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hybrid parallelism
by Hicham Mouline 05 Nov '10

05 Nov '10

Hello, Following a previous thread that asked about how to parallelize a large number of calculations, I took this summary: I am thinking of choosing a simple model whereby: There are M computers (possibly heterogeneous). I will stick to 1 process per computer. Each process will have N threads. Giving a total M*N "execution units". I will take a simple solution in that the M and N are fixed though determined at runtime. So there is this pool of M*N exec units and I give them 100 000 tasks to do. Those tasks get scheduled in the same process/computer, they share their memory. Each of the computers gets a duplicate of the memory used as inputs to the tasks. For thread pool, TBB, boost::asio were suggested. I believe there is also threadpool.sourceforge.net For the cross-computer communication, boost::mpi. Is this something boost::mpi + mpi can help with? Regards,

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Statistical distributions in Boost.Math
by Paul A. Bristow 05 Nov '10

05 Nov '10

Recently I have been working on a few more Statistical Distributions for Boost.Math. These will be in release in 1.45 and some more in 1.46, (and soon, an update to http://sourceforge.net/projects/distexplorer/ Distribution Explorer, a mixed C++ and C# Windows application that allows you to explore the properties of various statistical distributions, & calculate the Cumulative Distribution Function CDF, Probability Distribution Function PDF, or quantiles/percentiles). inverse chisquare, inverse gamma distribution, inverse Gaussian, Wald. 1 I am looking for some examples of their use for the documentation. If you could to propose and/or help work up some not-too-complicated examples of applications of these (they seem to be popular with followers of the Reverend Bayes ;-) - please contact me privately. 2 Are there other distributions (or 'special' functions) that you, or your colleagues, friends or relations, would find useful? If you have suggestions or requests, please tell me. Thanks Paul --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

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[boost] [Review] Formal Review of Proposed Boost.Chrono Library Starts TOMORROW
by Anthony Williams 05 Nov '10

05 Nov '10

Hi everyone, The review of Vicente Botet's Chrono library starts TOMORROW (November 6th) and lasts until November 15th unless an extension occurs. What is it? ======== Boost.Chrono aims to implement the new time facilities in C++0x, as proposed in N2661 - A Foundation to Sleep On (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2661.htm) That document provides background and motivation for key design decisions and is the source of a good deal of information in this documentation. See the current C++0x working draft at http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf for details of what was accepted. The Boost.Chrono library provides: * A means to represent time durations: managed by the generic duration class . Examples of time durations include days, minutes, seconds and nanoseconds, which can be represented with a fixed number of clock ticks per unit. All of these units of time duration are united with a generic interface by the duration facility. * A type for representing points in time: time_point. A time_point represents an epoch plus or minus a duration. The library leaves epochs unspecified. A time_point is associated with a clock. * Several clocks, some of which may not be available on a particular platform: system_clock, monotonic_clock and high_resolution_clock. A clock is a pairing of a time_point and duration, and a function which returns a time_point representing now. * To make the timing facilities more generally useful, Boost.Chrono provides a number of additional clocks that are thin wrappers around the operating system's time APIs, thereby allowing the extraction of read (wall clock) time, user CPU time, system CPU time, - process_real_cpu_clock, captures real (wall clock) CPU times. - process_user_cpu_clock, captures user-CPU times. - process_system_cpu_clock, captures system-CPU times. - A tuple-like class __process_cpuclock_, that captures real, user-CPU, and system-CPU times together. - A thread_clock thread monotonic clock, when supported by a platform. * Boost.Chrono also includes typeof registration for duration and time_point to permit using emulated auto with C++03 compilers. * Boost.Chrono also provides I/O for duration and time_point. It builds on <boost/ratio/ratio_io.hpp> to provide readable and flexible formatting and parsing for types in <boost/chrono.hpp>. The duration unit names can be customized through a new facet: duration_punct. Getting the library ============= The latest version of this library may be downloaded from vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=chrono… SVN: http://svn.boost.org/svn/boost/sandbox/chrono Boost.Chrono depends on Boost.Ratio http://www.boostpro.com/vault/index.php?action=downloadfile&filename=ratio.… and optionaly Boost.System Header Only http://www.boostpro.com/vault/index.php?action=downloadfile&filename=system…. and the docs may be viewed here HTML: http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/html/index.ht… PDF: http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/chrono.pdf You can get all these information also (which should avoid some long links) from http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Chrono Writing a review ================ If you feel this is an interesting library, then please submit your review to the developer list (preferably), or to the review manager. Here are some questions you might want to answer in your review: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick - reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Anthony Review Manager for the proposed Boost.Chrono library -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976 _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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[boost][icl/itl] Interval Container Library ready for inclusion
by Joachim Faulhaber 05 Nov '10

