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Very intermittent segmentation fault with boost::multiprecision
by tjisana (泰志) 11 Feb '22

11 Feb '22

Team, Trying to get to the root of a very intermittent seg fault in my program. Here's the snipped (not able to reproduce) as the section of code is part of a callback and I'm not sure how to reproduce it. Here's the tickPrice method and the trace from gdb is below that ... any thoughts? TJ void ib_trading_engine::tickPrice(TickerId tickerId, TickType field, double price, const TickAttrib& attribs) { this -> current_time(); ticksnapshot_complete_ = false; last_tick spy_call_trade; last_tick spy_put_trade; last_tick qqq_call_trade; last_tick qqq_put_trade; spy_call_trade.contract(spy_call_contract_); spy_call_trade.datetime(local_time_); spy_call_trade.symbol(spy_call_symbol_); spy_put_trade.contract(spy_put_contract_); spy_put_trade.datetime(local_time_); spy_put_trade.symbol(spy_put_symbol_); qqq_call_trade.contract(qqq_call_contract_); qqq_call_trade.datetime(local_time_); qqq_call_trade.symbol(qqq_call_symbol_); qqq_put_trade.contract(qqq_put_contract_); qqq_put_trade.datetime(local_time_); qqq_put_trade.symbol(qqq_put_symbol_); try { if (tickerId == 1001 && field == TickType::LAST) { spy_strike_ = (unsigned int)std::trunc(price); ticksnapshot_complete_ = true; last_spy_price_ = bmp::cpp_dec_float_50(price); } else if (tickerId == 1002) { switch (field) { case TickType::BID: last_call_bid_ = bmp::cpp_dec_float_50(price); break; case TickType::ASK: last_call_ask_ = bmp::cpp_dec_float_50(price); break; case TickType::LAST: spy_call_trade.last(bmp::cpp_dec_float_50(price)); trade_queue_.push(spy_call_trade); break; default: break; } } else if (tickerId == 1003) { switch (field) { case TickType::BID: last_put_bid_ = bmp::cpp_dec_float_50(price); break; case TickType::ASK: last_put_ask_= bmp::cpp_dec_float_50(price); break; case TickType::LAST: spy_put_trade.last(bmp::cpp_dec_float_50(price)); trade_queue_.push(spy_put_trade); break; default: break; } } else if (field == TickType::LAST && tickerId == 2001) { qqq_strike_ = (unsigned int)std::trunc(price); ticksnapshot_complete_ = true; last_qqq_price_ = bmp::cpp_dec_float_50(price); } else if (tickerId == 2002) { switch (field) { case TickType::BID: last_call_bid_ = bmp::cpp_dec_float_50(price); break; case TickType::ASK: last_call_ask_ = bmp::cpp_dec_float_50(price); break; case TickType::LAST: qqq_call_trade.last(bmp::cpp_dec_float_50(price)); trade_queue_.push(qqq_call_trade); break; default: break; } } else if (tickerId == 2003) { switch (field) { case TickType::BID: last_put_bid_ = bmp::cpp_dec_float_50(price); break; case TickType::ASK: last_put_ask_= bmp::cpp_dec_float_50(price); break; case TickType::LAST: qqq_put_trade.last(bmp::cpp_dec_float_50(price)); trade_queue_.push(qqq_put_trade); break; default: break; } } } catch (const std::exception& exception) { std::cerr << "ib_trading_engine::tickPrice() exception: " << exception.what() << "\n"; } } Core was generated by `./atm_call_paper_2.1'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x00000000004221fd in boost::multiprecision::backends::cpp_dec_float<50u, int, void>::pow2 (p=30) at /usr/include/boost/multiprecision/cpp_dec_float.hpp:2936 2936 cpp_dec_float<Digits10, ExponentType, Allocator> t; [Current thread is 1 (Thread 0x7fc4418027c0 (LWP 20245))] (gdb) bt #0 0x00000000004221fd in boost::multiprecision::backends::cpp_dec_float<50u, int, void>::pow2 (p=30) at /usr/include/boost/multiprecision/cpp_dec_float.hpp:2936 #1 0x00000000004157ba in boost::multiprecision::backends::cpp_dec_float<50u, int, void>::operator=<double> (this=0x7fc440fe2f40, a=2.9500000000000002) at /usr/include/boost/multiprecision/cpp_dec_float.hpp:2290 #2 0x0000000000411c17 in boost::multiprecision::backends::cpp_dec_float<50u, int, void>::cpp_dec_float<double>(double, std::enable_if<std::is_floating_point<double>::value&&(!std::is_same<double, __float128>::value), void>::type*) (this=0x7fc440fe2f40, val=2.9500000000000002) at /usr/include/boost/multiprecision/cpp_dec_float.hpp:249 #3 0x000000000040fcb6 in boost::multiprecision::number<boost::multiprecision::backends::cpp_dec_float<50u, int, void>, (boost::multiprecision::expression_template_option)1>::number<double>(double const&, std::enable_if<std::is_convertible<boost::multiprecision::detail::canonical<double, boost::multiprecision::backends::cpp_dec_float<50u, int, void> >::type, boost::multiprecision::backends::cpp_dec_float<50u, int, void> >::value&&(!boost::multiprecision::detail::is_restricted_conversion<boost::multiprecision::detail::canonical<double, boost::multiprecision::backends::cpp_dec_float<50u, int, void> >::type, boost::multiprecision::backends::cpp_dec_float<50u, int, void> >::value), void>::type*) (this=0x7fc440fe2f40, v=@0x7fc440fe1d60: 2.9500000000000002) at /usr/include/boost/multiprecision/number.hpp:64 #4 0x0000000000447332 in ib_trading_engine::tickPrice (this=0x1dd0650, tickerId=1002, field=BID, price=2.9500000000000002, attribs=...) at ../src/ib_trading_engine.cpp:700 #5 0x000000000049c5c4 in EDecoder::processTickPriceMsg (this=0x1dd30c0, ptr=0x7fc43c0077a6 "00%", endPtr=0x7fc43c0077a6 "00%") at ../src/client/EDecoder.cpp:65 #6 0x00000000004a7ea6 in EDecoder::parseAndProcessMsg (this=0x1dd30c0, beginPtr=@0x7fc440fe33e8: 0x7fc43c007790 "1", endPtr=0x7fc43c0077a6 "00%") at ../src/client/EDecoder.cpp:2247 #7 0x00000000004bee93 in EReader::processMsgs (this=0x1dd30b0) at ../src/client/EReader.cpp:282 #8 0x0000000000444630 in ib_trading_engine::process_messages (this=0x1dd0650) at ../src/ib_trading_engine.cpp:405 #9 0x000000000044465f in ib_trading_engine::current_time (this=0x1dd0650) at ../src/ib_trading_engine.cpp:410 #10 0x0000000000447086 in ib_trading_engine::tickPrice (this=0x1dd0650, tickerId=1002, field=BID, price=2.96, attribs=...) at ../src/ib_trading_engine.cpp:666

