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boost mpi and mvapich
by Cornelius Steinhardt 20 Apr '12

20 Apr '12

Hi, have somebody compiled the boost_1.48 with a mvapich compiler? The test from boost mpi get started, which tests the mpi installation works fine. Than i installed the whole library, with adding using mpi : path_to/mpiCC ; into the user-config.jam After this i run ./bootstrap --prefix=where_to_install and ./bjam --prefix=where_to_install install My next step was to test the installation with the first program code from the boost mpi tutorial. ("I am process " << world.rank() << " of " << world.size()) But i get a deadlock in the line mpi::environment env(argc, argv); Can somebody explain me why? or where my failure is? Regards Cornelius

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How to send list from Python to boost python
by Guruswamy B M 20 Apr '12

20 Apr '12

Hi, I have been using boost python for one of my application. In the same I have to send list from python to boost wrapper. Ex:. >From python. a = [1, 2, 3, 4] test(a); In wrapper my C++ fucntion should be like below: void test(list a) { list processing. } I tried similar way, but getting an signature error. I need a help on how to send list from the python, so that can access each element of list in C++ wrapper. Thanks and Regards, Guru

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How to send python list to c++ function
by Guruswamy B M 20 Apr '12

20 Apr '12

Hi, I have been using boost python for one of my application. In the same I have to send list from python to boost wrapper. Ex:. >From python. a = [1, 2, 3, 4] test(a); In wrapper my C++ fucntion should be like below: void test(list a) { list processing. } I tried similar way, but getting an signature error. I need a help on how to send list from the python, so that can access each element of list in C++ wrapper. Thanks and Regards, Guru

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Re: [Boost-users] Timeout on read/write using Boost.Asio
by boost 20 Apr '12

20 Apr '12

So, it implies that it is a bad idea to implement timeout read/write using timer and "cancel". Is there any better solution? Best Regards Zhanwei Wang ----- Original Message -----From: Igor R <boost.lists(a)gmail.com> To: boost-users(a)lists.boost.org > What if I cancel all the async operation, is there any partial data which has been read from or write to socket after the cancelation? > If partial data has been read from or write to socket, how can I issue both async read/write again? Right, some data might have been sent/received, and you have to re-synchronise somehow your client and server. Even if it's possible, it would be pretty complicated. Besides, cancellation is not quite portable: http://www.boost.org/doc/libs/1_49_0/doc/html/boost_asio/reference/basic_st… That's why it's usually a bad idea to cancel operations on a socket. Instead, you can just close the socket and then re-establish connection from scratch. > I cancel the read/write on a tcp connection because the current node I connected to may be too busy to response, so I can try another node. I do not want cancel all async request because the other pending operations may finish successfully, the workload on peer node is very heavy instead of failure. Well, I don't know what you application does, but I'm afraid it's not the right way to go. First of all, why can't you connect all the "nodes" you need? Anyway, you should decide for every particular connection whether it's ok or "faulty" (returned error, takes too much time, no ping, no heartbeat, etc...): if it's ok - wait for response, if it's faulty - just close it. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Re: [Boost-users] Timeout on read/write using Boost.Asio
by boost 19 Apr '12

19 Apr '12

hi, Thanks for your reply. I cancel the read/write on a tcp connection because the current node I connected to may be too busy to response, so I can try another node. I do not want cancel all async request because the other pending operations may finish successfully, the workload on peer node is very heavy instead of failure. Anyway, I can cancel all request, but I still have the question about the cancel. What if I cancel all the async operation, is there any partial data which has been read from or write to socket after the cancelation? If partial data has been read from or write to socket, how can I issue both async read/write again? Best Regards Zhanwei Wang ----- Original Message -----From: Igor R <boost.lists(a)gmail.com> To: boost-users(a)lists.boost.org > My question is: > the "cancel" call acutely cancel all the pending async operation, but only one of them is timeout. > For example, there is a pending async read and a pending async write operation, only read is timeout, I do not want cancel write any way. Yes, you're right. You'll have to issue both async read and write again. But usually "timeout" means that something goes wrong with the connection (i.e. you expected something, but it failed to happen). _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Questions about using "mcregor_common_subgraphs" algorithm in Boost Graph Library
by Bin Ren 19 Apr '12

