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[signals2][review] The review of the signals2 library is scheduled to end on Monday, November 10th
by Stjepan Rajko 10 Nov '08

10 Nov '08

Hello, The review of the signals2 library is scheduled to end on Monday, November 10th. We have had some good discussion so far and a couple of reviews. I hope the remaining few days will provide enough time to others that were planning on submitting a review. If anyone needs any more discussion time or time to write the review, please let me know (so we can see about extending the review period, or so that I know to wait for your review longer). Kind regards, Stjepan

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Boost.System support for Linux 2.4 kernel?
by J. van der Wulp 10 Nov '08

10 Nov '08

Hello Everyone, Is it possible to add compatibility for the Linux 2.4 kernel to the system library? The file boost/system/linux_error.hpp refers to a few macros/constants that are not defined for the linux 2.4 kernel. The exact names of the symbols are: EKEYEXPIRED, EKEYREJECTED, EKEYREVOKED ENOKEY. Is Linux 2.4 a supported platform for Boost? Thanks, Jeroen

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Library names in system layout on linux
by Vladimir Prus 10 Nov '08

10 Nov '08

Hi, we had discussion about the library names that are produced on Linux, with --layout system: http://thread.gmane.org/gmane.comp.lib.boost.build/19529 Two person who package Boost for different Linuxes participated, and I think we've agreed on some changes that will make them, and hopefully linux users, a bit happier. Now, with --layout=system, the libraries are named like this: libboost_filesystem_mt.so The proposal is to: 1. Drop 'mt', since most libraries are built with MT on Linux, and don't use such special decorations. 2. Add version number at end, to comply with standard packaging. So, we'd create: libboost_filesystem.so.1.38.0 together with a symlink to it, named libboost_filesystem.so I suspect some folks packaging Boost might not be reading Boost.Build list, so I wanted to mention this plan here. Anybody has objections? - Volodya

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[serialization] rvalues and const-correctness?
by David Abrahams 10 Nov '08

10 Nov '08

Consider: struct X { int f(); template <class Archive> void save(Archive& ar, unsigned) { ar << f(); // can't bind non-const reference to temporary } BOOST_SERIALIZATION_SPLIT_MEMBER() }; This error seems silly to me. Couldn't we add this overload to the archives, or even simply replace the existing operator with this one? template<class T> Archive & operator<<(T const & t){ // ^^^^^------------- Note this->This()->save_override(t, 0); return * this->This(); } TIA, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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Download links on Boost homepage
by Phil Endecott 10 Nov '08

10 Nov '08

Dear All, It seems to take more clicks than necessary to get from the Boost home page to the 1.37.0 download. On the Boost home page there is a heading "News" and under it a link "Version 1.37.0" to http://www.boost.org/users/news/version_1_37_0. To the right of this there's a heading "Downloads" and under it a link "Version 1.37.0" to http://www.boost.org/users/download/version_1_37_0. However, as far as I can see the latter page is identical to the former page; both are news pages listing new and updated libraries etc. The latter page should really have got me closer to being able to download the release, shouldn't it? Phil.

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[thread] shouldn't at_thread_exit work on the main thread?
by vicente.botet 10 Nov '08

10 Nov '08

Hi, in the following example mycallable1 is not called at exit of the main thread. Shouldn't at_thread_exit work on the main thread? What is wrong? Best, Vicente #include <boost/thread.hpp> #include <iostream> struct mycallable1 { void operator()() const { std::cout << "mycallable1" << std::endl; }; }; struct mycallable2 { void operator()() const { std::cout << "mycallable2" << std::endl; }; }; void my_thread() { std::cout << "my_thread" << std::endl; mycallable1 x; boost::this_thread::at_thread_exit(x); } int main() { mycallable2 x; boost::this_thread::at_thread_exit(x); boost::thread th(my_thread); th.join(); return 0; } Output: my_thread mycallable1 EXIT STATUS: 0

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Interest in an Active Object CRTP "decorator"?
by Dean Michael Berris 10 Nov '08

10 Nov '08

Hi Guys, I've recently been working a lot with Active Object implementations. Basically it's an instance of a class that has asynchronous operations scheduled to be executed in its own thread of execution. I'm posting (in-line) a very simple implementation of a CRTP "active object enabler". Any interest in something like this to be included in Boost? --->8-- [NOTE: untested, licensed under the Boost Software License, Copyright 2008 Dean Michael Berris] template <class Derived> struct active { private: shared_ptr<io_service> queue; shared_ptr<io_service::work> sentinel; shared_ptr<thread> lifetime_thread; protected: active() : queue(new io_service()), sentinel(new io_service::work(*queue)), lifetime_thread(new thread(bind(&io_service::run, queue))) { static_cast<Derived*>->init(); }; ~active() { sentinel.reset(); lifetime_thread->join(); static_cast<Derived*>->destroy(); }; void post(function<void()> f) { queue->post(f); }; }; --->8-- Example usage would be something like this: --->8-- struct logger : active<logger> { void init() { }; // required void destroy() { }; // required void operator() (string const & message) { active<logger>::post(bind(&logger::write, this, string(message))); } void write(string message) { cout << message << endl; } }; // ... vector<string> messages; logger log_; for_each(messages.begin(), messages.end(), ref(log_)); --->8-- Hope this helps! -- Dean Michael C. Berris Software Engineer, Friendster, Inc.

