November 2010 - Boost-users - lists.preview.boost.org

boost serialisation 1.45 portable binary archive fails for -1 on AIX
by Avi Bahra 26 Nov '10

26 Nov '10

//================ Main.cpp ========================= // This example demonstrates a bug in portable binary format on AIX when serialising -1 // that is specific only to the AIX compiler/platform // (i.e HPUX/Acc and linux/gcc run without any problems) // However on AIX on the restore, an exception is thrown // in load_impl(..) // // This test consists of 1 files // 1/ Main.cpp // // It appears that when restoring an integer of value -1, it binds to: // // void load(T & t){ // boost::intmax_t l; // load_impl(l, sizeof(T)); // // use cast to avoid compile time warning // //t = static_cast< T >(l); // t = T(l); // } // // void load_impl(boost::intmax_t & l, char maxsize); // // This appears to be the wrong load as the signature of load_impl() // will lead to truncation ! // //2/ Note: You will need to pull out and compile the portable // binary archive from the boost serialisation example dir. with this file #include <sstream> #include <ostream> #include <iostream> #include <fstream> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include "portable_binary_oarchive.hpp" #include "portable_binary_iarchive.hpp" #include <boost/serialization/serialization.hpp> using namespace std; void save(const std::string& fileName, const int& ts, bool textArchive) { if ( textArchive ) std::cout << "Text archive Saving " << ts ; else std::cout << "portable binary archive Saving " << ts; try { if (textArchive) { std::ofstream ofs( "fred.txt" ); boost::archive::text_oarchive ar( ofs ); ar << ts; } else { std::ofstream ofs( fileName.c_str(), ios::binary ); portable_binary_oarchive ar(ofs); ar << ts; } std::cout << " OK \n"; } catch (const boost::archive::archive_exception& ae) { std::cout << " save " << fileName << " failed. boost::archive exception " << ": " << ae.what() << std::endl; } } void restore(const std::string& fileName, int& restored, bool textArchive) { if ( textArchive ) std::cout << "Text archive Restoring "; else std::cout << "portable binary archive Restoring " ; try { if ( textArchive ) { std::ifstream ifs( fileName.c_str() ); boost::archive::text_iarchive ar( ifs ); ar >> restored; } else { std::ifstream ifs( fileName.c_str(), ios::binary ); portable_binary_iarchive ar( ifs ); ar >> restored; } std::cout << restored << " OK \n"; } catch ( const boost::archive::archive_exception& ae ) { std::cout << " restore " << fileName << " failed. boost::archive exception " << ": " << ae.what() << std::endl; } } int main() { { int saved = -1; save("fred.txt",saved,true); int restored = 44; restore("fred.txt",restored,true); assert(saved == restored); } { int saved = -1; save("fred.txt",saved,false); int restored = 44; restore("fred.txt",restored,false); assert(saved == restored); } return 0; }

1 0

boost filesystem temp_dir
by Kraus Philipp 26 Nov '10

26 Nov '10

Hello, I've found on the mailinglist a posting of Jeff Flinn (2010-10-12), that the Boost Filesystem gets a method for reading the temporary directory of the OS. The call should be boost::filesystem::temp_dir_path() I try to use the code with the 1.45 release, but I get compiler errors (not found). In the documentation I don't found anything else. If the code is inserted in the 1:45 version and how can I use it then? Thx Phil

