September 2010 - Boost-users - lists.preview.boost.org

[Asio]What's the behavior of socket.async_write() after socket.close() is called?
by 鑫炜廖 05 Nov '10

05 Nov '10

Hi, If I call socket.close() but I still have some data in my buffer, can I call async_write() later? When I call socket.close(), maybe an async_write operation is running, when it's complete I want to send data in another buffer(data written while previous async_write() is running, before socket.close() was called), but the socket is closed.Does it work in this situation?If not, what's the alternative way? The code looks like this: char front_buffer[kBufferSize]; char back_buffer[kBufferSize]; void HandleWrite(...) { //socket is closed. Does this work? socket.async_write(back_buffer, ...); } socket.async_write(front_buffer, HandleWrite); // write data to back_buffer socket.close();

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Polymorphic serialization with polymorphic archives problems... [part 2]
by Bogdan 03 Nov '10

03 Nov '10

First I would like to confirm I tested Robert Ramey's fix (@60273) for multiple registrations and it looks good in my runs. Thank you Robert! On the other hand, I am under the impression there is a bug in void_caster::recursive_unregister(), although I am not 100% certain about the reason: that function member is called in the destructors of the void caster template classes and makes use of the void_caster_registry singleton (more specifically the type_set). I believe it searches the set for all the void caster entries that are descendants of the current one (i.e., the one being destroyed) and performs the following ops: - delete the shortcuts. - remove the corresponding entries from the set. However, void_caster::recursive_unregister() DOESN'T REMOVE FROM THE REGISTRAR the entry corresponding to the current void_caster(). This creates the problem below: consider a scenario where a dll containing some serialization functionality is loaded explicitly at runtime (i.e., using LoadLibrary() on Windows or dlopen on Unix). There are no parent-child relationships among the serialized classes registered by that DLL: all serialized classes are derived from one abstract base. While unloading the library, its void_caster singletons are destroyed but there are no shortcuts to remove from the global registrar since there are no parent-child relationships. All entries corresponding to those are still in the global registrar and POINT TO THE void_caster SINGLETONS ALREADY DESTROYED AND DISCARDED. When the main process exits, the registrar traversal repeats for whatever process-bound void_caster singletons are about to be destroyed. During these subsequent traversals, void_caster::recursive_unregister() visits the entries left after the previous explicit dll download and tries to identify the parent-child relationship. In doing so, it accesses the dangling vc pointers generating access violations: void_cast.cpp(Line 286): const void_caster * vc = *it; void_cast.cpp(Line 287): if(vc->m_parent == this){ //<--------------------- here is the access violation I can reproduce the crash systematically, but I am not sure about the reason or whether a simple unregistration is enough. I believe this is (again) a question for Robert, but I thank for any feedback I might get. Bogdan

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[asio] Error running as Windows service; runs fine from console
by Evan Burkitt 26 Oct '10

26 Oct '10

I have a Windows application that uses ASIO to implement a server that listens on a TCP port. When I run it from the console it starts and operates without error. When I start the same application as a Windows service (it's written to be run either way) my call to boost::asio::ip::tcp::acceptor::async_accept() immediately calls the passed accept handler to report error 995: "The I/O operation has been aborted because of either a thread exit or an application request". This occurs even when I run the service under the same account as the logged-in user. I know I'm a bit sketchy with the details of my implementation, but I think this is at least as likely to be some Windows weirdness as an ASIO problem per se. I'm hoping someone else has encountered and fixed this problem before. Thanks. -evan

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[Boost.MPI] question about serializing custom object
by Cristobal Navarro 16 Oct '10

16 Oct '10

hello everybody, this is first post i have some questions after reading the Boost documentation of serialization and MPI, is it possible to serialize my custom objects with Boost.serialize and then send/receive them using plain openMPI as MPI_BYTE type?? the other question is on the tutorials i only found examples of serializing objects to archive and saving to file, but i didnt find any example where they serialize it to a binary form and send them through mpi, is there any example of this type on the documentation? best regards Cristobal

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[MPI, serialization] Segmentation fault in heterogeneous cluster
by Francesco Biscani 16 Oct '10

