July 2009 - Boost-users - lists.boost.org

using bjam to build multi thread library for visual studio 2003
by mike_wilson 15 Jul '09

15 Jul '09

Hi, I am trying to build the multi thread library for visual studio 2003. I built the bjam exe and run the following. bjam toolset=msvc-7.1 variant=debug threading=multi link=shared but I am returned C:\boost>bjam toolset=msvc-7.1 variant=debug threading=multi link=shared C:/boost/tools/build/v2/tools\msvc.jam:734: in configure-really *** argument error * rule path.make ( native ) * called with: ( ) * missing argument native C:/boost/tools/build/v2/util\path.jam:44:see definition of rule 'make' being called C:/boost/tools/build/v2/tools\msvc.jam:184: in configure C:/boost/tools/build/v2/tools\msvc.jam:137: in msvc.init C:/boost/tools/build/v2/build\toolset.jam:38: in toolset.using C:/boost/tools/build/v2/build\project.jam:862: in using C:\boost\tools/build/v2\user-config.jam:59: in modules.load C:/boost/tools/build/v2\build-system.jam:241: in load-config C:/boost/tools/build/v2\build-system.jam:383: in load-configuration-files C:/boost/tools/build/v2\build-system.jam:520: in load C:\boost\tools\build\v2/kernel\modules.jam:283: in import C:\boost\tools\build\v2\kernel\bootstrap.jam:138: in boost-build C:\boost\boost-build.jam:18: in module scope My bjam version is C:\boost>bjam --version Boost.Build V2 (Milestone 12) Boost.Jam 03.1.17 and my boost library version is 1.38. My boost library is in c:\boost so no spaces present in directory paths. Thanks for any advice. -- View this message in context: http://www.nabble.com/using-bjam-to-build-multi-thread-library-for-visual-s… Sent from the Boost - Users mailing list archive at Nabble.com.

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boost mutex locks
by mike_wilson 15 Jul '09

15 Jul '09

Hi, I am a newbie to C++ multi threading (did a bit in java) and would like for information on the following... consider:- class MyClass { void SetMyObject(SomeClass const& value) { boost::mutex::scoped_lock lock(objectMutex); myObject = value; } SomeClass SetMyObject() const { boost::mutex::scoped_lock lock(objectMutex); return myObject; } private: SomeClass myObject; boost::mutex objectMutex; }; Say one thread accesses the SetMyObject() , given that there is a lock in the function, it will also lock the GetMyObject() blocking any other thread from calling? This kind of implies that wherever in the object there is a lock, any function owned by the object will be locked to any other thread trying to access. Is this correct? Thanks again for your help. -- View this message in context: http://www.nabble.com/boost-mutex-locks-tp24406812p24406812.html Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] Unable to catch exception using boost::asio
by Alex Black 15 Jul '09