1 0

valgrind leak detector with boost serialization
by Oscar Pernas 26 Nov '10

26 Nov '10

Hi all, Im using boost serialization to serialize a base class and his derived classes. Like this: ParameterList is a list of parameters and parameters could be different types of parameters (string, blah blah blah). Im serializing well, and everything is going fine but with valdrind I can see a leak and i dont know why, because the way of I am serializing into the file is the same that is made in the tutorial. Like this: // create and open a character archive for output std::ofstream ofs(dataFilename.str().c_str(), std::ios::binary | std::ios::app); boost::archive::binary_oarchive persistenceFile(ofs); persistenceFile << activeMessage; logMessage << "Object serialized :" << activeMessage.getText() << "in position " << lastWrote; Valgrind shows me this information: =6208== 2,200 (2,000 direct, 200 indirect) bytes in 100 blocks are definitely lost in loss record 3 of 7 ==6208== at 0x40243C5: operator new(unsigned int) (vg_replace_malloc.c:214) ==6208== by 0x41201E3: boost::archive::detail::heap_allocator<BytesParameter>::doesnt_have_new_operator::invoke() (iserializer.hpp:247) ==6208== by 0x411FBAE: boost::archive::detail::heap_allocator<BytesParameter>::invoke() (iserializer.hpp:257) ==6208== by 0x411EC94: boost::archive::detail::pointer_iserializer<boost::archive::binary_iarchive, BytesParameter>::load_object_ptr(boost::archive::detail::basic_iarchive&, void*&, unsigned int) const (iserializer.hpp:299) ==6208== by 0x4C9879B: boost::archive::detail::basic_iarchive::load_pointer(void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (in /usr/lib/libboost_serialization.so.1.42.0) ==6208== by 0x412728D: void boost::archive::detail::load_pointer_type<boost::archive::binary_iarchive>::invoke<Parameter*>(boost::archive::binary_iarchive&, Parameter*&) (iserializer.hpp:512) ==6208== by 0x4127216: void boost::archive::load<boost::archive::binary_iarchive, Parameter*>(boost::archive::binary_iarchive&, Parameter*&) (iserializer.hpp:580) ==6208== by 0x41271D5: void boost::archive::detail::common_iarchive<boost::archive::binary_iarchive>::load_override<Parameter*>(Parameter*&, int) (common_iarchive.hpp:68) ==6208== by 0x4127190: void boost::archive::basic_binary_iarchive<boost::archive::binary_iarchive>::load_override<Parameter*>(Parameter*&, int) (basic_binary_iarchive.hpp:67) ==6208== by 0x412714D: void boost::archive::binary_iarchive_impl<boost::archive::binary_iarchive, char, std::char_traits<char> >::load_override<Parameter*>(Parameter*&, int) (binary_iarchive_impl.hpp:50) ==6208== by 0x41270D1: boost::archive::binary_iarchive& boost::archive::detail::interface_iarchive<boost::archive::binary_iarchive>::operator>><Parameter*>(Parameter*&) (interface_iarchive.hpp:61) ==6208== by 0x412704B: void boost::serialization::nvp<Parameter*>::load<boost::archive::binary_iarchive>(boost::archive::binary_iarchive&, unsigned int) (nvp.hpp:87) ==6208== ==6208== 2,400 bytes in 200 blocks are definitely lost in loss record 4 of 7 ==6208== at 0x40243C5: operator new(unsigned int) (vg_replace_malloc.c:214) ==6208== by 0x412022D: boost::archive::detail::heap_allocator<RealParameter>::doesnt_have_new_operator::invoke() (iserializer.hpp:247) ==6208== by 0x411FC8E: boost::archive::detail::heap_allocator<RealParameter>::invoke() (iserializer.hpp:257) ==6208== by 0x411EDF0: boost::archive::detail::pointer_iserializer<boost::archive::binary_iarchive, RealParameter>::load_object_ptr(boost::archive::detail::basic_iarchive&, void*&, unsigned int) const (iserializer.hpp:299) ==6208== by 0x4C9879B: boost::archive::detail::basic_iarchive::load_pointer(void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (in /usr/lib/libboost_serialization.so.1.42.0) ==6208== by 0x412728D: void boost::archive::detail::load_pointer_type<boost::archive::binary_iarchive>::invoke<Parameter*>(boost::archive::binary_iarchive&, Parameter*&) (iserializer.hpp:512) ==6208== by 0x4127216: void boost::archive::load<boost::archive::binary_iarchive, Parameter*>(boost::archive::binary_iarchive&, Parameter*&) (iserializer.hpp:580) ==6208== by 0x41271D5: void boost::archive::detail::common_iarchive<boost::archive::binary_iarchive>::load_override<Parameter*>(Parameter*&, int) (common_iarchive.hpp:68) ==6208== by 0x4127190: void boost::archive::basic_binary_iarchive<boost::archive::binary_iarchive>::load_override<Parameter*>(Parameter*&, int) (basic_binary_iarchive.hpp:67) ==6208== by 0x412714D: void boost::archive::binary_iarchive_impl<boost::archive::binary_iarchive, char, std::char_traits<char> >::load_override<Parameter*>(Parameter*&, int) (binary_iarchive_impl.hpp:50) ==6208== by 