May 2010 - Boost-users - lists.boost.org

Re: [Boost-users] shared_ptr question
by Peter Dimov 18 May '10

18 May '10

David Michael Bond wrote: ... > I looked into it more and it seems if I comment out the memcpy in the > get_ether_header function I do not get the segfault. > > ether_header Frame::get_ether_header( ) { > ether_header ret ; > memcpy( &ret, this->bytes.get(), this->size ) ; > return ret ; > } > > Its fine to return that stack var right there right? That should just copy > the memory into the return value for the stack? It's fine to return a stack variable, but it may not be fine to memcpy into it, depending on how ether_header is defined and whether this->size may exceed sizeof(ether_header). To investigate further, you might want to look at the stack backtrace when the segfault occurs. Your shared_ptr use seems fine, so it's probably ~Frame that is crashing (unless there is memory damage).

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[BGL] Is adjacency_iterator not Equality Comparable?
by Hossein Haeri 18 May '10

18 May '10

Dear all, [Boost 1.42, GCC 3.4.5 under MinGW in WinXP] I have a piece of program like this: typedef graph_type::adjacency_iterator iterator; iterator begin, end; boost::tie(begin, end) = boost::adjacent_vertices(curr_, *graph_ptr_); //... ArrFreq nextArr = l.front(); //... iterator i = find(begin, end, nextArr); And, I get the error message in the P.S. once I try the last line above. I was wondering if that's because: 1) adjacency_iterator is not equality comparable. Or, 2) the value type of adjacency_iterator is not comparable with the graph's vertex type. Or, 3) even something else? TIA, --Hossein P.S. /lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bits/stl_algo.h:172: error: no match for 'operator==' in '((boost::iterator_facade<boost::adjacency_iterator<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, ArrFreq, TransRule::Type, boost::no_property, boost::listS>, size_t, boost::detail::out_edge_iter<__gnu_cxx::__normal_iterator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> >*, std::vector<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> >, std::allocator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> > > > >, size_t, boost::detail::edge_desc_impl<boost::directed_tag, size_t>, ptrdiff_t>, ptrdiff_t>, size_t, boost::detail::iterator_category_with_traversal<std::input_iterator_tag, boost::random_access_traversal_tag>, size_t, ptrdiff_t>*)(&__first))->boost::iterator_facade<I, V, TC, R, D>::operator* [with Derived = boost::adjacency_iterator<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, ArrFreq, TransRule::Type, boost::no_property, boost::listS>, size_t, boost::detail::out_edge_iter<__gnu_cxx::__normal_iterator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> >*, std::vector<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> >, std::allocator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> > > > >, size_t, boost::detail::edge_desc_impl<boost::directed_tag, size_t>, ptrdiff_t>, ptrdiff_t>, Value = size_t, CategoryOrTraversal = boost::detail::iterator_category_with_traversal<std::input_iterator_tag, boost::random_access_traversal_tag>, Reference = size_t, Difference = ptrdiff_t]() == __val' FlowGraph.cpp:148: note: candidates are: bool operator==(const ArrFreq&, const ArrFreq&) bool operator==(const Arrangement&, const Arrangement&)

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error boost spirit
by khaled hamidouche 18 May '10

