August 2011 - Boost-users - lists.preview.boost.org

synchronize threads from a thread pool (using asio::io_service)
by Daren Lee 05 Aug '11

05 Aug '11

Hi - I'm using asio::io_service as a dispatcher for a thread pool. I'm wondering how I can synchronize the threads after I post the tasks to the io_service. I tried using a barrier but it doesn't always work correctly. The barrier waits indefinitely; although I verified the post() function gets called, the io_service doesn't seem to dispatch anything. I've also thread using the boost::threadpool library but the overall speed is slower. I'd appreciate any insight on what I'm doing wrong with the barrier or any other high performance thread pooling alternatives. Thanks, Daren <code> void handler ( int i, int nSize, double *pArray, double *pTemp, boost::barrier *pBarrier ) { // compute on pArrray --> write result to pTemp[i] .... pBarrier->wait(); } double doCalc ( int nSize, double *pArray, double *pTemp ) { unsigned int nNumThreads = 8; int nSubSize = nSize / nNumThreads; boost::barrier barrier( nNumThreads + 1 ); for( int i=0;i<nNumThreads;i++ ) { if( i == nNumThreads-1 ) { m_io_service.post( boost::bind( &handler, i, nSize-(i*nSubSize), pArray+(i*nSubSize), pTemp, &barrier )); } else { m_io_service.post( boost::bind( &handler, i, nSubSize, pArray+(i*nSubSize), pTemp, &barrier )); } } barrier.wait(); // sum results double fSum = 0; for( int i=0;i<nNumThreads;i++ ) { fSum += pTemp[i]; } return fSum; } I initialize the io_service with work elsewhere as: boost::asio::io_service::work m_work( m_io_service ); boost::thread_group m_threads; for (std::size_t i = 0; i < m_nNumThreads; ++i) m_threads.create_thread(boost::bind(&boost::asio::io_service::run, &m_io_service)); </code>

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What's wrong with this simple multithreaded function that uses regex?
by Andrew Yancy 05 Aug '11

05 Aug '11

The code snippet below is the core of a function mythreadfunc() that is run concurrently for several threads using the Win32 MSVC functions CreateThread() and WaitForMultipleObjects(). Everything seems to work fine except for actually using boost::regex_match(). For example, if that line below is changed to if(true), the entire multithreaded function works perfectly. Similarly, if mythreadfunc() as shown below is run without multiple threads, it works perfectly. But if mythreadfunc() as shown below is run with multiple threads, the entire program crashes with return value 0xc0000005, which is some kind of memory access violation. This leads me to believe that boost::regex does not play well with MSVC threads, but according to the Boost site, there aren't any bugs related to this issue for Boost 1.45. As far as I can tell I'm using Boost in thread safe mode (BOOST_HAS_THREADS is defined). I'm probably doing something really dumb related to MSVC threads or related to the way I configured Boost, but I'm not sure what it is! I could switch to using Boost threads, but I would like to minimize the changes to the code. Thanks very much for any help~ ... static const boost::regex expression("^[0-9]+"); ifstream myfile(x); //x is a different file name for every thread string line; if(myfile.is_open()) { while(myfile.good()) { getline(myfile, line); if(boost::regex_match(line, expression)) { //do stuff } } myfile.close(); } ...

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[Filesystem] There must be a better way to do path decomposition
by Ramon F Herrera 04 Aug '11

04 Aug '11

This code at least works: string directory_path(argv[1]); path p(directory_path); ostringstream component; string lastComponent; for (path::iterator it = p.begin(); it != p.end(); it++) { component.str(""); // Hack, to be replaced by better way component << *it; // to grab `*it' in a string lastComponent = component.str(); } lastComponent = lastComponent.substr(1, lastComponent.size()-2); According to the documentation examples, the item pointed to by `*it' is of the following type: path::iterator::value_type is path::string_type, and iteration treats path as a container of filenames. I tried to capture `*it' in a string and in a string_type but the compiler does not like the '=' operator. TIA, -RFH

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[iostreams] Unresolved external symbols gzip_footer::process etc.
by Clifford Cary 04 Aug '11

