May 2014 - Boost-users - lists.preview.boost.org

Why does async_connect() call listen()?
by Soren Dreijer 01 Jul '14

01 Jul '14

Hi there, By coincidence, I ended up looking at a stack trace where my application calls async_connect() on a asio::ip::tcp::socket. Two things took me by surprise: 1. Asio calls listen() under the hood. Why does it do that when I'm just trying to make an outbound TCP connection? 2. If the listen() call above is indeed required, why does it happen on the same thread where I call async_connect()? I thought the point of the method was to defer the work to the reactor? (For what it's worth, I've had a case on a customer's machine where the call to listen() would hang for 30 seconds before returning -- probably because of a bad firewall -- causing my entire app to hang since the code assumes async_connect() is indeed async.) I've included the full stack trace below. Thanks, Soren 0:000> k ChildEBP RetAddr 0117db50 0f681c65 WS2_32!listen 0117db70 0f691013 EvoClr!boost::asio::detail::socket_ops::listen+0x35 [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\impl\socket_ops.ipp @ 658] 0117dbd8 0f690e9f EvoClr!boost::asio::detail::socket_select_interrupter::open_descriptors+0x163 [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\impl\socket_select_interrupter.ipp @ 78] 0117dbe4 0f690cc0 EvoClr!boost::asio::detail::socket_select_interrupter::socket_select_interrupter+0xf [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\impl\socket_select_interrupter.ipp @ 42] 0117dc1c 0f690c1e EvoClr!boost::asio::detail::select_reactor::select_reactor+0x70 [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\impl\select_reactor.ipp @ 48] 0117dc44 0f17837e EvoClr!boost::asio::detail::service_registry::create<boost::asio::detail::select_reactor>+0x4e [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\impl\service_registry.hpp @ 81] 0117dc80 0f6909e9 EvoClr!boost::asio::detail::service_registry::do_use_service+0x9e [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\impl\service_registry.ipp @ 123] 0117dca0 0f6908ee EvoClr!boost::asio::detail::service_registry::use_service<boost::asio::detail::select_reactor>+0x39 [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\impl\service_registry.hpp @ 49] 0117dca8 0f68fab0 EvoClr!boost::asio::use_service<boost::asio::detail::select_reactor>+0xe [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\impl\io_service.hpp @ 34] 0117dcbc 0f68f731 EvoClr!boost::asio::detail::win_iocp_socket_service_base::get_reactor+0x30 [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\impl\win_iocp_socket_service_base.ipp @ 620] 0117dce4 0f68f6f1 EvoClr!boost::asio::detail::win_iocp_socket_service_base::start_connect_op+0x11 [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\impl\win_iocp_socket_service_base.ipp @ 550] 0117dd28 0f68ed22 EvoClr!boost::asio::detail::win_iocp_socket_service<boost::asio::ip::tcp>::async_connect<boost::_bi::bind_t<void,boost::_mfi::mf1<void,Swift::BoostConnection,boost::system::error_code const &>,boost::_bi::list2<boost::_bi::value<boost::shared_ptr<Swift::BoostConnection> >,boost::arg<1> > > >+0xc1 [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\detail\win_iocp_socket_service.hpp @ 515] 0117dd68 0f68c41a EvoClr!boost::asio::stream_socket_service<boost::asio::ip::tcp>::async_connect<boost::_bi::bind_t<void,boost::_mfi::mf1<void,Swift::BoostConnection,boost::system::error_code const &>,boost::_bi::list2<boost::_bi::value<boost::shared_ptr<Swift::BoostConnection> >,boost::arg<1> > > >+0x52 [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\stream_socket_service.hpp @ 234] 0117ddec 0f68a32e EvoClr!boost::asio::basic_socket<boost::asio::ip::tcp,boost::asio::stream_socket_service<boost::asio::ip::tcp> >::async_connect<boost::_bi::bind_t<void,boost::_mfi::mf1<void,Swift::BoostConnection,boost::system::error_code const &>,boost::_bi::list2<boost::_bi::value<boost::shared_ptr<Swift::BoostConnection> >,boost::arg<1> > > >+0x11a [c:\private\src\vendor\boost_1_55_0_sdk\include\boost\asio\basic_socket.hpp @ 779] 0117de9c 0f210146 EvoClr!Swift::BoostConnection::connect+0x11e [c:\private\src\vendor\swift\swiften\network\boostconnection.cpp @ 70]

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Autobahn for C++: RPC and PubSub
by Tobias Oberstein 24 Jun '14