18 May '10

Hello with Joel Falcou we are wondring to write a parser to parse mathematical expression like (N1*3+N2/N3) ... with N1, N2, N3 are variables where their value are in an std vector so I take the calc example and I change it. my code looks like this #include <boost/config/warning_disable.hpp> #include <boost/spirit/include/qi.hpp> #include <boost/spirit/include/phoenix_operator.hpp> #include <boost/spirit/home/phoenix/container.hpp> #include <iostream> #include <string> #include <vector> namespace client { namespace qi = boost::spirit::qi; namespace ascii = boost::spirit::ascii; void do_add() { std::cout << "add\n"; } /////////////////////////////////////////////////////////////////////////// // Our calculator grammar /////////////////////////////////////////////////////////////////////////// template <typename Iterator> struct calculator : qi::grammar<Iterator, int(), ascii::space_type> { calculator(std::vector<int> const & vec) : calculator::base_type(expression), vect(vec) { using qi::_val; using qi::_1; using qi::uint_; using ascii::char_; int index; // vect.resize(3); // // // vect[0]=10; // vect[1]=11; // vect[2]=12; //vect=vec; expression = term [_val = _1] >> *( ('+' >> term [_val += _1]) | ('-' >> term [_val -= _1]) ) ; term = factor [_val = _1] >> *( ('*' >> factor [_val *= _1]) | ('/' >> factor [_val /= _1]) ) ; factor = uint_ [_val = _1] | char_ >>uint_ [_val = at(vect,_1)] | '(' >> expression [_val = _1] >> ')' | ('-' >> factor [_val = -_1]) | ('+' >> factor [_val = _1]) ; } qi::rule<Iterator, int(), ascii::space_type> expression, term, factor; std::vector<int> vect; }; } /////////////////////////////////////////////////////////////////////////////// // Main program /////////////////////////////////////////////////////////////////////////////// int main() { std::cout << "/////////////////////////////////////////////////////////\n\n"; std::cout << "Expression parser...\n\n"; std::cout << "/////////////////////////////////////////////////////////\n\n"; std::cout << "Type an expression...or [q or Q] to quit\n\n"; using boost::spirit::ascii::space; typedef std::string::const_iterator iterator_type; typedef client::calculator<iterator_type> calculator; std::vector<int> vec(3); vec[0]=10; vec[1]=11; vec[2]=12; calculator calc(vec); // Our grammar std::string str; int result; while (std::getline(std::cin, str)) { if (str.empty() || str[0] == 'q' || str[0] == 'Q') break; std::string::const_iterator iter = str.begin(); std::string::const_iterator end = str.end(); bool r = phrase_parse(iter, end, calc, space, result); if (r && iter == end) { std::cout << "-------------------------\n"; std::cout << "Parsing succeeded\n"; std::cout << "result = " << result << std::endl; std::cout << "-------------------------\n"; } else { std::string rest(iter, end); std::cout << "-------------------------\n"; std::cout << "Parsing failed\n"; std::cout << "stopped at: \": " << rest << "\"\n"; std::cout << "-------------------------\n"; } } std::cout << "Bye... :-) \n\n"; return 0; } when I compile I get this error /home/hamidou/LLVM/parser /main.cpp:296: instantiated from here /usr/local/include/boost-1_42/boost/spirit/home/phoenix/core/detail/function_eval.hpp:135: error: invalid initialization of reference of type ‘int&’ from expression of type ‘const int’ Process terminated with status 1 (0 minutes, 11 seconds) 1 errors, 1 warnings when I remove the use of the vector vect inside my grammar it works fine !! So, please what I did wrong ?? Thank you so much for helping me

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Re: [Boost-users] shared_ptr question
by Soumen Ghosh 18 May '10

18 May '10

I'm not sure but can you test it following way: Defer this declaration " boost::shared_ptr<Frame> rx" in following way and see if that helps ... boost::shared_ptr<Frame> &rx = processing_queue.back( ) ; Regards, ~ Soumen On Tue, May 18, 2010 at 9:30 AM, David Michael Bond <david.bond(a)iol.unh.edu>wrote: > Hello, > I am learning shared_ptrs and I am running into a segfault. I'm fairly > certain it's because of some misunderstanding I have. > > Here is some code. I have altered it to just so the relevant data: > > ---- START CODE ---- > std::deque<boost::shared_ptr<Frame> > processing_queue ; > void this_is_called() { > boost::shared_ptr<Frame> rx ; > interface->open( "eth0" ) ; > while( running ) { > interface->rx_frame( this->processing_queue ) ; > if( !processing_queue.empty( ) ) { > rx = processing_queue.back( ) ; > if( rx ) { > std::cout > << "Received Frame of Ethertype " > << ntohs( rx->get_ether_header( ).ether_type ) > << "." << std::endl ; > } > } > } > } > } > > // rx frame from interface and add onto processing_queue > boost::shared_ptr<Frame> last_rx_frame ; // (CLASSXX member) > void CLASSXX::rx_frame( std::deque<boost::shared_ptr<Frame> >& > processing_queue ) { > // Do some stuff to receive frame.. (int size= # bytes in frame) > last_rx_frame.reset(new Frame( )) ; > last_rx_frame->bytes.reset( new u_char[size]) ; > memcpy( last_rx_frame->bytes.get(), frame_bytes, size) ; > last_rx_frame->size = size ; > processing_queue.push_back( this->last_rx_frame ) ; > } > > ---- END CODE ---- > > The program receives one frame and successful and outputs it: > Received Frame of Ethertype 0x800. > But the second time when it gets to 'rx = processing_queue.back( ) ;' I > have > a segfault. > > My understanding of shared_ptrs is that when this assignment is done rx > will > have its ref count decremented (possibly leading to it being deleted). The > back of the processing_queue will then become rx do to the assignment and > that shared ptrs reference count will be increased by one. Anyone know what > my misconception is? Any idea what's causing the segfault? > > Thanks! > -David > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Re: [Boost-users] linking for release, has debug baggage
by Edward Rankin 18 May '10