16 Oct '10

Hello, I'm getting a segfault when using Boost.MPI on a cluster of heterogeneous machines (x86_64 and ppc64). The problem arises when the "slave" machine, ppc64, receives its payload from the "master" machine, x86_64, and tries to unpack the archive. Tracing down the issue with valgrind and in debug mode, the problem arises here: ==28632== Invalid write of size 8 ==28632== at 0x10429DDC: boost::archive::detail::basic_iarchive_impl::load_pointer(boost::archive::detail::basic_iarchive&, void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (basic_iarchive.cpp:453) ==28632== by 0x1042772F: boost::archive::detail::basic_iarchive::load_pointer(void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (basic_iarchive.cpp:564) ==28632== by 0x10468707: void boost::archive::detail::load_pointer_type<boost::mpi::packed_iarchive>::invoke<pagmo::population*>(boost::mpi::packed_iarchive&, pagmo::population*&) (iserializer.hpp:518) ==28632== by 0x104683EF: void boost::archive::load<boost::mpi::packed_iarchive, pagmo::population*>(boost::mpi::packed_iarchive&, pagmo::population*&) (iserializer.hpp:586) ==28632== by 0x10468223: void boost::archive::detail::common_iarchive<boost::mpi::packed_iarchive>::load_override<pagmo::population*>(pagmo::population*&, int) (common_iarchive.hpp:68) ==28632== by 0x10468023: void boost::archive::basic_binary_iarchive<boost::mpi::packed_iarchive>::load_override<pagmo::population*>(pagmo::population*&, int) (basic_binary_iarchive.hpp:67) ==28632== by 0x10467E27: void boost::mpi::packed_iarchive::load_override<pagmo::population*>(pagmo::population*&, int, mpl_::bool_<false>) (packed_iarchive.hpp:98) ==28632== by 0x10467C27: void boost::mpi::packed_iarchive::load_override<pagmo::population*>(pagmo::population*&, int) (packed_iarchive.hpp:115) ==28632== by 0x1046798F: boost::mpi::packed_iarchive& boost::archive::detail::interface_iarchive<boost::mpi::packed_iarchive>::operator>><pagmo::population*>(pagmo::population*&) (interface_iarchive.hpp:60) ==28632== by 0x104676BB: void boost::serialization::nvp<pagmo::population*>::load<boost::mpi::packed_iarchive>(boost::mpi::packed_iarchive&, unsigned int) (nvp.hpp:87) ==28632== by 0x104674AF: void boost::serialization::access::member_load<boost::mpi::packed_iarchive, boost::serialization::nvp<pagmo::population*> >(boost::mpi::packed_iarchive&, boost::serialization::nvp<pagmo::population*>&, unsigned int) (access.hpp:101) ==28632== by 0x104672CF: boost::serialization::detail::member_loader<boost::mpi::packed_iarchive, boost::serialization::nvp<pagmo::population*> >::invoke(boost::mpi::packed_iarchive&, boost::serialization::nvp<pagmo::population*>&, unsigned int) (split_member.hpp:54) ==28632== Address 0x4b65d98 is not stack'd, malloc'd or (recently) free'd The issue is in the method basic_iarchive_impl::load_pointer, around line 450: int i = cid; cobject_id_vector[i].bpis_ptr = bpis_ptr; Indeed, a printf confirms that i == 512 while cobject_id_vector.size() == 3. This also provokes the assertion new_cid == cid to fail one line below (where new_cid == 2). The same code, run locally on the ppc64 acting both as slave and master with mpirun -np 2, runs ok. Boost version is 1.42.0, MPI implementation is openMPI 1.4.2. Can this be related to some endianness issue? Is Boost.MPI expected to work on heterogeneous clusters? Thanks, Francesco.

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[Fusion] How to join more than two sequences
by Clinton Mead 06 Oct '10

06 Oct '10

Hi All I've noticed the function "join" in the boost fusion library. However, it only joins two sequences. Was wondering whether there is (or can be easily made) a function that joins any number of sequences. For example: new_join(make_vector(1,2,3), make_vector(4,5), make_vector(6)) -> is the sequence 1,2,3,4,5,6 AND/OR (pass parameters in a sequence) new_join(make_vector(make_ vector(1,2,3), make_vector(4,5), make_vector(6))) -> is the sequence 1,2,3,4,5,6 I'd prefer both the first and second versions, but even one version would be ok. Thanks, Clinton

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Boost: Getting Started on Windows
by Olivier Bertrand 05 Oct '10

05 Oct '10

Using this tutorial I tried to build the first sample with Windows Visual C++ 6.0. All seems correct in the settings, but the compilation failed with the following messages: --------------------Configuration: Sample - Win32 Debug-------------------- Compiling... Lambda.cpp c:\boost_1_44\boost\config\suffix.hpp(588) : error C2039: 'typeinfo' : is not a member of '`global namespace'' c:\boost_1_44\boost\config\suffix.hpp(588) : error C2873: 'typeinfo' : symbol cannot be used in a using-declaration c:\boost_1_44\boost\mpl\aux_\yes_no.hpp(56) : fatal error C1506: unrecoverable block scoping error Error executing cl.exe. Sample.exe - 3 error(s), 0 warning(s) The second sample gave me similar errors. I need help to be able to use the Boost libs...