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Crash in async_handshake function
by Ales Mulej 08 Feb '22

08 Feb '22

Hi All, I'm writing TLS client/server and my server is continuously crashing in the async_handshake function. I'm running out of ideas of what I'm doing wrong or how to solve the issue. I'm using VS 2022 and the latest boost from github. Tested with 1.78.0 as well. Using OpenSSL 3.0.1. Code is compiled as x64, /std:c++20. Using a single thread. Simplified function call: on_accept: auto server = boost::make_shared<cserver_session_ws>(std::move(socket), m_ioc, m_ctx); server->run(); run: boost::asio::dispatch(m_ws.get_executor(), boost::beast::bind_front_handler(&cserver_session_ws::on_run, shared_from_this())); on_run: m_ws.next_layer().async_handshake(boost::asio::ssl::stream_base::server, boost::beast::bind_front_handler(&cserver_session_ws::on_handshake, shared_from_this())); on_handshake function never gets called, due to the crash in async_handshake function. m_ws is defined as: boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::tcp_stream>> m_ws; Exception call stack: Unhandled exception thrown: read access violation. **this** was 0x1. boost::asio::detail::scheduler::post_immediate_completion(boost::asio::detail::scheduler_operation ...... Line 349 boost::asio::detail::select_reactor::schedule_timer<boost::asio::detail::chrono_time_traits<std::chrono ..... Line 66 boost::asio::detail::deadline_timer_service<boost::asio::detail::chrono_time_traits ..... Line 273 boost::asio::basic_waitable_timer<std::chrono::steady_clock,boost::asio::wait_traits ...... Line 806 boost::asio::detail::completion_handler_async_result<boost::beast::basic_stream ..... Line 485 boost::asio::async_initiate<boost::beast::basic_stream<boost::asio::ip ..... Line 865 ..... Here are only the last few functions from the call stack. I can share the entire call stack if requested. I would appreciate any help on this as I can't figure out what caused the crash. Regards, A