04 Aug '11

We recently upgraded from Boost 1.34.1 to 1.46.1 and moved from Visual Studio 2005 to VS 2010. We have an application that uses the Gzip decompression feature. The implementation includes these lines: Declaration: #include <boost/iostreams/device/file_descriptor.hpp> #include <boost/iostreams/filtering_stream.hpp> #include <boost/iostreams/device/file.hpp> #include <boost/iostreams/filter/gzip.hpp> boost::iostreams::filtering_streambuf<boost::iostreams::input> m_filter_stream; Executed code: m_filter_stream.push(io::gzip_decompressor()); m_filter_stream.push(m_file); m_input_stream = new istream(&m_filter_stream); m_input_stream->read((char*)m_buffer, BUFSIZE); The application linked without errors against the 1.34.1 library using VS 2005, but with 1.46.1 and VS 2010 we get four unresolved external symbols: public: void __cdecl boost::iostreams::detail::gzip_footer::process(char) public: void __cdecl boost::iostreams::detail::gzip_footer::reset(void) public: void __cdecl boost::iostreams::detail::gzip_header::process(char) public: void __cdecl boost::iostreams::detail::gzip_header::reset(void) The build is done on Windows XP x64 using the Boost 64-bit Windows binaries downloaded from http://boost.teeks99.com<http://boost.teeks99.com/>. The zlib binaries are also linked. Can someone suggest what the problem might be?

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date _facet segmentation fault
by Kraus Philipp 04 Aug '11

04 Aug '11

Hello, I use this little code for formating a date value: std::stringstream l_stream; boost::gregorian::date_facet* l_format = new boost::gregorian::date_facet(); l_format->format("%Y-%m-%d"); l_stream.imbue(std::locale(std::locale::classic(), l_format)); If I call after the imbue a delete (delte l_format) to remove the date_facet from the heap the program creates a segmentation fault value. Does the std::stringstream remove the date_facet object from the heap? If not, how can I do a correct clear of the object? I hope, that question is not off topic. I would like to format a date value in a stringstream Thanks alot Phil

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[test][1.47] Test cases segfault after completion
by Thomas Taylor 04 Aug '11

04 Aug '11

Hi! When compiling my test cases with 1.47 (no matter if dynamically or statically linked) they fail. Not the test cases themselves, but a segfault after the test case is done. The very same code compiled with r73480 executes as expected. HTH, Thomas Please find relevant valgrind output attached: Running 1 test case... *** No errors detected ==11042== Invalid write of size 8 ==11042== at 0x481152: execution_monitor_jumping_signal_handler (in /discs/rest/home/anubis/CPP/mdy- svn/gepetto/branches/build/g2_147/source/hoost/3d/test-unit__vec3d) ==11042== by 0x851380F: ??? (in /lib/libc-2.14.so) ==11042== by 0x85B3F44: shutdown (in /lib/libc-2.14.so) ==11042== by 0xC6FE47F: ??? (in /usr/lib/openmpi/openmpi/mca_oob_tcp.so) ==11042== by 0x78491EE: mca_oob_base_close (in /usr/lib/openmpi/libmpi.so.1.0.1) ==11042== by 0x788D61A: mca_base_components_close (in /usr/lib/openmpi/libmpi.so.1.0.1) ==11042== by 0x7861C09: orte_rml_base_close (in /usr/lib/openmpi/libmpi.so.1.0.1) ==11042== by 0x7831B69: orte_ess_base_app_finalize (in /usr/lib/openmpi/libmpi.so.1.0.1) ==11042== by 0xC4F579D: ??? (in /usr/lib/openmpi/openmpi/mca_ess_singleton.so) ==11042== by 0x7805067: orte_finalize (in /usr/lib/openmpi/libmpi.so.1.0.1) ==11042== by 0x77B1174: ??? (in /usr/lib/openmpi/libmpi.so.1.0.1) ==11042== by 0x70B4881: boost::mpi::environment::~environment() (in /usr/lib/libboost_mpi.so.1.47.0) ==11042== Address 0xa98 is not stack'd, malloc'd or (recently) free'd

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Boost-log Formater with Syslog
by Shah, Gaurav N 04 Aug '11

04 Aug '11

Hi, I have any application running. I want to use boost.log for "syslog". How do I achive this? The log format I need is: <hostname> <LOGLEVEL> <appname> <timestamp> <threadid>message..... How to customize log format as above for syslog? Thanks for help in advance. _ Gaurav This email is confidential and subject to important disclaimers and conditions including on offers for the purchase or sale of securities, accuracy and completeness of information, viruses, confidentiality, legal privilege, and legal entity disclaimers, available at http://www.jpmorgan.com/pages/disclosures/email.

