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Fix for intrusive on Sun CC
by Chris Hite 30 Sep '09

30 Sep '09

I'm not sure if it fixes everything, but I was able debug some of the meta-programming and find a discrepancy between gcc and Sun CC which causes normal usage to break. http://www.boost.org/doc/libs/1_39_0/boost/intrusive/detail/utilities.hpp template <class T> struct internal_base_hook_bool { template<bool Add> struct two_or_three {one _[2 + Add];}; template <class U> static one test(...); template <class U> static two_or_three<U::boost_intrusive_tags::is_base_hook> test (detail::bool_<U::boost_intrusive_tags::is_base_hook>* = 0); static const std::size_t value = sizeof(test<T>(0)); }; On gcc it does what it's suppose to; value = 1 - iff T has no boost_intrusive_tags::is_base_hook 2 - iff T::boost_intrusive_tags::is_base_hook=false 3 - iff T::boost_intrusive_tags::is_base_hook=true On Sun CC it's always 1. So this is a usage of SFINAE which doesn't seem to work on SunCC, but other examples do work just fine: class_has_move_assign here: http://www.boost.org/doc/libs/1_38_0/boost/unordered/detail/move.hpp Note how they use a second test(int) function. This works on Sun CC! 1) I've never submitted a change. Will someone else take this over or do I need to dive in and submit changes to the repository? Do I need to talk this library's owner first? 2) Is this a definite CC compiler bug?

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[mpl] Can we generate this type in a simpler way?
by vicente.botet 30 Sep '09

30 Sep '09

Hi, I want to generate the following type R1::mth1_<T1, R3::mth1_<T3, C::mth1_> > > from mpl::vector<mpl::pair<R1, T1>, mpl::pair<R3, T3>, C and mth1_? I have started with this template <typename SequenceOfPairs, typename E, ??? MTH> struct generator { typedef ??? type; }; but I don't know what MTH'can be, because we have 3 different mth1_. So I have reached to make a specific mth1_generator (for the specific symbol 'mth1_') template <typename SequenceOfPairs, typename E> struct mth1_generator { typedef ??? type; // The details of the type are ommited using 'mth1' }; satisfying mth1_generate<mpl::vector<mpl::pair<R1, T1>, mpl::pair<R3, T3>, C>::type is equal to R1::mth1_<T1, R3::mth1_<T3, C::mth1_> > > ? As aal the mthX_generator follow the same structure, I have defined a macro DEFINE_GENERATOR which will define the specific generator for a symbol MTH #define DEFINE_GENERATOR(MTH) \ template <typename SequenceOfPairs, typename E> struct MTH##_generator { typedef ??? type; // The details of the type are ommited suing now MTH. } So the user will just have to do DEFINE_GENERATOR(mth1); Can I do it in a simpler way using some kind of traits or this is an inherent preprocessor problem? Thanks for clarifications, _____________________ Vicente Juan Botet Escribá

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[Thread] Naming threads
by Kenneth Porter 30 Sep '09

30 Sep '09

Some platforms offer a way to name threads, for use in a debugger or in process information tools. It would be nice if Boost.Thread encapsulated this. Here's a page with links to methods for Windows, Linux, and BSD: http://stackoverflow.com/questions/778085/how-to-name-a-thread-in-linux

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atomic_inc32 for fast integers
by Archie14 30 Sep '09

30 Sep '09

This boost::interprocess::detail function atomically increments fixed width integer returning old value. Questions: 1. Is there a version that uses fast integers defined in cstdint.hpp? 2. I don't think that it is safe to cast fixed width ints to fast ints. I did not find conversion functions/classes. Do they exists?

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[Proto] Forwarding evaluation via tag
by Joel Falcou 30 Sep '09

30 Sep '09

I have the following grammar that handles the evaluation of various matrix classes: struct eval_xpr : bp::or_< bp::when< bp::terminal< block<bp::_,bp::_> > , _load(bp::_) > , bp::when< bp::plus< eval_xpr,eval_xpr > , bp::call< functor<bp::tag::plus>(eval_xpr(bp::_left ), eval_xpr(bp::_right) ) > > > {}; As you can see, the functor<T> class is a Callable object but not a primitive Transform so I use call to be able to forward the proper things to it. Currently I only play with + but I wanted to know how i can use proto::tag_of and a clever way to conserve the recursive look so it works for any operator of any tag. Basically what should I do to have : bp::when< bp::nary_expr< bp::_, bp::vararg< eval_xpr > > , bp::call< functor< ???? >( eval_xpr(????), ???, ??? ) > > to work for any tag and any number of parameters while typiong the less code possible. I *think* I should make a new Primitive Transform that extarct tags and arguments from bp::_expr and then perform the call to functor but doesn't this mean I have to explicitly write the code for 1,2,3 etc arguments ?