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[cryptography] concept
by Kasra Nassiri(Math & ComSci) 10 Nov '08

10 Nov '08

Hi all, I mentioned not a while ago that I am planning to write a boost cryptographic library. I am getting there. We have template classes that implement a certain interface (not virtual functions). These classes are: secure_allocator: An allocator which removes the buffers allocated when they are destructed by overwriting them. block_cipher: Any class that could set a key and encrypt/decrypt a constant size of message. (I have included AES, Serpent, Twofish and MARS, however, we could always add more algorithms) stream_cipher: By definition stream_cipher is a cipher that could process messages of any length. hash_function: Is a class that could compute a cryptographically secure hash signature for an arbitrarily long messages. (I have added whirlpool and will be adding more). wipe_algorithm: An algorithm that provides the patterns of wipe for a given pass and fills a given buffer with patterns (It needs to have a prng template to be used on random patterns). By using a mode of operation we could turn the concept of block_cipher into a stream_cipher. For example cryptolib::ctr<cryptolib::aes> is a stream_cipher concept. I have implemented ictr, ctr and will be implementing XTS, LRW soon. classes: cryptolib::entropy_poll<cryptolib::hash_function>: A class that polls random data and mixes the data using a hash function. cryptolib::entropy_thread<cryptolib::entropy_poll>: Calling the polling function of the entropy_poll at "random" but regulated intervals using boost::thread library. cryptolib::crypto_istream<cryptolib::stream_cipher>: cryptolib::crypto_ostream<cryptolib::stream_cipher>: cryptolib::crypto_oistream<cryptolib::stream_cipher>: classes that behave similar to 'std' iostream ,however, they seamlessly encrypt/decrypt the data as they operate. cryptolib::wipe_fstream<cryptolib::wipe_algorithm>: Wipes the file using the patterns by the template wipe algorithm. This class would determine the cluster size and wipe the entire cluster occupied by the file (this is platform specific, so we need to implement the algorithm for different platforms). finally we have the cryptolib::crypto_fstream that could be given a direction (i.e. encryption or decryption) and will operate seamlessly on the data. What do you think? Anything that I am missing on? Best regards Kasra __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: [boost] [serialization] basic_text_iprimitive destructor throws
by John Salmon 10 Nov '08