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Disabling Tokenizer in Derived Classes - after their constructors have been executed.
by asif saeed 04 Aug '11

04 Aug '11

Hi, I have boost tokenizer and its iterator stored in my base class. The tokenizer got initialized with a const std::string&. I do the tokenization in my base class and provide the iterator, pointing to the first token, to the derived classes - but only to be used in their constructors. After the derived class constructor has been executed, the tokenizer and its iterator should not remain available - what can I do to accomplish that? Best regards, Asif

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[network] Bagged, Tagged, New Release 0.9.1
by Dean Michael Berris 04 Aug '11

04 Aug '11

Good day everyone! If you're not interested in cpp-netlib's progress, please stop reading now. :) I'm happy to announce that cpp-netlib (the library that's hoping to be Boost.Network someday) is now available for general availability. You can get the latest from https://github.com/cpp-netlib/cpp-netlib/downloads and find out what's new at http://cpp-netlib.github.com/0.9.1/whats_new.html . This is an updated release that's inching closer to the "1.0" release that's going to be up for review. I've also written a more detail-filled announcement that you can read over at http://cplusplus-soup.com/2011/08/04/cpp-netlib-0-9-1-released/ -- please feel free to comment and share as you see fit. I'm looking to work with Michael Caisse who has agreed to be the review manager for Boost.Network to hopefully have a review at a convenient time for both of us. Right now I'm gunning for Q4 of 2011, but that's still fairly a ways away so things may still change. Cheers everyone, I do hope this helps! -- Dean Michael Berris http://about.me/deanberris

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boost::thread - usage
by Christopher Pisz 03 Aug '11

03 Aug '11

I am trying to make a thread object, so I can later have better control of threads and the resources they are using. So, I started wrapping up a boost::thread. //----------------------------------------------------------------------------- ---------------------------------------------------------------- // BaseThread.h #include <boost/thread/thread.hpp> //----------------------------------------------------------------------------- - /// \brief Thread object that performs a task that is to run once (non- looped) /// \detail Derive from this class and implement the Work method to define the /// work this thread is to perform class BaseThread { public: BaseThread(); /// \brief Deconstructor /// \detail It is required that a derived class make a call to thread_.join() /// in its deconstructor virtual ~BaseThread(); virtual void Start(); virtual int Work() = 0; protected: void Run(); boost::thread thread_; }; //----------------------------------------------------------------------------- ---------------------------------------------------------------- // BaseThread.cpp #include "BaseThread.h" //----------------------------------------------------------------------------- - BaseThread::BaseThread() { } //----------------------------------------------------------------------------- - BaseThread::~BaseThread() { // Wait for the thread to complete thread_.join(); // DEBUG - Does join wait? int x = 1; } //----------------------------------------------------------------------------- - void BaseThread::Start() { boost::thread newThread(boost::bind(&BaseThread::Run, this)); thread_.swap(newThread); } //----------------------------------------------------------------------------- - void BaseThread::Run() { this->Work(); } I am kind of winging it here just going off of the boost documentation and guessing at what I should be doing. This code has a problem in that in order for us to wait for the thread to complete, the derived class is going to have to call thread_.join(). That leaves a bad taste in my mouth as I'd rather the base class take care of all the details, and all the derived class has to worry about is providing a Work method. This class doesn't provide much that boost::thread doesn't already have, but I want to make different classes for additonal requirements. One of which I have in mind is a thread with looped work and a start, stop, method. Making an object out of it will also probably help with derving classes that take care of locking their data...or at least organize it a bit. So the question 1 is, is there a way I can avoid the requirement here that derived classes call thread_.join() and do something different in the base class? Question 2 - What happens to the execution of the thread, when an exception is thrown from the thread that owns boost::thread object or the boost::thread object is destroyed? I'll probably have more questions as I progress.

