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[statechart] Running one scheduler in many threads
by Manuel Jung 10 Apr '08

10 Apr '08

Hi, The fifo_scheduler is limited to one execution at a time. I would like a schedule object, which can handle many processors in many threads at the same time. Lika a threadpool, where the threads takeover a fsm, when it has events posted and processes them then. But it should of course only one thread at a time process events from one machine. Maybe someone has done this and can show me his code? Or tell me if this is even possible? Greetings Manuel Jung

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Kudos to 1.35.0 release managers
by Jeffery Cavallaro 10 Apr '08

10 Apr '08

All of those people who are responsible for the 1.35.0 release deserve a big round of applause. I was starting to worry about the project getting off track. No more doubts. The new website L&F is slick. The documentation links are complete. The download is complete. Everything looks on track for convergence with C++ 09. Great work people! -- Jeffery Cavallaro, 1055 Joaquin-191A Infrastructure Engineering Google Inc. 1600 Amphitheatre Parkway Mountain View, CA 94043 650-214-2552

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Problems with char* serialization
by Ariel Brunetto 10 Apr '08

10 Apr '08

Hello! My name is Ariel and this is my first time with boost. I spent a few days looking arround the serialization library, and right now I have a project with my first serialized classes. I spent some time reading the documentation and the tutorial. I am having problems serializing pointers. I am trying to serialize a const char* and it seems that doesn't work in the trivial way. This is my code: //----------------------------------------------------------------------------- // myserializeclass.h //----------------------------------------------------------------------------- #include <fstream> #include <boost/archive/binary_iarchive.hpp> #include <boost/archive/binary_oarchive.hpp> #include <boost/serialization/base_object.hpp> //----------------------------------------------------------------------------- class MySerializeClass { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int uiVersion) { ar & m_pChar; } // members to serialize public: char* m_pChar; }; //----------------------------------------------------------------------------- BOOST_CLASS_TRACKING(MySerializeAbstractBase, ::boost::serialization::track_never) //----------------------------------------------------------------------------- //----------------------------------------------------------------------------- // myserializeclass.cpp //----------------------------------------------------------------------------- int main() { MySerializeClass MySerializeClassObject; std::ofstream ofs(akFilename); boost::archive::binary_oarchive oa(ofs); oa << MySerializeClassObject; return 0; } //----------------------------------------------------------------------------- It doesn't compile. I get the following error: 1>c:\program files\microsoft visual studio 8\vc\platformsdk\include\boost\serialization\access.hpp(109) : error C2228: left of '.serialize' must have class/struct/union I know that this is my mistake, but I don't know how to fix it ;). I know that there is a lot of consideration about pointer serialization. Could you point me in the right direction? Thanks in advance! Ariel

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Access to underlying system thread
by Yang Zhang 10 Apr '08

10 Apr '08

Hi, I like using boost threads, but I'm currently working on a project where I need to access the private handle to the underlying system thread (in the cases I'm concerned about, the pthread_t). This is so that I can take advantage of platform-specific functionality, such as setting CPU affinity and (more generally) calling into other libraries that expect a pthread_t. Is there any way to do get this handle? Thanks! -- Yang Zhang http://www.mit.edu/~y_z/

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[Boost Graph] Undefined symbols when loading a dynamic library using boost graphs
by Toni 10 Apr '08

