November 2012 - Boost-users

Is boost::this_thread::sleep_for interruption point?
by Serg Gulko 22 May '13

22 May '13

Hello! According to documentation(v 1.50.0) call boost::this_thread::sleep_for can be interrupted. For some reason this functionality not works for me. Here is code sample: //Simple thread function void Test::worker(int delay) { try { boost::this_thread::sleep_for(boost::chrono::milliseconds(delay)); cout << "Doing some work" << endl; } catch (boost::thread_interrupted const& e) { cout << "INTERRUPTED" << endl; } } //Far in the code boost::thread workerThread(boost::bind(&Test::worker, this, 1200)); boost::this_thread::sleep(boost::posix_time::milliseconds(30)); workerThread.interrupt(); boost::this_thread::sleep(boost::posix_time::milliseconds(1500)); I always getting 'Doing some work'... -- View this message in context: http://boost.2283326.n4.nabble.com/Is-boost-this-thread-sleep-for-interrupt… Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] [CMake] [boost][b2] Differenciate 32bit and 64 bit binaries when using CMake.
by Klaim - Joël Lamotte 16 Apr '13

16 Apr '13

Júlio Hoffimann said: > > I don't know if i understood correctly, but you can set the library > directory by hand, please refer to > /usr/share/cmake-<version>/Modules/FindBoost.cmake, in particular the > variable BOOST_LIBRARYDIR. On Thu, Oct 11, 2012 at 1:29 PM, Miller, Frank <FMiller(a)sjm.com> wrote: > A simple solution would be to install only the 64bit version of boost > into a new directory and change the environment variable to point there. > Then FindBoost will only be able to see the version you want. > Thanks, this will solve my immediate problem, but it don't solve it in general. (I will use it though, so thanks) I can't guarantee where the boost libraries are installed, that's why I use FindBoost. My current understanding is that boost don't have a specific default lib dir for different address models, which is the source of the problem as FindBoost script can't rely on a protocol to find these lib files. Am I correct? Joel Lamotte

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can't get first example in boost tutorial to work
by 7stud 10 Mar '13

10 Mar '13

I'm trying to install boost on mac osx 10.4.7. I followed the tutorial "Getting Started on Unix Variants" found here: http://www.boost.org/doc/libs/1_35_0/ more/getting_started/unix-variants.html Following the instructions in the tutorial, I installed boost in /usr/local as instructed, so my directory structure is: /usr/local/boost_1_34_1/boost But when I run the first example in the tutorial: #include <boost/lambda/lambda.hpp> #include <iostream> #include <iterator> #include <algorithm> int main() { using namespace boost::lambda; typedef std::istream_iterator<int> in; std::for_each(in(std::cin), in(), std::cout << (_1 * 3) << " " ); } I get the error(among others): error: boost/lambda/lambda.hpp: No such file or directory If I change the include path to: #include </user/local/boost_1_34_1/boost/lambda/lambda.hpp> I get the error(among others): error: boost/lambda/core.hpp: No such file or directory But core.hpp is in the lambda directory: /usr/local/boost_1_34_1/boost/lambda$ ls algorithm.hpp control_structures.hpp lambda.hpp bind.hpp core.hpp loops.hpp casts.hpp detail numeric.hpp closures.hpp exceptions.hpp switch.hpp construct.hpp if.hpp I'm using the Xcode 2.4 IDE to run my C++ programs. I also tried to execute the program from the command line with the original include path: #include <boost/lambda/lambda.hpp> but I get the same error: ~/2testing/dir1$ g++ prog1.cpp prog1.cpp:1:35: error: boost/lambda/lambda.hpp: No such file or directory prog1.cpp: In function 'int main()': prog1.cpp:8: error: 'boost' has not been declared prog1.cpp:8: error: expected namespace-name before ';' token prog1.cpp:8: error: '<type error>' is not a namespace prog1.cpp:11: error: '_1' was not declared in this scope I get the same errors again with the full include path: #include </user/local/boost_1_34_1/boost/lambda/lambda.hpp> $ g++ prog1.cpp In file included from prog1.cpp:1: /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:14:33: error: boost/lambda/core.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:21:52: error: boost/lambda/detail/operator_actions.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:22:61: error: boost/lambda/detail/operator_lambda_func_base.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:23:63: error: boost/lambda/detail/operator_return_type_traits.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:26:45: error: boost/lambda/detail/operators.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:30:46: error: boost/lambda/detail/member_ptr.hpp: No such file or directory prog1.cpp: In function 'int main()': prog1.cpp:8: error: 'boost' has not been declared prog1.cpp:8: error: expected namespace-name before ';' token prog1.cpp:8: error: '<type error>' is not a namespace prog1.cpp:11: error: '_1' was not declared in this scope What path should I be using? Or, should I set an environment variable somewhere?