19 Apr '12

Hi, I am a beginner of C++ Boost Library. I am doing a project about "Maximum Common Subgraph" Algorithm, and I found there is an implementation in Boost Graph Library: "boost/graph/mcgregor_common_subgraphs.hpp" I use it like this: (and my question is marked as red) ---------------------------------------------------------------------------------------------------- //Compare the input graphs against the Graph Forest for (int i = 0; i < graphInputs.size(); ++i){ graph_t * pInputGraphi = graphInputs[i]; for (int j = 0; j < graphForest.size(); ++j) { std::cout << "Common Sub graph of input graph" << i << " and graph" << j << " :" << std::endl; //Compare one to one among graphi and graphj graph_t * pGraphj = graphForest[j]; //Here I am using the callback function from the example code: "mcgregor_subgraphs_example.cpp" example_callback<graph_t> my_callback(*pInputGraphi); property_map<graph_t, vertex_name_t>::type vname_mapi = get(vertex_name, *pInputGraphi); property_map<graph_t, vertex_name_t>::type vname_mapj = get(vertex_name, *pGraphj); property_map<graph_t, edge_name_t>::type ename_mapi = get(edge_name, *pInputGraphi); property_map<graph_t, edge_name_t>::type ename_mapj = get(edge_name, *pGraphj); //Print out Maximum connected Common Subgraphs between graphi and graphj mcgregor_common_subgraphs_maximum_unique(*pInputGraphi, *pGraphj, true, my_callback, //edges_equivalent(make_property_map_equivalent(ename_mapi, ename_mapj)), //Here is my problem: if I use both edges_equivalent and vertices_equivalent, the code can not be compiled //However, if I only use vertices_equivalent, I doubt whether the maximum common subgraph result is correct. //If I use edges_equivalent only, the code can be compiled, however, it runs into an infinite loop. vertices_equivalent(make_property_map_equivalent(vname_mapi, vname_mapj))); } } ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Is there any way to use both the edges_equivalent and the vertices_equivalent (Or it is not necessary at all)? BTW, it seems the performance of this algorithm is not perfect; for a small test case below, it needs around 5 seconds by vertices_equivalent, while it loops for a very long time for edges_equivalent (it might be a infinite loop...). Looking forward to your feedback. Thanks and have a good night, Bin ----------------------------------------------------------------------------------------------- Small Test Case: For test, I only use one graph for "graphInputs", and one graph for "graphForest": graphInputs: (v: vertex, 1st number: the vertex id, 2nd number: the vertex name; e: edge, 1st: source vertex, 2nd: target vertex, 3rd: edge name) t # 0 v 0 0 v 1 0 v 2 0 v 3 0 v 4 0 v 5 0 v 6 1 v 7 1 v 8 1 v 9 1 v 10 2 v 11 0 v 12 0 v 13 2 v 14 0 v 15 0 v 16 0 v 17 0 v 18 1 v 19 1 v 20 1 v 21 3 v 22 3 v 23 4 v 24 5 v 25 5 e 0 1 3 e 1 2 3 e 2 3 3 e 3 4 3 e 4 5 3 e 5 0 3 e 0 6 0 e 1 7 0 e 4 8 0 e 5 9 0 e 2 10 0 e 10 11 0 e 11 12 3 e 12 13 0 e 13 3 0 e 11 14 3 e 14 15 3 e 15 16 3 e 16 17 3 e 17 12 3 e 14 18 0 e 15 19 0 e 17 20 0 e 13 21 1 e 10 22 1 e 16 23 0 e 23 24 0 e 23 25 0 graphForest: t # 1 v 0 0 v 1 0 v 2 0 v 3 0 v 4 0 v 5 0 v 6 1 v 7 1 v 8 1 v 9 1 v 10 1 v 11 4 v 12 4 v 13 6 v 14 5 v 15 3 e 0 1 3 e 1 2 3 e 2 3 3 e 3 4 3 e 4 5 3 e 5 0 3 e 0 6 0 e 1 7 0 e 2 8 0 e 3 9 0 e 5 10 0 e 4 11 0 e 11 12 0 e 11 13 0 e 13 14 0 e 12 15 1 If we only use vertex_equivalent, we can get some result like this: This is input Graph 0 <--> 1 5 6 1 <--> 0 2 7 2 <--> 1 3 10 3 <--> 2 4 13 4 <--> 3 5 8 5 <--> 4 0 9 6 <--> 0 7 <--> 1 8 <--> 4 9 <--> 5 10 <--> 2 11 22 11 <--> 10 12 14 12 <--> 11 13 17 13 <--> 12 3 21 14 <--> 11 15 18 15 <--> 14 16 19 16 <--> 15 17 23 17 <--> 16 12 20 18 <--> 14 19 <--> 15 20 <--> 17 21 <--> 13 22 <--> 10 23 <--> 16 24 25 24 <--> 23 25 <--> 23 This is the Graph in Forest: 0 <--> 1 5 6 1 <--> 0 2 7 2 <--> 1 3 8 3 <--> 2 4 9 4 <--> 3 5 11 5 <--> 4 0 10 6 <--> 0 7 <--> 1 8 <--> 2 9 <--> 3 10 <--> 5 11 <--> 4 12 13 12 <--> 11 15 13 <--> 11 14 14 <--> 13 15 <--> 12 Start to do Maximum Common Subgraph Search: Found common subgraph (size 10) 0 <--> 1 5 6 1 <--> 0 2 7 2 <--> 1 3 3 <--> 2 4 4 <--> 3 5 8 5 <--> 4 0 9 6 <--> 0 7 <--> 1 8 <--> 4 9 <--> 5 ....