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Boost SSL handshake(http_server_sync_ssl) : still reachable memory keeps increasing
by Sandeep Bhardwaj 03 Feb '22

03 Feb '22

Hi all, I am using boost 1.76.0 version. I have slightly modified the example program http_server_sync_ssl.cpp to just dump the payload it receives and i have used certificates with ssl context. When I run the program with valgrind, the "still reachable" memory keeps increasing with time. This is one example: ==17719== 38,880 bytes in 60 blocks are still reachable in loss record 740 of 740 ==17719== at 0x4C312EF: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==17719== by 0x567F438: CRYPTO_zalloc (in /usr/lib64/libcrypto.so.1.1) ==17719== by 0x52AA5CA: SSL_SESSION_new (in /usr/lib64/libssl.so.1.1) ==17719== by 0x52AAE22: ??? (in /usr/lib64/libssl.so.1.1) ==17719== by 0x52C8A06: ??? (in /usr/lib64/libssl.so.1.1) ==17719== by 0x52B7FF6: ??? (in /usr/lib64/libssl.so.1.1) ==17719== by 0x52A3F43: SSL_do_handshake (in /usr/lib64/libssl.so.1.1) ==17719== by 0x419630: boost::asio::ssl::detail::engine::do_accept(void*, unsigned long) (engine.ipp:316) ==17719== by 0x4193E3: boost::asio::ssl::detail::engine::perform(int (boost::asio::ssl::detail::engine::*)(void*, unsigned long), void*, unsigned long, boost::system::error_code&, unsigned long*) (engine.ipp:248) ==17719== by 0x418F6D: boost::asio::ssl::detail::engine::handshake(boost::asio::ssl::stream_base::handshake_type, boost::system::error_code&) (engine.ipp:148) ==17719== by 0x419778: boost::asio::ssl::detail::handshake_op::operator()(boost::asio::ssl::detail::engine&, boost::system::error_code&, unsigned long&) const (handshake_op.hpp:47) ==17719== by 0x424DB8: unsigned long boost::asio::ssl::detail::io<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor>, boost::asio::ssl::detail::handshake_op>(boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor>&, boost::asio::ssl::detail::stream_core&, boost::asio::ssl::detail::handshake_op const&, boost::system::error_code&) (io.hpp:38) ==17719== by 0x421332: boost::asio::ssl::stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor>&>::handshake(boost::asio::ssl::stream_base::handshake_type, boost::system::error_code&) (stream.hpp:389) ==17719== by 0x41D5FC: boost::beast::ssl_stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor>&>::handshake(boost::asio::ssl::stream_base::handshake_type, boost::system::error_code&) (ssl_stream.hpp:344) ==17719== by 0x406971: do_session(boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor>&, boost::asio::ssl::context&, std::shared_ptr<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const> const&) (boost_server.cpp:219) I have attached the test program. Can anyone point out what needs to be done here? Thanks & Regards, Sandeep

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Boost DLL shared library handling
by Nicholas Yue 02 Feb '22

02 Feb '22

Hi, I am learning about <boost/dll/shared_library.hpp> So far I have manage to follow along with the tutorial I believe https://www.boost.org/doc/libs/1_77_0/doc/html/boost_dll/tutorial.html Using tutorial 5 as an illustration https://github.com/apolukhin/Boost.DLL/blob/develop/example/tutorial5/load_… On this line, I will have the ability to reference the object of my_api_sum I believe https://github.com/apolukhin/Boost.DLL/blob/develop/example/tutorial5/load_… I have the following questions: 1. If I have a class that is e.g. a shape, say rectangle (of different sizes), what approach may I use to create different instances of the class from the plugin? 2. If my class requires parameters for it's construction, how do I pass it via the shared library loading mechanism ? Or have I been looking to use boost dll shared_library wrongly and that I might look at the plugin being some sort of factory design approach ? Thank you in advance. Cheers -- Nicholas Yue https://www.linkedin.com/in/nicholasyue/