05 Nov '10

Dear list! After the review of the Interval Template Library in February and its acceptance for inclusion, I worked on a number of suggestions and proposals from the reviewers, in order to improve the design and quality of the library. The library is now renamed to Boost.Icl: Interval Container Library. I have completed a release icl-4.0.0, where those suggestions are implemented. Apart from typos and flaws in the docs that might be there after renaming, this will be the version for inclusion into the next boost release (1.46.0). The now renamed library has a new path in the sandbox: https://svn.boost.org/svn/boost/sandbox/icl/ The sources are also in the vault http://www.boostpro.com/vault/index.php?&direction=0&order=&directory=Conta… and on sourceforge (extended version) http://sourceforge.net/projects/itl/ The BoostBook docs are online available here: http://www.joachim-faulhaber.de/boost_icl/doc/libs/icl/doc/html/index.html Many of the proposals from the reviewers were agreed upon during the discussion on the library. In particular I took into account suggestions by Jeff Flinn (JF), Luke Simonson (LS), Barend Gehrels (BG), Vicente Botet (VB), Thomas Klimpel (TK), Paul A. Bristow (PB), Robert Stewart (RS), John Reid (JR) and Markus Werle (MW). Some suggestions by Phil Endecott, Jerry Jeremiah, Brian Wood, Barend Gehrels, Luke Simonson and John Reid are not or not yet implemented for different reasons but they may be considered for the future evolution of the library. * The library has been renamed from Interval Template Library (ITL) to Interval Container Library (ICL) Its namespace is now icl instead of itl. (Renaming was suggested by MW). * Introduction of dynamically bounded and statically bounded intervals (JF,JR,VB) + The 'universal' interval class itl::interval has been replaced by + dynamically bounded discrete_interval and continuous_interval http://www.herold-faulhaber.de/boost_icl/doc/libs/icl/doc/html/boost_icl/ex… + statically bounded right_open_interval, left_open_interval closed_interval and open_interval and a uniform set of namespace global functions or interval_concept for them. Statically bounded intervals don't carry information about their interval bounds and use less memory. (JF,JR) http://www.herold-faulhaber.de/boost_icl/doc/libs/icl/doc/html/boost_icl/ex… + The interval class templates are now quite small. The functions are namespace global functions that make up an interval concept (JF,LS) + Added functions 'distance' and 'inner_complement' for intervals.(JR) http://www.herold-faulhaber.de/boost_icl/doc/libs/icl/doc/html/boost_icl/fu… * User defined interval types are now customizable (JF) + An interval_traits and dynamic_interval_traits template describes the generic properties of the interval concept ... + and allows to customize the icl library for user defined interval types. http://www.herold-faulhaber.de/boost_icl/doc/libs/icl/doc/html/boost_icl/ex… * Extraction of namespace global functions. (LS,JF,RS) + Member functions have been extracted form class templates as long as they are not needed to maintain type invariants. + The sets of namespace global functions build concepts icl::element_set, icl::element_map, icl::interval_set, icl::interval_map + Some functions have been renamed to conform existing standards (ISO/OGC). (BG) + std::set and other stl conformant set types are models of the icl's element_set concept. Class template icl::set has been removed. + Member functions for element iterations are extracted from the interval container class templates. (LS) * Names, referred to as 'colorful terminology' have been renamed (TK,VB,PB) + neutron -> identity_element + unon -> unit_element + ... and also their occurrence in composite identifiers If you find bugs in the library or typos or other flaws in the docs, please let me know so I can fix them before inclusion of the library into the next boost release. Enjoy, Joachim

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[BGL] edge() function also inside AdjacencyList-concept?
by Cedric Laczny 05 Nov '10

05 Nov '10

Hi, I was wondering that the edge()-function (to see if there is an edge between two vertices and if so also return it) also exists for the AdjacenyList- concept?! As in the documentation, I find it only under "AdjacencyMatrix refines Graph" but nowhere else. Where is it defined and what is it's time complexity (just to make sure that my assumptions on the complexity are correct) please? Best regards, Cedric

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[Asio]What's the behavior of socket.async_write() after socket.close() is called?
by 鑫炜廖 05 Nov '10

