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[BoostTest] 1.35.0: valgrind complains about uninitialized memory
by peter.klotz＠ith-icoserve.com 14 Apr '08

14 Apr '08

valgrind 3.3.0 complains about uninitialized memory in BoostTest 1.35.0: ==31740== Syscall param sigaltstack(ss) points to uninitialised byte(s) ==31740== at 0x413D811: sigaltstack (in /lib/tls/libc-2.3.2.so) ==31740== by 0x80863D8: boost::execution_monitor::catch_signals(boost::unit_test::callback0<int> const&) (in Application) ==31740== by 0x80864AB: boost::execution_monitor::execute(boost::unit_test::callback0<int> const&) (in Application) ==31740== by 0x8084AD7: boost::unit_test::unit_test_monitor_t::execute_and_translate(boost::unit_test::test_case const&) (in Application) ==31740== by 0x8081492: boost::unit_test::framework_impl::visit(boost::unit_test::test_case const&) (in Application) ==31740== by 0x8076684: boost::unit_test::traverse_test_tree(boost::unit_test::test_suite const&, boost::unit_test::test_tree_visitor&) (in Application) ==31740== by 0x8076658: boost::unit_test::traverse_test_tree(boost::unit_test::test_suite const&, boost::unit_test::test_tree_visitor&) (in Application) ==31740== by 0x8080443: boost::unit_test::framework::run(unsigned long, bool) (in Application) ==31740== by 0x806E093: boost::unit_test::unit_test_main(boost::unit_test::test_suite* (*)(int, char**), int, char**) (in Application) The attached patch fixes this error by initializing the structure passed to syscall sigaltstack(). Best regards, Peter.

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[Graph] Bug in depth_first_search
by Fonzi Chat 14 Apr '08

14 Apr '08

Hello, I'm trying to pass a distance_map PropertyMap into a depth_first_search call. I've done so without any problems for BFS and Dijkstra's, however I just cannot get DFS to update the distance_map. This is what I have: typedef adjacency_list<listS, vecS, directedS, no_property, property<edge_weight_t, int> > Graph; std::vector<int> d(NUMVERTICES); depth_first_search(G, visitor(*(new DFSVisitor(s, t))).distance_map(&d[0])); Where I have defined a DFSVisitor class that derives from dfs_visitor appropriately. I'm really stumped on this, so any help is appreciated. _________________________________________________________________ Get in touch in an instant. Get Windows Live Messenger now. http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refres…

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Egg review period extended until April 20th
by dan marsden 13 Apr '08

13 Apr '08

Hi All The Egg review has run for 2 weeks now with zero reviews, which is obviously disappointing. There has been some good and pretty thorough discussion, and a couple of promises of reviews. As such, I'm extending the review period by 1 week until 20th April 2008. Please do post a review if you have any interest in this library. In case anybody is unsure, in the case of zero votes being posted, the default result will be a rejection. Please lets make sure we don't have to fall through to this default case. Introduction: It is not so easy to define Function Objects especially if you want to support Boost.ResultOf and Boost.Lambda. Therefore, as Boost provides iterator_facade and iterator adaptors, Egg provides function_facade and function adaptors. Egg provides the following features: * Workaround for the Forwarding Problem http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2002/n1385.htm * Helpers to build Function Objects: * egg::function and egg::function_facade provides the way to build Function Objects which supports Boost.ResultOf and Lambda. * Function Objects Adaptors(in other words, higher-order functions): * egg::curryN supports the currying. * egg::pipable emulates extension methods(C#). * egg::fuse/unfuse emulates variadic functions. * egg::nestN represents nested lambda expressions. * etc... The documentation is on line: http://p-stade.sourceforge.net/boost/libs/egg/ The zipped source code is in Vault/FunctionObjects: http://tinyurl.com/34lgda Tested under: Boost Development Trunk and Boost Version1.34.1. --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Thanks Dan Marsden Review Manager ___________________________________________________________ Yahoo! For Good helps you make a difference http://uk.promotions.yahoo.com/forgood/

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[Random] Differing values from minstd_rand in v1.35.0
by Greg Landrum 13 Apr '08

