July 2008 - Boost-users - lists.preview.boost.org

[mpi] Any plan for mpi2 IO support ?
by Alain Miniussi 06 Aug '08

06 Aug '08

Hi, I have a code based on MPI uising MPI2 IO to read/writte its data on disk (all mpi procces perform concurrent read/writte on the same file). Boost::mpi does not seems to include whose functionnalities (parralllel IO, views, async ios, basically the stuff described in http://www.mpi-forum.org/docs/mpi-20-html/node171.htm#Node171 ). Is there a plan to support that in the near future ? I had a looks a boost serialization libraries but they do not seems provide whose functionnalities (or did I missed something ?). Thanks, -- Alain Miniussi Equipe CRIMSON Mesocentre de Calcul SIGAMM +33 492 00 30 09 https://crimson.oca.eu

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Cross-compiling Boost 1.35.0
by Grant Erickson 05 Aug '08

05 Aug '08

I have been attempting to generate a build environment for boost in which two targets are involved: 1) Native GCC (Whatever the host build system is) 2) DENX ELDK 4.1 (PowerPC 4xx / Linux) With the assumption that (1) and (2) are both GCC-based, I have (1) working well enough. However, the information at: http://lists.boost.org/boost-users/2007/01/24400.php Seems stale for 1.35.0 in that GCC_ROOT_DIRECTORY, GCC and GXX are no longer referenced. My general recipe in my top-level "glue" makefile is as follows, with commands to extract the source, build a link farm, build any objects and install the library: BoostArchive = boost_1_35_0.tar.gz BoostSource = boost_1_35_0 BoostConfigure = $(BuildDirectory)/configure BoostMakefile = $(BuildDirectory)/Makefile BoostUserConfig = $(BuildDirectory)/user-config.jam BoostLibraries = filesystem \ thread BoostLibrariesList = $(subst $(SPACE),$(COMMA),$(strip $(BoostLibraries))) $(BoostSource): $(BoostArchive) tar -zxvf $< $(BoostConfigure): | $(BoostSource) lndir -silent $(CURDIR)/$(BoostSource) $(BuildDirectory) $(BoostMakefile) $(BoostUserConfig): $(BoostConfigure) cd $(BuildDirectory) && \ BJAM_CONFIG="" \ $(BoostConfigure) \ --prefix=$(ResultDirectory) \ --with-toolset=gcc \ --without-icu \ --with-libraries=$(BoostLibrariesList) build: $(BoostMakefile) unset MAKEFLAGS && \ $(MAKE) -C $(BuildDirectory) \ BJAM_CONFIG="" \ all install: unset MAKEFLAGS && \ $(MAKE) -C $(BuildDirectory) \ BJAM_CONFIG="" \ install My suspicion is that there's some new 1.35.0-specific magic to pass via BJAM_CONFIG that allows me to specify the GCC and G++ executables (and longer-term, the OS since that might be cross-compiled too rather than Linux in both cases). Any insights on what that new magic might be? Regards, Grant

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[Test] New documentation
by Hrvoje Prgeša 03 Aug '08

03 Aug '08

There used to be a better version of the documentation at http://www.patmedia.net/~rogeeff/html/index.html. However it's down at the moment and the official/current documentation is very lacking (and broken). Can the new documentation be found elsewhere? Hrvoje Prgeša

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[DateTime] 1.35.0: Patch to fix warning
by Peter Klotz 03 Aug '08

03 Aug '08

The attached patch fixes an unused parameter warning in boost/date_time/time.hpp. Best regards, Peter.

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BGL newbie kamada_kawai_spring_layout never returns
by Eric B 03 Aug '08