05 Nov '10

Hi, If I call socket.close() but I still have some data in my buffer, can I call async_write() later? When I call socket.close(), maybe an async_write operation is running, when it's complete I want to send data in another buffer(data written while previous async_write() is running, before socket.close() was called), but the socket is closed.Does it work in this situation?If not, what's the alternative way? The code looks like this: char front_buffer[kBufferSize]; char back_buffer[kBufferSize]; void HandleWrite(...) { //socket is closed. Does this work? socket.async_write(back_buffer, ...); } socket.async_write(front_buffer, HandleWrite); // write data to back_buffer socket.close();

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[Range] Creating a range for a scoped_array (with known length)
by Matthieu Brucher 05 Nov '10

05 Nov '10

Hi, I have a scoped_array with some chars inside (so a boost::scoped_array<char>). I want to use the string algorithms, but I can't managed to get a range from the scoped_array. I don't know if the data ends with a '\0' (it's received from asio with a read()), so I can't rely on as_literal. Is there a way of creating a Range directly with two iterators? Matthieu -- Information System Engineer, Ph.D. Blog: http://matt.eifelle.com LinkedIn: http://www.linkedin.com/in/matthieubrucher

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get/set RTS on serial port - Linux
by Marce 05 Nov '10

05 Nov '10

Hi, In a later post of myself I asked about getting / setting the RTS line by software control (http://lists.boost.org/boost-users/2010/06/59700.php) I managed to get working as explained in Windows as replied in by Michael Caisse (http://lists.boost.org/boost-users/2010/06/59723.php) but in linux I'm not being able to get it working. I can control it in linux by calling ioctl ( ioctl(fd, TIOCMSET, &status) ) but in the set-option I do not have the file descriptor but the termios that I don't completely understand. Does someone provide me and example to make this 'option' This is my RTSControl option class: class RTSControl { public: explicit RTSControl(bool enable = false) : m_enable(enable) {}; boost::system::error_code store(BOOST_ASIO_OPTION_STORAGE& storage, boost::system::error_code& ec) const { #if defined(BOOST_WINDOWS) || defined(__CYGWIN__) if (m_enable) storage.fRtsControl = RTS_CONTROL_ENABLE; else storage.fRtsControl = RTS_CONTROL_DISABLE; #else #endif return ec; }; boost::system::error_code load(const BOOST_ASIO_OPTION_STORAGE& storage, boost::system::error_code& ec) { #if defined(BOOST_WINDOWS) || defined(__CYGWIN__) if (storage.fRtsControl == RTS_CONTROL_ENABLE) m_enable = true; else m_enable = true; #else #endif return ec; }; private: bool m_enable; }; BOOST_ASIO_OPTION_STORAGE is termios for Linux systems.

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[Proto] lambda functions with named variables
by Hossein Haeri 04 Nov '10

04 Nov '10

Dear all, I am thinking of having creatures like lam(x)(x + 2) in my code which would be the Haskell equivalent for \x -> x + 2. In fact, I am working in an untyped world (with very limited functionality) and my typical lambda expressions would only include (function) applications, (lambda) abstractions, and let-bindings. It is exactly for the existence of let-bindings that I guess I can't resort to placeholders like: template<int> placeholder; const terminal<placeholder<0> >::type _1 = {{}}; const terminal<placeholder<1> >::type _2 = {{}}; const terminal<placeholder<2> >::type _3 = {{}}; ... The point is that I need to store what each variable is bound to. And, AFAIK, I can't store such information in std::map<> for _1 has a different type than _2 for example. So, the two hopes that I have in Proto for solving this problem are: 1) To provide a type T instances of which can act like untyped variables in accepting values of different C++ types. T should also be storable in a map-like container. Boost.Any comes to mind for the first requirement but the problem is that there is no meaningful operator < or operator == to use map or unordered_map for boost::any objects. Note that a1 != a2 needs to the case only when a1 and a2 are distinct variables. Can proto::_ be of any help here? 2) To provide a map-like container in which I can store things like boost::any objects. OK, maybe this is not for Proto to address but though it might still have something to offer... TIA, --Hossein

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[proto]: Adding functions to the lazy vector example
by Noman 04 Nov '10

04 Nov '10

Hi I am experimenting with the lazy vector example. I want to add the functions to the example but not in the LazyVector class. Like for example I want to add a function INC which increments each element of the vector and returns a vector. How can I add this to the example? Thanks in anticipation Regards

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