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Re: [Boost-users] [Containers Library Review] The review of the Containers library by Ion Gaztanaga starts today
by Ion Gaztañaga 03 Aug '11

03 Aug '11

El 03/08/2011 14:41, Mathias Gaunard escribió: > I think it might be good for the people not quite ready to hop onto the > C++0x bandwagon yet. > Plus sometimes it's good to be able to rely on a single portable > reference implementation that actually works with stateful allocators > etc., while it is implementation-defined whether the standard one does. Now that the new standard is nearly finished, the idea is to make them fully compliant, backport to C++03 all possible features and also have a library to experiment new proposals (N1953: Upgrading the Interface of Allocators using API Versioning and N2045: Improving STL allocators), enhancement functions, etc. Best, Ion

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[multi-index][foreach] Iterating over a sequence index (worked in 1.46, broke in 1.47)
by Maxime van Noppen 03 Aug '11

03 Aug '11

Hi, I use BOOST_FOREACH to iterate of a BMI with a sequence index. The code used to work with Boost 1.46 and before, but broke with Boost 1.47. Am I doing something wrong ? ------------------------ #include <iostream> # include <boost/multi_index/hashed_index.hpp> # include <boost/multi_index/member.hpp> # include <boost/multi_index/sequenced_index.hpp> # include <boost/multi_index_container.hpp> # include <boost/foreach.hpp> using namespace ::boost::multi_index; typedef multi_index_container< int, indexed_by< sequenced<> > > bmi_t; typedef bmi_t::nth_index<0>::type seq_idx; const seq_idx& ret(const seq_idx& idx) { return idx; } int main() { bmi_t b; seq_idx& seq = b.get<0>(); // Works BOOST_FOREACH (int i, seq) std::cout << i << std::endl; // Doesn't compile BOOST_FOREACH (int i, ret(seq)) std::cout << i << std::endl; } ------------------------ Note that the offending part is the 'ret(seq)', without it, the code compiles. The error with g++ 4.6.1 is: > In file included from bmi.cc:9:0: > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp: In destructor ‘boost::foreach_detail_::simple_variant<T>::~simple_variant() [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >]’: > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:256:8: instantiated from here > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp:561:3: error: ‘boost::multi_index::detail::sequenced_index<SuperMeta, TagList>::~sequenced_index() [with SuperMeta = boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, TagList = boost::mpl::vector0<mpl_::na>]’ is protected > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:586:13: error: within this context > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp: In constructor ‘boost::foreach_detail_::simple_variant<T>::simple_variant(const T&) [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >]’: > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:648:95: instantiated from ‘boost::foreach_detail_::auto_any<boost::foreach_detail_::simple_variant<T> > boost::foreach_detail_::contain(const T&, bool*) [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >]’ > bmi.cc:28:3: instantiated from here > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp:549:3: error: ‘boost::multi_index::detail::sequenced_index<SuperMeta, TagList>::sequenced_index(const boost::multi_index::detail::sequenced_index<SuperMeta, TagList>&) [with SuperMeta = boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, TagList = boost::mpl::vector0<mpl_::na>]’ is protected > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:571:9: error: within this context > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp: In copy constructor ‘boost::foreach_detail_::simple_variant<T>::simple_variant(const boost::foreach_detail_::simple_variant<T>&) [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >, boost::foreach_detail_::simple_variant<T> = boost::foreach_detail_::simple_variant<boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> > >]’: > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:256:8: instantiated from ‘boost::foreach_detail_::auto_any<boost::foreach_detail_::simple_variant<T> > boost::foreach_detail_::contain(const T&, bool*) [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >]’ > bmi.cc:28:3: instantiated from here > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp:549:3: error: ‘boost::multi_index::detail::sequenced_index<SuperMeta, TagList>::sequenced_index(const boost::multi_index::detail::sequenced_index<SuperMeta, TagList>&) [with SuperMeta = boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, TagList = boost::mpl::vector0<mpl_::na>]’ is protected > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:578:13: error: within this context Note that with clang++ 2.9 the code doesn't compile at all either with Boost 1.46 or Boost 1.47. Thanks! -- Maxime

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[Concept] Ignoring return types
by Robert Jones 03 Aug '11

03 Aug '11

I have a template that I instantiate with a type that has to be nullary callable, so template <typename NullaryCallable> struct X { /*....*/ }; I'd like to be a good boy scout here, so I should constrain the template parameter, so template <typename NullaryCallablle> struct X { BOOST_CONCEPT_ASSERT(( Generator<NullaryCallable, void> )); // ... }; However, that constrains it to be nullary callable and returning void, and I'd prefer to avoid the void condition. Is all that sensible, true, and fixable? Thx - Rob.