10 Apr '08

Hi to everyone in the list. First of all, thanks in advance for your help and your time, that I'm pretty sure is very valuable. I will try to describe the problem I'm getting while using boost graph's library. I've been developping an algorithm that makes use of the boost graph library. During the development, I coded everything in a cpp file and made some testing. In this phase all my code was compiled and linked within an executable file and everything worked fine. Imagine that my code was the following one (this code actually does nothing but it is enough to explain the problems I'm experiencing): void f1 (void) { Graph g (100); for (unsigned i = 1; i < 100; i++) boost::add_edge (i - 1, i, g); boost::graph_traits<Graph>::edge_iterator it, it_end; for (boost::tie (it, it_end) = boost::edges (g); (it != it_end); it++); } int main (void) { f1 (); return 0; } This example program compiled, linked and executed fine. Once my code was ready, I decided to integrate this code into the library it should go. This library is a dynamic library that is loaded by another program with dlopen, and some symbols are read from it and used. So, imagine the following scenario (again, very simplified, but enough to explain the problem): main.cc: int main (void) { char* libpath = "mylib.so"; void* handle; handle = dlopen (libpath, RTLD_NOW | RTLD_GLOBAL); // Some symbols are read with dlsym return 0; } mylib.cc: extern "C" bool someFunction (int* data) { // do some things return true; } void f1 (void) { Graph g (100); for (unsigned i = 1; i < 100; i++) boost::add_edge (i - 1, i, g); boost::graph_traits<Graph>::edge_iterator it, it_end; for (boost::tie (it, it_end) = boost::edges (g); (it != it_end); it++); } Both the main program and the library compile fine, but when I try to execute the program I get undefined symbols errors: /home/me/lib/mylib.so: undefined symbol: _ZneIN5boost6detail20undirected_edge_iterISt14_List_iteratorINS0_9list_edgeIjNS0_11no_propertyEEEENS1_14edge_desc_implINS0_14undirected_tagEjEEiEEEiRKT_SE_ If I demangle the symbol I get: c++filt _ZneIN5boost6detail20undirected_edge_iterISt14_List_iteratorINS0_9list_edgeIjNS0_11no_propertyEEEENS1_14edge_desc_implINS0_14undirected_tagEjEEiEEEiRKT_SE_ int operator!=<boost::detail::undirected_edge_iter<std::_List_iterator<boost::list_edge<unsigned int, boost::no_property> >, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, int> >(boost::detail::undirected_edge_iter<std::_List_iterator<boost::list_edge<unsigned int, boost::no_property> >, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, int> const&, boost::detail::undirected_edge_iter<std::_List_iterator<boost::list_edge<unsigned int, boost::no_property> >, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, int> const&) The problem is, I think, that the operator!= is not compiled within the dynamic library for some reason. Any hints or ideas to solve the problem? Thanks again for your time.

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Unordered not 1.35.0?
by Andreas Klöckner 10 Apr '08

10 Apr '08

Hi all, I just updated to 1.35.0 from an old-ish svn snapshot, only to learn that boost/unordered_{map,set}.hpp are not in the release. I thought unordered had gotten accepted *way* before 1.35? Thanks, Andreas

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any advantage of using property_map over std::map
by Abir Basak 10 Apr '08

10 Apr '08

Though it is a stupid question, is there any advantage i will get if i use boost property_map instead of std::map for my name value property pairs ? I am working for a statistical system, where i have certain parameter names (20-50 names at max) mostly fixed defined in terms of compile time constants (enums) but sometimes are from a variable set, and values which changes during adaptation (a small statistical distribution struct contains mean & sigma usually). so far i have used things like, enum height{ class1, class2,class3}; struct dist{ float mean; float sigma; }; typedef std::map<height,dist> height_prop; ( i also thought of having a compile time lookup based on a lookup table, but not sure if that is worth esp when search is among small no of elements) and similarly other properties. so will i get any benefit using boost::property_map instead of std::map (or unordered_map ) . in future i may want these properties to be associated with a Boost graph node & edge. thanks abir

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[1.35] Weird behavior while building bjam under linuxx86_64 platform.
by Lian Cheng 10 Apr '08