15 Jul '09

(Response below) > > Alex Black wrote: > > (Response is below) > > > > > >> On Tue, Jul 14, 2009 at 7:49 PM, Alex > Black<alex(a)alexblack.ca> wrote: > >>>>> I'm using boost::asio for sockets, writing a response out to a > >>> client. > >>>>> If the client stops part way through getting the > >> response, then my > >>>>> server process dies: > >>>>> > >>>>> terminate called after throwing an instance of > >>>>> > >> > 'boost::exception_detail::clone_impl<boost::exception_detail::error_in > >>>>> fo_injector<boost::system::system_error> > >>>>>> ' > >>>>> ? what():? Broken pipe > >>>>> > >>>>> The code though is surrounded by try catch like this: > >>>>> > >>>>> try > >>>>> { > >>>>> ??? ... > >>>>> } > >>>>> catch ( std::exception& e ) > >>>>> { > >>>>> ??? cout << e.what() << endl; > >>>>> } > >>>>> catch ( ... ) > >>>>> { > >>>>> ???? cout << "unexpected exception" << endl; } > >>>>> > >>>>> How do I prevent my process from aborting/terminating like this? > >>> v > >>> > >>>> Have you verified that the code inside the try block > executes on the > >>> same thread that the exception is occuring in? > >>> > >>> Not explicitly, how would I do that? > >>> > >>> thx > >>> > >> First put a breakpoint inside the try block. When it gets > >> hit use whatever mechanism your debugger provides to see what > >> thread you're in. In windows using MSVC, for example, you'd > >> just add a watch for a variable called $TID which a special > >> pseudo-variable that shows you the thread id. For other > >> debuggers you'd have to consult the manual. > >> Next register an unhandled exception handler. > >> > >> #include <exception> > >> > >> void unhandled_exception_handler() > >> { > >> std::cout << "Got an unhandled exception!" << std::endl; } > >> > >> int main(int argc, char** argv) > >> { > >> std::set_terminate(unhandled_exception_handler); > >> > >> //rest of your program. > >> } > >> > >> Then put a breakpoint inside unhandled_exception_handler and > >> when it gets hit walk up the callstack in the debugger to see > >> where the exception is occuring. In addition you can > >> determine the thread id again using the same method you used > >> in the first step. My guess is that they're not in the same > >> thread. I'm not sure if it applies to your scenario, but > >> remember that the operation's completion handler is invoked > >> on is not necessarily the same thread that the request is > >> issued on depending on how you're using the io_service > >> object. So while you have a try {} catch(...) {} in the > >> completion handler, if the exception is on the other thread > >> that does you no good. > >> > > > > Thanks for the tip, I didn't know about set_terminate, I made that > > change. > > > > I put a breakpoint in my terminate handler, and the callstack looks > > like: > > > > 32 unhandled_exception_handler() /home/noirs/workspace/myfile.cpp:35 > > 0x0000000000438764 > > 31 <symbol is not available> 0x00007f9ceb0d04b6 > > 30 <symbol is not available> 0x00007f9ceb0cf6ab > > 29 __gxx_personality_v0() 0x00007f9ceb0d0278 > > 28 <symbol is not available> 0x00007f9ceab7cff3 > > 27 _Unwind_Resume() 0x00007f9ceab7d0b8 > > 26 ~ProtoBufStreamAdaptor() /home/noirs/workspace/myfile2.cpp:10 > > 0x000000000042c6e5 > > 25 CWebServer::HandleGetNeighbors() > > /home/noirs/workspace/myfile3.cpp:215 0x000000000041d2d8 > > 24 CWebServer::OnHttpRequest() /home/noirs/workspace/myfile3.cpp:89 > > 0x000000000041e790 > > 23 CBaseWebServer::HandleHTTPRequest() > > /home/noirs/workspace/myfile4.cpp:92 0x00000000004092ef > > 22 CBaseWebServer::HandleAccept() > /home/noirs/workspace/myfile4.cpp:61 > > 0x0000000000409a9e > > > > HandleAccept looks like: > > > > void CBaseWebServer::HandleAccept(shared_ptr<tcp::socket> > pSocket, const > > boost::system::error_code& error) > > { if ( !error ) > > { > > try > > { > > HandleHTTPRequest(pSocket); > > > > StartAccept(); > > } > > catch ( ... ) > > { > > cout << "Unhandled exception in HandleAccept"; > > } > > } > > else > > { > > cout << "HandleAccept received error: " << > > error.message().c_str() << endl; > > } > > } > > _______________________________________________ > > Boost-users mailing list > > Boost-users(a)lists.boost.org > > http://lists.boost.org/mailman/listinfo.cgi/boost-users > > Um, broken pipe = closed file desciptor. > > Check if the socket is actually valid in the shard_ptr... > > BTW, are you using Async operations.... if so then the exception will > not originate from your code but from io_service.run(). I wrapped my call to run() in a try-catch, no luck, no exception appears to be being thrown by io_service.run(). void CBaseWebServer::RunIoService() { try { m_IoService.run(); } catch ( ... ) { cout << "Unhandled exception in RunIoService"; } }

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[statechart] Substates in dll
by Bill Clark 15 Jul '09

15 Jul '09

Is there any way to partition a state machine using boost::statechart such that the main state machine is in one dll, and its substates (and possibly their substates) are in separate dll's? It would seem that this would create a cyclic dependency. Suppose you have e.g. a simple statechart called MyStatechart containing an initial state State1 which transitions to State2 in response to some event. Is it possible to implement MyStatechart and State1 in MyStatechart.dll, and State2 in State2.dll? Since the code for State1 will need to reference State2 (in order to transition to it), MyStatechart.dll will have a dependency on State2.dll. But since State2 is contained in MyStatechart, its type will have to look something like struct State2: sc::state<State2, MyStatechart> { //... }; which means that State2.dll will have a dependency on MyStatechart.dll. Is it possible to avoid this cycle? Thanks for any help, Bill

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Re: [Boost-users] Unable to catch exception using boost::asio
by Alex Black 15 Jul '09