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#define BOOST_ASSERT_MSG_OSTREAM std::cout - message is not displayed
by asif saeed 03 Aug '11

03 Aug '11

Hi, After I have #defined BOOST_ASSERT_MSG_OSTREAM std::cout, using BOOST_ASSERT_MSG with a customized message does not display the message and, instead, I get the following message from Visual C++ 2010 Express: R6010 Abort() has been called What can I do to display the customized message? Best, Asif

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Boost Book - comments?
by Robert Jones 03 Aug '11

03 Aug '11

Morning All Does anyone have any knowledge of this book? http://www.amazon.co.uk/Boost-C-Libraries/dp/3639942310/ref=sr_1_7?s=books&… <http://www.amazon.co.uk/Boost-C-Libraries/dp/3639942310/ref=sr_1_7?s=books&…>It's genesis, currency, provenance, and possibly a few review-like comments? Thx - Rob.

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Re: [Boost-users] boost.regex with ICU memory cleanup on windows
by Alex Perry 03 Aug '11

03 Aug '11

John Maddock wrote on Tue, 2 Aug 2011 12:14:53 +0100 > There are a number of issues here: > > 1) Your call to u_cleanup() occurs while a u32regex object is still in existence, > so any ICU data being cached is actually still being used at that point. I couldn't get u_cleanup() to work anywhere - ie BOOST_AUTO_TEST_CASE( u32_regex ) { { boost::u32regex re( boost::make_u32regex("\\d{3}")); } u_cleanup(); } Or having u_cleanup() in a fixture teardown (which is how it was in the original code) doesn't seem to make any difference > 2) Boost.Regex does cache some internal data for improved performance - > this is relatively small and gets cleared after main() exits. > 3) Point (2) means that a call to _CrtDumpMemoryLeaks() before main exits > will report leaks, where as using something like: > > struct cleanup > { > ~cleanup() > { > _CrtDumpMemoryLeaks(); > } > }; > > cleanup c; The boost unit test framework does appear to do the memory dump in a destructor of a static object - I guess whether the regex library statics are destructed first depends on the order of loading - not sure if there is any easy way of ensuring that the unit test framework is destructed last (perhaps if I link to UTF as a static library?). > 4) Other leak detectors such as valgrind and VLD report no errors (and give > much more useful reports than the brain-dead MS ones IMO). > > HTH, John. :-) yes I agree - my current solution is --detect_memory_leaks=0 when running the unit tests - which at least stops the report. I was hoping that this was a reasonably common issue and there was some clean up function (like u_cleanup()) specifically for the regex library but if not can live with switching off memory loss detection. Thanks a lot for the help here though - it is much appreciated. Alex

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Re: [Boost-users] [Repost][Boost][Serialization] ASSERTtriggered during reading 1.40 binary archive w/ Boost 1.47
by marc.viala＠sfr.fr 03 Aug '11

03 Aug '11

> De la part de Pfligersdorffer, Christian > > We were facing similar problems jumping from 1.36 to 1.45. > Binary archive backwards compatibility is broken in a few places. > > But: it is fixable. We may provide a patch Thanks Christian for your reply to this annoying issue. If you confirm that the backward compatibility is broken for Boost.Serialization #1.40 to #1.47 then *Yes* I would really appreciate any king of patch to address this issue. Looking the Boost.Serialization code, my first feeling would be to patch the implementation of basic_binary_iarchive::load_override(class_id_type & t, int version) for the library_version_type(5) ('5' stands for the library version for the release #1.40) but maybe this patch is too naïve and insufficient. If you can send me back a patch for this issue, I'll use it ASAP. > is there a TRAK ticket? I'm not sure but the ticket #5567 (https://svn.boost.org/trac/boost/ticket/5567) seems to address this bug. Thanks in advance and best regards, Marc Viala

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Re: [Boost-users] [Repost][Boost][Serialization] ASSERT triggeredduring reading 1.40 binary archive w/ Boost 1.47
by Pfligersdorffer, Christian 03 Aug '11

