May 2018 - Boost-users - lists.preview.boost.org

[interprocess] Determine size of managed_shared_memory
by Kai Benndorf 12 Oct '19

12 Oct '19

Hi all, I want to create a managed_shared_memory in exactly the size I needed. Therefore I do something like this: size = sizeof( common_managed_shared_memory ); size += sizeof( MyClassInSharedMem ); managed_shared_memory segment(create_only, "name", size ); MyClassInSharedMem allocates itself some memory by segment->allocate(). I added this also to the size, but get a boost::interprocess::bad_alloc exception on allocating this additional memory. Are there some magic bytes I forgot to add? Many thanks in advance Kai

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boost::filtered_graph filtering on vertex color... if I only had a colormap
by Brian Davis 19 Jul '19

19 Jul '19

Lets say I have a graph g (of type graph_t) and a color map (boy I wish I had a colormap): typedef boost::property_map<graph_t, boost::vertex_color_t>::type color_map_t; or is it? auto indexmap = boost::get(boost::vertex_index, g); auto colors = boost::make_vector_property_map<boost::default_color_type>(indexmap); or maybe? auto indexmap = boost::get(boost::vertex_index, g); auto colors = boost::make_vector_property_map<boost::vertex_color_t>(indexmap); or possibly some goop found on the internet? boost::make_iterator_property_map(color_map.begin(), boost::get(boost::vertex_index, data_->g), color_map[0]) or other internet goop? typedef boost::property_map<GraphType, boost::vertex_color_t>::type color_map_t; color_map_t colorMap; boost::color_map(colorMap)) or other internet goop?? std::vector<int> colorMap(num_vertices(g), boost::white_color); so confused... (certainly not surprised why bgl is not a part of stl) Can someone help explain the various types and ways of specifying colormaps and the logic for each way and means? and a function (if I could get that far without VS syntax highlighter going bonkers and gobs of compiler errors.. you know the type): make_pretty(g, colormap ) which colors the graph colormap and a filter struct for boost::filtered_graph<Graph, EdgePredicate, VertexPredicate> (where I wonder why if I only want to filter vertices I have to set boost::keep_all for EdgePredicate... sigh... I know the answer... and also know how long it found me to find/figure out boost::keep_all - and if you are looking for boost::keep_all and found it here... your welcome ;-) ) and modifying (probably incorrectly) boost::filtered_graph example to: template <typename ColorMap> struct vertex_color_filter_eq { vertex_color_filter_eq() { } vertex_color_filter_eq(ColorMap colormap/*, boost::default_color_type c*/) : m_colormap(colormap)/*, m_c(c)*/ { } template <typename Vertex> bool operator()(const Vertex& v) const { return 0 < get(m_colormap, v); //return c < get(m_colormap, v); } ColorMap m_colormap; //boost::default_color_type m_c; }; auto indexmap = boost::get(boost::vertex_index, g); auto colors = boost::make_vector_property_map<boost::default_color_type>(indexmap); // some where here I would call make_pretty(g, colors) typedef property_map<graph_t, boost::vertex_color_t>::type ColorMap_t; vertex_color_filter<ColorMap_t> filter(colors); // boost::filtered_graph<graph_t, boost::keep_all, VertexPredicate> boost::filtered_graph<graph_t, boost::keep_all, vertex_color_filter> fg(g, filter); // Later say if I could get it compile and better if it compiled and worked I could move on and auto color = boost::red_color; typedef property_map<graph_t, boost::vertex_color_t>::type ColorMap_t; vertex_color_filter<ColorMap_t> filter(colors, color); boost::filtered_graph<graph_t, boost::keep_all, vertex_color_filter> fg(g, filter); Maybe if I color them yellow, I can then reach the wizard pull back the curtain and ask how to create a color map... If I only had a color map.

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Boost.Test BOOST_TEST/BOOST_REQUIRE_MESSAGE message arg problems
by Olaf Peter 27 Aug '18