03 Aug '08

Hi I'm trying to use BGL to build a layout for a graph. I have my own graph representation which is used to feed a boost graph which I intend to use to compute vertices positions. The positions will then be used to update my own graph representation. It works for some graph but for some others kamada_kawai_spring_layout never returns. So I think the code is ok But I Might have missed something when using kamada_kawai_spring_layout. Is it limited to some specific graph topologies ?!!! Some hints or help would be greatly appreciated. Thank you. Here after the relevant part of the code and the execution logs The log produced: NB DE VERTICES 10 NB DE EDGES 14 UNDIRECTEED NB DE VERTICES 10 UNDIRECTEED NB DE EDGES 13 vertex 32426192 is L1T1 boost id 0 nb edges 5 vertex 32429496 is L1T2 boost id 1 nb edges 4 vertex 32432404 is L1T3 boost id 2 nb edges 1 vertex 32434028 is L1T4 boost id 3 nb edges 1 vertex 32435652 is L1T5 boost id 4 nb edges 1 vertex 32438816 is L2T1 boost id 5 nb edges 2 vertex 32440868 is L2T2 boost id 6 nb edges 6 vertex 32445060 is L2T3 boost id 7 nb edges 2 vertex 32446684 is L2T4 boost id 8 nb edges 2 vertex 32448308 is L2T5 boost id 9 nb edges 2 edge from L1T1 to L2T1 edge from L1T1 to L2T2 edge from L1T1 to L2T3 edge from L1T1 to L2T4 edge from L1T1 to L2T5 edge from L1T2 to L1T3 edge from L1T2 to L1T4 edge from L1T2 to L1T5 edge from L1T2 to L2T2 edge from L2T1 to L2T2 edge from L2T2 to L2T3 edge from L2T2 to L2T4 edge from L2T2 to L2T5 BOOST GRAPH DESSCRIPTION using internal ids 0 <--> 5 6 7 8 9 1 <--> 2 3 4 6 2 <--> 1 3 <--> 1 4 <--> 1 5 <--> 0 6 6 <--> 0 1 5 7 8 9 7 <--> 0 6 8 <--> 0 6 9 <--> 0 6 BOOST GRAPH DESSCRIPTION using my ids 32426192 <--> 32438816 32440868 32445060 32446684 32448308 32429496 <--> 32432404 32434028 32435652 32440868 32432404 <--> 32429496 32434028 <--> 32429496 32435652 <--> 32429496 32438816 <--> 32426192 32440868 32440868 <--> 32426192 32429496 32438816 32445060 32446684 32448308 32445060 <--> 32426192 32440868 32446684 <--> 32426192 32440868 32448308 <--> 32426192 32440868 Computing circle_graph_layout Computing kamada_kawai_spring_layout <<<<< NEVER RETURNS The code: // TYPES DECLARATIONS AND INCLUDES #include <boost/utility.hpp> #include <boost/graph/graph_utility.hpp> #include <boost/graph/random.hpp> #include <boost/pending/indirect_cmp.hpp> enum vertex_id_t { vertex_id = 500 }; enum edge_id_t { edge_id = 501 }; enum vertex_position_t { vertex_position = 502 }; namespace boost { BOOST_INSTALL_PROPERTY(vertex, id); BOOST_INSTALL_PROPERTY(edge, id); BOOST_INSTALL_PROPERTY(vertex, position); } struct point { double x; double y; }; #include <boost/graph/adjacency_list.hpp> typedef boost::adjacency_list< boost::vecS , boost::vecS , boost::undirectedS , boost::property<vertex_id_t, int , boost::property<vertex_position_t, point> > , boost::property<edge_id_t, int> > Graph; typedef boost::property<vertex_id_t, int> VertexId; typedef boost::property<edge_id_t, int> EdgeID; #include <boost/graph/fruchterman_reingold.hpp> #include <boost/graph/random_layout.hpp> #include <boost/graph/kamada_kawai_spring_layout.hpp> #include <boost/graph/circle_layout.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/random/linear_congruential.hpp> // #include <boost/test/minimal.hpp> #include <iostream> #include <boost/limits.hpp> // CODE TO COMPUTE THE LAYOUT Extract::Graph gr; // this is my own graph representation // feeds gr .... std::cout << " NB DE VERTICES " << gr.Vertices.size() << std::endl; std::cout << " NB DE EDGES " << gr.Edges.size() << std::endl; if ( gr.Edges.size() ) { Graph g; // boost graph Extract::Graph::Undirected undirected_graph(gr); std::cout << " UNDIRECTEED NB DE VERTICES " << undirected_graph.Vertices.size() << std::endl; std::cout << " UNDIRECTEED NB DE EDGES " << undirected_graph.Edges.size() << std::endl; boost::property_map<Graph, vertex_id_t>::type vertex_id_map = get(vertex_id, g); // Add vertices to boost graph int vertex_internal_id = 0; for (Extract::Graph::Undirected::tVertices::iterator elt = undirected_graph.Vertices.begin() , stop = undirected_graph.Vertices.end() ; elt != stop ; ++elt) { // boost vertex are the same as index in set add_vertex( (int)elt->first // this the memory location of my own vertice data , g ); std::cout << " vertex " << (int)elt->first << " is " << elt->first->Name->get().c_str() << " boost id " << vertex_internal_id << " nb edges " << elt->second << std::endl; elt->second = vertex_internal_id; // use map for later edge addition => we associate internal data and boost vertices ids ++vertex_internal_id; } // Add edges to boost graph int current_edge_id = 0; for (Extract::Graph::Undirected::tEdges::iterator elt = undirected_graph.Edges.begin() , stop = undirected_graph.Edges.end() ; elt != stop ; ++elt) { add_edge( undirected_graph.Vertices[*elt->begin()] // use map to get the boost vertex_internal_id for first , undirected_graph.Vertices[*elt->rbegin()] // use map to get the boost vertex_internal_id for second , 1 , g ); std::cout << " edge from " << (*elt->begin())->Name->get().c_str() << " to " << (*elt->rbegin())->Name->get().c_str() << std::endl; } std::cout << "BOOST GRAPH DESSCRIPTION using internal ids" << std::endl; print_graph(g); std::cout << "BOOST GRAPH DESSCRIPTION using my ids" << std::endl; print_graph(g,vertex_id_map); std::cout << "Computing circle_graph_layout" << std::endl; boost::circle_graph_layout( g , get(vertex_position, g) , 10.0 ); std::cout << "Computing kamada_kawai_spring_layout" << std::endl; boost::kamada_kawai_spring_layout( g , get(vertex_position, g) , get(edge_id, g) , boost::side_length(50.0) ); // THE PROGRAM NEVER RETURNS HERE <<<<<<<<<<<<<<<<<<<<<<<<<< print_graph_layout( g , get(vertex_position, g) ); }

