July 2008 - Boost - lists.preview.boost.org

Boost.Process 0.2 released
by Boris 07 Jul '08

07 Jul '08

I stumbled over Boost.Process some months ago. The library was created as a Google Summer of Code project in 2006 (see http://www.netbsd.org/~jmmv/process/) As I needed the functionality provided by this library and didn't manage to contact the author I went through the code myself to tidy it up, fix various bugs, convert the documentation to DocBook etc. I also added one minor but important improvement: With Boost.Asio 1.1 it's now possible to use asynchronous I/O (on Windows the macro BOOST_PROCESS_WINDOWS_USE_NAMED_PIPE must be defined as on Windows only named pipes support asynchronous I/O). I've been using the library myself only on Windows so far where it seems to work fine. I didn't make any tests yet on a POSIX platform. I didn't update the documentation yet much either. And I have no idea how to integrate the samples and test programs into Boost.Build (there are two Jamfiles but don't be surprised if they don't work :). As this library wasn't touched for nearly 2 years I don't know if there is any interest at all. As I had tidied up the code now anyway for my own purposes I provide a new snapshot for the community. You can find everything (including a link to download version 0.2) here: http://www.highscore.de/boost/process/ Boris

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[test] test_tools.hpp: gcc-warnings patch
by Juergen Hunold 07 Jul '08

07 Jul '08

Hi ! The attached patch fixes two gcc warnings about unused parameters in BOOST_TEST_DONT_PRINT_LOG_VALUE. Okay to commit to trunk ? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! Ingenieurgesellschaft für * voice: ++49 511 262926 57 ! Verkehrs- und Eisenbahnwesen mbH * fax : ++49 511 262926 99 ! Lister Straße 15 * juergen.hunold(a)ivembh.de ! www.ivembh.de * * Geschäftsführer: ! Sitz des Unternehmens: Hannover * Prof. Dr.-Ing. Thomas Siefer ! Amtsgericht Hannover, HRB 56965 * PD Dr.-Ing. Alfons Radtke !

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[metagraph] definition
by Gordon Woodhull 07 Jul '08

07 Jul '08

I just have to share this little insight: finally, a concise definition. A metagraph is a system of objects where the types of the objects (classes) and the relations between them (e.g. pointers, mappings, containers) can be described in a graph called a pattern. In the C++ implementation, the patterns are metadata, which allows static typing and static polymorphism and moves the abstraction penalty to compile time (when the pattern is known at coding time). Patterns and their implementation code are combined into larger patterns; the "total pattern" is what actually gets instantiated. The library allows implementation of hypergraphs, subgraphs, various nested/mixed/ clustered layout schemes, constraints on graphs, and generally graphs- of-graphs, hence the name metagraph. Can any static analysis fans out there tell me if there's already a name for this? Note that in this definition, metagraph is something which already exists in lots of forms. This library proposes (for now) to implement the data structures in a nicer way and (in the future) to describe and access existing structures in a consistent way. My profuse apologies for continuing to talk about code that doesn't yet exist. Soon, soon. Cheers, Gordon

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Re: [boost] [integer] Can anyone double-check this test?
by Vladimir Prus 07 Jul '08

07 Jul '08

Daryle Walker wrote: > I'm trying to tweak Boost.Integer, and I noticed that only 3 of the 6 > test files there are being used. I changed the jam-file there, but I > don't use Boost.Build myself, so can someone here confirm that the > changes work. You can check out the exact changes with Change-set > 47123 at <http://svn.boost.org/trac/boost/changeset/47123>. In other words, you've checked in something, and you don't know if that works? You really better learn how to use Boost.Build -- for the mainstream toolsets and operating systems, it's trivial. - Volodya

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Graph library noise in logs
by Emil Dotchevski 07 Jul '08

07 Jul '08

Isn't it a good idea to remove these messages from the Graph library Jamfile? warning: Graph library does not contain optional GraphML reader. note: to enable GraphML support, set EXPAT_INCLUDE and EXPAT_LIBPATH to the note: directories containing the Expat headers and libraries, respectively. warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. IMO this information belongs in the documentation. At present it is displayed every time I build anything that uses Boost, even if it doesn't use Graph. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

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[test][darwin][trunk] using some undefined signal macros on Power PC
by JOAQUIN M. LOPEZ MUÑOZ 07 Jul '08