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chaining functions input output
by MM 19 Feb '13

19 Feb '13

Hello, i have these 2 functions provided to me and I wonder whether they can somehow be chained without using intermediary memory? http://codepad.org/tTwkUQhp Rds, MM

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[Program Options] terminate parsing after first positional argument
by Stuart Pook 22 Jan '13

22 Jan '13

Hello, How can I tell Boost Program Options to stop parsing the arguments as soon as it finds a positional argument? I'd like to be able to parse the argument list "-v chmod -R -v 600 foo" as having one argument for my program (-v) and the rest as a std::vector of std::string (including the -v). In the attached program I have tried 2 different approaches. The first uses multitoken with the arguments "--command date -u -v", it fails because "-u" isn't known. The second uses collect_unrecognized with "chmod -R -v 600", it doesn't work because -v is interpreted by boost and doesn't end up in the vector. As someone said back in 2005, perhaps I'm trying to write xargs: http://thread.gmane.org/gmane.comp.lib.boost.user/9529/focus=9641 I know that I can ask my users to write a.out -v -- chmod -R -v 600 foo but I don't want to do that. I want them to write "a.out -v chmod -R -v 600 foo". The first positional argument should should tell boost to stop processing. Another slightly different question. If I have a multitoken option that takes doubles how can I get it to accept negative values? If I give my program "--floats 1 8 -4 6" where --floats starts a multitoken option that accepts double, I get an exception saying that "-4" is an unknown option. thanks Stuart This is what my test program gives me with boost 1.50: argv: dd --command date -u -v unrecognised option '-u' Allowed options: -v [ --verbose ] verbose --command arg command to run 2nd try argv: dd chmod -R -v 600 I'm verbose v: chmod -R 600 3rd try argv: dd --floats 1 8 -4 6 unrecognised option '-4' Allowed options: -v [ --verbose ] verbose -f [ --floats ] arg numbers and my program (formatted to fit in 80 characters) #include <boost/program_options.hpp> #include <boost/range/algorithm.hpp> #include <boost/program_options/parsers.hpp> #include <boost/program_options/options_description.hpp> #include <iostream> namespace po = boost::program_options; #define nelements(a) (sizeof (a) / sizeof (a)[0]) void print(char const * * b, char const * * e) { std::cout << "argv: "; std::copy(b, e, std::ostream_iterator<char const *>(std::cout, " ")); std::cout << std::endl; } int main(int argc, char ** argv) { { bool verbose; std::vector<std::string> command; po::options_description desc("Allowed options"); desc.add_options() ("verbose,v", po::bool_switch(&verbose)->default_value(false), "verbose") ("command", po::value<std::vector<std::string> >(&command) ->multitoken(), "command to run") ; char const * args[] = { "dd", "--command", "date", "-u", "-v", 0 }; print(args, args + nelements(args) - 1); po::variables_map vm; try { po::store(po::command_line_parser(nelements(args) - 1, args) .options(desc).run(), vm); po::notify(vm); if (verbose) std::cout << "I'm verbose\n"; std::cout << "command: "; boost::copy(command, std::ostream_iterator<std::string>(std::cout, " ")); std::cout << std::endl; } catch (boost::program_options::unknown_option & x) { std::cerr << x.what() << "\n" << desc << "\n"; } } std::cout << "2nd try\n"; { bool verbose; po::options_description desc("Allowed options"); desc.add_options() ("verbose,v", po::bool_switch(&verbose)->default_value(false), "verbose") ; char const * args[] = { "dd", "chmod", "-R", "-v", "600", 0 }; print(args, args + nelements(args) - 1); po::variables_map vm; po::parsed_options parsed = po::command_line_parser(nelements(args) - 1, args). options(desc).allow_unregistered().run(); try { po::store(parsed, vm); } catch (boost::program_options::unknown_option & x) { std::cerr << x.what() << "\n" << desc << "\n"; exit(2); } po::notify(vm); if (verbose) std::cout << "I'm verbose\n"; std::cout << "v: "; std::vector<std::string> v = po::collect_unrecognized( parsed.options, po::include_positional); boost::copy(v, std::ostream_iterator<std::string>(std::cout, " ")); std::cout << std::endl; } std::cout << "3rd try\n"; { bool verbose; std::vector<double> f; po::options_description all("Allowed options"); all.add_options() ("verbose,v", po::bool_switch(&verbose)->default_value(false), "verbose") ("floats,f", po::value<std::vector<double> >(&f)->multitoken(), "numbers") ; char const * args[] = { "dd", "--floats", "1", "8", "-4", "6", 0 }; print(args, args + nelements(args) - 1); po::variables_map vm; try { po::store(po::command_line_parser(nelements(args) - 1, args) .options(all).run(), vm); po::notify(vm); if (verbose) std::cout << "I'm verbose\n"; std::cout << "floats: "; boost::copy(f, std::ostream_iterator<double>(std::cout, " ")); std::cout << std::endl; } catch (boost::program_options::unknown_option & x) { std::cerr << x.what() << "\n" << all << "\n"; } } }

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Manually cleaning up TSS data in boost 1.49
by Andrew Harvey 07 Dec '12

