Herve Bronnimann ha scritto:
Cosimo: if you've got one thread that reads and one that modifies your adjacency list, you must protect your graph with a (per vertex) Mutex. If you insist that you are not accessing the same edges at the same time, you still must. If you insist you are not accessing the adj lists at the same time, then maybe (but I doubt you can make that guarantee and the fact you crash means that you probably aren't).
If you go all listS (both tmpl args) you still must use a mutex unless you somehow hack BGL to use lockfree lists. I doubt anyone has ever done that.
You seem to think the crash is because of invalidation of iterators. It isn't. It's because of the lack of synchronization between your threads.
Hi Herve, Thanks for your contribute, but I'm not sure I understand what you've said: each vertex must have a mutex? So, I'm trying to implementing a sync_adjacency_list module, a graph adaptor similar to filtered_graph and reverse_graph; I've reimplemented every function required by the concepts modeled by the adjacency_list; each function has synchronized with the others by the same mutex, so every function that works on a sync_adjacency_list is atomic. I've implemented every graph traversal concept without problems, like this: template <typename G> typename sync_adjacency_list<G>::edges_size_type num_edges(const sync_adjacency_list<G>& g) { interprocess::scoped_lock<interprocess::interprocess_mutex> lock( sync_adjacency_list_mutex ); return num_edges(g.m_g); } Now I'm trying to implement the EdgeMutableGraph concept, in order to obtain the add_edge() support, but I've a problem. template <typename G> std::pair<typename sync_adjacency_list<G>::edge_descriptor, bool> add_edge(const typename sync_adjacency_list<G>::vertex_descriptor u, const typename sync_adjacency_list<G>::vertex_descriptor v, const sync_adjacency_list<G>& g) { interprocess::scoped_lock<interprocess::interprocess_mutex> lock( sync_adjacency_list_mutex ); return add_edge(u, v, g.m_g); } When I try to use it with G = adjacency_list< listS, vecS, directedS, vertexs_properties, edges_properties >, I'm obtaining the follow compile error message: "error C2665: 'boost::add_edge' : none of the 2 overloads could convert all the argument types" It seems that the compiler can't find the right implementation of add_edge(). It's strange, because I'm sure that the add_edge() exists for adjacency_list<...>. The add_edge() version I've implementated is only a wrapper of it. Where I'm wrong? Is it a MSVC 2005 function resolution bug? Thanks in advance, Cosimo Calabrese.