03 Aug '11

We were facing similar problems jumping from 1.36 to 1.45. Binary archive backwards compatibility is broken in a few places. But: it is fixable. We may provide a patch - is there a TRAK ticket? Regards, -- Christian Pfligersdorffer Software Engineering www.eos.info > -----Ursprüngliche Nachricht----- > Von: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] Im Auftrag von > Marc Perso > Gesendet: Mittwoch, 3. August 2011 07:30 > An: boost-users(a)lists.boost.org > Betreff: [Boost-users] [Repost][Boost][Serialization] ASSERT triggeredduring reading 1.40 binary archive > w/ Boost 1.47 > > Let me forward this message posted few days ago since nobody has confirmed > that the issue described hereafter exists. I would really appreciate if > someone could take a look (maybe Mr Robert Ramey) and give some advice on > this subject. > > Best regards, > > Marc Viala > > ------------------------------------------------------------------------ > > Hello Booster, > > We are trying to jump from Boost 1.40 to Boost 1.47 but we are facing an > issue: an ASSERT is raised in debug mode when reading back binary archive > generated by Boost.Serialization 1.40 with the Boost.Serialization 1.47. > This ASSERT is at line 116 in basic_archive.hpp: > > BOOST_ASSERT(t_ <= boost::integer_traits<base_type>::const_max) > > And it occurs with the following platform: MSVC 8.0 and Windows XP/32bits or > Win7/64bits. > > Looking at the load_override and save_override implementations for > class_id_type in #1.40, they seem loading and saving an 'int_least16_t' > (equiv. to a short for our platform) while load_override(class_id_type) for > #1.47 attempts to read an 'int' (file: basic_binary_iarchive.hpp @ line 98). > > My questions are: > - This assert suggests that we can't read back previous binary archives > (#1.40 at least) with Boost.Serialization 1.47, is this a known pending > issue for Boost.Serialization? > > - If yes, how we can manage that and how we can complete the migration to > 1.47 in our case (it should be noted that we must be able to read back our > 1.40 binary archives)? Is there any known patch for this problem? > > Any assistance will be greatly appreciated. > > Best regards, > > Marc Viala > > PS: I'm not sure but ticket #5567 seems already opened on this issue but has > not been yet fixed (https://svn.boost.org/trac/boost/ticket/5567) > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Boost.Tokenizer / Sep - Compile-time errors ...
by asif saeed 03 Aug '11

03 Aug '11

Hi, Here is a piece of code that _only_ works when I provide it a hard-coded constant ";": typedef boost::char_separator<char_type_t> sep_type_t; typedef boost::tokenizer<sep_type_t> tokenizer_t; sep_(pa_->separator_.c_str()), t_(messageString,sep_), i_(t_.begin()) It wouldn't work with the separator passed in a variable (pa_->separator.c_str()). Tokenizer wouldn't work even if I initialize a const char* with a ";" and then pass that const char *variable to sep_ above. It gives me the following errors on if I pass separator in a variable: error C2780: 'bool boost::char_separator<Char>::operator ()(InputIterator &,InputIterator,Token &)' : expects 3 arguments - 1 provided Any idea how I can pass it a separator in a variable? Best, Asif

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[Repost][Boost][Serialization] ASSERT triggered during reading 1.40 binary archive w/ Boost 1.47
by Marc Perso 03 Aug '11

03 Aug '11

Let me forward this message posted few days ago since nobody has confirmed that the issue described hereafter exists. I would really appreciate if someone could take a look (maybe Mr Robert Ramey) and give some advice on this subject. Best regards, Marc Viala ------------------------------------------------------------------------ Hello Booster, We are trying to jump from Boost 1.40 to Boost 1.47 but we are facing an issue: an ASSERT is raised in debug mode when reading back binary archive generated by Boost.Serialization 1.40 with the Boost.Serialization 1.47. This ASSERT is at line 116 in basic_archive.hpp: BOOST_ASSERT(t_ <= boost::integer_traits<base_type>::const_max) And it occurs with the following platform: MSVC 8.0 and Windows XP/32bits or Win7/64bits. Looking at the load_override and save_override implementations for class_id_type in #1.40, they seem loading and saving an 'int_least16_t' (equiv. to a short for our platform) while load_override(class_id_type) for #1.47 attempts to read an 'int' (file: basic_binary_iarchive.hpp @ line 98). My questions are: - This assert suggests that we can't read back previous binary archives (#1.40 at least) with Boost.Serialization 1.47, is this a known pending issue for Boost.Serialization? - If yes, how we can manage that and how we can complete the migration to 1.47 in our case (it should be noted that we must be able to read back our 1.40 binary archives)? Is there any known patch for this problem? Any assistance will be greatly appreciated. Best regards, Marc Viala PS: I'm not sure but ticket #5567 seems already opened on this issue but has not been yet fixed (https://svn.boost.org/trac/boost/ticket/5567)