07 Dec '12

Hi, I am using boost::thread for a plug-in that is loaded by a third-party Linux application. I have no control over the host's threading or when it chooses to unload my code. Unfortunately I experience a crash every time the host thread unloads the .so and terminates. I get the following backtrace: (gdb) bt #0 0x00007fffde12c460 in ?? () #1 0x00000032cf607889 in start_thread () from /lib64/libpthread.so.0 #2 0x00000032cf2e5ccd in clone () from /lib64/libc.so.6 Not much to go on... I am pretty confident the crash is happening in a pthread key destructor registered by Boost. The only parts of the boost::thread library I am currently using are the synchronization classes: shared_mutex, shared_lock, unique_lock, upgrade_lock, upgrade_to_unique_lock I'm not directly using any thread-specific storage myself. What I would like to do is force boost to call its TSS destructor in my plug-in's destroy_dso() function. Is this at all possible? Many thanks, - Andrew

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Boost::Asio read_until and streambuf usage
by Gonzalo Garramuno 06 Dec '12

06 Dec '12

I have a server that sends three lines, each of which have to be parsed independently. I am using read_until but have a problem with its usage. When read_until reads once, the streambuf seems to contain the three lines but not in the istream and only when I call read_until several times, I get the lines. I am wondering how can I safely read_until the buffer is empty (the 3 or more lines are read) and then exit the loop. boost::asio::streambuf buf; while( 1 ) { size_t reply_length = boost::asio::read_until( socket_, buf, '\n' ); std::istream is(&buf); std::string reply; std::getline(is, reply); // only 1 line obtained }

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Asio and software interrupts
by Joseph Sulewski 03 Dec '12

03 Dec '12

Hello, I’m use the Boost::Asio libraries to read data from multicast sockets. This is a high rate application that needs to listen to data coming on a large number of multicast addresses (up to 500 different addresses). I would like to funnel all the multicast traffic to a single class where the data can get handled very quickly. I have the code working now using the socket->async_receive_from() method but the system is getting bogged down handling a large number of software interrupts. 51% of the CPU time is spent handling software interrupts. I create each multicast socket (up to 500 of them) like so: socket = new udp::socket(io_service); socket->open(listenEndPoint.protocol()); socket->set_option(boost::asio::ip::udp::socket::resuse_address(true)); socket->bind(listenEndPoint); socket->set_option(boost::asio::ip::multicast::join_group(multicastAddress.to_v4())); Slightly after that I register for data like so: socket->async_receive_from(buffer,senderEndPoint,boost::bind(&EthernetCapture::receiveData,this,boost::asio::placeholders::bytes_transferred)); Is there a more efficient way to receive multicast data without incurring so many software interrupts? By the way this is for an application to run on 32 bit Linux for an embedded application. Thanks

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[Who's using boost?] Algocoders : books on c++11, Boost and Beyond
by Algocoders . 03 Dec '12

03 Dec '12

Algocoders <http://www.algocoders.com> Algocoders has been using boost since last 6+ years with a mission to help people build a better software eco-system by standing on the shoulder of giants. If it wasn't not for boost, then it could have been really difficult for us to build our framework based on sound mathematical foundation of computer science using modern C++. It is the pioneering efforts at boost towards "Using and Extending C++11, Boost and Beyond" which has motivated us to devote ourself in developing bullet-size capsules in the form of tiny booklets with industrial-set framework to lift the thin veil with initial focus on practical usage of C++11 vis-a-vis mathematical foundation behind it. Web Page : http://www.algocoders.com Enthused by boost, we are working tirelessly towards *publishing a series of books(or booklets) which will bridge the gap between esoteric and street-side ones. Initial focus will be on C++11, Boost, Loki, STL, Algorithms, Data Structures, Multi-threading, Design Patterns, gcc, clang, valgrind.* *First book in this series is :*(will be available by end of November 2012) *Foundation of Algorithms in C++11, Volume 1* Using and Extending C++11, Boost and BeyondList of books(in progress): - *C++11 Algorithms : *Using and Extending C++11, Boost and Beyond - *Smart Pointers** : Tips and Techniques in C++ :* Using and Extending C++11, Boost and Beyond - *C++11 FAQs :* Using and Extending C++11, Boost and Beyond - *Concepts & Traits C++ **:* Using and Extending C++11, Boost and Beyond and so on. We use almost all the libraries under boost including trunk and branches, especially Spirit, Phoenix, Proto, MPL, Fusion to mention a few. Thanks, Algocoders www.algocoders.com

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boost managed shared memory: RUN FAILED
by Olivier Austina 03 Dec '12

03 Dec '12

Hello, I try to run an example from this online book( http://en.highscore.de/cpp/boost/interprocesscommunication.html) and I got "RUN FAILED (exit value 1, total time: 938ms) ". I am using Netbeans. This is the example: #include <boost/interprocess/managed_shared_memory.hpp> #include <iostream> int main() { boost::interprocess::shared_memory_object::remove("Highscore"); boost::interprocess::managed_shared_memory managed_shm(boost::interprocess::open_or_create, "Highscore", 1024); int *i = managed_shm.construct<int>("Integer")(99); std::cout << *i << std::endl; std::pair<int*, std::size_t> p = managed_shm.find<int>("Integer"); if (p.first) std::cout << *p.first << std::endl; } Thanks very much. -- Regards Austina

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