18 May '10

On Mon, May 17, 2010 at 6:53 PM, <boost-users-request(a)lists.boost.org>wrote: > > Message: 3 > Date: Sun, 16 May 2010 20:25:14 -0700 > From: Dan Bloomquist <danb(a)lakeweb.net> > To: boost-users(a)lists.boost.org > Subject: [Boost-users] linking for release, has debug baggage > Message-ID: <4BF0B71A.7020804(a)lakeweb.net> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > > Hi, > I have a large project and for what ever reason if I add xpressive.hpp > in my precompiled header, it completly kills intelligence. So I figured > I'd move the stuff I want to use off to a lib. Works fine in debug but > if I build the release, this lib tries to link in the Microsoft debug libs. > > In my project: > 1>mfcs90.lib(nolib.obj) : warning LNK4098: defaultlib 'mfc90d.lib' > conflicts with use of other libs; use /NODEFAULTLIB:library > 1>mfcs90.lib(nolib.obj) : warning LNK4098: defaultlib 'mfcs90d.lib' > conflicts with use of other libs; use /NODEFAULTLIB:library > and just this one in the test solution: > 1>msvcrt.lib(cinitexe.obj) : warning LNK4098: defaultlib 'msvcrtd.lib' > conflicts with use of other libs; use /NODEFAULTLIB:library > > I have been able to recreate the problem in a small solution that should > not dependent on my directories other than setting the boost path: > > <http://lakeweb.net/downloads/RaVpath.zip> > (20k) vc 2008 (9.0) boost 1_42 > > And I don't know, this may have nothing to do with boost, but I have > other dlls and libs without this problem. It is coming from > 'boost::filesystem' as best as I can determine. > > And maybe someone has seen this before and knows off the top of their head. > > Thanks, Dan. > What's happening here is that the libs you built were built against the microsoft debug libs. You will need to build a separate set of libs which were built against the microsoft release libs. This means when you are compiling your actual program in release mode, you will need to point the linker to the new set of libs you built. Edward

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Re: [Boost-users] shared_ptr question
by Michael Jackson 18 May '10

18 May '10

On 5/18/10 12:00 AM, in article 37128.3139721074$1274188512(a)news.gmane.org, "David Michael Bond" wrote: > rx = processing_queue.back( ) ; > if( rx ) { I think your problem is the misunderstanding of the shared_ptr. The shared_ptr is a class that _wraps_ another pointer (whether valid or not) and keeps a reference count to how many other variables are using the pointer. The following line: if (rx) is only testing if the wrapper is valid, NOT the actual pointer itself that is being wrapped. What you really want is: If (rx.get() != NULL) -- Mike Jackson

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Re: [Boost-users] shared_ptr question
by richard.carless＠uk.bnpparibas.com 18 May '10

18 May '10

I think it's down to your use of reset. Why not just assign? last_rx_frame = new Frame; On the multiple thread note, when you put these functions on seperate threads you will need to marshal the use of the queue. Cheers Rich Internet david.bond(a)iol.unh.edu Sent by: boost-users-bounces(a)lists.boost.org 18/05/2010 14:23 Please respond to boost-users(a)lists.boost.org To boost-users(a)lists.boost.org cc Subject Re: [Boost-users] shared_ptr question No, but eventually I will be accessing the shared_ptrs from different threads. -David From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of richard.carless(a)uk.bnpparibas.com Sent: Tuesday, May 18, 2010 9:22 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] shared_ptr question are you running these functions on different threads? Internet david.bond(a)iol.unh.edu Sent by: boost-users-bounces(a)lists.boost.org 18/05/2010 05:00 Please respond to boost-users(a)lists.boost.org To Boost-users(a)lists.boost.org cc Subject [Boost-users] shared_ptr question Hello, I am learning shared_ptrs and I am running into a segfault. I'm fairly certain it's because of some misunderstanding I have. Here is some code. I have altered it to just so the relevant data: ---- START CODE ---- std::deque<boost::shared_ptr<Frame> > processing_queue ; void this_is_called() { boost::shared_ptr<Frame> rx ; interface->open( "eth0" ) ; while( running ) { interface->rx_frame( this->processing_queue ) ; if( !processing_queue.empty( ) ) { rx = processing_queue.back( ) ; if( rx ) { std::cout << "Received Frame of Ethertype " << ntohs( rx->get_ether_header( ).ether_type ) << "." << std::endl ; } } } } } // rx frame from interface and add onto processing_queue boost::shared_ptr<Frame> last_rx_frame ; // (CLASSXX member) void CLASSXX::rx_frame( std::deque<boost::shared_ptr<Frame> >& processing_queue ) { // Do some stuff to receive frame.. (int size= # bytes in frame) last_rx_frame.reset(new Frame( )) ; last_rx_frame->bytes.reset( new u_char[size]) ; memcpy( last_rx_frame->bytes.get(), frame_bytes, size) ; last_rx_frame->size = size ; processing_queue.push_back( this->last_rx_frame ) ; } ---- END CODE ---- The program receives one frame and successful and outputs it: Received Frame of Ethertype 0x800. But the second time when it gets to 'rx = processing_queue.back( ) ;' I have a segfault. My understanding of shared_ptrs is that when this assignment is done rx will have its ref count decremented (possibly leading to it being deleted). The back of the processing_queue will then become rx do to the assignment and that shared ptrs reference count will be increased by one. Anyone know what my misconception is? Any idea what's causing the segfault? Thanks! -David _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