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[serialization] boost::serialization adds huge amounts of exports to resultant Windows PE file
by Chris Yuen 04 Oct '10

04 Oct '10

Hey guys, I am using boost::serialization from 1.44.0. One thing that I noticed is that linking statically to the serialization libs will add several hundred exports in the final exe file that I get. Using `dumpbin /exports my_program.exe` Here's a brief illustration: Let's say we have a typical Hello World program (code example at the end of this message) that uses `iostream`. Here's what we get when we run `dumpbin /exports my_program.exe`. Dump of file my_program.exe File Type: EXECUTABLE IMAGE Summary 4000 .data 2000 .pdata 7000 .rdata 1000 .rsrc 18000 .text However, if we just add 6 lines of code to include boost::serialization (code example at the end of this message), we would get tons of exports. Dump of file my_program.exe File Type: EXECUTABLE IMAGE Section contains the following exports for my_program.exe 00000000 characteristics 4CA376FA time date stamp Thu Sep 30 01:27:22 2010 0.00 version 1 ordinal base 14 number of functions 14 number of names ordinal hint RVA name 1 0 00029480 ??_B?1??get_instance@?$singleton@V?$map@Vtext_oarchive@archive@boost@@@?A0xca82ee40@detail@archive@boost@@@serialization@boost@@CAAEAV?$map@Vtext_oarchive@archive@boost@@@?A0xca82ee40@detail@archive@3@XZ@51 = ??_B?1??get_instance@?$singleton@V?$map@Vtext_oarchive@archive@boost@@@?A0xca82ee40@detail@archive@boost@@@serialization@boost@@CAAEAV?$map@Vtext_oarchive@archive@boost@@@?A0xca82ee40@detail@archive@3@XZ@51 (`private: static class boost::archive::detail::`anonymous namespace'::map<class boost::archive::text_oarchive> & __cdecl boost::serialization::singleton<class boost::archive::detail::`anonymous namespace'::map<class boost::archive::text_oarchive> >::get_instance(void)'::`2'::`local static guard'{2}') 2 1 000294B0 ??_B?1??get_instance@?$singleton@V?$multiset@PEBVextended_type_info@serialization@boost@@Ukey_compare@detail@23@V?$allocator@PEBVextended_type_info@serialization@boost@@@std@@@std@@@serialization@boost@@CAAEAV?$multiset@PEBVextended_type_info@serialization@boost@@Ukey_compare@detail@23@V?$allocator@PEBVextended_type_info@serialization@boost@@@std@@@std@@XZ@51 = ??_B?1??get_instance@?$singleton@V?$multiset@PEBVextended_type_info@serialization@boost@@Ukey_compare@detail@23@V?$allocator@PEBVextended_type_info@serialization@boost@@@std@@@std@@@serialization@boost@@CAAEAV?$multi ...elided This is indeed very strange since compiling a `exe` file shouldn't get me any of these "exports" at all. Anyone has an idea what's going wrong? I am using MSVS2005 Release|x64. I compiled boost with `bjam threading=multi link=static runtime-link=static toolset=msvc-8.0`. Thank you for guidance in advance! Best regards, Chris Yuen // Source code to my_program.exe #include <iostream> #include <sstream> // Uncommenting the following block would introduce tons of // exports in the final exe. Even though this block of code // is never executed. //#include <boost/archive/text_oarchive.hpp> //void nothing() { //std::stringstream stream; //boost::archive::text_oarchive oa(stream); //} int main() { using namespace std; std::cout << "Hello World" << std::endl; return 0; }

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Boost Logos
by Ruediger Berlich 04 Oct '10

04 Oct '10

Dear all, I remember that there was a discussion a while ago about logos. Among the proposals was a logo of the type "This code uses Boost". I'd like to acknowledge the great work of the Boost library authors and would thus like to add the logo to the manual of our software. Therefore: I cannot find any "official" logos on the Boost web page that would allow me to do this. What has become of this effort ? Best Regards, Ruediger

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[BGL] SPPRC formulation
by Adam Spargo 02 Oct '10

02 Oct '10

Hi, I would like to use the r_c_shortest_paths algorithm. My constraint is that given pairs of vertices i, j (each i have a single mate j) must have a distance between them which is consistent with a given distribution. I am looking for the path which is most consistent with this distribution. Does anybody have any experience of formulating such a constraint in BGL? The second problem is that I am currently modelling the problem with an undirected graph. The edges could be viewed as bi-directional, but only due to the double stranded nature of DNA. Once I have started on a path I just choose the label which is consistent with the direction I am going, but the graph is essentially undirected, you can always go in either direction down an edge. Could an undirected graph be used with this algorithm or must I use a directed graph? I have tried to ask this question before, hopefully this time I have phrased it better - plus I am actually ready to code it now. As always, any advice gratefully received. Adam. -- Dr Adam Spargo High Performance Assembly Group email: aws(a)sanger.ac.uk Wellcome Trust Sanger Institute Tel: +44 (0)1223 834244 x7728 Hinxton, Cambridge CB10 1SA Fax: +44 (0)1223 494919 -- The Wellcome Trust Sanger Institute is operated by Genome Research Limited, a charity registered in England with number 1021457 and a company registered in England with number 2742969, whose registered office is 215 Euston Road, London, NW1 2BE.

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