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[Interprocess] Opposite of find_or_construct()
by Aaron_Wright＠selinc.com 19 Apr '12

19 Apr '12

I feel like I'm missing something simple. I have multiple processes that are going to use an object in shared memory. The find_or_construct() method lets these processes get a pointer to the object without worrying about startup order. What about the opposite? When a process is done with the object in shared memory it can't destroy it because the other processes may be using it. Is there a destroy_or_not() method that would only destroy the object when everyone is done with it? Normally I would solve this with a smart pointer like shared_ptr, but I think I'm miss understanding smart_ptr and I can't get it to work right. It seems like the shared_ptr is created in shared memory and needs to be explicitly destroyed, which would bring me back to the original problem, of who actually gets to destroy it. Should I be looking at intrusive_ptr? --- Aaron Wright

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Calling dijkstra on a filtered graph with bundled properties?
by Berit Dangaard Brouer 18 Apr '12

18 Apr '12

Hi there, First of all thank you for the boost graph library - I really enjoy working with it. However I have become challenged in calling Dijkstra on a filtered graph with bundled properties: My graph structure "mcf_graph" looks like this: #ifndef MCF_GRAPH_HPP #define MCF_GRAPH_HPP #include <boost/config.hpp> #include <boost/graph/adjacency_list.hpp> #include <iostream> using namespace boost; using namespace std; struct Port { Port(int index=-1, int type=0, int port_code=0, string UN="NN", string name="NN", int service_id=-1 ): m_index(index), m_type(type), m_port_code( port_code), UNLOCODE(UN), m_name(name), m_service_id(service_id) {} int m_index; int m_type;//0 port, 1 port call int m_port_code; string UNLOCODE; string m_name; int m_service_id; }; struct Edge { Edge( int id=0, int type=0, double weight=0.0, double dual_cost=0.0, double util=0.0, double cap=0.0, double r_cap=0.0 ) : m_idx(id), m_type(type), m_weight(weight) , m_dual_cost(dual_cost), m_utilization(util), m_capacity(cap), m_res_cap(r_cap) {} unsigned int m_idx; int m_type; double m_weight; double m_dual_cost; double m_utilization; double m_capacity; double m_res_cap; //residual capacity }; template <typename res_cap_map> struct positive_res_cap { positive_res_cap() { } positive_res_cap( res_cap_map cap) : res_cap(cap) { } bool operator()(const Edge& e) const { return 0 < e.m_res_cap; } res_cap_map res_cap; }; //Graph typedef adjacency_list< vecS , vecS , bidirectionalS, Port, Edge> mcf_graph; private: mcf_graph& g; }; #endif I am filtering an mcf_graph like this: //filter positive residual capacity graph positive_res_cap<res_cap_map> filter(get(&Edge::m_res_cap, m_mcf->graph())); filtered_graph<mcf_graph, positive_res_cap<res_cap_map> > fg(m_mcf->graph(), filter); and then calling Dijkstra like this: vertex_descriptor o_vd; std::vector<vertex_descriptor> p ( num_vertices ( fg ) ); std::vector<double> d ( num_vertices ( fg ) ); dijkstra_shortest_paths ( fg, o_vd, predecessor_map ( &p[0] ).distance_map ( &d[0] ).weight_map ( get ( &Edge::m_weight,fg ) ).vertex_index_map ( get ( vertex_index,fg ) ) ); and