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[1.36.0 beta] Beta release available on SourceForge
by Beman Dawes 02 Aug '08

02 Aug '08

New libraries: Accumulators, Exception, Units, Unordered. Updated Libraries: Assign, Foreach, Interprocess, Intrusive, Math, Multi-index Containers, PtrContainer, Spirit, Thread, Xpressive, plus a bunch more. Many thanks to Daniel James, Rene Rivera, Marshall Clow, Eric Niebler, the testers, and all the others who helped to get this beta release together. The beta period will be approximately one week. Please post bug reports here, but also let us hear about success stories too! --Beman

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[boost] [interprocess] Semaphore cleanup after crash
by Sachin Garg 02 Aug '08

02 Aug '08

When using semaphores to synchronize separate processes, everything works fine when each process exits nicely (closing its semaphores before exit). But things get really messy when a process might crash. I am unable to figure out how to recover from such a crash which leaves semaphores in inconsistent state. If a semaphore is not in-use (open) by any process, in this case (in my application) I can safely 'remove' it and start afresh. Is there some way to find out if any process is using a semaphore at a time so that I can call 'remove'? When I just add a 'remove' on process start this works great on windows (as remove just fails if another process has the semaphore open), but on linux sem_unlink is used which has the behavior of deleting it even if its in use. What is the general practice when it comes to cleaning up semaphores after process crashes? Maybe some way to ensure that 'post' and 'close' are always called even when application has otherwise crashed? Is there some way to use boost's windows style semaphores on linux instead of native posix style? I tried looking and many have asked this question (in context of recovering from posix semaphores, which are used by boost on linux), but I couldn't find any answers. Lars had asked this here also, almost an year ago but no answers in that thread either. This seems like a basic issue but am totally lost on how to even approach it. Sachin Garg

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Boost.Endian missing integer_cover_operators.hpp
by Seika van Olstroem 02 Aug '08

02 Aug '08

Hello, in 2000 and 2006 Darin Adler and Berman Dawes tried to get a library called Boost.Endian into Boost, but it seems the process stopped somewhere. This library would help me a lot when working with different byte orders. Here are the threads: http://lists.boost.org/Archives/boost/2000/03/2495.php http://lists.boost.org/Archives/boost/2006/06/106655.php Using Google I've found a recent endian.hpp but I can't find integer_cover_operators.hpp. http://lists.boost.org/Archives/boost/att-105789/endian.hpp Berman, what happend with Boost.Endian? -- -Seika

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[intrusive_ptr] Counting implementation
by Alexander Gutenev 01 Aug '08

01 Aug '08

Hello. I want to use intrusive_ptr as a smart pointer to have reference counting without shared_ptr overhead. There's no implementation for embedding reference counting into a pointee class provided by Boost.Smart Ptr library. I'd like to have reference counting easily embedded, like thru inheritance: class test : public intrusive_pointee_base<test> { ... }; I come to an implementation of this. As i'm sure this was coded many times before, two questions: (1) Why stock implementation of intrusive counter is not included to Smart Pointers library ? (2) Is there something wrong with my code ? struct refcount { refcount(void) : count_(0) {} refcount(refcount const&) : count_(0) {} refcount& operator=(refcount const&) {} long operator++(void) { return ::InterlockedIncrement(&count_); } long operator--(void) { return ::InterlockedDecrement(&count_); } private: mutable volatile long count_; }; template<class T> void intrusive_ptr_add_ref(T * p); template<class T> void intrusive_ptr_release(T * p); template<class Derived> class intrusive_pointee_base { friend void intrusive_ptr_add_ref<Derived>(Derived * p); friend void intrusive_ptr_release<Derived>(Derived * p); refcount reference_counter_; protected: ~intrusive_pointee_base(void) {} }; template<class T> void intrusive_ptr_add_ref(T * p) { intrusive_pointee_base<T> * pbase = p; ++(pbase->reference_counter_); } template<class T> void intrusive_ptr_release(T * p) { intrusive_pointee_base<T> * pbase = p; if (!--(pbase->reference_counter_)) delete p; }