1 0

boost placeholders help
by Hariharan.A.S 25 Jan '22

25 Jan '22

Hi, I am trying to build my catkin workspace for Ros Noetic in my raspberry pi 400 running Buster. I get the following message while building roscpp Scanning dependencies of target roscpp_generate_messages Scanning dependencies of target roscpp [ 31%] Built target roscpp_generate_messages [ 36%] Building CXX object CMakeFiles/roscpp.dir/src/libros/master.cpp.o [ 36%] Building CXX object CMakeFiles/roscpp.dir/src/libros/network.cpp.o [ 36%] Building CXX object CMakeFiles/roscpp.dir/src/libros/subscriber.cpp.o [ 37%] Building CXX object CMakeFiles/roscpp.dir/src/libros/common.cpp.o [ 38%] Building CXX object CMakeFiles/roscpp.dir/src/libros/publisher_link.cpp.o In file included from /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h:32, from /home/pi/ros_catkin_ws/src/ros_comm/roscpp/src/libros/subscriber.cpp:29: /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/publisher.h: In member function ‘boost::function<void(const boost::shared_ptr<ros::SubscriberLink>&)> ros::Publisher::getLastMessageCallback()’: /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/publisher.h:174:70: error: ‘boost::placeholders’ has not been declared return boost::bind(&Impl::pushLastMessage, impl_.get(), boost::placeholders::_1); ^~~~~~~~~~~~ In file included from /home/pi/ros_catkin_ws/src/ros_comm/roscpp/src/libros/subscriber.cpp:29: /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h: In member function ‘ros::Subscriber ros::NodeHandle::subscribe(const string&, uint32_t, void (T::*)(M), T*, const ros::TransportHints&)’: /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h:406:91: error: ‘boost::placeholders’ has not been declared ops.template initByFullCallbackType<M>(topic, queue_size, boost::bind(fp, obj, boost::placeholders::_1)); ^~~~~~~~~~~~ /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h: In member function ‘ros::Subscriber ros::NodeHandle::subscribe(const string&, uint32_t, void (T::*)(M) const, T*, const ros::TransportHints&)’: /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h:417:91: error: ‘boost::placeholders’ has not been declared ops.template initByFullCallbackType<M>(topic, queue_size, boost::bind(fp, obj, boost::placeholders::_1)); ^~~~~~~~~~~~ /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h: In member function ‘ros::Subscriber ros::NodeHandle::subscribe(const string&, uint32_t, void (T::*)(const boost::shared_ptr<const M>&), T*, const ros::TransportHints&)’: /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h:470:73: error: ‘boost::placeholders’ has not been declared ops.template init<M>(topic, queue_size, boost::bind(fp, obj, boost::placeholders::_1)); ^~~~~~~~~~~~ /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h: In member function ‘ros::Subscriber ros::NodeHandle::subscribe(const string&, uint32_t, void (T::*)(const boost::shared_ptr<const M>&) const, T*, const ros::TransportHints&)’: /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h:480:73: error: ‘boost::placeholders’ has not been declared ops.template init<M>(topic, queue_size, boost::bind(fp, obj, boost::placeholders::_1)); ^~~~~~~~~~~~ /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h: In member function ‘ros::Subscriber ros::NodeHandle::subscribe(const string&, uint32_t, void (T::*)(M), const boost::shared_ptr<U>&, const ros::TransportHints&)’: /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h:533:97: error: ‘boost::placeholders’ has not been declared ops.template initByFullCallbackType<M>(topic, queue_size, boost::bind(fp, obj.get(), boost::placeholders::_1)); ^~~~~~~~~~~~ /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h: In member function ‘ros::Subscriber ros::NodeHandle::subscribe(const string&, uint32_t, void (T::*)(M) const, const boost::shared_ptr<U>&, const ros::TransportHints&)’: /home/pi/ros_catkin_ws/src/ros_comm/roscpp/include/ros/node_handle.h:544:97: error: ‘boost::placeholders’ has not been declared ops.template initByFullCallbackType<M>(topic, queue_size, boost::bind(fp, obj.get(), boost::placeholders::_1)); I am not sure how to fix this problem. Any help is much appreciated Thank you Hariharan -- Hariharan.A.S