10 Apr '08

Hi, all I'm trying to build boost 1.35 within a RedHat x86-84 box. The gcc version information is here: $ gcc -v Reading specs from /usr/lib/gcc/x86_64-redhat-linux/3.4.5/specs Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-java-awt=gtk --host=x86_64-redhat-linux Thread model: posix gcc version 3.4.5 20051201 (Red Hat 3.4.5-2) $gcc --version gcc (GCC) 3.4.5 20051201 (Red Hat 3.4.5-2) Copyright (C) 2004 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. While building bjam by invoking $BOOST_ROOT/tools/jam/build_dist.sh, I got error messages as following: ./bootstrap/jam0 -f build.jam --toolset=gcc --toolset-root= clean ...found 1 target... ...updating 1 target... ...updated 1 target... ./bootstrap/jam0 -f build.jam --toolset=gcc --toolset-root= ...found 47 targets... ...updating 2 targets... [MKDIR] :bin.linuxx86_64 <--- *NOTICE THIS LINE* [COMPILE] :bin.linuxx86_64/bjam filemac.c:115:5: warning: C++ style comments are not allowed in ISO C90 filemac.c:115:5: warning: (this will be reported only once per input file) /tmp/ccjqZ5Qv.o(.text+0x903): In function `var_expand': : undefined reference to `path_parse' /tmp/ccjqZ5Qv.o(.text+0x9ee): In function `var_expand': : undefined reference to `path_build' /tmp/ccjqZ5Qv.o(.text+0xa1d): In function `var_expand': : undefined reference to `path_parent' [...] You see, the bin directory name is ":bin.linuxx86_64" rather than "bin.linuxx86_64". Weird? I've build boost 1.35 successfully under cygwin, and the bin directory name is exactly "bin.cygwinx86". I think it is this wrong directory name that causes following linkage errors. Is it a bug or I missed something obvious in the documentation? Any suggestion is appreciated! -- Cheers Cheng

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Boost.Exception
by Olaf Peter 10 Apr '08

10 Apr '08

with interest I did follow the discussion about boost.exeception some times ago. At http://www.revergestudios.com/boost-exception/boost-exception.html I read: Note: Boost Exception was accepted as a Boost library on November 7, 2007; however it has not yet been part of an official Boost release. Why is it not in release 1.35?? Is it safe to use it out of the boost distribution (concerning API changes). Thanks, Olaf

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boost.variant as argument
by Olaf Peter 10 Apr '08

10 Apr '08

Hi, I've wrapped a variant<double,bool> into a tuple. Unpacking the tuple works as far I can see. I want to print the tuple for doubles with one pretty print functor and for booleans with another functor (not shown here). Anyway, variant_print takes a long argument list as the error message shows. How can I pass it convinient? I guess, inside the variant_print I have to use the vistor to dispatch the print functors, isn't? BTW, fusion could be used? On debian/linux 1.35 is not released yet, so I use 1.34.1. Thanks, Olaf ---8<--- #include <boost/variant.hpp> #include <boost/tuple/tuple.hpp> #include <boost/tuple/tuple_io.hpp> #include <iostream> struct pretty_print { pretty_print( double d ) : m_d( d ) { } std::ostream& print_on( std::ostream& os ) const { os << m_d; return os; } double m_d; }; std::ostream& operator<<( std::ostream& os, const pretty_print& p ) { return p.print_on( os ); } struct variant_print { // ????????? variant_print(::boost::variant<double, bool>& v) { } }; using namespace std; using namespace boost::tuples; using namespace boost; int main() { typedef variant<double, bool> double_variant; typedef tuple<double_variant> double_tuple; double_tuple v1; double_tuple v2; get<0>( v1 ) = 3.14; get<0>( v2 ) = true; // This works cout << pretty_print( get<double>( get<0>( v1 ) ) ) << endl; // This not cout << variant_print( get<0>( v1 ) ) << endl; } --->8--- $ LANG=en g++ -Wall tuple.cpp -o tuple && ./tuple tuple.cpp: In function 'int main()': tuple.cpp:55: error: no match for 'operator<<' in 'std::cout << variant_print(((boost::variant<double, bool, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>&)((boost::variant<double, bool, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>*)boost::tuples::get [with int N = 0, HT = boost::variant<double, bool, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>, TT = boost::tuples::null_type](((boost::tuples::cons<boost::variant<double, bool, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>, boost::tuples::null_type>&)(& v1.boost::tuples::tuple<boost::variant<double, bool, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>::<anonymous>))))))' ...

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