July 2004 - Boost - lists.boost.org

Re: Re:[boost] [1.32 release] TODO list synchronization
by JOAQUIN LOPEZ MU?Z 13 Jul '04

13 Jul '04

----- Mensaje original ----- De: Robert Ramey <ramey(a)rrsd.com> Fecha: Martes, Julio 13, 2004 6:52 pm Asunto: Re:[boost] [1.32 release] TODO list synchronization [...] > >> Serialization > >> ///////////// > > > >> Robert Ramey writes: > > > > c) check in > [...] > I haven't seen any test results from boost test servers for the > serialization library - I expect to see some soon. Excuse me if I'm wrong, but seems to me you've forgotten to add an entry for your library in status/Jamfile to enable automatic testing. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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CVS error for boost/config/platform/win32.hpp
by Michael Glassford 13 Jul '04

13 Jul '04

cvs commit: [14:55:18] waiting for david_abrahams's lock in /cvsroot/boost/boost/boost/config/platform Mike

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RE: [boost] Re: "memory access violation" in boost::serialization
by Robert Ramey 13 Jul '04

13 Jul '04

Dirk Griffioen wrote: > I also outcommented line 125. > We will, however, upgrade to #20 as soon as possible. Note that #20 and subsequent versions do not have boost/serialization/shared_count.hpp but rather use a very crude hack to gain access to private variables within shared_count. Hopefully this will be addressed in a better way in the near future. You might want to wait just a tiny bit. It looks like serialization may be included in the upcoming boost release. If the release works out soon you might want to move right to boost 1.32. If the release boggs down or for some reason its inconvenient for you do move to 1.32 - you can use to #20. #20 is the last draft. I've tested it extensively with 1.31. >We have a lot of platforms here (HP, AIX, SUN, VMS, AS400 and Mainframe >- with different versions of native compilers and/or gcc) and it is >likely we will port to those platforms. If there's an interest, it might >be possible to gather some figures. Hmmm - embarrassment of riches. It is possible you might be able to run - at least occasionally the bjam test suite for some of the less common platforms? I would love to know how boost (and of course serialization) work with AS400 and Mainframe(?). I believe the others are already covered. If you're willing to run the tests, developers might be more willing the help with the porting. Robert Ramey

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[program_options] Comeau DLL failures
by Vladimir Prus 13 Jul '04

13 Jul '04

Hello, the program_options test results for Comeau (e.g. http://tinyurl.com/4zl6f) show that it does not understand __declspec. Anybody has ideas why? Maybe, we should pass "--windows" to that compiler, or somehow enable __declspec support? - Volodya

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Sombody broke the build system?
by David Abrahams 13 Jul '04

13 Jul '04

This just started happening: cd c:/tmp/ myjam -sTOOLS=gcc foo.obj BD Software STL Message Decryptor v2.43 for gcc c:\tmp\../boost/tools/build/v1\testing.jam:51: in boost-test *** argument error * rule get-library-name ( path ) * called with: ( ) * missing argument path c:\tmp\../boost/tools/build/v1\testing.jam:21:see definition of rule 'get-library-name' being called c:\tmp\../boost/tools/build/v1\testing.jam:470: in run Jamfile:3: in load-jamfiles c:\tmp\..\boost\tools\build\v1\bootstrap.jam:22: in boost-build c:\tmp\boost-build.jam:6: in module scope Compilation finished at Tue Jul 13 08:46:09 -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

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RE: [boost] Re: "memory access violation" in boost::serialization
by Dirk Griffioen 13 Jul '04