0x41270D1: boost::archive::binary_iarchive& boost::archive::detail::interface_iarchive<boost::archive::binary_iarchive>::operator>><Parameter*>(Parameter*&) (interface_iarchive.hpp:61) ==6208== by 0x412704B: void boost::serialization::nvp<Parameter*>::load<boost::archive::binary_iarchive>(boost::archive::binary_iarchive&, unsigned int) (nvp.hpp:87) ==6208== ==6208== 3,600 bytes in 300 blocks are definitely lost in loss record 5 of 7 ==6208== at 0x40243C5: operator new(unsigned int) (vg_replace_malloc.c:214) ==6208== by 0x4120199: boost::archive::detail::heap_allocator<IntParameter>::doesnt_have_new_operator::invoke() (iserializer.hpp:247) ==6208== by 0x411FA6E: boost::archive::detail::heap_allocator<IntParameter>::invoke() (iserializer.hpp:257) ==6208== by 0x411EB38: boost::archive::detail::pointer_iserializer<boost::archive::binary_iarchive, IntParameter>::load_object_ptr(boost::archive::detail::basic_iarchive&, void*&, unsigned int) const (iserializer.hpp:299) ==6208== by 0x4C9879B: boost::archive::detail::basic_iarchive::load_pointer(void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (in /usr/lib/libboost_serialization.so.1.42.0) ==6208== by 0x412728D: void boost::archive::detail::load_pointer_type<boost::archive::binary_iarchive>::invoke<Parameter*>(boost::archive::binary_iarchive&, Parameter*&) (iserializer.hpp:512) ==6208== by 0x4127216: void boost::archive::load<boost::archive::binary_iarchive, Parameter*>(boost::archive::binary_iarchive&, Parameter*&) (iserializer.hpp:580) ==6208== by 0x41271D5: void boost::archive::detail::common_iarchive<boost::archive::binary_iarchive>::load_override<Parameter*>(Parameter*&, int) (common_iarchive.hpp:68) ==6208== by 0x4127190: void boost::archive::basic_binary_iarchive<boost::archive::binary_iarchive>::load_override<Parameter*>(Parameter*&, int) (basic_binary_iarchive.hpp:67) ==6208== by 0x412714D: void boost::archive::binary_iarchive_impl<boost::archive::binary_iarchive, char, std::char_traits<char> >::load_override<Parameter*>(Parameter*&, int) (binary_iarchive_impl.hpp:50) ==6208== by 0x41270D1: boost::archive::binary_iarchive& boost::archive::detail::interface_iarchive<boost::archive::binary_iarchive>::operator>><Parameter*>(Parameter*&) (interface_iarchive.hpp:61) ==6208== by 0x412704B: void boost::serialization::nvp<Parameter*>::load<boost::archive::binary_iarchive>(boost::archive::binary_iarchive&, unsigned int) (nvp.hpp:87) ==6208== ==6208== 10,300 (3,600 direct, 6,700 indirect) bytes in 300 blocks are definitely lost in loss record 7 of 7 ==6208== at 0x40243C5: operator new(unsigned int) (vg_replace_malloc.c:214) ==6208== by 0x4120277: boost::archive::detail::heap_allocator<StringParameter>::doesnt_have_new_operator::invoke() (iserializer.hpp:247) ==6208== by 0x411FD6E: boost::archive::detail::heap_allocator<StringParameter>::invoke() (iserializer.hpp:257) ==6208== by 0x411EF4C: boost::archive::detail::pointer_iserializer<boost::archive::binary_iarchive, StringParameter>::load_object_ptr(boost::archive::detail::basic_iarchive&, void*&, unsigned int) const (iserializer.hpp:299) ==6208== by 0x4C9879B: boost::archive::detail::basic_iarchive::load_pointer(void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (in /usr/lib/libboost_serialization.so.1.42.0) ==6208== by 0x412728D: void boost::archive::detail::load_pointer_type<boost::archive::binary_iarchive>::invoke<Parameter*>(boost::archive::binary_iarchive&, Parameter*&) (iserializer.hpp:512) ==6208== by 0x4127216: void boost::archive::load<boost::archive::binary_iarchive, Parameter*>(boost::archive::binary_iarchive&, Parameter*&) (iserializer.hpp:580) ==6208== by 0x41271D5: void boost::archive::detail::common_iarchive<boost::archive::binary_iarchive>::load_override<Parameter*>(Parameter*&, int) (common_iarchive.hpp:68) ==6208== by 0x4127190: void boost::archive::basic_binary_iarchive<boost::archive::binary_iarchive>::load_override<Parameter*>(Parameter*&, int) (basic_binary_iarchive.hpp:67) ==6208== by 0x412714D: void boost::archive::binary_iarchive_impl<boost::archive::binary_iarchive, char, std::char_traits<char> >::load_override<Parameter*>(Parameter*&, int) (binary_iarchive_impl.hpp:50) ==6208== by 0x41270D1: boost::archive::binary_iarchive& boost::archive::detail::interface_iarchive<boost::archive::binary_iarchive>::operator>><Parameter*>(Parameter*&) (interface_iarchive.hpp:61) ==6208== by 0x412704B: void boost::serialization::nvp<Parameter*>::load<boost::archive::binary_iarchive>(boost::archive::binary_iarchive&, unsigned int) (nvp.hpp:87) what could be? any idea? regards! -- Óscar Pernas Plaza.