07 Jul '08

Hello, I guess it is pretty apparent by now, but Boost.Test is causing a lot of regressions in the Sandia-darwin-ppc regression runner with the following: http://tinyurl.com/689u7x ../boost/test/impl/execution_monitor.ipp: In member function 'void boost::detail::system_signal_exception::report() const': ../boost/test/impl/execution_monitor.ipp:292: error: 'ILL_ILLOPN' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:297: error: 'ILL_ILLADR' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:312: error: 'ILL_PRVREG' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:317: error: 'ILL_COPROC' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:322: error: 'ILL_BADSTK' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:332: error: 'FPE_INTDIV' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:337: error: 'FPE_INTOVF' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:367: error: 'FPE_FLTSUB' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:397: error: 'BUS_ADRERR' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:402: error: 'BUS_OBJERR' was not declared in this scope AFACIS <signal.h> does not define these macros in Power PC architectures, further confirmation of this fact here http://source.winehq.org/source/dlls/ntdll/signal_powerpc.c I guess it's easy enough to conditionally #define the offending parts out relying on defined(__POWERPC__). I'd propose a patch mysel but I don't have the appropriate environment to test locally with. And unfortunately we don't have a Darwin/PPC champion yet: http://svn.boost.org/trac/boost/wiki/PlatformChampions HTH, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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[flyweight] rw_locking policy patch for review
by Tim Blechmann 06 Jul '08

06 Jul '08

i have implemented a rw_locking policy for flyweight factories, based on boost::shared_mutex. to achieve that, i had to adapt the factory interface ... joaquín, would it be possible for you to review the patch? it is based against the version of flyweight from the boost sandbox svn ... best, tim -- tim(a)klingt.org http://tim.klingt.org Cheat your landlord if you can and must, but do not try to shortchange the Muse. It cannot be done. You can't fake quality any more than you can fake a good meal. William S. Burroughs

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BGL: Graph edges with greater than 2 vertices
by Aman Sinha 06 Jul '08

06 Jul '08

I am looking to build a graph where an edge can be incident on multiple vertices. I believe this is also called a hypergraph. The boost archives have some discussion of hypergraphs from way back in year 2002. Does anyone know what is the status of that? If is is not supported, is there a reasonable workaround to build such graphs? Thanks, Aman

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[utility/swap] Okay to add array support to Boost.Swap (sandbox/swap)?
by Niels Dekker - mail address until 2008-12-31 06 Jul '08

06 Jul '08

Hi Joe, hi Steven, Would it be okay to you if we would add support for array types to the Boost.Swap utility that is located in the sandbox? I'm asking now, because I wrote an issue, asking the C++ Standards Committee to add an overload of std::swap for array types. And Howard Hinnant just mailed me the other day that the issue has reached status Ready. :-) LWG issue 809, "std::swap should be overloaded for array types" http://home.twcny.rr.com/hinnant/cpp_extensions/issues_preview/lwg-active.h… Of course, it will still take a while before STL implementations will actually add such an std::swap overload. It isn't yet part of the Standard, officially. So I would very much appreciate if boost::swap would already start supporting array types. And I think it would be helpful when implementing swap member functions for templates like boost::value_initialized<T>. Array support could easily be added to swap/boost/utility/swap.hpp (http://svn.boost.org/trac/boost/browser/sandbox/swap/boost/utility/swap.hpp) by overloading boost_swap_impl::swap_impl, as follows: template<class T, std::size_t N> void swap_impl(T (& left)[N], T (& right)[N]) { for (std::size_t i = 0; i < N; ++i) { ::boost_swap_impl::swap_impl(left[i], right[i]); } } Please tell me what you think. I do have SVN write access, so I wouldn't mind committing the necessary changes. :-) Kind regards, -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center

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Question about boost::asio's design
by Yingfeng 06 Jul '08

06 Jul '08

I am using asio to my software and i have some design issue about asio and hope could get your idea about it. I plan to develop a server based on asio, which could support high concurrency with complicated back end tasks to be provided, that is to say, when received a request from a client, there exists a task involved with lots of disk io and many cpu cycles to serve that request. Therefore, some concurrency design pattern would be used together with a thread pool, such as Half-Asyn/Half-Syn or Leader/Followers. I have read some sources of Asio, i think the idea of using Reactor to implement Proactor is pretty cool. Here is what I have got from the code about the working flow: Take asyn_receive as an example: 1. A functor of receive_handler together with the socket descriptor is added to the read operation queue. 2. Reactor is blocked on the demulplex call such as select 3. When read is available, Reactor retrieves the read op from the read operation queue and invoke the functor named receive_handler 4. Reactor receive the data 5. After the data has been finished reading, another event with the handler which could be customed by users is posted to the read operation queue. ... According to the above flow, I can see that there exist two kinds of events in the operation queue: events to handle socket IO and events with completion handler customed by users. In the users' eye, the process of retrieving operation from queue and then invoke handler is proceeded within io_service::run(), therefore a thread pool should be binded with io_service::run(), which is just shown in the example of Http server 3. In the design pattern of Half-Asyn/Half-Syn or Leader/Followers, the working flow is: after retrieving an operation from the queue, then dispatch a thread to process that operation handler. However, in the asio's design, if I used the threadpool to io_service::run(), then both events of processing socket IO and completion handler will occupy the thread. I think this will cause more threading overhead. I think it is reasonable that only one thread to process the network IO, and other threads to process the task of completion handler. However, it is difficult to do that in the current design. Do you have any opinion about my situation? Very grateful! Yingfeng

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