24 Jun '14

Hi, I'm happy to anounce Autobahn|Cpp - another subproject of Autobahn (http://autobahn.ws) this time for C++ 11 / Boost. Autobahn|Cpp allows remote procedure calls and publish & subscribe messaging for C++ application components and uses boost::future, continuations and Boost/ASIO as underlying network library. Here is how app code looks like: https://github.com/tavendo/AutobahnCpp/blob/master/README.md#show-me-some-c… Using Autobahn|Cpp, you can e.g. call your C++ code from JavaScript running in a browser. And much more. This is an early alpha version, things aren't fully hashed out, but there are a couple of examples included here: https://github.com/tavendo/AutobahnCpp/blob/master/README.md#examples Cheers, /Tobias

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[Python]compiling python library
by Miklós Tóth 19 Jun '14

19 Jun '14

Hi All, I want to embed python in my c++ code using boost.python library. As far as I understand I need python headers and libs. So my python27.lib is "incompatible". I want to compile it from code but I failed with mingw32. Could you give me some advice, or links to achieve my goal? I'm using gcc4.6.3 and qt 4.8.2 and boost 1.49 on windows 7. Thanks, Miklós

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Sanity check please?: Boost 1_55_0 and building VS2012 static libs?
by g4＠novadsp.com 04 Jun '14

04 Jun '14

Revisiting Boost after a long absence. Any thoughts on the following problem(s)? W7x64 with VS2008,2010,2012 and 2013 installed. VS2012 preferred for regular use. Built with boostrap and b2 b2 -link=static -runtime-link=static -toolset=msvc-11.0. I compile a debug test app with /MTd and attempt to link with libboost_system-vc110-mt-gd-1_55.lib which is the only library close to matching the ABI tag specified here : http://www.boost.org/doc/libs/1_55_0/more/getting_started/windows.html#id46 Ensuing link errors are: 1>libboost_system-vc110-mt-gd-1_55.lib(error_code.obj) : error LNK2038: mismatch detected for '_ITERATOR_DEBUG_LEVEL': value '2' doesn't match value '0' in tcpproxy_server.obj 1>libboost_system-vc110-mt-gd-1_55.lib(error_code.obj) : error LNK2038: mismatch detected for 'RuntimeLibrary': value 'MDd_DynamicDebug' doesn't match value 'MT_StaticRelease' in tcpproxy_server.obj 1>LINK : warning LNK4098: defaultlib 'MSVCRTD' conflicts with use of other libs; use /NODEFAULTLIB:library Many thanks.

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Re: [Boost-users] [serialization] deserialized instance empty even though proper serialize methods called
by Hickman, Steve (AdvTech) 31 May '14

31 May '14

From: Robert Ramey [mailto:robertmacleranramey@gmail.com] Sent: Friday, May 30, 2014 3:43 PM To: boostusers(a)googlegroups.com Cc: robertmacleranramey(a)gmail.com; boost-users(a)lists.boost.org; boost-users(a)lists.boost.org; Hickman, Steve (AdvTech) Subject: Re: [Boost-users] [serialization] deserialized instance empty even though proper serialize methods called On Friday, May 30, 2014 2:37:00 PM UTC-7, Hickman, Steve (AdvTech) wrote: I corrected the problem with the DLL import. That had no discernible effect. lol - you didn't tell me there was a problem with DLL import. The issue here was link warnings due to the fact that I was importing back into the DLL exported interfaces. I fixed this by changing how my DLL import macros in my header files expand for the library being built. When used in the library, they expand to nothing, otherwise they expand to “__declspec(dllimport)”. The actual function definitions in the .cpp files always expand to “__declspec(dllexport)” when the library is built as a DLL. It does not throw an unregistered_cast() exception (which it seems like it should). Consider filing a trac item for this. Done this strongly suggests a problem with EXPORT ing the derived class. Note that that each DLL contains it's own casting table. Of hand I don't remember which EXPORT s get added to which table. Certainly the EXPORT IMPLEMENT should be the *cpp file which is part of the DLL. It is One way to test this would be to verify that the static library build/test works. This always has only one table so such problem wouldn't come up. Building/linking my library statically does solve the problem. And it works for the application I need to use it for, so I’m going with that approach for now. . But it still leaves open the question of why we're getting to this point. There are two approaches to a problem like this: a) Just "make it work" by adding stuff until it seems to work. This is the approach favored by management. Given my current time constraints, using a static library works and will be my approach until I see it break. b) Get to the bottom of it and fix it once it once an for all - and add notes/comments and/or tests to make sure the bugger stays dead. This is the approach favored by (unemployed) programmers. And since I’m trying to avoid unemployment, I’ll have to delay this for now. The former seems to work - but the problem keeps sucking up time in the future. The latter is tedious and frustrating - but this keeps one from getting stuck in a dead end job constantly fixing the same problems. Robert Ramey --- Steve H.

