byte message in a loop. In asynchronous server case as well it spawns a new thread per client connection and the thread keeps sending the 25-byte message in a loop, using asynchronous write (main thread is the one which calls ioservice.run()). For the performance testing I'm using only one client. *Synchronous server code* #include <iostream> #include <boost/bind.hpp> #include <boost/shared_ptr.hpp> #include <boost/enable_shared_from_this.hpp> #include <boost/asio.hpp> #include <boost/thread.hpp> using boost::asio::ip::tcp; class tcp_connection : public boost::enable_shared_from_this<tcp_connection> { public: typedef boost::shared_ptr<tcp_connection> pointer; static pointer create(boost::asio::io_service& io_service) { return pointer(new tcp_connection(io_service)); } tcp::socket& socket() { return socket_; } void start() { for (;;) { try { ssize_t len = boost::asio::write(socket_, boost::asio::buffer(message_)); if (len != message_.length()) { std::cerr<<"Unable to write all the bytes"<<std::endl; break; } if (len == -1) { std::cerr<<"Remote end closed the connection"<<std::endl; break; } } catch (std::exception& e) { std::cerr<<"Error while sending data"<<std::endl; break; } } } private: tcp_connection(boost::asio::io_service& io_service) : socket_(io_service), message_(25, 'A') { } tcp::socket socket_; std::string message_; }; class tcp_server { public: tcp_server(boost::asio::io_service& io_service) : acceptor_(io_service, tcp::endpoint(tcp::v4(), 1234)) { start_accept(); } private: void start_accept() { for (;;) { tcp_connection::pointer new_connection = tcp_connection::create(acceptor_.get_io_service()); acceptor_.accept(new_connection->socket()); boost::thread(boost::bind(&tcp_connection::start, new_connection)); } } tcp::acceptor acceptor_; }; int main() { try { boost::asio::io_service io_service; tcp_server server(io_service); } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } *ASynchronous server code:* #include <iostream> #include <string> #include <boost/bind.hpp> #include <boost/shared_ptr.hpp> #include <boost/enable_shared_from_this.hpp> #include <boost/asio.hpp> #include <boost/thread.hpp> using boost::asio::ip::tcp; class tcp_connection : public boost::enable_shared_from_this<tcp_connection> { public: typedef boost::shared_ptr<tcp_connection> pointer; static pointer create(boost::asio::io_service& io_service) { return pointer(new tcp_connection(io_service)); } tcp::socket& socket() { return socket_; } void start() { while (socket_.is_open()) { boost::asio::async_write(socket_, boost::asio::buffer(message_), boost::bind(&tcp_connection::handle_write, shared_from_this(), boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } } private: tcp_connection(boost::asio::io_service& io_service) : socket_(io_service), message_(25, 'A') { } void handle_write(const boost::system::error_code& error, size_t bytes_transferred) { if (error) { if (socket_.is_open()) { std::cout<<"Error while sending data asynchronously"<<std::endl; socket_.close(); } } } tcp::socket socket_; std::string message_; }; class tcp_server { public: tcp_server(boost::asio::io_service& io_service) : acceptor_(io_service, tcp::endpoint(tcp::v4(), 1234)) { start_accept(); } private: void start_accept() { tcp_connection::pointer new_connection = tcp_connection::create(acceptor_.get_io_service()); acceptor_.async_accept(new_connection->socket(), boost::bind(&tcp_server::handle_accept, this, new_connection, boost::asio::placeholders::error)); } void handle_accept(tcp_connection::pointer new_connection, const boost::system::error_code& error) { if (!error) { boost::thread(boost::bind(&tcp_connection::start, new_connection)); } start_accept(); } tcp::acceptor acceptor_; }; int main() { try { boost::asio::io_service io_service; tcp_server server(io_service); io_service.run(); } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } *Client code* #include <iostream> #include <boost/asio.hpp> #include <boost/array.hpp> int main(int argc, char* argv[]) { if (argc != 3) { std::cerr<<"Usage: client <server-host> <server-port>"<<std::endl; return 1; } boost::asio::io_service io_service; boost::asio::ip::tcp::resolver resolver(io_service); boost::asio::ip::tcp::resolver::query query(argv[1], argv[2]); boost::asio::ip::tcp::resolver::iterator it = resolver.resolve(query); boost::asio::ip::tcp::resolver::iterator end; boost::asio::ip::tcp::socket socket(io_service); boost::asio::connect(socket, it); // Statscollector to periodically print received messages stats // sample::myboost::StatsCollector stats_collector(5); // sample::myboost::StatsCollectorScheduler statsScheduler(stats_collector); // statsScheduler.start(); for (;;) { boost::array<char, 25> buf; boost::system::error_code error; size_t len = socket.read_some(boost::asio::buffer(buf), error); // size_t len = boost::asio::read(socket, boost::asio::buffer(buf)); if (len != buf.size()) { std::cerr<<"Length is not "<< buf.size() << " but "<<len<<std::endl; } // stats_collector.incr_msgs_received(); } } <b>Question:* When the client is running against synchronous server it is able to receive around 700K msgs/sec but when it is running against asynchronous server the performance is dropped to around 100K-120K msgs/sec. I know that one should use asynchronous IO for scalability when we have more number of clients and in the above case as I'm using only a single client, the obvious advantage of asynchronous IO is not evident. But the question is, is asynchronous IO expected to effect the performance so badly for a single client case or am I missing some obvious best practices to follow with asynchronous IO? Is the significant drop in the performance is because of the thread switch between ioservice thread (which is main thread in the above case) and connection thread? *Setup:* I'm using BOOST 1.47 on Linux machine. -- View this message in context: http://boost.2283326.n4.nabble.com/boost-asio-synchronous-vs-asynchronous-o… Sent from the Boost - Users mailing list archive at Nabble.com.