1 0

boost build 1.45 filesystem v3 broken
by Avi Bahra 25 Nov '10

25 Nov '10

Boost 1.45 does not build on AIX using the latest compiler. v11.1 Error's of the following are shown: vacpp.compile.c++ tmpBuildDir/boost/bin.v2/libs/filesystem/build/vacpp/debug/link-static/threading-multi/v3/src/operations.o "./boost/filesystem/v3/path.hpp", line 482.7: 1540-0716 (S) The template argument "boost::iterator" does not match the template parameter "class Derived". It appears that this has been broken for quite a while. At least since boost 1.44 Are the authors of file system aware of this issue and are there any plans to get this fixed ? Does any one know of any work around ? Any help appreciated. Best regards, Ta, Avi

1 0

Error when calling boost::asio::async_read on a boost::asio::serial_port
by Whitham Reeve 25 Nov '10

25 Nov '10

Hello all, I am having trouble getting asio serial ports to work. Specifically when I call boost::asio::async_read, it immediately calls the read completion handler with error EINVAL aka Invalid argument. Please help! I have invested significant time in asio serial ports! Mac OSX 10.6.4 GCC 4.2.1 boost version 1.44.0 The test case console output: $ ./test ERROR 22 Invalid argument $ The test case code: #include <iostream> #include <cstdlib> #include <vector> #include <boost/asio.hpp> #include <boost/bind.hpp> const int HeaderSize = 2; std::vector<char> ReadVector; void ReadHandler(const boost::system::error_code& error, std::size_t bytes_transferred) { if (error) { std::cout << "ERROR " << error.value() << " " << error.category().message( error.value()) << std::endl; return; } else { std::cout << "Bytes Received" << std::endl; } } int main () { ReadVector.resize(2000); boost::asio::io_service SerialService; boost::asio::serial_port SerialPort(SerialService, "/dev/tty.usbserial-FTCW1RJN"); boost::asio::serial_port_base::baud_rate baud_option(115200); SerialPort.set_option(baud_option); assert(SerialPort.is_open()); boost::asio::async_read(SerialPort, boost::asio::buffer(ReadVector, HeaderSize), boost::bind(&ReadHandler, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); SerialService.run(); } -- Whitham D. Reeve II 907-764-5263

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[spirit] qi::raw and skip parsers
by Juraj Ivančić 25 Nov '10

25 Nov '10

Hi. I got unexpected results when I introduced qi::raw[] inside qi expressions. It seems that under certain circumstances qi::raw[] inhibits skip parser and thus fails to parse valid input. Furthermore, parse error only occurs if expression is stored in a rule - if expression is used directly as an argument to qi::parse everything works. Example attached. Is this a bug? If not - could someone kindly explain the rationale for this behavior. Best Regards, Juraj Ivančić