13 Jul '04

Thanks Jeff, Your solution works - with a little twist: I took the solution from #20 (thanks Robert!) and now it loooks like: if(NULL != t.pi_) t.pi_->add_ref_copy(); I also outcommented line 125. & now my app works fine! We will, however, upgrade to #20 as soon as possible. Regarding the little discussion: it might very well be the case that uses find the library very usefull, without too many a problem. We certainly do, for instance on windows 2k (vc71) and HP True64 (probably gcc but I'm not sure). We have a lot of platforms here (HP, AIX, SUN, VMS, AS400 and Mainframe - with different versions of native compilers and/or gcc) and it is likely we will port to those platforms. If there's an interest, it might be possible to gather some figures. Cheers, Dirk -----Original Message----- From: boost-bounces(a)lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Jeff Flinn Sent: maandag 12 juli 2004 17:07 To: boost(a)lists.boost.org Subject: [boost] Re: "memory access violation" in boost::serialization "Dirk Griffioen" <d.griffioen(a)HumanInference.com> wrote in message news:2505062E579A9B45888B70D9BCFB3C073BA8BD@ex03.hidomain... > Hi, > > I encountered the following little problem: > > I would like to use the following datastructures with boost::serialize: > > struct Match {}; > typedef std::string Key; > typedef tst< Match, Key > TernarySearchTree; //this one has a shared_ptr > > typedef std::vector< TernarySearchTree > Trees; > typedef std::map< std::string, Trees > Symbols; > > I have defined some serialize overloads so saving goes fine, but when > loading I get a "memory acces violation" inside the following code: > > { > boost::archive::text_iarchive ia(ifs); > ia >> symbols_; > } > > More specific, inside <boost/serializiton/shared_count.hpp> > > void add_ref_copy() > { > #if defined(BOOST_HAS_THREADS) > mutex_type::scoped_lock lock(mtx_); > #endif > ++use_count_; > } > > Which constructs a scoped_lock, and there, the "explicit > scoped_lock(lightweight_mutex & m): m_(m)" seems to go wrong. Actually you'll find that the this pointer is either NULL or invalid. > > What could be the reason? The more since all worked fine (saving and > loading) when I used a simple vector of tst's. The following changes to .../boost/serialization/shared_ptr.hpp should do it: change line 74: if(t) t->add_ref_copy(); and comment out line 125: // shared_ptr_access::weak_count(*t) = 0; IIRC, line 125 is the primary culprit. ----------------- Jeff Flinn Applied Dynamics, International _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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Pretty Good Initialization Library
by Andrei Alexandrescu (See Website for Email) 13 Jul '04

13 Jul '04

Just sent the message below to clc++m. Any comments are welcome. There's a library that I understand is being proposed for Boost: http://www.codeproject.com/vcpp/stl/PGIL.asp It does useful things, but it runs straight against the commonly given advice (with which I happen to agree) that one should not override operator, unless using expression templates that ensure left-to-right evaluation. So now, in the referenced article, the author makes the comment: " Overloading operator comma is sometimes viewed as a bad practice [3]. However, it has been done with success in eg. the Generative Matrix Computation Library and Blitz to initialize matrices (see [4]) and [5]). The Initialization Library overloads the comma operator in a safe manner by letting set_cont and set_map return an object that is responsible for the initialization. Therefore it takes explicit action from the programmer to begin using the overloaded operator,(). " I think the mentioned libraries do employ expression templates, while the initialization library does not. So I am unsatisfied. Anyone here can soothe my concerns? Is overloading the comma operator considered harmless after all? Andrei

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"bin" directories clean-up [Was: Regression testing goes horribly wrong! (+ patch)]
by Aleksey Gurtovoy 13 Jul '04

13 Jul '04

Guillaume Melquiond writes: > Le lun 12/07/2004 à 04:22, Aleksey Gurtovoy a écrit : > > [...] > > > > Maybe you did patch some Jamfiles or bjam? > > > > "boost\tools\build\v1\testing.jam" > > Great! > > > I don't know if it is actually necessary (or if it is even possible), > but maybe a similar patch should be applied to bjam v2? Most likely, but that's something we can worry about after the release. > I have another concern. Maybe I'm overly pessimistic, but I think > regression testers should restart their testing from scratch (rm -r > boost/bin, or whatever it is called) now that the format has changed, > shouldn't they? If somebody is still experiencing the problems we were fighting, yes. Looking at the reports, it seems that SunOS and Darwin platforms might need it. BTW, it would be nice if these reports' comments listed a contact point. -- Aleksey Gurtovoy MetaCommunications Engineering

