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[boost.asio] Concurrently Ping 1000+ Hosts
by Kyle Ketterer 21 Dec '13

21 Dec '13

Hello, So the subject line pretty much says it all. Basically, I am trying to expand off of the icmp ping example given by the boost library documentation. I would like to ping 1000+ hosts in say, a matter of minutes rather than a matter of hours. I have already expanded the class shown here: http://www.boost.org/doc/libs/1_40_0/doc/html/boost_asio/example/icmp/ping.… Before I start posting code, I would like to discuss the strategy of trying to do this. In my Main thread, I was thinking about creating a vector of PingX objects. In the PingX class, I would have a separate io_service as well as wrap the async() functions in strands. I set the deadline timer at 800ms that way the io_service should return in less than a second. I would then call io_service run() in separate threads to *concurrently* ping these hosts. The problem appears to be that even through the async handers are wrapped in strands, there is data corruption. Is it true that when async handlers are wrapped in strands, they still cannot be executed *concurrently* ? My understanding of strand was that it serializes the handler functions to allow for thread safe access. However, I think that because I am accessing the same resources in multiple threads (such as the socket() object ), it is corrupting my expected output as well as occasionally throwing some exceptions. Are there any suggestions for the logic surrounding this or if this can be done in a multithreaded environment? Thanks! -- Kyle Ketterer

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Boost.Coroutine and Object Inheritance
by Carlos Ferreira 20 Dec '13

20 Dec '13

Hello to all. I need some help using the Boost.Coroutine lib. I wanted to use the coroutines as objects and for that, I tried to build a simple object and inherit the boost::coroutines::coroutine template. ex: class SimpleObj : public boost::coroutines::coroutine<SimpleObj>{ private: std::unique_ptr<boost::asio::ip::tcp::socket> tcpSkt_uPtr; std::unique_ptr<boost::asio::ip::tcp::acceptor> acc_uPtr; public: SimpleObj(std::shared_ptr<boost::asio::io_service> ioService_ptr, boost::asio::ip::tcp::endpoint &endPoint); ~SimpleObj(); void run(); }; Is this right? Can I actually inherit from the boost::coroutines::coroutine template ? If yes, how can I proceed from here, to use the run() object method as the coroutine itself, with an io_service provided through the constructor ? Thanks for any assistance! -- Carlos Miguel Ferreira Researcher at Telecommunications Institute Aveiro - Portugal Work E-mail - cmf(a)av.it.pt Skype & GTalk -> carlosmf.pt(a)gmail.com LinkedIn -> http://www.linkedin.com/in/carlosmferreira

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[git][testing] regression testing?
by Joaquín Mª López Muñoz 19 Dec '13

19 Dec '13

There's been some unanswered questions around this. I understand that regression tests, which are critical to ensure clean develop->master merges, will be eventually updated to work against git rather than the abandoned SVN, but I can't find any info on the progress of this. FWIW, I see some authors are going ahead and merging their libs anyway, which will bring breakages etc if changes are not properly validated through regression testing. Any indication on how this is progressing much appreciated. Best, Joaquín M López Muñoz Telefónica Digital ________________________________ Este mensaje se dirige exclusivamente a su destinatario. Puede consultar nuestra política de envío y recepción de correo electrónico en el enlace situado más abajo. This message is intended exclusively for its addressee. We only send and receive email on the basis of the terms set out at: http://www.tid.es/ES/PAGINAS/disclaimer.aspx

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How to use the optional with property_tree‏
by 王郁槐 19 Dec '13

19 Dec '13

Could anyone help? Why the below code will crash on the below line? I'm using the boost property_tree. Thanks. child1.get().put(sub_field, strValue); ========================================================= #include <fstream> #include <boost/filesystem.hpp> #include <boost/property_tree/ptree.hpp> #include <boost/property_tree/ini_parser.hpp> #include <boost/any.hpp> #include <boost/optional.hpp> void writeConfig(const std::string &field, const std::string &sub_field, const std::string & strValue) { if (!boost::filesystem::exists(prog_cfg_file)) { std::ofstream ofIniConfig(prog_cfg_file, std::ofstream::out|std::ofstream::app); ofIniConfig.close(); } boost::property_tree::ptree pt; boost::property_tree::ini_parser::read_ini(prog_cfg_file, pt); boost::optional<boost::property_tree::ptree&> child1 = pt.get_child_optional(field); if (child1) { boost::optional<boost::property_tree::ptree&> child2 = child1.get().get_child_optional(sub_field); if (child2) { child2.get().put_value(strValue); }else { child2.get().put_value(strValue); } }else { child1.get().put(sub_field, strValue); } boost::property_tree::ini_parser::write_ini(prog_cfg_file, pt); } int main() { writeConfig("test", "a", "OK"); return 0; } -- 兰生幽谷, 不以无人而不芳...

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Caching the iterator of async_resolve()?
by Kaspar Fischer 18 Dec '13

18 Dec '13

Hi everybody, Just to be on the safe side: I assume that I can cache the iterator returned by async_resolve<http://www.boost.org/doc/libs/1_49_0/doc/html/boost_asio/reference/ip__basi…>'s handler, correct? The fact that it's a forward iterator suggests so... Thanks! Kaspar

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[MPL] How to generate pre-generated header files for a mpl::list containing more than 50 entries?
by Klaus.Kempf＠industronic.de 18 Dec '13