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[Assign] Error using list_of() with Visual C++ 2010 Beta 1
by Paul Baker 30 Sep '09

30 Sep '09

In the Boost.Assign documentation, the following example of list_of() is given: const list<int> primes = list_of(2)(3)(5)(7)(11); However, I have tended to write this instead: const list<int> primes(list_of(2)(3)(5)(7)(11)); This is causing problems with the Microsoft Visual C++ 2010 Beta 1 compiler. Using Visual C++ 2008, both lines compile fine but with 2010 Beta 1, the second produces the following error: error C2668: 'std::list<_Ty>::list' : ambiguous call to overloaded function with [_Ty=int] could be 'std::list<_Ty>::list(std::list<_Ty> &&)' with [_Ty=int] or 'std::list<_Ty>::list(unsigned int)' with [_Ty=int] while trying to match the argument list '(boost::assign_detail::generic_list<T>)' with [T=int] Is this: a) My fault? Should I be using copy initialization rather than direct initialization? b) A problem with the 2010 beta compiler? or c) A problem with Boost.Assign? Thanks

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Re: [Boost-users] request for help re:, brandes_betweenness_centrality for weighted graph
by Emily Greenfest-Allen 30 Sep '09

30 Sep '09

Thank you very much; I had a hunch it had something to do w/default parameters but was unsure how the library handled them. I appreciate the help, Emily Message: 3 Date: Tue, 29 Sep 2009 17:07:30 -0400 (EDT) From: Jeremiah Willcock <jewillco(a)osl.iu.edu> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] request for help re: brandes_betweenness_centrality for weighted graph Message-ID: <alpine.OSX.1.10.0909291705020.77663(a)marvin.osl.iu.edu> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed On Tue, 29 Sep 2009, allenem(a)pcbi.upenn.edu wrote: > > Hi- > > > > I've just recently started to use the BGL and was wondering if someone could > > provide an example (and/or just let me know where I am going wrong) in trying > > to execute the brandes_betweenness_centrality algorithm for a weighted graph. > > Below are the relevant code snippets from my program. I am able to compile > > and run the code, and have successfully iterated over all elements (vertices, > > edges, and "interaction_weights" to verify that the data are stored > > correctly) but the calculated betweenness values are the same whether or not > > I use the edge weight map, which suggests that they are not being considered > > in the calculation even when passed as a parameter to the > > brandes_betweenness_centrality function. What am I missing? > The three-parameter version of brandes_betweenness_centrality has its third parameter as the (output) edge centrality map, not the weight map which you are trying to provide. Try using the named parameter version (as shown on <URL:http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/betweenness_central…>). How to provide named parameters is described at <URL:http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/bgl_named_params.ht…>. -- Jeremiah Willcock

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[Boost Statechart] Execute Function
by Georg Gast 30 Sep '09