15 Jul '09

(Response is below) > On Tue, Jul 14, 2009 at 7:49 PM, Alex Black<alex(a)alexblack.ca> wrote: > >>> I'm using boost::asio for sockets, writing a response out to a > > client. > >>> > >>> If the client stops part way through getting the > response, then my > >>> server process dies: > >>> > >>> terminate called after throwing an instance of > >>> > > > 'boost::exception_detail::clone_impl<boost::exception_detail::error_in > >>> fo_injector<boost::system::system_error> > >>>>' > >>> ? what():? Broken pipe > >>> > >>> The code though is surrounded by try catch like this: > >>> > >>> try > >>> { > >>> ??? ... > >>> } > >>> catch ( std::exception& e ) > >>> { > >>> ??? cout << e.what() << endl; > >>> } > >>> catch ( ... ) > >>> { > >>> ???? cout << "unexpected exception" << endl; } > >>> > >>> How do I prevent my process from aborting/terminating like this? > > v > > > >>Have you verified that the code inside the try block executes on the > > same thread that the exception is occuring in? > > > > Not explicitly, how would I do that? > > > > thx > > > > First put a breakpoint inside the try block. When it gets > hit use whatever mechanism your debugger provides to see what > thread you're in. In windows using MSVC, for example, you'd > just add a watch for a variable called $TID which a special > pseudo-variable that shows you the thread id. For other > debuggers you'd have to consult the manual. > Next register an unhandled exception handler. > > #include <exception> > > void unhandled_exception_handler() > { > std::cout << "Got an unhandled exception!" << std::endl; } > > int main(int argc, char** argv) > { > std::set_terminate(unhandled_exception_handler); > > //rest of your program. > } > > Then put a breakpoint inside unhandled_exception_handler and > when it gets hit walk up the callstack in the debugger to see > where the exception is occuring. In addition you can > determine the thread id again using the same method you used > in the first step. My guess is that they're not in the same > thread. I'm not sure if it applies to your scenario, but > remember that the operation's completion handler is invoked > on is not necessarily the same thread that the request is > issued on depending on how you're using the io_service > object. So while you have a try {} catch(...) {} in the > completion handler, if the exception is on the other thread > that does you no good. > Thanks for the tip, I didn't know about set_terminate, I made that change. I put a breakpoint in my terminate handler, and the callstack looks like: 32 unhandled_exception_handler() /home/noirs/workspace/myfile.cpp:35 0x0000000000438764 31 <symbol is not available> 0x00007f9ceb0d04b6 30 <symbol is not available> 0x00007f9ceb0cf6ab 29 __gxx_personality_v0() 0x00007f9ceb0d0278 28 <symbol is not available> 0x00007f9ceab7cff3 27 _Unwind_Resume() 0x00007f9ceab7d0b8 26 ~ProtoBufStreamAdaptor() /home/noirs/workspace/myfile2.cpp:10 0x000000000042c6e5 25 CWebServer::HandleGetNeighbors() /home/noirs/workspace/myfile3.cpp:215 0x000000000041d2d8 24 CWebServer::OnHttpRequest() /home/noirs/workspace/myfile3.cpp:89 0x000000000041e790 23 CBaseWebServer::HandleHTTPRequest() /home/noirs/workspace/myfile4.cpp:92 0x00000000004092ef 22 CBaseWebServer::HandleAccept() /home/noirs/workspace/myfile4.cpp:61 0x0000000000409a9e HandleAccept looks like: void CBaseWebServer::HandleAccept(shared_ptr<tcp::socket> pSocket, const boost::system::error_code& error) { if ( !error ) { try { HandleHTTPRequest(pSocket); StartAccept(); } catch ( ... ) { cout << "Unhandled exception in HandleAccept"; } } else { cout << "HandleAccept received error: " << error.message().c_str() << endl; } }

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[Bind] Does not compile with local classes
by Rudi Dittrich 15 Jul '09