18 Dec '13

Hello MPL experts, I want to code a state machine which has a reaction list containing more than 50 entries. I found here [http://svn.boost.org/svn/boost/trunk/libs/mpl/preprocessed/] some python scripts to generate header files for a mpl::list containing more than 50 entries. But I cannot manage to generate a single header file. Can someone please explain to me how to use these scripts? I also didn't find any help in boost documention. Command line messages of the related script were also not helpful for me: preprocess_list.py Usage: preprocess_list.py <mode> <boost_root> [<source_file>] Purpose: updates preprocessed version(s) of the header(s) in "boost\mpl\list\aux_\preprocessed" directory Example: the following command will re-generate and update all 'apply.hpp' headers: preprocess_list.py all f:\cvs\boost apply.cpp What is the meaning of [<source_file>] here? And how/where do I have to specify the count of list entries in order to generate the header files "list60.hpp", "list70.hpp" and so on? Many thanks for any help you could provide. Best regards, Klaus

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async_send handler problem
by Alexander Carôt 17 Dec '13

17 Dec '13

Hello all, I am new to boost and asio in particular. For now I am implementing a simple UDP sender. The sending process itself works fine but for some reason the send handler does not execute. The call itself looks like this: In my class sender.cpp I have a functions called void sender::sendIt(){ sj->dFC->s->async_send_to(boost::asio::buffer( this->charBuffer,sendBytes), *sj->dFC->e, boost::bind(&sender::sendHandler,this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred); } and the corresponding handler is this: void sender::sendHandler(const boost::system::error_code& error,std::size_t bytes_transferred){ cout << "TRIGGER" << endl; } Can anyone give me a hint what the reason for the not-working handler might be ? Thanks in advance, best Alex

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[Asio] io_service(std::size_t concurrency_hint) constructor
by maks 16 Dec '13

16 Dec '13

Hello All In what cases using "io_service(std::size_t concurrency_hint)" ctor is more effective? 1. Use multiple threads - multiple io_service 2. Use multiple threads on one io_service object Thanks.

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Delegating to boost::function with arbitrary signature
by Alexander Lamaison 16 Dec '13

16 Dec '13

I've asked this question on Stack Overflow but not found a solution yet: http://stackoverflow.com/q/20578575/67013. It's Boost.Function/MPL-related so I'll ask here too. I'm trying to create something like a `boost::function`, but with an extra 'smart handle' tucked inside, which controls the lifetime of a resource the functions needs to execute correctly. If I didn't need the function signature to be completely generic, this would be easy. I would just create a functor with the correct signature, and keep a `boost::function` and the handle as members. However, I do need generic signatures. The code below is as close as I've got but gets a compile error, presumably, because I'm not able to unpack a list of arguments like this: template<typename Signature> class library_function { public: library_function( library_handle handle, boost::function<result_type(arg1_type, arg2_type)> function) : m_handle(handle), m_function(function) {} typename result_type operator()(arg1_type arg1, arg2_type arg2) { return m_function(arg1, arg2); } // I don't think I can declare the 'params' like this ... typename boost::function_types::result_type<Signature>::type operator()( boost::function_types::parameter_types<Signature> params) { return m_function(params); // ... nor unpack them like this } private: boost::function<Signature> m_function; library_handle m_library; }; I think `params` is an MPL list, so what I've actually done is declare a call operator with a single MPL-list parameter. My MPL-foo is not good. Is there a way to convert the list to a legal definition of multiple function paramters? A suggested solution on SO is to use `boost::bind`, but I still don't see how to bind an arbitrary number of arguments. All advice greatly appreciated. Alex -- Swish - Easy SFTP for Windows Explorer (http://www.swish-sftp.org)

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[asio][openssl]Boost SSL with Visual Studio 2012 and OpenSSL
by lx 16 Dec '13

16 Dec '13

hello: I use : windows 7 64bit, vs 2012 , boost 1.5.4 , Win64OpenSSL_Light-1_0_1e. the codes is: ######################## #include <boost/asio.hpp> #include <boost/asio/ssl.hpp> ######################## When I complie it, the wrong messages is: ########################################## 1>gtest.obj : error LNK2019: unresolved external symbol _CRYPTO_cleanup_all_ex_data referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::~do_init(void)" (??1do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _CRYPTO_num_locks referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::do_init(void)" (??0do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _CRYPTO_set_locking_callback referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::do_init(void)" (??0do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _CRYPTO_set_id_callback referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::do_init(void)" (??0do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _CONF_modules_unload referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::~do_init(void)" (??1do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _OPENSSL_add_all_algorithms_noconf referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::do_init(void)" (??0do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _EVP_cleanup referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::~do_init(void)" (??1do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _SSL_load_error_strings referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::do_init(void)" (??0do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _SSL_library_init referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::do_init(void)" (??0do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _ERR_reason_error_string referenced in function "public: virtual class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __thiscall boost::asio::error::detail::ssl_category::message(int)const " (?message@ssl_category@detail@error@asio@boost@@UBE?AV?$basic_string@DU ?$char_traits@D@std@@V?$allocator@D@2@@std@@H@Z) 1>gtest.obj : error LNK2019: unresolved external symbol _ERR_free_strings referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::~do_init(void)" (??1do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _ERR_remove_state referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::~do_init(void)" (??1do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>gtest.obj : error LNK2019: unresolved external symbol _ENGINE_cleanup referenced in function "public: __thiscall boost::asio::ssl::detail::openssl_init_base::do_init::~do_init(void)" (??1do_init@openssl_init_base@detail@ssl@asio@boost@@QAE@XZ) 1>D:\program\gdnscenter-1.12.2\src\Debug\gtest.exe : fatal error LNK1120: 13 unresolved externals ========== Build: 0 succeeded, 1 failed, 3 up-to-date, 0 skipped ========== ########################################## the simiar question in stackoverflow : http://stackoverflow.com/questions/9357751/boost-ssl-with-visual-studio-201… . I use the openssl win64. So, Maybe a bug in asio? Thank you.

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