30 Sep '09

Hi, i try to build a easy statechart to learn and understand how to use boost::statechart. All i used until today was "homemade" statemachines. At some states i need a "Execute" function. In the FAQ i read, that therefore i should use a a thread and send there an event to the statemachine and process this event. So i wrote a timerclass which uses a thread to process an event via signals2. <code> ----------- timeout.h #ifndef __timeout_h__ #define __timeout_h__ #include <boost/thread.hpp> #include <boost/signals2.hpp> #include <boost/date_time/posix_time/posix_time.hpp> class Timeout { public: typedef boost::signals2::signal<void ()> signal_t; Timeout() : mp_thread(0) { lock lk(m_monitor); } ~Timeout() { lock lk(m_monitor); Terminate(); } boost::signals2::connection connect(const signal_t::slot_type &subscriber) { lock lk(m_monitor); return m_sig.connect(subscriber); } void Start(boost::posix_time::time_duration delta_time, bool repeat = false) { lock lk(m_monitor); if (mp_thread) { Terminate(); } m_repeat = repeat; m_delta_time = delta_time; mp_thread = new boost::thread( boost::bind( &Timeout::Execute, this)); } void Stop() { lock lk(m_monitor); if (mp_thread) { Terminate(); } } private: typedef boost::mutex::scoped_lock lock; void Execute() { try { do { boost::this_thread::sleep(m_delta_time); { lock lk(m_monitor); m_sig(); } } while (m_repeat); } catch(boost::thread_exception& /* e */) { // we got interrupted } } void Terminate() { if (mp_thread) { mp_thread->interrupt(); delete mp_thread; mp_thread = 0; } } signal_t m_sig; boost::thread* mp_thread; boost::mutex m_monitor; boost::posix_time::time_duration m_delta_time; bool m_repeat; }; ----------- main.cpp // SimpleBoostSCProblem // main.cpp #include "Timeout.h" #include <boost/statechart/event.hpp> #include <boost/statechart/transition.hpp> #include <boost/statechart/custom_reaction.hpp> #include <boost/statechart/state_machine.hpp> #include <boost/statechart/simple_state.hpp> #include <boost/statechart/state.hpp> #include <boost/mpl/list.hpp> namespace MyTest { namespace sc = boost::statechart; namespace mpl = boost::mpl; // Our objects struct Obj1 {}; // -------------------------------------------------- // Events // -------------------------------------------------- struct EvWork : sc::event< EvWork > {}; struct EvExit : sc::event< EvExit > {}; // -------------------------------------------------- // Forward deklaration of states // -------------------------------------------------- struct Active; struct DoStuff1; struct DoStuff2; struct Exit; // -------------------------------------------------- // Statemachine // -------------------------------------------------- struct TestMachine : sc::state_machine< TestMachine, Active > { TestMachine() { } ~TestMachine() { } }; // -------------------------------------------------- // States // -------------------------------------------------- // TestMachine / Active struct Active : sc::state<Active, TestMachine, mpl::list< DoStuff1 > > { typedef mpl::list< sc::transition< EvExit , Exit > > reactions; Active(my_context ctx) : my_base(ctx) { m_worker_connection = m_worker.connect(boost::bind(&Active::ProcessEvent<EvWork>, this)); } ~Active() { m_worker.Stop(); m_worker_connection.disconnect(); } template<typename ev> void ProcessEvent() { outermost_context().process_event(ev()); } Timeout m_worker; private: boost::signals2::connection m_worker_connection; }; // TestMachine / Active / DoStuff1 struct DoStuff1 : sc::state<DoStuff1, Active > { typedef mpl::list< sc::transition< EvWork, DoStuff2 > > reactions; DoStuff1(my_context ctx) : my_base(ctx) { // start work timeout : Repeat every 10 ms context< Active >().m_worker.Start(boost::posix_time::milliseconds(100)); } ~DoStuff1() { } }; // TestMachine / Active / DoStuff2 struct DoStuff2 : sc::state<DoStuff2, Active > { typedef mpl::list< sc::custom_reaction< EvWork > > reactions; DoStuff2(my_context ctx) : my_base(ctx) { // start work timeout : Repeat every 10 ms context< Active >().m_worker.Start(boost::posix_time::milliseconds(1),true); } ~DoStuff2() { } sc::result react( const EvWork & ) { // do stuff // .. // Nothing more to do with this event return discard_event(); } }; // TestMachine / Exit struct Exit : sc::state<Exit, TestMachine > { Exit(my_context ctx) : my_base(ctx) { } ~Exit() { } }; }; int main(int argc, char* argv[]) { MyTest::TestMachine machine; machine.initiate(); boost::this_thread::sleep(boost::posix_time::seconds(10)); machine.process_event(MyTest::EvExit()); return 0; } </code> It the statemachine exits, i get constantly crashes in the process_event<EvWork>() function, because the statemachine itself got destructed and outermost_context() is no more vaild, but the state which holds my timeout object (and the thread) did not yet got destructed and therefore the thread stopped. I dont have an idea to solve that problem. There is an assertion: "get_pointer( pOutermostUnstableState_ )==0" in state_machine.hpp. It does only happen if there was a transition from one state (DoStuff1) to DoState2. Thanks in advance! Georg Gast P.S.: My system: Windows XP / Visualstudio 2008 / Boost 1.40.0

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Any complier can support lambda expression? Can any one with kindness help me?
by fmingu 30 Sep '09

30 Sep '09

I am using lambda expression under Dev-C++ for scientific computing. And the program run well. But the time consumed by the program is too much for data execution. I think this may be happened by the complier of Dev-C++(for compatibility). I am using C++ builder2009 for RAD. And this is said not suooprt Lambda expression. My computer is too limited for Visual C++ studio being installed ,which is supposed to support lambda expression. Can anyone with kindness tell me which complier can be used for lambda expression?