6 18

[fusion 1.55.0] fusion::map avoid copy construction for elements
by Frank Bergemann 30 Mar '14

30 Mar '14

3 2

[Thread] why isn't it possible to acquire 2 different upgrade_lock from 2 different threads?
by Elad Moshe 30 Mar '14

30 Mar '14

Hi, this is my first post here so please bare with me :) . I recently used upgrade_lock to try access a shared resource from 2 different threads. I noticed that once the first thread acquired its upgrade_lock the second thread was blacked until the first thread unlock it. can someone please explain me the logic behind this behavior? isn't an upgrade lock just a shared_lock that can be upgraded to unique_lock? why not let both threads acquire it just like shared_lock until, and if, they decide to upgrade it to unique_lock? Thanks a lot, Elad.

4 6

cross compiling boost python (64->32bits)
by Stéphane ANCELOT 29 Mar '14

29 Mar '14

Hi, I need to compile boost python from my linux system. the host system is a 64bits , and the target a 32 bit one. when I try using it on the target system, I have this message, ImportError: ./libboost_python.so.1.55.0: undefined symbol: Py_InitModule4_64 So, I suppose it is not compiled for 32bits system . I have tried many things, what is the right way to compile a 32 bits boost python lib, from a linux 64 bits system ? Regards, Steph