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Re: [Boost-users] shared_ptr question
by richard.carless＠uk.bnpparibas.com 18 May '10

18 May '10

are you running these functions on different threads? Internet david.bond(a)iol.unh.edu Sent by: boost-users-bounces(a)lists.boost.org 18/05/2010 05:00 Please respond to boost-users(a)lists.boost.org To Boost-users(a)lists.boost.org cc Subject [Boost-users] shared_ptr question Hello, I am learning shared_ptrs and I am running into a segfault. I'm fairly certain it's because of some misunderstanding I have. Here is some code. I have altered it to just so the relevant data: ---- START CODE ---- std::deque<boost::shared_ptr<Frame> > processing_queue ; void this_is_called() { boost::shared_ptr<Frame> rx ; interface->open( "eth0" ) ; while( running ) { interface->rx_frame( this->processing_queue ) ; if( !processing_queue.empty( ) ) { rx = processing_queue.back( ) ; if( rx ) { std::cout << "Received Frame of Ethertype " << ntohs( rx->get_ether_header( ).ether_type ) << "." << std::endl ; } } } } } // rx frame from interface and add onto processing_queue boost::shared_ptr<Frame> last_rx_frame ; // (CLASSXX member) void CLASSXX::rx_frame( std::deque<boost::shared_ptr<Frame> >& processing_queue ) { // Do some stuff to receive frame.. (int size= # bytes in frame) last_rx_frame.reset(new Frame( )) ; last_rx_frame->bytes.reset( new u_char[size]) ; memcpy( last_rx_frame->bytes.get(), frame_bytes, size) ; last_rx_frame->size = size ; processing_queue.push_back( this->last_rx_frame ) ; } ---- END CODE ---- The program receives one frame and successful and outputs it: Received Frame of Ethertype 0x800. But the second time when it gets to 'rx = processing_queue.back( ) ;' I have a segfault. My understanding of shared_ptrs is that when this assignment is done rx will have its ref count decremented (possibly leading to it being deleted). The back of the processing_queue will then become rx do to the assignment and that shared ptrs reference count will be increased by one. Anyone know what my misconception is? Any idea what's causing the segfault? Thanks! -David _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

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[date-time] converting milliseconds to time_duration - overflow issue
by Johan Ditmar 18 May '10

18 May '10

Hello, When I convert a (large) number of milliseconds to a time_duration, I noticed a truncation error. This is shown in the following example: BOOST_AUTO_TEST_CASE(test_time_duration) { static const boost::posix_time::ptime ref(boost::gregorian::date(1400,1,1)); static const boost::posix_time::ptime now(boost::gregorian::date(2010,5,18)); boost::int64_t elapsed = (now-ref).total_milliseconds(); boost::posix_time::time_duration d1 = boost::posix_time::millisec(elapsed); BOOST_CHECK_EQUAL(d1.total_milliseconds(), elapsed); } error in "test_time_duration": check d1.total_milliseconds() == elapsed failed [814839926290 != 19261584000000] This is caused by an overflow issue in the constructor of subsecond_duration (called by boost::posix_time::millisec): template<class base_duration, boost::int64_t frac_of_second> class subsecond_duration : public base_duration { public: typedef typename base_duration::traits_type traits_type; explicit subsecond_duration(boost::int64_t ss) : base_duration(0,0,0,ss*traits_type::res_adjust()/frac_of_second) {} }; Shouldn't this constructor check whether traits_type::res_adjust()>frac_of_second and then do “base_duration(0,0,0,ss*(traits_type::res_adjust()/frac_of_second))” (note the brackets)? Thanks, Johan _________________________________________________________________ http://clk.atdmt.com/UKM/go/195013117/direct/01/