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boost 1.40 build error with VC++ 2008
by Newsuser 30 Sep '09

30 Sep '09

Hi All, I encounter build error on Windows XP system when building with Visual Studio 2008 Profession (with Feature Pack, without SP1). Here is the trimmed output on my console window. Does someone know what is wrong here? I just run two commands "bootstrap.bat" and then ".\bjam" to build the library. Thanks a lot for your help. Setting environment for using Microsoft Visual Studio 2008 x86 tools. C:\>cd /d d:\opensource\boost_1_40_0 D:\opensource\boost_1_40_0>bootstrap.bat Building Boost.Jam build engine The system cannot find the file specified. Bootstrapping is done. To build, run: .\bjam D:\opensource\boost_1_40_0>.\bjam Building the Boost C++ Libraries. After the build, the headers will be located at D:\opensource\boost_1_40_0 The libraries will be located at D:\opensource\boost_1_40_0\stage\lib Use 'bjam install --prefix=<path>' if you wish to install headers and libraries to a different location and remove the source tree. warning: Building Boost.Regex with the optional Unicode/ICU support disabled. note: Please refer to the Boost.Regex documentation for more information note: this is a strictly optional feature. warning: Graph library does not contain optional GraphML reader. note: to enable GraphML support, set EXPAT_INCLUDE and EXPAT_LIBPATH to the note: directories containing the Expat headers and libraries, respectively. warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. ...patience... ...patience... ...patience... ...found 6570 targets... ...updating 824 targets... common.mkdir stage ... common.mkdir bin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi compile-c-c++-pch bin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi\pch.pch cl : Command line error D8022 : cannot open 'bin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi\pch.pch.rsp' call "C:\Program Files\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi\pch.pch.rsp" "bin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi\pch.pch.cpp" ...failed compile-c-c++-pch bin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi\pch.pch bin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi\pch.obj... ...skipped <pbin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi>ellint_1f.obj for lack of <pbin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi>pch.pch... ...skipped <pstage\lib>libboost_math_tr1f-vc90-mt-gd-1_40.lib for lack of <pbin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi>libboost_math_tr1f-vc90-mt-gd-1_40.lib... common.mkdir bin.v2\libs\math\config common.mkdir bin.v2\libs\math\config\msvc-9.0 common.mkdir bin.v2\libs\math\config\msvc-9.0\debug common.mkdir bin.v2\libs\math\config\msvc-9.0\debug\link-static common.mkdir bin.v2\libs\math\config\msvc-9.0\debug\link-static\threading-multi compile-c-c++ bin.v2\libs\math\config\msvc-9.0\debug\link-static\threading-multi\has_long_double_support.obj cl : Command line error D8022 : cannot open 'bin.v2\libs\math\config\msvc-9.0\debug\link-static\threading-multi\has_long_double_support.obj.rsp' call "C:\Program Files\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\math\config\msvc-9.0\debug\link-static\threading-multi\has_long_double_support.obj.rsp" ...failed compile-c-c++ bin.v2\libs\math\config\msvc-9.0\debug\link-static\threading-multi\has_long_double_support.obj... ...skipped <pbin.v2\libs\math\build\msvc-9.0\debug\link-static\threading-multi>assoc_laguerrel.obj for lack of <pbin.v2\libs\math\config\msvc-9.0\debug\link-static\threading-multi>has_long_double_support.obj... call "C:\Program Files\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\serialization\build\msvc-9.0\debug\link-static\threading-multi\extended_type_info.obj.rsp" ...failed compile-c-c++ bin.v2\libs\serialization\build\msvc-9.0\debug\link-static\threading-multi\extended_type_info.obj... ...interrupted compile-c-c++ bin.v2\libs\serialization\build\msvc-9.0\debug\link-static\threading-multi\extended_type_info_typeid.obj cl : Command line error D8022 : cannot open 'bin.v2\libs\serialization\build\msvc-9.0\debug\link-static\threading-multi\extended_type_info_typeid.obj.rsp' ...failed updating 55 targets... ...skipped 119 targets... ...updated 35 targets... D:\opensource\boost_1_40_0>

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request for help re: brandes_betweenness_centrality for weighted graph
by allenem＠pcbi.upenn.edu 29 Sep '09