15 Jul '09

Hello, I tried to use a local class as a callback function registering with a boost signal. The example below shall illustrate this scenario. There are two classes: class Foo which triggers a signal when its member function set_k( k ) is called. Each object which wants to receive this signal has to subscribe with it, calling on_k_changed(...). The second class is Bar which has one member function change_k(...). There is a local class KChanged inside this member function. KChanged has one function k_changed(...) which shall be called whenever the signal in Foo is triggered. Thus, it shall act as a callback function. Therefore, I used boost bind with k_changed(...) and tried to register with Foo's signal. After compiling I get the following compilation error: g++ -Wall -o local_class local_class.cpp -lboost_signals In member function ‘void Bar::change_k(uint32_t)’: nested_function.cpp:56: error: no matching function for call to ‘bind(void (Bar::change_k(uint32_t)::KChanged::*)(uint32_t), Bar::change_k(uint32_t)::KChanged*, boost::arg<1>&)’ I do not really understand why this doesn't work. If I make k_changed(...) static then it works and I do not get any compilation errors. So my questions are: 1.) Is this a compiler problem? I use g++ (GCC) 4.1.2 20080704 (Red Hat 4.1.2-44) 2.) Or is such a construct not supported by the C++ language in general? 3.) Or is boost bind not able to handle local classes. 4.) And if it is possible to use bind with local functions how, do I have to implement it? I would really appreciate if somebody could help me. Best regards, Rudolf Dittrich. #include <iostream> #include <boost/bind.hpp> #include <boost/signals.hpp> typedef boost::signals::connection connection_t; class Foo { public: private: typedef boost::signal<void (uint32_t)> sig_k_t; sig_k_t _sigK; public: Foo() {} ~Foo() {} connection_t on_k_changed( const sig_k_t::slot_function_type& subscriber ) { return _sigK.connect( subscriber ); } void disconnect( connection_t subscriber ) { subscriber.disconnect(); } void set_k( uint32_t k ) { _sigK( k ); } }; class Bar { private: Foo& _foo; public: Bar( Foo& foo ) : _foo( foo ) {} void change_k( uint32_t k ) { static uint32_t k_new; struct KChanged { void k_changed( uint32_t k ) { k_new = k; } } k_changed; connection_t conn; conn = _foo.on_k_changed( boost::bind( &KChanged::k_changed, &k_changed, _1 ) ); _foo.set_k( k ); _foo.disconnect( conn ); } }; int main( int argc, char *argv[] ) { Foo foo; Bar bar( foo ); bar.change_k( 100 ); return 0; } -- Jetzt kostenlos herunterladen: Internet Explorer 8 und Mozilla Firefox 3 - sicherer, schneller und einfacher! http://portal.gmx.net/de/go/chbrowser

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[boost][graph] update adjacency_list from boost 1.33 to 1.39
by Andrey Torba 15 Jul '09

15 Jul '09

I update boost in a project from 1.33 to 1.39. In elier boost.graph adjacency_list had last template parameter 'Allocator'. Now this parameter is abcent. The question is how was it used? In my example there is a Graph type: typedef boost::adjacency_list<list_pooledS, list_pooledS, boost::directedS, NodeInfo, EdgeInfo, boost::no_property, list_pooledS, * boost::get_mat_fast_pool_alloc<char>::allocator*> Graph; as i can see allocator is defined in `list_pooledS`. Will it be enough to define such type (without last parameter)? typedef boost::adjacency_list<list_pooledS, list_pooledS, boost::directedS, NodeInfo, EdgeInfo, boost::no_property, list_pooledS> Graph; -- Regards, Andrey

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[boost][thread] Breaking Changes
by Andrey Torba 15 Jul '09

15 Jul '09

Hi all! One of breaking changes of boost.thread since 1.34 are changes in the scoped_lock interface: was: boost::mutex::scoped_lock some_lock(some_mutex,false); now: boost::mutex::scoped_lock some_lock(some_mutex,boost::defer_lock); I update boost. So i have many methods in a project which accepts a boolean variable initial_lock. void c::fff(bool initial_lock) { scoped_lock lk(m_mutex, initial_lock); // do fff .... } Now it's impossible because of different types: const defer_lock_t defer_lock={}; const try_to_lock_t try_to_lock={}; const adopt_lock_t adopt_lock={}; For example if with boost 1.33 method looked like: void c::fff(bool initial_lock) { scoped_lock lk(m_mutex, initial_lock); // do fff .... } what kind of refactoring should i do? to pass locking strategy as a template parameter? template<class Lock> void c::fff(Lock initial_lock) { scoped_lock lk(m_mutex, initial_lock); invoke_fff(); } What was the reason to have a different locking types and not enum{defer_lock, try_to_lock, adopt_lock}. Does aproach lead to any errors? -- Regards, Andrey

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Boost Unordered Map
by Wong Peter 15 Jul '09

15 Jul '09

Hello to all, does boost unordered map have a member function called find and after the key, i would manipulate the value in the hash table. Thanks. -- Linux

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[Pool] questions
by Pearl Rothman 15 Jul '09

15 Jul '09

I am using Fedora 9, gcc 4.3.0, and boost 1.38.0. I am inheriting from object_pool so I have access to some of object_pool's hidden members. Is there a way for me to find out how many memory blocks or allocated chunks there are in the free list vs how many chunks are currently being used? Is the object_pool thread safe? Does set_next_size have a permanent effect or will the double algorithm start being used after the next allocation? If it's a permanent effect, is there something I can call to start using the double algorithm again? Thanks

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