10 Nov '08

Here's a two-line patch (not counting the comment). This patch simply ignores any ios_base::failure excpetions from is.sync(). There are certainly other possibilities, but I don't see any good reason to prefer, e.g., checking the result of std::uncaught_exception() first or to broaden the class of caught exceptions. John P.S. I've changed the subject to adhere to conventions. salmonj(a)drdblogin6.en.desres$ diff -u boost/archive/impl/basic_text_iprimitive.ipp.orig boost/archive/impl/basic_text_iprimitive.ipp --- boost/archive/impl/basic_text_iprimitive.ipp.orig 2008-11-09 16:32:30.003405292 -0500 +++ boost/archive/impl/basic_text_iprimitive.ipp 2008-11-09 16:38:51.755281718 -0500 @@ -147,7 +147,17 @@ template<class IStream> BOOST_ARCHIVE_OR_WARCHIVE_DECL(BOOST_PP_EMPTY()) basic_text_iprimitive<IStream>::~basic_text_iprimitive(){ - is.sync(); + try{ + is.sync(); + }catch(std::ios_base::failure& e){ + // is.sync might throw ios_base::failure if an error + // occurs and 'is' has the badbit exception + // mask set. Should this exception be allowed to "leak out" + // of this destructor: + // a) never? + // b) only if std::uncaught_exception() is false? + // c) under some other set of circumstances? + } } } // namespace archive salmonj(a)drdblogin6.en.desres$ On Tue, Nov 4, 2008 at 4:17 PM, John Salmon <john(a)thesalmons.org> wrote: > I tried turning on exceptions on the input stream that I use for a > text_iarchive, hoping to catch user-level errors such as an attempt to > treat a non-archive file as an archive. It seems that when exceptions > are enabled on the underlying stream, the basic_text_iprimitive > destructor throws a second(?) basic_ios::failure exception, during > stack unwinding, which lands me unhappily in the terminate handler. > > Can the basic_text_iprimitive destructor be protected against > accidentally throwing? > > Here's an demonstration. This is on a Linux system with gcc/4.1.2. > > John Salmon > > salmonj(a)drdblogin6.en.desres$ cat ser.cpp > #include <boost/archive/text_iarchive.hpp> > #include <boost/serialization/serialization.hpp> > #include <stdexcept> > > #include <fstream> > > struct Foo{ > int i, j; > private: > friend class boost::serialization::access; > template <class Archive> > void serialize(Archive & ar, const unsigned int version) > { > ar & i & j; > } > }; > > int main(){ > Foo foo; > std::ifstream ifs("/dev/null"); > ifs.exceptions(std::istream::failbit | std::istream::badbit); > > try{ > boost::archive::text_iarchive tia(ifs); > tia >> foo; > }catch(std::ios_base::failure &e){ > std::cerr << "Caught std::ios_base::failure. What: " << > e.what() << "\n"; > }catch(std::exception &e){ > std::cerr << "Caught exception. What: " << e.what() << "\n"; > } > > return 0; > } > > salmonj(a)drdblogin6.en.desres$ xmk > g++ -I/proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/include > -g -L/proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib > -Wl,-rpath,/proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib > ser.cpp -lboost_serialization -o ser > salmonj(a)drdblogin6.en.desres$ ser > terminate called after throwing an instance of 'std::ios_base::failure' > what(): basic_ios::clear > Aborted (core dumped) > salmonj(a)drdblogin6.en.desres$ gdb -c > drdblogin6.en.desres.deshaw.com-6718.core ser > GNU gdb 6.8 > Copyright (C) 2008 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > and "show warranty" for details. > This GDB was configured as "x86_64-unknown-linux-gnu"... > Reading symbols from > /proj/desrad-c/root/Linux/x86_64/boost/1_37_0-13/Release/lib/libboost_serialization.so...done. > Loaded symbols for > /proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib/libboost_serialization.so > Reading symbols from > /proj/desrad-c/root/Linux/x86_64/gcc/4.1.2-10/lib64/libstdc++.so.6...done. > Loaded symbols for > /proj/desres/root/Linux/x86_64/gcc/4.1.2-10/lib64/libstdc++.so.6 > Reading symbols from /lib64/tls/libm.so.6...done. > Loaded symbols for /lib64/tls/libm.so.6 > Reading symbols from > /proj/desrad-c/root/Linux/x86_64/gcc/4.1.2-10/lib64/libgcc_s.so.1...done. > Loaded symbols for > /proj/desres/root/Linux/x86_64/gcc/4.1.2-10/lib64/libgcc_s.so.1 > Reading symbols from /lib64/tls/libc.so.6...done. > Loaded symbols for /lib64/tls/libc.so.6 > Reading symbols from /lib64/ld-linux-x86-64.so.2...done. > Loaded symbols for /lib64/ld-linux-x86-64.so.2 > Core was generated by `ser'. > Program terminated with signal 6, Aborted. > [New process 6718] > #0 0x0000003f72a2e25d in raise () from /lib64/tls/libc.so.6 > (gdb) where > #0 0x0000003f72a2e25d in raise () from /lib64/tls/libc.so.6 > #1 0x0000003f72a2fa5e in abort () from /lib64/tls/libc.so.6 > #2 0x00002b5ab82f5f84 in __gnu_cxx::__verbose_terminate_handler () > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/libstdc++-v3/libsupc++/vterminate.cc:97 > #3 0x00002b5ab82f4106 in __cxxabiv1::__terminate (handler=0x1a3e) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/libstdc++-v3/libsupc++/eh_terminate.cc:43 > #4 0x00002b5ab82f350b in __cxa_call_terminate (ue_header=0x50b730) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/libstdc++-v3/libsupc++/eh_call.cc:60 > #5 0x00002b5ab82f3fa7 in __gxx_personality_v0 ( > version=<value optimized out>, actions=6, > exception_class=<value optimized out>, ue_header=0x50b730, > context=0x7ffff29e5610) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/libstdc++-v3/libsupc++/eh_personality.cc:637 > #6 0x00002b5ab846a068 in _Unwind_RaiseException_Phase2 (exc=0x50b730, > context=0x7ffff29e5610) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/gcc/unwind.inc:66 > #7 0x00002b5ab846a2db in _Unwind_Resume (exc=0x50b730) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/gcc/unwind.inc:234 > #8 0x00002b5ab80fd790 in > boost::archive::basic_text_iprimitive<std::istream>::~basic_text_iprimitive > () > from /proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib/libboost_serialization.so > #9 0x00002b5ab8109e0c in > boost::archive::text_iarchive_impl<boost::archive::text_iarchive>::text_iarchive_impl > () > from /proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib/libboost_serialization.so > #10 0x00000000004045ab in text_iarchive (this=0x7ffff29e5ae0, > is=@0x7ffff29e58d0, flags=0) > at /proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/include/boost/archive/text_iarchive.hpp:110 > #11 0x0000000000402c84 in main () at ser.cpp:24 > (gdb) quit > salmonj(a)drdblogin6.en.desres$ >

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[serialization] "Wrapper Type?"
by David Abrahams 09 Nov '08

09 Nov '08

Hi, The documentation uses this term AFAICT without definition anywhere. How am I supposed to know that what I've defined is a "wrapper type" and is_wrapper should be specialized? TIA, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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