27 Aug '18

Hello Boost Users, for my project I'm testing using BOOST_AUTO_TEST_SUITE and data driven test sets (BOOST_DATA_TEST_CASE). The goal is to check the proper working of a parser by checking success as such and compare the result with a "expected" data (string) vector. In case of parse error, I want to write the captured cout/cerr by boost.test into a file. In case of compare error the parsed result also shall be written to a file. The fragments show the concept/current state: namespace x3_test { // aka utils .... /* [Detect if boost test case failed]( * https://stackoverflow.com/questions/18466857/detect-if-boost-test-case-fail…) */ bool current_test_passing() { using namespace boost::unit_test; auto const id = framework::current_test_case().p_id; auto const test_results = results_collector.results(id); return test_results.passed(); } std::string report_diagnostic(fs::path const& test_case_name, std::string const& input, std::string const& result) { ... if(!x3_test::current_test_passing()) { // only write in case of failed test test_case_result_writer result_writer(test_case_name); result_writer.write(result); } return ss.str(); } } // x3_test ... BOOST_AUTO_TEST_SUITE(.... BOOST_DATA_TEST_CASE( declaration, dataset.input() ^ dataset.expect() ^ dataset.test_case_name(), code, expect_AST, test_case_name) { using attribute_type = ast::declaration; auto const parser = parser::declaration; x3_test::testing_parser<attribute_type> parse; auto [parse_ok, parsed_AST] = parse(code, parser); BOOST_TEST(parse_ok); BOOST_REQUIRE_MESSAGE(parse_ok, x3_test::report_diagnostic(test_case_name, code, parsed_AST) ); BOOST_TEST(parsed_AST == expect_AST, btt::per_element()); BOOST_REQUIRE_MESSAGE(x3_test::current_test_passing(), x3_test::report_diagnostic(test_case_name, code, parsed_AST) ); } BOOST_AUTO_TEST_SUITE_END() After some testing, the error count is twice the real (obviously here) but it's all above a work arround. It seems, that BOOST_REQUIRE_MESSAGE evaluates always the message predicate (shown by using --log_level=all) nevertheless the test case successed or failed. If failed it is streamed to the console. My first thoughs where that the message is called only in case of test failure which isn't true. The problem is now, that my report_diagnostic function write the test output (parsed_AST) to a special dir/file for later evaluating etc. The intuitive way would be: std::string report_diagnostic(fs::path const& test_case_name, std::string const& input, std::string const& result) { ... test_case_result_writer result_writer(test_case_name); result_writer.write(result); return ss.str(); } BOOST_REQUIRE_MESSAGE(parse_ok, // call diagnostic only in failure case and write then x3_test::report_diagnostic(test_case_name, code, parsed_AST) ); BOOST_REQUIRE_MESSAGE((parsed_AST == expect_AST, btt::per_element()), // call diagnostic only in failure case and write then x3_test::report_diagnostic(test_case_name, code, parsed_AST) ); Hence not depending on current_test_passing() any more. How to get this? Further, how can I get the captured std::cerr in case of '!parse_ok' inside report_diagnostic? Thanks, Olaf

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setup_error: test unit with name 'free_test_function' registered multiple times
by dinesh kumar 12 Jul '18

12 Jul '18

Hi Team, Greetings for the day. I apologies if this is a duplicate case which is already reported, but I am unable to find a suitable answer for this. I have installed boost(1.67.0.1) via brew, and created a simple unit test case as below. #define BOOST_TEST_DYN_LINK #define BOOST_TEST_MODULE super #include <boost/test/unit_test.hpp> using namespace boost::unit_test; std::string uri; std::string versionNum; BOOST_AUTO_TEST_CASE( free_test_function ) { BOOST_CHECK(true /* test assertion */); } *Compiled this code as below.* g++ obj/main.o -L /Library/PostgreSQL/9.6/lib -L /usr/local/lib -L /usr/local/opt/openssl/lib/ -o test_integration -lpq -lcpprest -lboost_regex-mt -lboost_system-mt -lboost_thread-mt -lssl -lcrypto -lboost_chrono-mt -lboost_log-mt -lboost_locale-mt -lboost_date_time-mt -lboost_program_options-mt -lboost_stacktrace_noop-mt -lboost_filesystem-mt -lboost_unit_test_framework-mt test integration installation is completed. *Got the error, while I execute the binary.* ./test_integration libc++abi.dylib: terminating with uncaught exception of type boost::unit_test::framework::setup_error: test unit with name 'free_test_function' registered multiple times [1] 59619 abort ./test_integration *I have tried to debug the binary, which execution is successful.* lldb -- ./pgBucket_integration (lldb) target create "./pgBucket_integration" Current executable set to './pgBucket_integration' (x86_64). (lldb) r Process 60066 launched: './pgBucket_integration' (x86_64) Running 1 test case... *** No errors detected Process 60066 exited with status = 0 (0x00000000) I would like to request you to guide me on what/where I am missing. *Below are my g++ version details.* $ g++ --version Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 8.1.0 (clang-802.0.42) Target: x86_64-apple-darwin16.4.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin -- Regards, Dinesh manojadinesh.blogspot.com

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[Test] Test executable crashes always
by Nate Widmyer 26 Jun '18