13 Apr '08

Dear all, After moving from boost 1.34.1 to 1.35.0 I have noticed that the sequence of values returned by the minstd_rand generator has changed. The following code snippet generates different values with 1.35.0 than it did with 1.34.x and 1.33.x: //------------------------- typedef boost::minstd_rand rng_type; typedef boost::uniform_int<> distrib_type; typedef boost::variate_generator<rng_type &,distrib_type> source_type; rng_type generator(42u); unsigned int seeds[] = {12,23,42}; distrib_type dist(0,INT_MAX); source_type randomSource(generator,dist); for(unsigned int i=0;i<3;++i){ generator.seed(seeds[i]); std::cerr << seeds[i]; for(unsigned int j=0;j<5;++j){ unsigned int bit = randomSource(); std::cerr<<" "<<bit%1024; } std::cerr<<std::endl; } //------------------------- Output with v1.35.0: 12 691 854 1010 690 696 23 444 337 394 1000 751 42 404 8 37 977 972 and with v1.34.1: 12 691 844 854 975 292 23 214 852 444 337 394 42 883 404 943 348 8 If I use the mt19937 generator instead of minstd_rand, the sequences are the same across versions. In the event it matters, I'm using g++ v4.1.3 on an Ubuntu Linux system. Is this user error, the result of a bug fix in Boost.Random, a new bug in Boost.Random, or is my expectation that the output of the RNG should not change across releases unreasonable? Thanks in advance for any help. Best Regards, -greg

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boost.interprocess dynamic segment size?
by hgdhfdghsa＠Safe-mail.net 13 Apr '08

13 Apr '08

Hello, in my application I am forced to create a shared memory segment whose size can change at runtime. Is it possible to implement such a shared memory segment using the boost.interprocess library? I do not want to pre-allocate a big shared memory segment, as in most cases the segment is small (about 100bytes). Just in some very rare cases it gets very big (5MB or even more). Thank you

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Hide the predicate type of a filter_iterator?
by Jean-Pierre Bergamin 13 Apr '08

13 Apr '08

Hello everyone Imagine a class "numbers" that contains some values and methods like getEvenValues(), getOddValues(), getValuesLarger100() etc. Those methods return an iterator range of filter_iterators. In the the code I posted below, I'd have to define a different iterator_range of filter_iterator types for all the different methods (numbers::EvenFilterRange, numbers::OddFilterRange etc.). Is there some way to "hide" the type of the predicate used in a filter_iterator, so that it would be possible to have a generic "NumberRange" type for the return values of all methods? Something like: class numbers { typedef NumberRange ????; NumberRange getEvenValues() const; NumberRange getOddValues() const; NumberRange getValuesLarger100() const; } Thanks for your hints James /*********************************************/ #include <vector> #include <iostream> #include <boost/iterator/filter_iterator.hpp> #include <boost/iterator/counting_iterator.hpp> #include <boost/range/iterator_range.hpp> using namespace std; using namespace boost; /*********************************************/ template<typename T> struct is_even { bool operator()(const T &t) { return t % 2 == 0; } }; template<typename T> struct is_odd { bool operator()(const T &t) { return t % 2 != 0; } }; /*********************************************/ class numbers { public: typedef vector<int> NumberContainer; typedef NumberContainer::const_iterator NumberIter; typedef iterator_range< filter_iterator< is_even<numbers::NumberContainer::value_type>, NumberIter> > EvenFilterRange; numbers() { copy( counting_iterator<NumberContainer::value_type>(0), counting_iterator<NumberContainer::value_type>(100), back_inserter(m_vec) ); } template<typename Pred> iterator_range<filter_iterator<Pred, NumberIter> > getValues(const Pred &pred) { return make_iterator_range( make_filter_iterator(pred, m_vec.begin(), m_vec.end()), make_filter_iterator(pred, m_vec.end(), m_vec.end()) ); } EvenFilterRange getEvenValues() { typedef is_even<numbers::NumberContainer::value_type> PredType; PredType is_even_predicate; return getValues(is_even_predicate); }; private: NumberContainer m_vec; }; /*********************************************/ template<typename T> struct print_number { void operator()(const T &t) { cout << "Number: " << t << endl; } }; /*********************************************/ int main() { numbers n; numbers::EvenFilterRange even_filter_range = n.getEvenValues(); print_number<numbers::NumberContainer::value_type> printer; for_each(begin(even_filter_range), end(even_filter_range), printer); }

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Best way to share data in an object between two threads?
by boost＠celticblues.com 13 Apr '08

13 Apr '08

WinXP, Visual Studio 2003 I have a dialog based application which consists of the main thread and a data collection thread. The main thread updates a graph from data read by the data collection thread. I want to use an object, which is of type MyData to share the data between the threads. So , basically the data collection thread which collects data from a piece of hardware and places it in the MyData object, then the main thread reads from the MyData object and updates the graph. After reading a bit on shared memory, managed mapped memory etc. in Boost, I am a bit confused on how to do this. What is the best boost classes to use for this? Will I also need a sync object to synchronize the threads? Thanks, Ed

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Re: [Boost-users] [boost] [gil] [announcement] New IO lib
by Christian Henning 12 Apr '08