29 Sep '09

Hi- I've just recently started to use the BGL and was wondering if someone could provide an example (and/or just let me know where I am going wrong) in trying to execute the brandes_betweenness_centrality algorithm for a weighted graph. Below are the relevant code snippets from my program. I am able to compile and run the code, and have successfully iterated over all elements (vertices, edges, and "interaction_weights" to verify that the data are stored correctly) but the calculated betweenness values are the same whether or not I use the edge weight map, which suggests that they are not being considered in the calculation even when passed as a parameter to the brandes_betweenness_centrality function. What am I missing? Thank you, Emily #include <boost/graph/graph_traits.hpp> // iterator functions #include <boost/graph/adjacency_list.hpp> #include <boost/graph/betweenness_centrality.hpp> #include <map> #include <vector> using namespace std; using namespace boost; struct order_edges { template <typename T> bool operator() (const T& x, const T& y) const { return x.get_property() < y.get_property(); } }; /* ============================================================= Main ============================================================ */ int main(int argc, char **argv) { // Define the Graph typedef property < vertex_centrality_t, double > CentralityMap; typedef adjacency_list<vecS, vecS, bidirectionalS, CentralityMap> Graph; typedef graph_traits<Graph>::vertex_descriptor Vertex; typedef graph_traits<Graph>::edge_descriptor Edge; typedef map<Edge, double, order_edges> edge_weight_map_t; edge_weight_map_t base_map; associative_property_map<edge_weight_map_t> interaction_weight(base_map); Graph g; // instance of the graph // determine vertices based upon input from a file // add edges and assign values to associated interaction weights from a file .... brandes_betweenness_centrality(g, get(vertex_centrality,g), interaction_weight); }

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how to concatenate program_options::parsed_options
by Caleb Cushing 29 Sep '09

29 Sep '09

this is a quick summation of the code I'm trying to build // get home directory parsed_options home = parse_environment(desc, "HOME"); // add the relative path to the home directory making it a full path parsed_options rcfile = home + "/.koramarc"; // parse the config file store(parse_config_file(rcfile, desc), vm); honestly all I need to do is parse a config that's in hidden file relative to the users home directory. so if there's a better way that'd work lete me know. -- Caleb Cushing http://xenoterracide.blogspot.com

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[statechart] Passing parameters to state objects
by Robert Dailey 29 Sep '09

29 Sep '09

Hello, I was thinking of using Boost.Statechart as a state machine to manage widget states in my wxWidgets application. Depending on what menu options the user picks in my program, certain buttons on the main window will be enabled or disabled. I figured this would be a good opportunity to use Boost's state machine system. I would create states that would enable or disable certain buttons depending on what events I publish. For example, when the user chooses the "Edit Name" menu item, then buttons for editing a name would be enabled. This means I'd publish a EditNameEnabled event, or something, and then the EditNameMode state would become active, and its constructor would enable certain buttons. Of course, this means I'll need to be able to pass construction parameters to certain fsm state objects, and in the Statechart tutorial they only use default constructors. I'm not sure how I'd pass button object pointers to these state classes so they can work with them. I have two questions: First, does Boost.Statechart seem like the right tool for this job? If yes, then how can I pass parameters to state object constructors? Would I pass the parameters to the Event's constructor, and then somehow access that event instance from the state's constructor? Thanks in advance. --------- Robert Dailey

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serialization of an dynamic array to read/write a image in xml
by Markus Bader 29 Sep '09

29 Sep '09

Hello I like to store and load images from a xml file. My problem is now the dynamic array which keeps the image data. I do not want to copy it into a container and I do not want to go in a for loop over every pixel. Any suggestions? Thanks Max #include <fstream> #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/serialization/nvp.hpp> class Image { public: Image() : mWidth(0) , mHeight(0) , mpData(NULL) { } Image(int width, int height, char *pData) : mWidth(width) , mHeight(height) , mpData(pData) { } ~Image() { } template<class archive> void serialize(archive& ar, const unsigned int version) { int i; using boost::serialization::make_nvp; ar & make_nvp("width", mWidth); ar & make_nvp("height", mHeight); // ar & make_nvp("data", mpData, mWidth*mHeight); I know this can not work but --> is there something like this //** How can I serialize the serialization array without making a copy to a container **// } void save(const std::string& rFileName) { std::ofstream ofs(rFileName.c_str()); assert(ofs.good()); boost::archive::xml_oarchive xml(ofs); xml << boost::serialization::make_nvp("Image", this); } void load(const std::string& rFileName) { std::ifstream ifs(rFileName.c_str()); assert(ifs.good()); boost::archive::xml_iarchive xml(ifs); xml >> boost::serialization::make_nvp("Image", *this); } private: int mWidth; int mHeight; char *mpData; }; int main ( int argc, char** argv ) { int h = 640; int w = 480; char *p = new char[w*h]; Image img(w,h,p); img.save("/tmp/img.xml"); img.load("/tmp/img.xml"); delete p; return 0; }

