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Re: [Boost-users] [Chrono] Memory leak in Chrono?
by Don 16 Feb '13

16 Feb '13

On 2/16/2013 Vincent wrote: > Please, could you create a Trac ticket so this issue not lost? Submitted as ticket #8079 https://svn.boost.org/trac/boost/ticket/8079 Thanks, Don

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Re: [Boost-users] [Chrono] Memory leak in Chrono?
by Don 16 Feb '13

16 Feb '13

-------- Original Message -------- Subject: Boost-users Digest, Vol 3358, Issue 4 From: boost-users-request(a)lists.boost.org To: boost-users(a)lists.boost.org Date: 2/13/2013 1:33 PM > Subject: Re: [Boost-users] [Chrono] Memory leak in Chrono? > From: "Vicente J. Botet Escriba" <vicente.botet(a)wanadoo.fr> > Date: 2/13/2013 1:11 PM > > Le 13/02/13 14:30, Don a écrit : >>> Subject: Re: [Boost-users] [Chrono] Memory leak in Chrono? >>> From: "Vicente J. Botet Escriba" <vicente.botet(a)wanadoo.fr> >>> Date: 2/12/2013 1:17 PM >>> >>> Le 12/02/13 18:13, gast128 a écrit : >>>> we use Boost.Chrono too. MFC applications incorrectly report memory leaks, which can easily be solved. >>> Hi, >>> >>> if you have some patches to propose to avoids this incorrect reports I would try to include them. >> >> Vincente, >> >> I am using MFC, but I don't believe this is a MFC false-leak report. >> >> I added a destructor for duration_units_default_initializer_t, like this (near the end of chrono/io/duration_units.hpp): >> >> ~duration_units_default_initializer_t() >> { >> if (duration_units_default_holder<CharT>::initialized_) >> { >> delete[] duration_units_default_holder<CharT>::n_d_valid_units_; >> duration_units_default_holder<CharT>::n_d_valid_units_ = 0; >> delete[] duration_units_default_holder<CharT>::valid_units_; >> duration_units_default_holder<CharT>::valid_units_ = 0; >> duration_units_default_holder<CharT>::initialized_ = false; >> } >> } >> >> This solves the memory leak, and seems to work fine for my simple test program. > I could add this is this helps on the MFC report. Thanks, that would be useful. It would probably help with other memory leak detectors, as well. Since you are allocating heap that you are never freeing, most leak detectors are going to report this. >> But n_d_valid_units_, valid_units_, and initialized_ are static >> variables, so I assume you want to only create these variables >> once. > > Right. > >> When run with my test program and step through it in the debugger, >> only one instantiation of duration_units_default_initializer_t >> occurs. (That is, once for each char type, single-byte and wide.) > This is the goal of the type (implement a singleton). This technique > is used in some Boost libraries already > >> This occurs when the duration_units_default_initializer is >> instantiated (at the very end of duration_units.hpp). Since this is >> a global variable, this occurs during application startup and the >> destructor runs during application shuttdown. > > Right, this was the reason the destructor didn't do anything. >> >> But presumably this can occur in some other situations, otherwise >> why would you have all the logic of making valid_units_ etc. >> class-static variables.> > On which other situation do you think this could occur? I have no idea, that's what confused me. If duration_units_default_initializer_t is only instantiated as a global (static) variable), then I don't see any reason for making n_d_valid_units_, valid_units_, and initialized_ static variables -- they could be regular member variables. Making them static doesn't hurt, but it's confusing (to me at least) because it looks like you want to share those variables among multiple instantiations, and there is only ever one instantiation. If one can somehow instantiate multiple duration_units_default_initializer_t objects, then making the member variables static does make this behave as a singleton. In that case the simple destructor I wrote will not work, since it will delete the member variables when the first object destructs, not the last. In that case I would use a reference count or smart pointers to only delete when the final object destructs. Thanks for your help, I appreciate your spending the time to answer my questions. Don

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[Asio] How to implement my own TCP?
by Chengu Wang 16 Feb '13

16 Feb '13

Hi all, I'd like to implement the TCP over UDP, because I want to change TCP a little. The implementation includes the three-way handshake, retransmission, etc. My TCP must have the basic interfaces as the original TCP does, i.e. a my_tcp::acceptor class supporting bind, listen, accept, async_accept and close, and a my_tcp::socket supporting bind, connect, async_connect, send, async_send, receive, async_receive and close. Of course I can write these two classes from scratch, but can I do it in the framework of asio and reuse some codes of asio? What classes should I implement and what do the inherit from? Any help would be appreciated. -- Best, Chengu Wang

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Ideas for UT needed
by Olaf Peter 15 Feb '13