2 1

cygwin 64 boost install
by jfrm.maurel＠gmail.com 29 Mar '14

29 Mar '14

Hi, Trying to install boost 1_54 (I had the same problem with 1.55) on my laptop Windows 7 (64bits RAM 6 Go), I have following failure (details in attached file): common.mkdir bin.v2/libs/context/build common.mkdir bin.v2/libs/context/build/gcc-4.8.2 common.mkdir bin.v2/libs/context/build/gcc-4.8.2/release common.mkdir bin.v2/libs/context/build/gcc-4.8.2/release/address-model-64 common.mkdir bin.v2/libs/context/build/gcc-4.8.2/release/address-model-64/link-static common.mkdir bin.v2/libs/context/build/gcc-4.8.2/release/address-model-64/link-static/asm gcc.compile.asm bin.v2/libs/context/build/gcc-4.8.2/release/address-model-64/link-static/asm/make_x86_64_sysv_elf_gas.o libs/context/src/asm/make_x86_64_sysv_elf_gas.S: Messages de l'assembleur: libs/context/src/asm/make_x86_64_sysv_elf_gas.S:43: Avertissement: .type pseudo opérateur utilisé à l'extérieur de .def/.endef ignoré. libs/context/src/asm/make_x86_64_sysv_elf_gas.S:43: Erreur: rebut à la fin de la ligne, premier caractère non reconnu est « m » libs/context/src/asm/make_x86_64_sysv_elf_gas.S:73: Avertissement: .size pseudo opérateur utilisé à l'extérieur de .def/.endef ignoré. libs/context/src/asm/make_x86_64_sysv_elf_gas.S:73: Erreur: rebut à la fin de la ligne, premier caractère non reconnu est « m » "g++" -x assembler-with-cpp -O3 -finline-functions -Wno-inline -Wall -m64 -DBOOST_ALL_NO_LIB=1 -DNDEBUG -I"." -c -o "bin.v2/libs/context/build/gcc-4.8.2/release/address-model-64/link-static/asm/make_x86_64_sysv_elf_gas.o" "libs/context/src/asm/make_x86_64_sysv_elf_gas.S" ...failed gcc.compile.asm bin.v2/libs/context/build/gcc-4.8.2/release/address-model-64/link-static/asm/make_x86_64_sysv_elf_gas.o... gcc.compile.asm bin.v2/libs/context/build/gcc-4.8.2/release/address-model-64/link-static/asm/jump_x86_64_sysv_elf_gas.o The process I followed after fresh cygwin 64 install: tar --bzip2 -xf boost_1_54_0.tar.bz2 cd boost_1_54_0/ ./bootstrap.sh #./b2 -j8 --prefix=$PWD --libdir=$PWD/lib64 --layout=tagged link=static threading=multi,single install || echo FAILURE ./b2 --prefix=$PWD --libdir=$PWD/lib64 --layout=tagged link=static threading=single address-model=64 install >build.log Could you please tell me what I am doing wrong ? I have read https://groups.google.com/forum/#!msg/boost-devel-archive/vqK2MXdmUZ0/cvhmd… but don't know if this is related. Regards -- Jean-François MAUREL PIMECA http://www.pimeca.com

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[BOOST Users] serialize a pointer
by Andy Sardina 28 Mar '14

28 Mar '14

Hello, I would like to just serialize a pointer value. I have understood that boost save the pointer value, and serialize the object it points. How can I do?

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[serialization] serialization of an ifstream/ofstream class member
by Pablo Madoery 28 Mar '14

28 Mar '14

Hi. Do You know if there is a way to serialize an ifstream/ofstream class member. I have this class for example class Object { public: Object(); Object(string name); virtual ~Object(); string getName() const; private: string name_; ifstream file_; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & name_; ar & file_; } }; when I try to serialize it throw compilation error : error: 'struct std::basic_ifstream<char>' has no member named 'serialize'. Is there a specific header i must include ?

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[serialization] of nested stl containers
by Pablo Madoery 27 Mar '14

27 Mar '14

I have the following code: #include <list> #include <utility> #include <vector> #include <string> #include <fstream> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/access.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/vector.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/map.hpp> #include <boost/serialization/base_object.hpp> using namespace std; int main() { list< pair<string, string> > stlStr; pair<string, string> par1("aaa", "bbb"); stlStr.push_back(make_pair("key", par1)); std::ofstream ofs("filename"); { boost::archive::text_oarchive serial(ofs); serial << stlStr; } std::ifstream ifs("filename"); boost::archive::text_iarchive serial2(ifs); list<pair<string, string> > lst; serial2 >> lst; return 0; } that throw the following compilation error: error: 'class std::list<std::pair<std::basic_string<char>, std::basic_string<char> > >' has no member named 'serialize'. I'd like to know if I have to manually implement the serialization of this nested list. Because for example I haven't problems with maps that have inside a pair : map<string, pair<string, string> >. Thanks !

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