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Generalizing the shared_ptr
by Maciej Sobczak 13 Jul '04

13 Jul '04

Hi, (not sure if it was discussed before) I've found Boost smart pointers inflexible in the sense that they operate only on pointers. It would be a good idea to generalize their interface to handle just about anything that requires special care when destroying. HANDLE (on Windows), FILE*, file descriptors (on Unix), third-party API handles, etc. come to mind. I wrote a very simple class (see attachments), scoped_handle, which encapsulates the resource (whatever it is) and its disposing (whatever that means). The techniques used are similar to those used in implementation of boost::shared_ptr. The example file shows how the class can be used to guard resources allocated by operator new, fopen, open, etc. Is it possible to achieve the same results with the existing Boost libraries? If not, is there any interest in developing this kind of class? -- Maciej Sobczak : http://www.msobczak.com/ Programming : http://www.msobczak.com/prog/ // // Copyright (C) 2004 Maciej Sobczak // http://www.msobczak.com/ // // Permission to copy, use, modify, sell and distribute this software // is granted provided this copyright notice appears in all copies. // This software is provided "as is" without express or implied // warranty, and with no claim as to its suitability for any purpose. // #ifndef SCOPED_HANDLER_H_INCLUDED #define SCOPED_HANDLER_H_INCLUDED template <typename Resource> class disposer_base { public: virtual ~disposer_base() {} virtual void dispose(Resource) = 0; }; template <typename Resource, typename Deleter> class disposer_impl : public disposer_base<Resource> { public: disposer_impl(Deleter d) : d_(d) {} void dispose(Resource r) { d_(r); } private: Deleter d_; }; template <typename Resource> void simpleDeleter(Resource r) { delete r; } template <typename Resource> void arrayDeleter(Resource r) { delete [] r; } // requirements: // Resource and Deleter are copy-constructible and do not throw while copying // For Resource r and Deleter d, d(r) is a valid expression that doesn't throw template <typename Resource> class scoped_handle { public: scoped_handle(Resource r) : r_(r) { initDeleter(simpleDeleter<Resource>); } template <typename Deleter> scoped_handle(Resource r, Deleter d) : r_(r) { initDeleter(d); } ~scoped_handle() { disp_->dispose(r_); delete disp_; } Resource get() const { return r_; } private: scoped_handle(const scoped_handle &); scoped_handle & operator=(const scoped_handle &); template <typename Deleter> void initDeleter(Deleter d) { try { disp_ = new disposer_impl<Resource, Deleter>(d); } catch (...) { d(r_); throw; } } disposer_base<Resource> *disp_; Resource r_; }; #endif // SCOPED_HANDLER_H_INCLUDED #include "scoped_handle.h" #include <iostream> #include <functional> // this is for Unix only #include <fcntl.h> #include <unistd.h> using namespace std; class A { public: A() { cout << "A()\n"; } ~A() { cout << "~A()\n"; } }; void specialDeleter(A *p) { cout << "special deleter: "; delete p; } void anotherSpecialDeleter(A *p, int i) { cout << "another special deleter (" << i << "): "; delete p; } int main() { { scoped_handle<A*> h1(new A); scoped_handle<A*> h2(new A, specialDeleter); scoped_handle<A*> h3(new A, bind2nd(ptr_fun(anotherSpecialDeleter), 7)); // resources are released in the reverse order } { scoped_handle<FILE*> h4(fopen("test.txt", "w"), fclose); // ... } { // this is for Unix only scoped_handle<int> h5(open("test.txt", O_RDONLY), close); // ... } // etc. }

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New version of MPL?
by Joaquín Mª López Muñoz 13 Jul '04

13 Jul '04

According to 1.32 release plans, a new version of MPL would have to be checked in main CVS by Sunday; if I'm not wrong, this hasn't happened yet. * Any news regarding the new MPL? * Is still July 16 a realistic date for branching? Unless the new MPL checks in real smooth, I'm afraid 4 days is probably too little time to tidy everything up. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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