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Time management using posix time
by Sarkar, Arup 03 Aug '11

03 Aug '11

Hi: This is what is I am trying to achieve. I would like to run the program for 6 minutes, within the six minutes I would like to toggle for 2 minutes data operation and for 1 minute trade operation, so there will be 2 cycle of data operation and 2 cycle of trade operation. I am setting and getting the ptime outside the main program, but what is happening is that the getPtime of the template class is always return the +2 minutes of the current time, that is why diff is never reducing less than 2 minutes, why is that happening, the setter have been instantiated only once. I would really appreciate if someone can help me out. [code] // boost_example.cpp : Defines the entry point for the console application. // #include "boost/date_time/posix_time/posix_time.hpp" #include <iostream> #include <stdio.h> #include <stdio.h> #include "windows.h" using namespace std; template <typename ptime_type> class timeManagement { private: ptime_type tradingTime; public: timeManagement(){}; void setPtime (const ptime_type& _val){tradingTime = _val; } ptime_type const& getPtime() {return (tradingTime);} ~timeManagement(){}; }; int main() { bool btradingIndicator = false; std::ostringstream msg; using namespace boost::posix_time; const ptime start = second_clock::local_time(); time_duration td = minutes(6); time_duration tdDataCollection = minutes(2); time_duration tdTrading = minutes(1); bool bTradingIndicator = false; const ptime end = start + td; const ptime tTimeWindow = start + tdDataCollection; int i = 0; int switchTime = 0; timeManagement <ptime> tradingWindow; tradingWindow.setPtime(tTimeWindow); //std::cout << tradingWindow.getPtime() << std::endl; while(second_clock::local_time() <= end){ ptime currentTime = second_clock::local_time(); time_duration diff = tradingWindow.getPtime() - currentTime; if(diff.total_seconds() >= 0 && !bTradingIndicator){ std::cout << "Data.) " << currentTime << "|" << tradingWindow.getPtime() << "|" << diff << std::endl; }else{ const ptime tTimeWindow1 = currentTime + tdTrading; tradingWindow.setPtime(tTimeWindow1); bTradingIndicator = true; } if(diff.total_seconds() >= 0 && bTradingIndicator){ std::cout << "Trade.) " << diff << std::endl; }else{ const ptime tTimeWindow2 = currentTime + tdDataCollection; tradingWindow.setPtime(tTimeWindow2); bTradingIndicator = false; } } std::cout << "Start Time: " << start << std::endl; std::cout << "End Time: " << end << std::endl; std::cout << "Time Now: "<< end << std::endl; return 0; } [/code] Regards, Arup *"I don't need to know everything, I just need to KNOW where to find it, when I need it"*. -*Albert Einstein *

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Re: [Boost-users] What's wrong with this simple multithreaded function that uses regex?
by Andrew Yancy 03 Aug '11

03 Aug '11

>I don't see anything obviously wrong with that. My only question, is you >say BOOST_HAS_THREADS is defined, are you defining it, or is Boost.Config >defining it (if Boost.Config *isn't* setting it, then your project >settings >are wrong for multithreaded code)? Are you selecting the regex lib to >link >to manually or letting the auto-linking code do it's work (for minimum >chances of bad things happening you should let the auto-linking code >select >the correct binary)? >HTH, John. >You should use _beginthread or _beginthreadex to start C++ thread when >using >MSVC. >CreateThread is too low level and does not do the per thread >initialization >required. If you read MSDN documentation it explain why CreateThread >cannot >be use with C++ program. >Daniel Anderson Thanks for the replies John and Daniel. I've reinstalled boost 1.47 making sure that all the multithreaded options were built and am using _beginthreadex() now, but the exact same problem seems to occur where the code snippet below crashes if and only if boost::regex_match() is called. I am not defining BOOST_HAS_THREADS in my code, it is defined automatically although I'm not sure how exactly. Also, as far as I know I am not manually linking to the necessary libraries; all I do is tell MSVC to look in "C:\Program Files\boost\boost_1_47_0\stage\lib" for additional libraries so presumably it chooses whichever one it needs. There are no thread or boost-related warnings in the build. Any other ideas? I really appreciate the help~ ... static const boost::regex expression("^[0-9]+"); ifstream myfile(x); //x is a different file name for every thread string line; if(myfile.is_open()) { while(myfile.good()) { getline(myfile, line); if(boost::regex_match(line, expression)) { //do stuff } } myfile.close(); } ...