26 Jun '18

Hello, I've made some unit tests with boost test before without issue, but on my latest rather ordinary test, I've been able to get Boost test to crash the executable in debug and release mode when boost test is making a report before terminating. test_exe.exe!boost::unit_test::framework::get(unsigned long id, boost::unit_test::test_unit_type t) Line 1388 C++ test_exe.exe!boost::unit_test::framework::get<boost::unit_test::test_unit>(unsigned long id) Line 208 C++ test_exe.exe!boost::unit_test::results_reporter::make_report(boost::unit_test::report_level l, unsigned long id) Line 175 C++ test_exe.exe!boost::unit_test::unit_test_main(boost::unit_test::test_suite *(*)(int, char * *) init_func, int argc, char * * argv) Line 235 C++ test_exe.exe!main(int argc, char * * argv) Line 287 C++ That's the default report_level of 'confirm' If I use report_level=short or detailed, I get a similar crash: test_exe.exe!boost::unit_test::framework::get(unsigned long id, boost::unit_test::test_unit_type t) Line 1388 C++ test_exe.exe!boost::unit_test::framework::get<boost::unit_test::test_suite>(unsigned long id) Line 207 C++ test_exe.exe!boost::unit_test::traverse_test_tree(unsigned long id, boost::unit_test::test_tree_visitor & V, bool ignore_status) Line 365 C++ test_exe.exe!boost::unit_test::results_reporter::make_report(boost::unit_test::report_level l, unsigned long id) Line 185 C++ test_exe.exe!boost::unit_test::unit_test_main(boost::unit_test::test_suite *(*)(int, char * *) init_func, int argc, char * * argv) Line 235 C++ test_exe.exe!main(int argc, char * * argv) Line 287 C++ Here's the get() method: test_unit& get( test_unit_id id, test_unit_type t ) { test_unit* res = impl::s_frk_state().m_test_units[id]; BOOST_TEST_I_ASSRT( (res->p_type & t) != 0, internal_error( "Invalid test unit type" ) ); return *res; } Crash occurs on line 2 of the function. I logged 'res' each time the function is called and many times its valid, but when it runs this one test (by itself or with others), 'res' always ends up being NULL. id seems to always be '1', and t is TUT_ANY (17) if generating a confirmation report or TUT_SUITE (16) if generating a short or detailed report. If I use the option '--report_level=no', then execution does complete fine. I followed through on some process of elimination and it seems to be related to using a fixture? Having no test body still causes the crash. It wasn't until I removed the fixture (and its usage in the body of the test) did the executable not crash. I ensured that I was using the standard fixture model found here: http://www.boost.org/doc/libs/1_64_0/libs/test/doc/html/boost_test/tests_or… OS is Win 7 w/ VS2015 boost is 1.64.0 and was built with: b2 toolset=msvc-14.0 link=static runtime-link=static variant=debug address-model=64 --without-atomic --without-container --without-context --without-coroutine --without-coroutine2 --without-graph --without-graph_parallel --without-iostreams --without-locale --without-math --without-mpi --without-serialization --without-signals --without-type_erasure --without-wave -j4 --abbreviate-paths --without-python -d2 Any help would of something to look at or change would be appreciated. Thanks for your time, Nathan

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Plans to add parameter parsing in Beast?
by David Demelier 30 May '18

30 May '18

Hello, I'm trying to use Beast, it works fine and looks promising. Unfortunately, it looks like (unless I'm wrong) that there is no facilities to parse URL parameters or POST data. Such as /foo&option1=1&option2=2 Or simply form data: option1=1&option2=2 Are there plans to add such things or is definitely a non-goal of Boost Beast? Regards, -- David

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Boost::Log memory allocation
by Olivier Tristan 29 May '18

29 May '18

Hi, I was wondering if it is possible to avoid allocation in the thread trying to log stuff ? I thought that using asynchronous_sink and bounded_fifo_queue with drop_on_overflow would be enough but it do not look like to be the case. Thanks ! -- Olivier Tristan Research & Development www.uvi.net

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boost-iostreams problem
by Theodore Papadopoulo 28 May '18