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Use of ccache with Boost
by Dalton, Tom 29 Sep '09

29 Sep '09

Hi, I'm using Boost on Linux however for various reasons I need to rebuild parts of it occasionally. For other C/C++-based tools that are built with autoconf/automake, I've started to use ccache (http://ccache.samba.org/) to speed up recompilation. This is done simply by setting the CC / CXX environment variables to "ccache gcc" / "ccache g++" respectively. I have had a look through the Jam documentation but I can't see an easy way to achieve the same thing when building the Boost distribution. The closest I came was a bit on the trac that simply said I can add a new toolset, but had no real instructions as to how. Thanks for any help! Tom Dalton

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[Proto] grammar matching terminal or pointer to terminal
by joel 29 Sep '09

29 Sep '09

I need to have a proto grammar that matches char, float or any pointer to either char or float. I tried : struct cfptr : or_< terminal<char> , terminal<short> , and_< cfptr , if_< is_pointer< remove_pointer< bp::value_>() >() > > {}; but it faisl to compile when i do : cout << matches< typename terminal<short>::type, cfptr>::value ; by telling me short is not a class or union. should I cut this in two parts or is there a way to do this in one shot? -- ___________________________________________ Joel Falcou - Assistant Professor PARALL Team - LRI - Universite Paris Sud XI Tel : (+33)1 69 15 66 35

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[LockFree] compile problems under VS 2008 sp1
by Roman Shmelev 29 Sep '09

29 Sep '09

Hi! I've written quite simple app to test lockfree::atomic_int. What I see: struct atomic_cas64 { ... #elif defined(_M_IX86) return InterlockedCompareExchange(reinterpret_cast<volatile LONG*>(addr), reinterpret_cast<LONG>(nw), // reinterpret_cast: cannot cast boost::int64_t to LONG reinterpret_cast<LONG>(old)) == old; // reinterpret_cast: cannot cast boost::int64_t to LONG I can give you source code of my simple program if you want. More questions: what is the status of LockFree? Are there any alternatives for atomic_int? Thank you!

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How to Read the stored memory map in C++
by manish4gupta 29 Sep '09