12 Apr '08

I'm sorry my link to the library needs a password. Instead, please use the following link: http://gil-contributions.googlecode.com/svn/trunk/gil_2/boost/gil/extension… > Is there any documentation yet? No, not yet. My announcement is all I have so far. I'll work on it. > > Definately get this added to the review queue. If nothing else it > will create lots > of interesting discussions. Nice work. I'll be using it. Thanks. I hope people will start a discussion. Christian

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(no subject)
by lolsson＠comhem.se 12 Apr '08

12 Apr '08

Hello! I'm having problems building boost 1.35 on a solaris machine with gcc 3.4.2. Pretty early on I get: gcc.compile.c++bin.v2/libs/test/build/gcc-3.4.2/release/threading-multi/debug.o /usr/ccs/bin/as: "/var/tmp//ccLNzYoL.s", line 3775: error: cannot use v8plus instructions in a non-v8plus target binary /usr/ccs/bin/as: "/var/tmp//ccLNzYoL.s", line 3815: error: cannot use v8plus instructions in a non-v8plus target binary ..... Here's some info about my system: $ uname -a SunOS se06pluto 5.8 Generic_117350-51 sun4u sparc SUNW,Sun-Fire-880 $ gcc -v Reading specs from /usr/local/lib/gcc/sparc-sun-solaris2.8/3.4.2/specs Configured with: ../configure --with-as=/usr/ccs/bin/as --with-ld=/usr/ccs/bin/ld --disable-nls --disable-libgcj --enable-languages=c, c++ Thread model: posix gcc version 3.4.2 I have found the following thread which seems to address my problem: http://www.nabble.com/-detail--sparc-v8plus-build-problem-td7944960.html After reading this I'm still unsure about what to do. Should I edit tools/build/v2/tools/gcc.jam and do something with one of these lines? # Sparc flags gcc OPTIONS <architecture>sparc/<address-model>32 : -m32 ; flags gcc OPTIONS <architecture>sparc/<address-model>64 : -m64 ; cpu-flags gcc OPTIONS : sparc : c3 : -mcpu=c3 : default ; cpu-flags gcc OPTIONS : sparc : v7 : -mcpu=v7 ; cpu-flags gcc OPTIONS : sparc : cypress : -mcpu=cypress ; cpu-flags gcc OPTIONS : sparc : v8 : -mcpu=v8 ; cpu-flags gcc OPTIONS : sparc : supersparc : -mcpu=supersparc ; cpu-flags gcc OPTIONS : sparc : sparclite : -mcpu=sparclite ; cpu-flags gcc OPTIONS : sparc : hypersparc : -mcpu=hypersparc ; cpu-flags gcc OPTIONS : sparc : sparclite86x : -mcpu=sparclite86x ; cpu-flags gcc OPTIONS : sparc : f930 : -mcpu=f930 ; cpu-flags gcc OPTIONS : sparc : f934 : -mcpu=f934 ; cpu-flags gcc OPTIONS : sparc : sparclet : -mcpu=sparclet ; cpu-flags gcc OPTIONS : sparc : tsc701 : -mcpu=tsc701 ; cpu-flags gcc OPTIONS : sparc : v9 : -mcpu=v9 ; cpu-flags gcc OPTIONS : sparc : ultrasparc : -mcpu=ultrasparc ; cpu-flags gcc OPTIONS : sparc : ultrasparc3 : -mcpu=ultrasparc3 ; Or is there something else I can do? Thanks, Lars

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[Graph] distance_map Property not working for DFS?
by Fonzi Chat 12 Apr '08

12 Apr '08

Hello, I just started using the Boost graph library a few days ago, so I am pretty new to all of this. What I'm trying to do is to record the path distance between a given source and target vertex using a variety of algorithms. So far, I've gotten BFS and Dijkstra's working correctly, however I'm having some trouble having distance information recorded in my distance_map Property when attempting to do this with DFS. For instance, this is what I wrote for Dijkstra's: dijkstra_shortest_paths(G, s, distance_map(&d[0]).visitor(*(new DijkstraVisitor(s, t)))); where G is a Graph, s is the start Vertex, d is defined as an integer vector and DijkstraVisitor is a class I have defined that is used as the visitor for the algorithm. Similarly, for DFS I have: depth_first_search(G, visitor(*(new DFSVisitor(s, t))).distance_map(&d[0]).root_vertex(s)); Unfortunately, when I try reading the d vector, all the values are zero and seem to have never been updated. My question is: what am I doing wrong and what can I do to record the distance correctly? Another somewhat related problem I have is that the algorithms seem to take VERY long to complete when larger graphs are processed. For instance, a graph with 100 vertices and 10,000 edges (mesh topology) takes about 10 minutes to complete the shortest path problem between two given vertices. Is this normal? Thank you for putting up with my amateur questions! Any and all help is appreciated. _________________________________________________________________ Get in touch in an instant. Get Windows Live Messenger now. http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refres…

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