28 May '18

Hi, I'm trying to use boost_iostream in a way that is probably not intented. My use case is the following, I have a C++ stream. I want to read its first bytes to determine if its gzip or Bzip2 or none of those, putback the characters to the stream and then create the appropriate pipeline to read the stream. Ideally, I'd then restart the procedure, so that I can incrementally build a pipeline based on the successive magic numbers read at the begining of the stream after different level of decoding. Imagine a file that has been gzipped and uuencoded. Let's call its stream ifs. Reading the first bytes of ifs, I would detect that it's an uuencoded file, so I construct a pipeline ifs1 = ifs | uudecode. Reading the first bytes of ifs1, I would detect that it's a gzipped file, and will construct a new pipeline ifs2 = ifs | uuencode | gzip (the reverse ordering for reading pipelines does not help here, but I can manage that). And so on.... Unfortunately, this does not work as I'm expecting it. The attached code is a small example showing the problem. When, reading the stream after having pushed the gzip filter (line 23), I get an exception. boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::iostreams::gzip_error> > Digging a little with gdb seems to show that the putback buffer is somehow lost, so the gzip filter does not read the proper header and hence the exception. The raw in.read does not throw exceptions but returns random bytes after the first 1f.... What is strange is that if I do the sequence: in.push(file); read(in,buffer,1); putback(in,buffer[0]); in.pop(); in.push(file); read(in,buffer,1); std::cout << std::hex << static_cast<int>(static_cast<unsigned char>(buffer[0])) << std::endl; putback(in,buffer[0]); The second read correctly reads the character put back (1f), but the second putback triggers an exception (putback buffer full). If the first read/putback is done directly on file, everything works as expected. I'm really stuck at this point, so any help would be welcome.... I hope there is a way to use boost_iostreams to achieve what I want to do. Thank's in advance for any clue on how to solve this... Theo.

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[asio] continuous reads into streambuf
by Stephan Menzel 25 May '18

25 May '18

Hello all, once again I find myself struggling with asio streambufs but wanted to ask here before chicken out to char buffers again. My problem is that I cannot read more than one protocol loop successfully. I got a TCP connection here that continuously receives messages on a simple protocol like that: header_size CRLF header (contains payload size) payload <repeat> I thought this is a prime use case for reading into a streambuf as I can easily deal with additional data being in there and the client pushing as fast as it can. Here is what I do (simplified quite a bit, sorry for copy and paste and simplify errors): (m_socket and m_streambuf are only used by one io_context, one thread, no races as far as I can tell) void read_header_size() { asio::async_read_until(m_socket, m_streambuf, "\r\n", [self](const boost::system::error_code, const std::size_t) { // < handle error skipped > std::string hsizestr; hsizestr.reserve(32); { std::istream is(&self->m_streambuf); std::getline(is, hsizestr); } std::size_t header_size = parse(hsizestr); self->read_header(header_size); }); } void read_header(const std::size_t n_header_size) { asio::async_read(m_socket, m_streambuf, boost::asio::transfer_exactly(n_header_size), [self, packet, n_header_size](const boost::system::error_code, const std::size_t) { // < handle error skipped > // Tried two versions of parsing the header (manual consume and istreams of various sorts) // manual consume: size_t payload_size = parse_header(n_streambuf.data().data(), n_header_size)) { n_streambuf.consume(n_header_size); self->read_payload(payload_size); }); } void read_payload(const std::size_t n_payload_size) { asio::async_read(m_socket, m_streambuf, boost::asio::transfer_exactly(payload_size), [self, n_packet, packet_size](const boost::system::error_code, const std::size_t) { // < handle error skipped > { std::istream is(&self->m_streambuf, std::ios::binary); is.read(target_buffer, target_buffer_size); // target buffer is elsewhere and well guarded } // read next message self->read_header_size(); }); } When I run this and make sure the client pushes at least 2 packets I can safely receive and process the first but after that the next asnc_read() in read_header never returns. As in never calls its handler. From debugging and looking at the streambuf I can reasonably assume the buffer contains all the data after the first async_read_until because the packages are very small (only about 60 bytes total). This leads me to believe the transfer_exactly don't return unless something is actually really transferred. But if such is the case, why does the first loop succeed? I am quite lost here. If anybody has some suggestion it is much appreciated. Thanks a bunch! Stephan

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Boost Process continuously read output
by Surya Kiran Gullapalli 16 May '18

16 May '18

Hi, I'm trying to read outputs/logs from different processes and display them in a GUI. The processes will be running for long time and produce huge output. I'm planning to stream the output from those processes and display them according to my needs. All the while allow my gui application to take user inputs and perform other actions. What I've done here is, from main thread launch two threads for each process. One for launching the process and another for reading output from the process. This is the solution I've come up thus far. // Process Class class MyProcess { namespace bp = boost::process; boost::asio::io_service mService; // member variable of the class bp::ipstream mStream // member variable of the class std::thread mProcessThread, mReaderThread // member variables of the class. public void launch(); }; void MyProcess::launch() { mReaderThread = std::thread([&](){ std::string line; while(getline(mStream, line)) { std::cout << line << std::endl; } }); mProcessThread = std::thread([&]() { auto c = boost::child ("/path/of/executable", bp::std_out > mStream, mService); mService.run(); mStream.pipe().close(); } } // Main Gui class class MyGui { MyProcess process; void launchProcess(); } MyGui::launchProcess() { process.launch(); doSomethingElse(); } The program is working as expected so far. But I'm not sure if this is the correct solution. Please let me know if there's any alternative/better/correct solution Thanks, Surya

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