29 Sep '09

I am loading the map into memory with one program and retrieving the map values by another program. Process1. #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/containers/map.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/containers/string.hpp> #include <iostream> using namespace boost::interprocess; //Typedefs of allocators and containers typedef managed_shared_memory::segment_manager segment_manager_t; typedef allocator<void, segment_manager_t> void_allocator; typedef allocator<int, segment_manager_t> int_allocator; typedef vector<int, int_allocator> int_vector; typedef allocator<int_vector, segment_manager_t> int_vector_allocator; typedef vector<int_vector, int_vector_allocator> int_vector_vector; typedef allocator<char, segment_manager_t> char_allocator; typedef basic_string<char, std::char_traits<char>, char_allocator> char_string; class complex_data { int id_; char_string char_string_; int_vector_vector int_vector_vector_; public: //Since void_allocator is convertible to any other allocator<T>, we can simplify //the initialization taking just one allocator for all inner containers. complex_data(int id, const char *name, const void_allocator &void_alloc) : id_(id), char_string_(name, void_alloc), int_vector_vector_(void_alloc) {} //Other members... }; //Definition of the map holding a string as key and complex_data as mapped type typedef std::pair<const char_string, int> map_value_type; typedef std::pair<char_string, int> movable_to_map_value_type; typedef allocator<map_value_type, segment_manager_t> map_value_type_allocator; typedef map< char_string, int , std::less<char_string>, map_value_type_allocator> complex_map_type; int main () { //Remove shared memory on construction and destruction struct shm_remove { shm_remove() { shared_memory_object::remove("MySharedMemory"); } ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); } } remover; //Create shared memory managed_shared_memory segment(create_only,"MySharedMemory", 65536); //An allocator convertible to any allocator<T, segment_manager_t> type void_allocator alloc_inst (segment.get_segment_manager()); //Construct the shared memory map and fill it complex_map_type *mymap = segment.construct<complex_map_type> //(object name), (first ctor parameter, second ctor parameter) ("MyMap")(std::less<char_string>(), alloc_inst); std::string s = "test"; char_string cs(s.c_str(), alloc_inst); //string y (cs.c_str()); //std::cout << y <<"\n"; // = (char_string)s; for(int i = 0; i < 100; ++i) { mymap->insert(std::pair<char_string, int>(cs , i)); //char_string key_object(alloc_inst); //map_value_type value(key_object, i); // mymap->insert(value); } return 0; } Process2. #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/containers/map.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/containers/string.hpp> #include <iostream> #include <boost/interprocess/containers/vector.hpp> #include <algorithm> using namespace boost::interprocess; typedef managed_shared_memory::segment_manager segment_manager_t; typedef allocator<void, segment_manager_t> void_allocator; typedef allocator<int, segment_manager_t> int_allocator; typedef vector<int, int_allocator> int_vector; typedef allocator<int_vector, segment_manager_t> int_vector_allocator; typedef vector<int_vector, int_vector_allocator> int_vector_vector; typedef allocator<char, segment_manager_t> char_allocator; typedef basic_string<char, std::char_traits<char>, char_allocator> char_string; class complex_data { int id_; char_string char_string_; int_vector_vector int_vector_vector_; public: complex_data(int id, const char *name, const void_allocator &void_alloc): id_(id), char_string_(name, void_alloc), int_vector_vector_(void_alloc) {} }; typedef std::pair<const char_string, int> map_value_type; typedef std::pair<char_string, int> movable_to_map_value_type; typedef allocator<map_value_type, segment_manager_t> map_value_type_allocator; typedef map< char_string, int,std::less<char_string>, map_value_type_allocator> complex_map_type; int main () { using namespace boost::interprocess; try { managed_shared_memory segment(open_only ,"MySharedMemory"); typedef map< char_string, int, std::less<char_string>, map_value_type_allocator> complex_map_type; complex_map_type *MyMap = segment.find<complex_map_type>("MyMap").first; for (complex_map_type::iterator it = MyMap->begin(); it != MyMap->end(); it++) { std::cout << it->first << "\n"; } segment.destroy<complex_map_type>("MyMap"); } catch(...) { shared_memory_object::remove("MySharedMemory"); throw; } shared_memory_object::remove("MySharedMemory"); return 0; } But i am getting the following error message terminate called after throwing an instance of 'boost::interprocess::interprocess_exception' what(): No such file or directory Aborted What is the reason for this? Thanks in advance. -- View this message in context: http://www.nabble.com/How-to-Read-the-stored-memory-map-in-C%2B%2B-tp255063… Sent from the Boost - Users mailing list archive at Nabble.com.

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[MultiArray] How to create / handle a collection of multi-array with varying dimensions?
by Oliver Fochler 28 Sep '09

28 Sep '09

Hi, I'm trying to write some dimension independent routine that makes use of Boost.MultiArray containers. The thing is that I would need several such MultiArrays within this routine with the number of MultiArrays depending on the overall number of dimensions. And here is where it becomes complicated (at least for me). Let N be the overall number of dimensions the routine works with. Then I would a collection of N MultiArrays - but not with fixed dimensions but rather with varying (internal) dimension. That is, a collection like this: boost::multi_array<int, N> A boost::multi_array<int, N-1> B boost::multi_array<int, N-2> C ... However, since N may vary when the routine is called I cannot hardcode the array as above. I was thinking of a vector of multi_array or something like that. But then I don't know how to treat the second template parameter in defining the type of the vector (array, ...). Is there a simple and efficient way to do this? Cheers, Oliver

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[boost][shared_ptr] Trying to make a thread safe Copy-on-write class
by Haledor wow 28 Sep '09

28 Sep '09

Hi, Im trying to make a thread safe Copy-on-write class, but i am unsure how. I want a template class that stores a std::set<T> and i want to be able to add/remove elements while using iterators at the same time without conflicts. I would like to avoid making copies of the entire set each time i want to iterate over the elements. I have tried to use shared_ptr.unique() to decide when to create a new copy of the set but i have been unsuccessful since shared_ptr.use_count() stays at the value 1. I am doing something wrong. I have tried to use something like this as my add function: mutable boost::mutex _mutex; typedef std::set<T> Set; typedef boost::shared_ptr<Set> SetPtr; void add(T element) { boost::unique_lock<boost::mutex> lock(_mutex); if (!(_mySet.unique() || _mySet == 0)) { Set* tmp = _mySet.get(); _mySet = SetPtr(new Set(*tmp)); } _mySet->insert(element); } My thought was that each time an iterator accesses the set the count would increase. Could i make it so (should i)? Any other ideas about a thread safe implementation of a set of elements? I hope someone can help me. Thanks.