I get the following compilation error: /usr/include/boost/graph/filtered_graph.hpp:75:63: error: no match for call to '(const positive_res_cap<boost::bundle_property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge>, boost::detail::edge_desc_impl<boost::bidirectional_tag, unsigned int>, Edge, double> >) (const boost::detail::edge_desc_impl<boost::bidirectional_tag, unsigned int>&)' /home/berit/svn/MCF/src/IPH/include/mcf_graph.h:54:8: note: candidate is: /home/berit/svn/MCF/src/IPH/include/mcf_graph.h:57:7: note: bool positive_res_cap<res_cap_map>::operator()(const Edge&) const [with res_cap_map = boost::bundle_property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge>, boost::detail::edge_desc_impl<boost::bidirectional_tag, unsigned int>, Edge, double>] /home/berit/svn/MCF/src/IPH/include/mcf_graph.h:57:7: note: no known conversion for argument 1 from 'const boost::detail::edge_desc_impl<boost::bidirectional_tag, unsigned int>' to 'const Edge&' The above call to Dijkstra works on a non-filtered graph. Can anyone help me out in both understanding why it does not work for the predicate (Is it because the iterators are different???) and how to solve my problem? Thanks in advance ! Berit -- Best Regards, Berit Dangaard Brouer (formerly Løfstedt) PhD. Student DTU Management Engineering, Operations Research Technical University of Denmark Department of Management Engineering Produktionstorvet, Bygning 426 2800 Kgs. Lyngby blof(a)dtu.dk <mailto:blof@man.dtu.dk> www.or.man.dtu.dk <http://www.or.man.dtu.dk>

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Timeout on read/write using Boost.Asio
by boost 18 Apr '12

18 Apr '12

Hi everyone I'm using boost asio to implement a tcp client in my project, and it is my first time of using asio. I need timeout when read/write on the socket and I found the solution of using async io plus a timer, if timeout, cancel the async io operation. My question is: the "cancel" call acutely cancel all the pending async operation, but only one of them is timeout. For example, there is a pending async read and a pending async write operation, only read is timeout, I do not want cancel write any way. Any suggestion of the solution? Or I' m wrong? Thanks

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shared_ptr and container iterators
by Johannes Totz 18 Apr '12

18 Apr '12

Hi all, just started playing with boost::shared_ptr. How do I get a const iterator pointing to a shared_ptr pointing to a const object? See code below, I'd like to prevent a MyItem being changed through const iterators. struct MyItem { int value; }; struct MyContainer { typedef std::set<boost::shared_ptr<MyItem> > MySet; MySet set; }; int main(int argc, char* argv[]) { MyContainer mc; boost::shared_ptr<MyItem> p(new MyItem); p->value = 5; mc.set.insert(p); MyContainer::MySet::const_iterator i = mc.set.begin(); // cannot mutate shared_ptr pointed to by iterator: ok //(*i).reset(new MyItem); // cannot change ptr but can change value: ok (*i)->value = 6; MyContainer::MySet::iterator j = mc.set.begin(); (*j).reset(new MyItem); // how to do this? // should not change ptr nor MyItem std::set<boost::shared_ptr<const MyItem> >::const_iterator k = mc.set.begin(); return 0; }

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