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[boost.msm] BOOST_MSM_EUML_DECLARE_STATE_MACHINE with state base class
by Stefan Näwe 31 May '14

31 May '14

Hi there, I use MSM from boost 1.49 with VC9 on Windows XP. I want to use the eUML front end. My states shall use a polymorphic base class and are defined like this: // State base class struct Worker { virtual void work() = 0; }; // a state struct Running_ : msmf::state<Worker>, euml_state<Running_> { void work() { ... } } const Running; My transition table is defined with BOOST_MSM_EUML_TRANSITION_TABLE() My state machine is defined like this: BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( trans_table, init_ << AnyState, no_action, // fsm_entry no_action, // fsm_exit attributes_ << one_attr << another_attr, configure_ << no_configure_, Log_No_Transition, Log_Exception), MyFSM_fe) struct FSM : msmb::state_machine<MyFSM_fe> {}; All OK until here. But now I want to add the state base class to the above invocation of BOOST_MSM_EUML_DECLARE_STATE_MACHINE to be able to say : fsm.get_state_by_id(fsm.current_state()[0])->work() at any given time. BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( trans_table, init_ << Running, no_action, // fsm_entry no_action, // fsm_exit attributes_ << one_attr << another_attr, configure_ << no_configure_, Log_No_Transition, Log_Exception, Worker), MyFSM_fe) But this gives me a compile error: C2275: 'Worker' : illegal use of this type as an expression. Is there any way to achieve what I need ? Can I somehow _NOT_ use the macro and create the same state machine (i.e. with attributes!) ? Thanks for any help! Stefan -- ---------------------------------------------------------------- /dev/random says: A Bugless Program is an Abstract Theoretical Concept. python -c "print '73746566616e2e6e616577654061746c61732d656c656b74726f6e696b2e636f6d'.decode('hex')" GPG Key fingerprint = 2DF5 E01B 09C3 7501 BCA9 9666 829B 49C5 9221 27AF

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Directed graph, incoming edges
by Jeremy Murphy 31 May '14

31 May '14

Just wondering what people generally do when they want to model a directed graph but they also want efficient access to the incoming edges of a vertex? Make a bidirectional graph and store directionality as a property of an edge? Thanks, cheers. Jeremy

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Re: [Boost-users] [serialization] deserialized instance empty even though proper serialize methods called
by Hickman, Steve (AdvTech) 30 May '14

30 May '14

I corrected the problem with the DLL import. That had no discernible effect. FWIW, I also note at this point that I have set all serializable classes to BOOST_CLASS_IMPLEMENTATION(fully_qualified_classname,boost::serialization::object_serializable); because I don’t save any of the archives. Since I’m only using this for immediate “over the wire” communication, I don’t need backwards compatibility. On the tracking bug: It would also be interesting to run your own test with the default tracking behavior to see if the symptom disappears. I set up to run with default tracking behavior. This had no discernible effect on stopping pointer_tweak (line 527 in iserializer.hpp) from nullifying the pointer to the deserialized instance. I didn’t look to see if it had an impact on the tracking flag (not certain how I would know since now tracking *should* be on) In the .cpp files of all serialized classes. This shouldn’t matter because I never read references to prior instances As far as we know. I never reference prior instances because, at least for the tests I’m running, the data structures don’t contain pointers. They do contain members that are also defined in the library. These members are never, at least in the tests I’m running, handled via pointers. In addition, I using this facility to serialize data that I send “over the wire” one data structure at a time. In each case I open a new archive to serialize one data structure instance, then extract the buffer created and close the archive. Similarly, on the receiving side, I open an archive for each structure I deserialize, do the deserialization, then close the archive (in both cases the archive stack variables go out of scope). It may be that on the receive side that there is some static data in the serialization library that thinks it needs to turn serialization on – I don’t know. I haven’t dug into that. Using/not using tracking is subservient to actually getting the deserialized data, so I’ll leave it with the default behavior for now. There remains the core problem that the call to pointer_tweak on line 527 of iserailzer.hpp causes the t pointer (the one containing the deserialized data) to be nullified. Digging into pointer_tweak, it appears that the problem lies in void_upcast(lines 314-334) in void_cast.cpp. While it receives the appropriate type information for both the base and derived class, it cannot find any info in the void_caster_register (which has size zero) to tell it how to convert one to the other, so it returns null. (line 333). It does not throw an unregistered_cast() exception (which it seems like it should). Could the problem lie in that because this is a DLL, its singletons (like void_caster_registry) are singletons across all EXEs that use that DLL ? Microsoft doc seems to indicate that isn’t the case (see http://msdn.microsoft.com/en-us/library/h90dkhs0(v=vs.90).aspx ) by default at least. If there is a problem here, I could envision the following scenario: In my case, both the serializing and deserializing EXEs are running in parallel, so they could be affecting any static data in the DLL. In particular, they both could be updating and clearing the void_caster_registry. If void_caster::recursive_unregister() has been called by the serializing EXE, it may not contain anything that is now needed by the deserializing EXE. Does that make sense? Is that possible? Regardless of what is causing the problem, should this be solvable by adding the explicit // method 2 : explicitly register base/derived relationship boost::serialization::void_cast_register<derived, base>( static_cast<derived *>=NULL), static_cast<base *>(NULL) to all my serialize methods? It doesn’t fix it for me(I added the appropriate calls as the first statement after a logging statement in all the serialize methods). Furthermore, the void_cast_registry still has size 0. --- Steve H.