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[program_options] Best practices, esp. for multi-app-projects?
by Carlos Franke 02 Aug '11

02 Aug '11

I am wondering if there is a recommended way how the boost::program_options library should be integrated in a (relatively) complex project. To be more specific, these are my situation and my requirements: – A C++ project consisting of several applications, which are to share many, but not all options. – The interface to the options used in each app's code should be as boost-unspecific (i. e. abstract) as possible, so that I could later switch to another option library without having to edit much more than one file. – The option data should be somehow encapsulated. After pondering on this task for quite some time, I came up with this: – A single header file "options.h" shared by all the applications, providing a function read_options(int argc, char* argv[], const po::options_description& local_options = 0) , which scans the command line and the usual configuration files* for the common options (which are defined in the same header file, of course) as well asoptional app-specific options, and saves them (next paragraph). *(There is of course the problem of each app's name being part of its config-file's name. I found a solution for this, but I am not sure if it is relevant here. Or is it?) – Regarding the encapsulation, I found any kind of class or struct containing the options (possibly with get and set methods) unsuitable or overkill, as I would have to deal with instantiation and possible problems of multiple instantiation (singleton?). Also, I did not feel the need for the security provided by get and set methods. So what I did is: put all option variables in one namespace, like this: namespace options { int option1; std::string option2; ///... } A namespace has the further great advantage of being extendable after creation. Programme-specific options can be added easily. So in the end, in each programme I only have to do: //optional: define local options namespace options { /* . . . */ } po::options_description my_options /* . . . */ ; //read and save options: options::read_options(argc, argv, my_options) //from now on access the options' values by //options::option1; As I see it, this approach has only two drawbacks: – In each programme's code I have to deal with options twice: 1) declare the storage variables in the options namespace (globally); 2) declare local options_description and call read_options (in the main function). – There is no way to tell if the option variables are in a valid state, unless one is sure that read_options has been called and has set all values (at least to valid default values). I am inclined to tolerate the first issue and resolve the second by: – not using "default_value" in any po::options_description – instead intializing the option variables with their default values. That way, at any time each option variable either stores its default value or the assigned to it from the command line or a configuration file. Oh my, that ended up much longer than I expected. Those of you who read this far: What are your thoughts about using boost::program_options in general and about my particular approach? Regards! Carlos Franke

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[units] derived_dimension<volume_dimension, 1> units showing as "dimensionless"
by Michael Powell 02 Aug '11

02 Aug '11

Units users, I'm sure this is an include I am missing somewhere. I've got a derived physical dimension defined as derived_dimension<volume_dimension,1>, and the corresponding unit<my_dimension,si::system>, however the to_string() of the quantity shows "dimensionless". I am expecting this should be "m^3"? Regards, Michael

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[units] setting up a derived dimensionless with a custom name/symbol
by Michael Powell 02 Aug '11

02 Aug '11

Boost::Units users, How would we go about setting up a custom unit with its own name/symbol? We would derive another unit that incorporates this one and probably one of the built-in ones. So we might have something like "volume per custom units", or "custom units per time". * From the sounds of things, we would need to setup a custom base unit with its own info struct defining name() and symbol()? * Probably starting out included in the SI system to get the thing working; plausibly extending into other systems/views as we get further along. I'm making an effort to keep our local usages/extensions to the boost::units framework in the same style/structure, so as to keep things flowing well into our application. I am also using meter as a template, but I'm not sure that's quite the template which would get us what we need? Yes, no, maybe? Any insights? Thank you... Regards, Michael

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