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[Asio] problem with deadline_timer
by moffet 28 Sep '09

28 Sep '09

This is a small program using deadline_timer with expiration time 1 millisecond. http://snipt.org/nKm When I run it over and over it will evantually stuck lie this: http://img39.imageshack.us/img39/1292/handh.jpg and I don't know why. The io_service.run() is started in another thread. The main thread is waiting for pressing 'any key', the I call post() method to cancel() the timer. But sometimes as you can see on the screenshot, cancel() is invoked, but the timer continues to run. It seems that run() method doesn't invoke the timer handler with boost::asio::error::operation_aborted error. I've noticed this effect will be encouraged by high CPU usage. Vista 64bit, VC++ 2008 Express, Boost 1.40.0 Why this is happening?

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Asio uses select instead of kqueue by default on FreeBSD?
by Lych 28 Sep '09

28 Sep '09

Hi, It seems so in v1.39 and 1.40, without the macro BOOST_ASIO_DISABLE_KQUEUE defined. I've found it's due to a line in the file [boost/trunk/boost/asio/detail/kqueue_reactor_fwd.hpp]: ------------------------------------------------------------- #if defined(__MACH__) && defined(__APPLE__) // Define this to indicate that epoll is supported on the target platform. #define BOOST_ASIO_HAS_KQUEUE 1 ------------------------------------------------------------- That only checks whether it is a MacOS system to enable kqueue, but doesn't care any of FreeBSD. One said it's because some issues are not yet fixed on use of kqueue on FreeBSD, but this seems to exist for quite long. Is there any more information? Thanks

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[fusion] problem with make_map
by Jean-Louis Leroy 28 Sep '09

28 Sep '09

I'm trying the make_map example from the doc, nearly verbatim : #include <boost/fusion/container/generation/make_map.hpp> #include <boost/fusion/include/make_map.hpp> int main() { using namespace boost::fusion; make_map( make_pair<int>('X') , make_pair<double>("Men")); } Both msvc9 and g++ 4.4.1 tell me that there is no make_map function that takes two parameters. g++ mentions that it sees a parameter-less make_map(). I use Boost 1.40. What's up ? Thanks, J-L

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[fusion] "modify" value in map
by Jean-Louis Leroy 27 Sep '09

27 Sep '09

How can I create a map that has the same content as another rmap, except for a given key which has a new associated value ? I'm looking for something like replace_key<Key>(Sequence, Value) in the doc but I cannot find it. I think I can build it with push_back(erase_key<Key>(seq), make_pair<Key>(newval)) but if it already exists... Thanks, J-L

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Regex problem: cannot parse terms containing OR
by Ramon F Herrera 27 Sep '09

27 Sep '09

I have been able to parse stuff more complicated than this, but now I am stuck with something seemingly simpler. The expression being parsed is the common sequence: 1,2-5,7,8-11 Question 1: Notice my approach. I first match the whole expression, with "regex_match", to make sure that it is valid (that works great). Next, I use "regex_iterator" to break down the parts. Is that good practice? Am I being inefficient/redundant? Question 2: My code below only extracts "range terms" ("x-y"), for some reason I cannot extract "number terms". As a workaround, I can always feed my data like this: 1-1,2-5,7-7,8-11 but, after a lot of tries, would love to learn how to do this properly. TIA, -Ramon ----------------------------------------------------- #include <iostream> #include <boost/regex.hpp> using namespace std; bool term_callback(const boost::match_results<std::string::const_iterator>& what) { for (unsigned int i = 0; i < what.size(); i++) { cout << "what[" << i << "]: " << what[i].str() << endl; cout << "---------" << endl; } return true; } int main(int argc, char *argv[]) { const char hyphen = '-'; const char left_paren = '('; const char right_paren = ')'; const char bar = '|'; const char comma = ','; const char star = '*'; const string number = "[0-9]+"; const string range = number + hyphen + number; const string term = left_paren + number + bar + range + right_paren; const string sequence = term + bar + left_paren + term + comma + right_paren + star + term; boost::regex expression(sequence); boost::regex piece(range); boost::cmatch matches; char argument[1024]; strcpy(argument, argv[1]); if (!boost::regex_match(argument, matches, expression)) { cerr << "There is no match" << endl; return 1; } string text = argument; boost::sregex_iterator m1(text.begin(), text.end(), piece); boost::sregex_iterator m2; for_each(m1, m2, &term_callback); return 0; }

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