15 Feb '13

Hello, for my project I use the ideas used on spirit's conjure2 example. Now I like to do some test with the lexer/grammar using boost::test. The example uses sequentially initializing all iterators, lexer and grammar. I like to put this into the fixture but I run into the problem that the error_handler requires begin/end of iterator. ---8<--- original from conjure2 main typedef std::string::const_iterator base_iterator_type; typedef client::lexer::conjure_tokens<base_iterator_type> lexer_type; typedef lexer_type::iterator_type iterator_type; lexer_type lexer; // Our lexer base_iterator_type first = source_code.begin(); base_iterator_type last = source_code.end(); iterator_type iter = lexer.begin(first, last); iterator_type end = lexer.end(); client::error_handler<base_iterator_type, iterator_type> error_handler(first, last); // Our error handler client::parser::function<iterator_type, lexer_type> function(error_handler, lexer); // Our parser --->8--- My fixture looks so far: ---8<--- typedef std::string::const_iterator base_iterator_type; typedef my_tokens<base_iterator_type> lexer_type; typedef lexer_type::iterator_type iterator_type; typedef error_handler<base_iterator_type, iterator_type> error_handler_type; struct fixture : private boost::base_from_member<error_handler_type>, private boost::base_from_member<lexer_type>, my_grammar<iterator_type, lexer_type> { typedef boost::base_from_member<lexer_type> lexer_base; typedef boost::base_from_member<error_handler_type> error_handler_base; typedef my_grammar<iterator_type, lexer_type> grammar_base; fixture() : grammar_base(error_handler_base::member, lexer_base::member) { } }; --->8--- error_handler_base::member requires therefore the iterators first/last. How to give them? In the UT I have further a "test" function object so I can use e.g. it like here: ---8<--- BOOST_FIXTURE_TEST_SUITE(parameter_test, fixture) BOOST_AUTO_TEST_CASE(my_test) { BOOST_CHECK(test(rule_to_test, "input to parse", "expected output")); } --->8--- The next problem is related to the original use case. conjure2 is design as a compiler: initialize, analyse, generate and exit - no reuse of the grammar. I like to instance the grammar once (static) and use it several times using the qi::parse function. Since the iterators are fixed, they can't be changed later to point to other sources, isn't it? Is this the right approach for my problem? Thanks, Olaf

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Re: [Boost-users] [LockFree] a queue of std::shared_ptr?
by chris 15 Feb '13

15 Feb '13

Hello All, If we can't use shared_ptr in a lockfree queue, how can I share data between different queue ? I have some data that I have to be put in different queues and I want to avoid that I have to copy this data for each queue. -- View this message in context: http://boost.2283326.n4.nabble.com/LockFree-a-queue-of-std-shared-ptr-tp464… Sent from the Boost - Users mailing list archive at Nabble.com.

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Question about installing and using boost library.
by pan yi 15 Feb '13

15 Feb '13

Hi all, I'm a beginner to use boost library for my c++ coding project. After I include the <boost/algorithm/string.hpp> in my cpp file and compile the code, the compiling error indicates that: fatal error: boost/algorithm/string.hpp: No such file or directory I search on internet and knows that I need to install some boost library. But which library should I install? (I tried to install the whole library with "sudo apt-get install libboost*", but it doesn't work.) Can any one help me? I'm compiling and executing c++ on ubuntu Version12.04 environment Thank you so much. Best Regards Pan

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Re: [Boost-users] Boost-users Digest, Vol 3359, Issue 1
by John M. Dlugosz 14 Feb '13

14 Feb '13

On 2/14/2013 2:26 AM, boost-users-request-at-lists.boost.org |Boost/Allow to home| wrote: > Message: 5 > Date: Wed, 13 Feb 2013 19:20:40 -0500 > From: Edward Diener<eldiener(a)tropicsoft.com> > To:boost-users@lists.boost.org > Subject: Re: [Boost-users] [Preprocessor] Generate #include directive > with preprocessor > Message-ID:<kfhaku$ikt$1(a)ger.gmane.org> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > On 2/13/2013 6:43 AM, Adam Badura wrote: >> >Is it possible to use preprocessor to generate #include directives (or >> >in any other way include the files)? > No it is not possible. You cannot define a macro which expands to other > another macro definition or any other basic preprocessor construct, > including the #include. > > It is possible to use a macro as the name of the file to include. So you can choose the file via preprocessing logic, but not alter the fact that some file is to be included. So... given an empty file and a file with #include M1 #include M2 you can use recursion to include an arbitrary number of different files based on preprocessor logic. --John

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[GIL] About `packed_channel_value` (possible improvement)
by TONGARI 14 Feb '13

14 Feb '13

Hi, I took a look into "channel.hpp" and found that packed_channel_value is not very efficient in construction. There are: packed_channel_value(integer_t v) { _value = static_cast< integer_t >( v % num_values ); } // I have no idea why this exists, seems OK to remove it template <typename Scalar> packed_channel_value(Scalar v) { _value = static_cast< integer_t >( v ) % num_values; } IIUC, "v % num_values" above could be replaced with a much cheaper "v & low_bits_mask_t<NumBits>::sig_bits_fast". That is: packed_channel_value(integer_t v) : _value(v & low_bits_mask_t<NumBits>::sig_bits_fast) {} What do you think? Am I missing some point? Thanks.

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[ASIO] Any HTML5 video streaming server with boost asio?
by Goran 14 Feb '13

14 Feb '13

Hi all, do anybody knows something about HTML5 video streaming with boost::asio? I've looked into the tutorials and would like to use the html server examples to integrate into my app. So far anything is clear but video streaming is something I've never done. Are any resources out there? Thanks in advance! G.

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Documentation Install
by Robert Patterson 14 Feb '13

14 Feb '13

I download a tar ball, configured, built and installed (thank you). I then removed the entire build tree and realised I no longer had the docs (linked via libs/index.html). Obviously I can explode the tar ball again, but is there a simple way of keeping the docs without the whole tree - something like ./make installdocs ? Thanks Robert Patterson

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