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[PATCH]: filesystem: Shadow Variables Cause Warnings/Errors When Headers Are Not in System Path
by Grant Erickson 01 Aug '08

01 Aug '08

In working through cross-compilation issues with boost, particularly the filesystem library, I discovered the following error reproduced with the following test case with both boost 1.34.1 and 1.35.0: FAILS: echo "#include <boost/filesystem.hpp>\nint main (void) { return (0); }" | g++ -o test -I/${BuildRoot}/results/boost/include -Werror -Wall -Wshadow -x c++ - PASSES: echo "#include <boost/filesystem.hpp>\nint main (void) { return (0); }" | g++ -o test -I/usr/include -Werror -Wall -Wshadow -x c++ - The failing case complains about 'what', 'path1' and 'path2' argument shadowing in boost/filesystem/path.hpp with respect to like-named member functions. Since GCC does not enforce warning options on headers in /usr/include, this only shows up when building against a boost installation outside /usr/include, as in the above failure example. The patch to address this is: Signed-off-by: Grant Erickson <gerickson(a)nuovations.com> --- --- boost_1_35_0/boost/filesystem/path.hpp 2008-07-30 16:54:53.000000000 -0700 +++ boost_1_35_0/boost/filesystem/path.hpp.N 2008-07-30 16:59:42.000000000 -0700 @@ -577,23 +577,23 @@ // BOOST_FILESYSTEM_DECL version works for VC++ but not GCC. Go figure! inline const char * what( const char * sys_err_what, - const path & path1, const path & path2, std::string & target ) + const path & path1_arg, const path & path2_arg, std::string & target ) { try { if ( target.empty() ) { target = sys_err_what; - if ( !path1.empty() ) + if ( !path1_arg.empty() ) { target += ": \""; - target += path1.file_string(); + target += path1_arg.file_string(); target += "\""; } - if ( !path2.empty() ) + if ( !path2_arg.empty() ) { target += ", \""; - target += path2.file_string(); + target += path2_arg.file_string(); target += "\""; } } @@ -607,7 +607,7 @@ template<class Path> const char * what( const char * sys_err_what, - const Path & /*path1*/, const Path & /*path2*/, std::string & /*target*/ ) + const Path & /*path1_arg*/, const Path & /*path2_arg*/, std::string & /*target*/ ) { return sys_err_what; } @@ -624,14 +624,14 @@ typedef Path path_type; - basic_filesystem_error( const std::string & what, + basic_filesystem_error( const std::string & what_arg, system::error_code ec ); - basic_filesystem_error( const std::string & what, - const path_type & path1, system::error_code ec ); + basic_filesystem_error( const std::string & what_arg, + const path_type & path1_arg, system::error_code ec ); - basic_filesystem_error( const std::string & what, const path_type & path1, - const path_type & path2, system::error_code ec ); + basic_filesystem_error( const std::string & what_arg, const path_type & path1_arg, + const path_type & path2_arg, system::error_code ec ); ~basic_filesystem_error() throw() {} @@ -1385,8 +1385,8 @@ template<class Path> basic_filesystem_error<Path>::basic_filesystem_error( - const std::string & what, system::error_code ec ) - : system::system_error(ec, what) + const std::string & what_arg, system::error_code ec ) + : system::system_error(ec, what_arg) { try { @@ -1397,29 +1397,29 @@ template<class Path> basic_filesystem_error<Path>::basic_filesystem_error( - const std::string & what, const path_type & path1, + const std::string & what_arg, const path_type & path1_arg, system::error_code ec ) - : system::system_error(ec, what) + : system::system_error(ec, what_arg) { try { m_imp_ptr.reset( new m_imp ); - m_imp_ptr->m_path1 = path1; + m_imp_ptr->m_path1 = path1_arg; } catch (...) { m_imp_ptr.reset(); } } template<class Path> basic_filesystem_error<Path>::basic_filesystem_error( - const std::string & what, const path_type & path1, - const path_type & path2, system::error_code ec ) - : system::system_error(ec, what) + const std::string & what_arg, const path_type & path1_arg, + const path_type & path2_arg, system::error_code ec ) + : system::system_error(ec, what_arg) { try { m_imp_ptr.reset( new m_imp ); - m_imp_ptr->m_path1 = path1; - m_imp_ptr->m_path2 = path2; + m_imp_ptr->m_path1 = path1_arg; + m_imp_ptr->m_path2 = path2_arg; } catch (...) { m_imp_ptr.reset(); } } ---

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