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Vector values gradients for vector -> scalar function
by Amit Gupta 25 Jan '22

25 Jan '22

I am currently exploring boost as autodiff framework for my application. I would like to calculate the derivative of a vector->scalar function. However I could not find a way to evaluate the same, rather I always get total gradient. Example: How to get the following program yield output equivalent to JAX fwd? #include <boost/math/differentiation/autodiff.hpp> #include <iostream> #include<vector> template <typename T> T power_sum(double p, std::vector<T> &z){ T y=0.0; for (int i=0; i<6;i++){ y += pow(z[i], p); } return y; } int main() { using namespace boost::math::differentiation; constexpr unsigned Order = 2; std::vector<double> z_v = {1.,2.,3.,4.,5.,6.}; std::vector<autodiff_fvar<double, Order> > z; for (int i=0; i<6;i++){ z.push_back(make_fvar<double, Order>(z_v[i])); } auto y = power_sum(2.0,z); std::cout<<y<<"\n"; std::cout<<y.derivative(1)<<"\n"; return 0; } JAX output: import jax as jx import jax.numpy as jnp x = jnp.array([1.0, 2.0, 3.0, 4.0, 5.0, 6.0]) def power_sum(x, p): y = x[0] ** p + x[1] ** p + x[2] ** p + x[3] ** p + x[4] ** p + x[5] ** p return y f_prime = jx.jacfwd(power_sum)(x,2.0) f_prime # DeviceArray([ 2., 4., 6., 8., 10., 12.], dtype=float32) I understand I can do it by send array 6 times with all other vvector values being zero. Is there a better way?

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Re: [Boost-users] casually blocked UDP port
by Alexander Carôt 17 Jan '22

17 Jan '22

Hello again, I'd consider using boost asio SO_REUSEPORT option in order to reuse the port if already taken according to this thread: https://stackoverflow.com/questions/34596638/boost-asio-so-reuseport I will try it asap but please let me know if you have concerns or better solutions. Thanks and best Alex P.S.: see below – I now know how to reproduce the issue: When my application does receive UDP streaming data I spontaneously quit the application. Then doing: "netstat -p UDP" shows me the following Proto Recv-Q Send-Q Local Address Foreign Address (state) udp4 1026 0 *.50050 *.* So, basically the receive queue for this socket is not empty and the previous bind port is indeed still there. If anyone has an idea how to proceed from here on please let me know but now I might be able to fix it myself already. Best Alex Thanks for the swift response, Andreas ! In fact I am aware of what you wrote but with regard to the conditions my app works under it is extremely unlikely that some other process is taking this port. However, the next step for me is to identify which process actually has taken it. In that regard a follow-up question: Once an application (which uses boost sockets) has shut down (for crash or other reasons) the local bind port is also automatically released, right ? In other words: Can the OS stick a port although the corresponding application is not existent anymore ? I've been assuming no so far but maybe I am mistaken so I just need confirmation. Thank you, best Alex -- http://www.carot.de Email : Alexander(a)Carot.de Tel.: +49 (0)177 5719797 > Gesendet: Samstag, 15. Januar 2022 um 23:46 Uhr > Von: "Andreas Wehrmann via Boost-users" <boost-users(a)lists.boost.org> > An: boost-users(a)lists.boost.org > Cc: "Andreas Wehrmann" <a.wehrmann(a)yandex.com> > Betreff: Re: [Boost-users] casually blocked UDP port > > Am 14.01.2022 um 22:50 schrieb Alexander Carôt via Boost-users: > > Hello all, > > > > I have a problem with a a casually blocked UDP bind port: My application uses UDP port 50050 and initiates the socket this way: > > > > So I am basically using bind port 50050 and if it fails I am increasing it by one until the bind suceeds. In most cases the bind to port 50050 works fine but casually after a relaunch of the app or a crash the bind port 50050 appears to be blocked which is why it increases to higher numbers. > > > > Hi, > be aware that UDP sockets may are opened and closed for sending a single > request only by many applications/services. > If the sending application doesn't care about the local port and leaves > it up to the OS to assign a local port number, > you may run into the situation that another application/service/daemon > is opening a UDP socket, > not caring about the local port and the OS happens to assign the port > number that you want to bind your own socket to. > > All the best, > Andreas > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > https://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Re: [Boost-users] casually blocked UDP port
by Alexander Carôt 16 Jan '22