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Boost + Android NDK
by NuSkooler 18 May '10

18 May '10

I've searched the archives quite a bit and haven't run into any answers to this -- if I'm missing something please let me know. I've been working on getting Boost to work with the Android NDK (modified "Crystax" version with RTTI & exceptions) under Cygwin. I now have it working, but what I've come up with seems to be very messy and a couple of the modifications break the standard Linux build. I'm hoping someone can provide pointers to clean this up a bit (and/or this may be useful to anyone out there trying to do the same thing). Step 1: I had to build bjam.exe under Cygwin. This required the following simple patch: --- c:\Unzipped\boost-build\jam_src\expand.c 2007-09-30 23:12:48.000000000 -0600 +++ c:\dev\ghoti\client\external\boost-build\jam_src\expand.c 2010-04-29 14:25:38.322025800 -0600 @@ -749,7 +749,7 @@ assert(l != 0); assert(list_next(l) == 0); # ifdef OS_CYGWIN - assert( !strcmp( l->string, "c:\\foo\\bar" ) ); + //assert( !strcmp( l->string, "c:\\foo\\bar" ) ); # else assert( !strcmp( l->string, cygpath ) ); # endif Step 2: Build Boost under Cygwin against the modified NDK: user-config.jam - Added this entry: # Android ARM Linux Compiler using gcc : arm : /cygdrive/c/dev/ghoti/client/external/android/android-ndk-r3-crystax/build/prebuilt/windows/arm-eabi-4.4.0/bin/arm-eabi-g++ : \ <cxxflags>-I$NDK_ROOT/build/platforms/android-5/arch-arm/usr/include/ \ <cflags>-nostdlib \ <cxxflags>-DBOOST_THREAD_LINUX \ <cxxflags>-DBOOST_HAS_PTHREADS \ <cxxflags>-pthread \ <cxxflags>-D__arm__ \ <cxxflags>-D_REENTRANT \ <cxxflags>-D_GLIBCXX__PTHREADS \ <cxxflags>-DBOOST_HAS_GETTIMEOFDAY \ <cxxflags>-DBOOST_HAS_THREADS \ <cxxflags>-DANDROID \ <cxxflags>--sysroot=$NDK_ROOT/build/platforms/android-5/arch-arm <cxxflags>-D__NEW__ \ <cxxflags>-D__SGI_STL_INTERNAL_PAIR_H \ <cxxflags>-fno-short-enums \ <architecture>arm \ <linkflags>-lc \ <linkflags>-nostdlib \ <linkflags>-Wl,-rpath-link=$NDK_ROOT/build/platforms/android-5/arch-arm/usr/lib/ \ <linkflags>-L$NDK_ROOT/build/platforms/android-5/arch-arm/usr/lib/ \ ; Don't need to link in librt: --- c:\Unzipped\boost_1_42_0\tools\build\v2\tools\gcc.jam 2009-10-28 01:47:51.602868000 -0600 +++ c:\dev\ghoti\client\external\boost_1_42_0\tools\build\v2\tools\gcc.jam 2010-04-30 15:37:39.383973800 -0600 @@ -906,7 +906,8 @@ case * : { option = -pthread ; - libs = rt ; + # BDA: + #libs = rt ; } } ----- --- c:\Unzipped\boost_1_42_0\tools\build\v2\tools\stlport.jam 2009-05-22 05:36:46.841847000 -0600 +++ c:\dev\ghoti\client\external\boost_1_42_0\tools\build\v2\tools\stlport.jam 2010-04-30 15:30:31.864521000 -0600 @@ -198,7 +198,9 @@ # name: stlport_<toolset>(_stldebug)? local name = stlport ; - name = $(name)_$(toolset) ; + # BDA: + #name = $(name)_$(toolset) ; + if [ feature.get-values <runtime-debugging> : $(raw) ] = "on" { name = $(name)_stldebug ; Building: bjam toolset=gcc-arm target-os=linux stdlib=stlport define=_LITTLE_ENDIAN Again, all of this seems very messy. Some of it may not even be necessary. STLPort was something I was messing with; I'm not sure if it's ultimately required (the patch/stdllib=stlport). Any pointers greatly appreciated!

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