2 2

thread lock-guard race condition
by Kraus Philipp 25 Nov '10

25 Nov '10

Hello, I have written this little example: boost::mutex mutex; void thread() { for (int i = 0; i < 5; ++i) { boost::this_thread::sleep(boost::posix_time::seconds(3)); boost::lock_guard<boost::mutex> lock(mutex); std::cout << "Thread " << boost::this_thread::get_id() << ": " << i << std::endl; } } int main(int argc, char *argv[]) { boost::thread t1(thread); boost::thread t2(thread); t1.join(); t2.join(); } I compile the code with pthread option on the gcc (4.0.1). In the first case the program works, but if I use the helgrind tool of valgrind I'll get this errors (sorry for the long messages). I would like to understand what I have done wrong. I hope I understand the lock_guard in the correct way: If I create the lock with the mutex variable the thread, that creates the lock runs down the next lines. All other threads that run into the lock_guard line blocks until the lock variable of the first thread call the destructor (which should be on every loop iteration). Thanks for help Phil ------Valgrind Logs----------- ==19846== Thread #1 is the program's root thread ==19846== Thread #3 & #2 was created ==19846== at 0x15A1FDE: __bsdthread_create (in /usr/lib/ libSystem.B.dylib) ==19846== by 0x378F4: pthread_create_WRK (hg_intercepts.c:257) ==19846== by 0x379C8: pthread_create (hg_intercepts.c:294) ==19846== by 0x55C06: boost::thread::start_thread() (in libboost_thread.dylib) ==19846== by 0x9FED: boost::thread::thread<void (*)()>(void (*)(), boost::disable_if<boost::is_convertible<void (*&)(), boost::detail::thread_move_t<void (*)()> >, boost::thread::dummy*>::type) (in ./main) ==19846== by 0x2A82: main (in ./main) This message is show for thread #1, #2 and #3 ==19846== Possible data race during read of size 4 at 0x5e008 by thread #3 ==19846== at 0x56381: void boost::call_once<void (*) ()>(boost::once_flag&, void (*)()) (in libboost_thread.dylib) ==19846== by 0x545AC: thread_proxy (in libboost_thread.dylib) ==19846== by 0x37828: mythread_wrapper (hg_intercepts.c:221) ==19846== by 0x15A2154: _pthread_start (in /usr/lib/ libSystem.B.dylib) ==19846== by 0x15A2011: thread_start (in /usr/lib/libSystem.B.dylib) ==19846== This conflicts with a previous write of size 4 by thread #2 ==19846== at 0x5647F: void boost::call_once<void (*) ()>(boost::once_flag&, void (*)()) (in /libboost_thread.dylib) ==19846== by 0x545AC: thread_proxy (in /libboost_thread.dylib) ==19846== by 0x37828: mythread_wrapper (hg_intercepts.c:221) ==19846== by 0x15A2154: _pthread_start (in /usr/lib/ libSystem.B.dylib) ==19846== by 0x15A2011: thread_start (in /usr/lib/libSystem.B.dylib) ==19846== Thread #2: Bug in libpthread: recursive write lock granted on mutex/wrlock which does not support recursion ==19846== at 0x385D2: pthread_cond_timedwait_WRK (hg_intercepts.c: 764) ==19846== by 0x386B0: pthread_cond_timedwait$* (hg_intercepts.c:798) ==19846== by 0x5AABB: boost ::condition_variable::timed_wait(boost::unique_lock<boost::mutex>&, boost::posix_time::ptime const&) (in libboost_thread.dylib) ==19846== by 0x54DC5: boost::this_thread::sleep(boost::posix_time::ptime const&) (in libboost_thread.dylib) ==19846== by 0xEE31: void boost ::this_thread ::sleep<boost::posix_time::seconds>(boost::posix_time::seconds const&) (in ./main) ==19846== by 0x23F8: thread() (in ./main) ==19846== by 0x545CC: thread_proxy (in libboost_thread.dylib) ==19846== by 0x37828: mythread_wrapper (hg_intercepts.c:221) ==19846== by 0x15A2154: _pthread_start (in /usr/lib/ libSystem.B.dylib) ==19846== by 0x15A2011: thread_start (in /usr/lib/libSystem.B.dylib) The next message is shown for the thread #2 & #3 ==19846== Thread #3: lock order "0x2500668 before 0x25005C8" violated ==19846== at 0x37E1B: pthread_mutex_lock (hg_intercepts.c:496) ==19846== by 0x5ABA3: boost ::condition_variable::timed_wait(boost::unique_lock<boost::mutex>&, boost::posix_time::ptime const&) (in libboost_thread.dylib) ==19846== by 0x54DC5: boost::this_thread::sleep(boost::posix_time::ptime const&) (in libboost_thread.dylib) ==19846== by 0xEE31: void boost ::this_thread ::sleep<boost::posix_time::seconds>(boost::posix_time::seconds const&) (in ./main) ==19846== by 0x23F8: thread() (in ./main) ==19846== by 0x545CC: thread_proxy (in libboost_thread.dylib) ==19846== by 0x37828: mythread_wrapper (hg_intercepts.c:221) ==19846== by 0x15A2154: _pthread_start (in /usr/lib/ libSystem.B.dylib) ==19846== by 0x15A2011: thread_start (in /usr/lib/libSystem.B.dylib) ==19846== Required order was established by acquisition of lock at 0x2500668 ==19846== at 0x37E1B: pthread_mutex_lock (hg_intercepts.c:496) ==19846== by 0x15A3452: _pthread_cond_wait (in /usr/lib/ libSystem.B.dylib) ==19846== by 0x15C89F7: pthread_cond_timedwait$UNIX2003 (in /usr/ lib/libSystem.B.dylib) ==19846== by 0x38575: pthread_cond_timedwait_WRK (hg_intercepts.c: 760) ==19846== by 0x386B0: pthread_cond_timedwait$* (hg_intercepts.c:798) ==19846== by 0x5AABB: boost ::condition_variable::timed_wait(boost::unique_lock<boost::mutex>&, boost::posix_time::ptime const&) (in libboost_thread.dylib) ==19846== by 0x54DC5: boost::this_thread::sleep(boost::posix_time::ptime const&) (in libboost_thread.dylib) ==19846== by 0xEE31: void boost ::this_thread ::sleep<boost::posix_time::seconds>(boost::posix_time::seconds const&) (in ./main) ==19846== by 0x23F8: thread() (in ./main) ==19846== by 0x545CC: thread_proxy (in libboost_thread.dylib) ==19846== by 0x37828: mythread_wrapper (hg_intercepts.c:221) ==19846== by 0x15A2154: _pthread_start (in /usr/lib/ libSystem.B.dylib) ==19846== followed by a later acquisition of lock at 0x25005C8 ==19846== at 0x37E1B: pthread_mutex_lock (hg_intercepts.c:496) ==19846== by 0x53E6A: boost::this_thread::interruption_point() (in libboost_thread.dylib) ==19846== by 0x5AAC2: boost ::condition_variable::timed_wait(boost::unique_lock<boost::mutex>&, boost::posix_time::ptime const&) (in /libboost_thread.dylib) ==19846== by 0x54DC5: boost::this_thread::sleep(boost::posix_time::ptime const&) (in libboost_thread.dylib) ==19846== by 0xEE31: void boost ::this_thread ::sleep<boost::posix_time::seconds>(boost::posix_time::seconds const&) (in ./main) ==19846== by 0x23F8: thread() (in ./main) ==19846== by 0x545CC: thread_proxy (in libboost_thread.dylib) ==19846== by 0x37828: mythread_wrapper (hg_intercepts.c:221) ==19846== by 0x15A2154: _pthread_start (in /usr/lib/ libSystem.B.dylib) ==19846== by 0x15A2011: thread_start (in /usr/lib/libSystem.B.dylib)