16 Jan '22

P.S.: see below – I now know how to reproduce the issue: When my application does receive UDP streaming data I spontaneously quit the application. Then doing: "netstat -p UDP" shows me the following Proto Recv-Q Send-Q Local Address Foreign Address (state) udp4 1026 0 *.50050 *.* So, basically the receive queue for this socket is not empty and the previous bind port is indeed still there. If anyone has an idea how to proceed from here on please let me know but now I might be able to fix it myself already. Best Alex Thanks for the swift response, Andreas ! In fact I am aware of what you wrote but with regard to the conditions my app works under it is extremely unlikely that some other process is taking this port. However, the next step for me is to identify which process actually has taken it. In that regard a follow-up question: Once an application (which uses boost sockets) has shut down (for crash or other reasons) the local bind port is also automatically released, right ? In other words: Can the OS stick a port although the corresponding application is not existent anymore ? I've been assuming no so far but maybe I am mistaken so I just need confirmation. Thank you, best Alex -- http://www.carot.de Email : Alexander(a)Carot.de Tel.: +49 (0)177 5719797 > Gesendet: Samstag, 15. Januar 2022 um 23:46 Uhr > Von: "Andreas Wehrmann via Boost-users" <boost-users(a)lists.boost.org> > An: boost-users(a)lists.boost.org > Cc: "Andreas Wehrmann" <a.wehrmann(a)yandex.com> > Betreff: Re: [Boost-users] casually blocked UDP port > > Am 14.01.2022 um 22:50 schrieb Alexander Carôt via Boost-users: > > Hello all, > > > > I have a problem with a a casually blocked UDP bind port: My application uses UDP port 50050 and initiates the socket this way: > > > > So I am basically using bind port 50050 and if it fails I am increasing it by one until the bind suceeds. In most cases the bind to port 50050 works fine but casually after a relaunch of the app or a crash the bind port 50050 appears to be blocked which is why it increases to higher numbers. > > > > Hi, > be aware that UDP sockets may are opened and closed for sending a single > request only by many applications/services. > If the sending application doesn't care about the local port and leaves > it up to the OS to assign a local port number, > you may run into the situation that another application/service/daemon > is opening a UDP socket, > not caring about the local port and the OS happens to assign the port > number that you want to bind your own socket to. > > All the best, > Andreas > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > https://lists.boost.org/mailman/listinfo.cgi/boost-users >

1 0

casually blocked UDP port
by Alexander Carôt 16 Jan '22

16 Jan '22

Hello all, I have a problem with a a casually blocked UDP bind port: My application uses UDP port 50050 and initiates the socket this way: udp::resolver resolver(dFC->myIoService); int port = 50050; bool failed; do{ failed = false; udp::resolver::query query(udp::v4(), IPAddress, port); try { dFC->s = new udp::socket( dFC->myIoService, udp::endpoint(*resolver.resolve(query))); } catch (std::exception &e) { failed = true; int intPort = this->intConverter(port); intPort++; ostringstream conv; conv << intPort; port = conv.str(); cout << "new port: " << port << endl; } while (failed); So I am basically using bind port 50050 and if it fails I am increasing it by one until the bind suceeds. In most cases the bind to port 50050 works fine but casually after a relaunch of the app or a crash the bind port 50050 appears to be blocked which is why it increases to higher numbers. Now I wonder how the port can still be taken although the app has terminated and if there is way to force the app / the OS using port 50050 ? So far I have seen this on OSX only – on Windows and Linux I haven't noticed it yet. Thanks in advance for any pointer how to resolve my isse, best Alex -- http://www.carot.de Email : Alexander(a)Carot.de Tel.: +49 (0)177 5719797

2 2

exception on boost serialization
by Alessio Mochi 13 Jan '22

13 Jan '22

Hello, I can't resolve my exception when I compile my qt project with visual studio 2022. Error C2039 'throw_exception': is not a member of 'boost' DentalCad E:\boost_1_78_0\boost\serialization\throw_exception.hpp 30 I tried a compile a small example and work correctly without exception. I don't understand how solve the problem. Have you a suggest? Thanks in advance.

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