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date_time: nth friday of month
by MM 30 May '14

30 May '14

Hello, Is there an object that encodes "second friday of month", rather than "second friday of april"? Then you would pass to it month + year to get a date? If not, how would I implement such a type? Extend nth_day_of_the_week_in_month? Thanks,

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how to correctly compile and use math module (for gmp) (b1.55 win32)
by eaj68 30 May '14

30 May '14

When compiling only regex module all works ok, but when I substitute 'math' for regex in command i get this: b2 -a --debug-configuration --prefix=C:\boost --address-model=32 --with math --layout=tagged toolset=gcc variant=release link=static threading=single runtime-link=static optimization=off notice: found boost-build.jam at C:/boost/boost-build.jam notice: loading Boost.Build from C:/boost/tools/build/v2 notice: Searching 'C:\WINDOWS' 'C:\Documents and Settings\Administrator' 'C:\Documents and Settings\Administrator' 'C:\boost\tools/build/v2' 'C:/boost/tools/build/v2/kernel' 'C:/boost/tools/build/v2/util' 'C:/boost/tools/build/v2/build' 'C:/boost/tools/build/v2/tools' 'C:/boost/tools/build/v2/contrib' 'C:/boost/tools/build/v2/.' for site-config configuration file 'site-config.jam'. notice: Loading site-config configuration file 'site-config.jam' from 'C:/boost/tools/build/v2'. notice: Searching 'C:\Documents and Settings\Administrator' 'C:\Documents and Settings\Administrator' 'C:\boost\tools/build/v2' 'C:/boost/tools/build/v2/kernel' 'C:/boost/tools/build/v2/util' 'C:/boost/tools/build/v2/build' 'C:/boost/tools/build/v2/tools' 'C:/boost/tools/build/v2/contrib' 'C:/boost/tools/build/v2/.' for user-config configuration file 'user-config.jam'. notice: Loading user-config configuration file 'user-config.jam' from 'C:/boost/tools/build/v2'. notice: Searching '.' for project-config configuration file 'project-config.jam'. notice: Loading project-config configuration file 'project-config.jam' from '.'. warning: toolset msvc initialization: can not find tool cl.exe warning: initialized from project-config.jam:3 notice: will use 'cl.exe' for msvc, condition <toolset>msvc notice: [msvc-cfg] condition: '<toolset>msvc/<architecture>/<address-model>', setup: '' notice: [msvc-cfg] condition: '<toolset>msvc/<architecture>/<address-model>32', setup: '' notice: [msvc-cfg] condition: '<toolset>msvc/<architecture>x86/<address-model>', setup: '' notice: [msvc-cfg] condition: '<toolset>msvc/<architecture>x86/<address-model>32', setup: '' notice: [msvc-cfg] condition: '<toolset>msvc/<architecture>/<address-model>64', setup: '' notice: [msvc-cfg] condition: '<toolset>msvc/<architecture>x86/<address-model>64', setup: '' notice: [msvc-cfg] condition: '<toolset>msvc/<architecture>ia64/<address-model>', setup: '' notice: [msvc-cfg] condition: '<toolset>msvc/<architecture>ia64/<address-model>64', setup: '' notice: [msvc-cfg] condition: '<toolset>msvc/<architecture>arm/<address-model>32', setup: '' notice: [cmdline-cfg] toolset gcc not previously configured; attempting to auto-configure now notice: will use 'g++' for gcc, condition <toolset>gcc-4.10.0-mingw notice: using gcc libraries :: <toolset>gcc-4.10.0-mingw :: C:\gcc/bin C:\gcc/lib C:\gcc/lib32 C:\gcc/lib64 warning: toolset gcc initialization: can not find tool C:/gcc/i686-pc-mingw32/bin/ar.exe warning: initialized from notice: using gcc archiver :: <toolset>gcc-4.10.0-mingw :: C:/gcc/i686-pc-mingw32/bin/ar.exe warning: toolset gcc initialization: can not find tool C:/gcc/i686-pc-mingw32/bin/ranlib.exe warning: initialized from notice: using gcc ranlib :: <toolset>gcc-4.10.0-mingw :: C:/gcc/i686-pc-mingw32/bin/ranlib.exe notice: using rc compiler :: <toolset>gcc-4.10.0-mingw :: C:\gcc\bin\windres.exe link.jam: No such file or directory notice: [zlib] Using pre-installed library notice: [zlib] Condition notice: iostreams: not using bzip2 compression notice: iostreams: not using bzip2 compression notice: [python-cfg] Configuring python... notice: [python-cfg] Registry indicates Python 2.6 installed at "C:\Python26\" notice: [python-cfg] Checking interpreter command "python"... notice: [python-cfg] running command 'python -c "from sys import *; print('version=%d.%d\nplatform=%s\nprefix=%s\nexec_prefix=%s\nexecutable=%s' % (version_info[0],version_info[1],platform,prefix,exec_prefix,executable))" 2>&1' notice: [python-cfg] ...does not invoke a working interpreter notice: [python-cfg] Checking interpreter command "C:\Python26\python"... notice: [python-cfg] running command 'C:\Python26\python -c "from sys import *; print('version=%d.%d\nplatform=%s\nprefix=%s\nexec_prefix=%s\nexecutable=%s' % (version_info[0],version_info[1],platform,prefix,exec_prefix,executable))" 2>&1' notice: [python-cfg] ...does not invoke a working interpreter notice: [python-cfg] No working Python interpreter found. notice: [python-cfg] falling back to "python" notice: [python-cfg] Details of this Python configuration: notice: [python-cfg] interpreter commanC: "python" notice: [python-cfg] include path: "Include" notice: [python-cfg] library path: "\libs" notice: [python-cfg] DLL search path: "<empty>" error: Unable to find file or target named error: 'libs/math/build//boost_math' error: referred to from project at error: '.' compiling all the modules without `--where` switch seems to work ok and produce these modules: libboost_atomic-mt-s.a libboost_chrono-mt-s.a libboost_chrono-s.a libboost_coroutine-s.a libboost_date_time-s.a libboost_exception-s.a libboost_filesystem-s.a libboost_graph-s.a libboost_iostreams-s.a libboost_locale-mt-s.a libboost_log_setup-s.a libboost_log-s.a libboost_math_c99f-s.a libboost_math_c99l-s.a libboost_math_c99-s.a libboost_math_tr1f-s.a libboost_math_tr1l-s.a libboost_math_tr1-s.a libboost_prg_exec_monitor-s.a libboost_program_options-s.a libboost_random-s.a libboost_regex-s.a libboost_serialization-s.a libboost_signals-s.a libboost_system-mt-s.a libboost_system-s.a libboost_test_exec_monitor-s.a libboost_thread-mt-s.a libboost_timer-s.a libboost_unit_test_framework-s.a libboost_wave-s.a libboost_wserialization-s.a but when I try to make an appication that uses gmp: (from : http://www.boost.org/doc/libs/1_53_0/libs/multiprecision/doc/html/boost_mul… ) that is only the include part to see it works: #include <iostream> #include <boost/multiprecision/gmp.hpp> int main() { return 0; } I get: In file included from C:\boost_gmp_test.cpp:2:0: c:\boost/boost/multiprecision/gmp.hpp:19:17: fatal error: gmp.h: No such file or directory #include <gmp.h> ^ compilation terminated. But I am sure that I have correctly installed boost ang GCC because regex module compiles and works without any issue. -- View this message in context: http://boost.2283326.n4.nabble.com/how-to-correctly-compile-and-use-math-mo… Sent from the Boost - Users mailing list archive at Nabble.com.

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