3 3

filesystem::current_path() memory leak?
by clarkm2 25 Nov '10

25 Nov '10

After a few hour searching for a memory leak, the cause seems to be related to the following line: boost::filesystem::path full_path( boost::filesystem2::current_path() ); or boost::filesystem2::current_path(); I'm loading the boost filesystem library as a dynamically linked library ( boost_filesystem-vc100-mt-gd-1_44.dll ) in a MFC application using VC++ 2010. I'm calling the current_path function during the application's InitInstance method. I'm a little clueless about the cause of the memory leak, so any suggestions would be helpful. I doubt the the memory dump will be useful, but here it is: Detected memory leaks! Dumping objects -> {285} normal block at 0x00036578, 80 bytes long. Data: <ABCDEFGHIJKLMNOP> 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50 {284} normal block at 0x00035278, 8 bytes long. Data: < ![ > EC FD 21 5B 00 00 00 00 {283} normal block at 0x00036418, 48 bytes long. Data: < > 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 {282} normal block at 0x00035CB8, 8 bytes long. Data: < ![ > 0C FE 21 5B 00 00 00 00 {281} normal block at 0x00035C70, 8 bytes long. Data: < ![ > CC FD 21 5B 00 00 00 00 {159} normal block at 0x00035798, 8 bytes long. Data: < ![ > AC FD 21 5B 00 00 00 00 {158} normal block at 0x00035708, 80 bytes long. Data: <ABCDEFGHIJKLMNOP> 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50 {157} normal block at 0x000356C0, 8 bytes long. Data: < ![ > 18 FD 21 5B 00 00 00 00 {156} normal block at 0x00035650, 48 bytes long. Data: < > 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 {155} normal block at 0x00035608, 8 bytes long. Data: <8 ![ > 38 FD 21 5B 00 00 00 00 Object dump complete. -- View this message in context: http://boost.2283326.n4.nabble.com/filesystem-current-path-memory-leak-tp30… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

[Spirit]Kleene star with arguments having optional attributes.
by Paul Graphov 25 Nov '10

25 Nov '10

Hello Boost Users, I'm now building configuration file parser with Boost.Spirit. I have a little trouble understanding how this parser builds attribute: It was supposed to parse strings throwing 'p' letter away. *((qi::char_ - 'p') | qi::lit('p')) attribute of qi::lit is Unused. attribute of (qi::char_ - 'p') is char. so attribute of ((qi::char_ - 'p') | qi::lit('p')) should be optional<char> that is uninitialized optional value when matched against character 'p' After applying Kleene star it should became vector<optional<char> >. It seems to be compatible with string (at least it compiles). But 'p' letters are not thrown away. The full example is here: http://pastebin.com/tCMw22Zy The output of that example is: Full parsing Result: "abcpppdef" Is it possible to make such a parser without using semantic actions like [bind(&string::append, res, _1)] or something like that, which seem to be less elegant solution. Thanks!

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questions about recursing a directory tree
by Zsolt Ero 25 Nov '10

25 Nov '10

I am just learning C++ and for a first project I would like to write a program which goes recursively through a directory tree and returns the newest and the oldest file date. I have been following the documentation, but I couldn't really find a working example for a recursive algorithm. Shell I start by using this code from the v2 documentation? ---------------------------------- bool find_file( const path & dir_path, // in this directory, const std::string & file_name, // search for this name, path & path_found ) // placing path here if found { if ( !exists( dir_path ) ) return false; directory_iterator end_itr; // default construction yields past-the-end for ( directory_iterator itr( dir_path ); itr != end_itr; ++itr ) { if ( is_directory(itr->status()) ) { if ( find_file( itr->path(), file_name, path_found ) ) return true; } else if ( itr->path().filename() == file_name ) // see below { path_found = itr->path(); return true; } } return false; } ------------------------------- The other way I figured out is with recursive_directory_iterator: ------------------------------ #include "boost/filesystem.hpp" #include <iostream> namespace fs = boost::filesystem; fs::recursive_directory_iterator end; fs::recursive_directory_iterator dir("e:\\docs"); void main() { for ( ; dir != end; ++dir ) { std::cout << *dir << std::endl; } } ------------------------------- Is it safe to use recursive_directory_iterator on a really big directory tree? I mean is it going to copy the whole tree into memory? Does it walk through the whole directory tree the moment it's called, or it only accesses the disk on a ++ operation one-by-one? I still haven't looked into how to compare two files' date, but could you give a hint about which function shell I use? Is it possible to use just a simple < or > operation on file dates, or I need to write manually if year1 > year2 and if month1 > month2, etc? Thanks in advance, Zsolt

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