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Re: [Boost-users] Does anybody interested in active object
by Marat Abrarov 08 Nov '10

08 Nov '10

To Dean Michael Berris: > You'd be better of doing data parallelism with Boost.MPI No. Because I'm speaking about thread-based parallelism (with shared memory access). Processed-based parallelism and IPC supplement but don't replace thread-based parallelism in general. > and/or Boost.Asio's io_service > run on multiple threads, and having independent tasks multiplexed > across a number of processors (either through processes or threads) Tie this tasks with the data they share and You will have an active object. If the tasks don't have shared data - they don't need an active object. I think - active object is built on task-based parallelism but it does not mean that "active object" should replace "task-based parallelism" everywhere. > But what you're describing is not the active object pattern. ;) http://en.wikipedia.org/wiki/Active_object http://en.wikipedia.org/wiki/Active_object_(Symbian_OS) What about ma::echo::server::session class - is it an active object? http://www.boost.org/doc/libs/1_44_0/doc/html/boost_asio/example/chat/chat_c lient.cpp Is chat_client an active object? If "yes" then why? chat_client::write have no completion callback - and this is not enough sometimes (I can say "always", if You don't implementing "fire-and-forget" logic which is rather seldom). http://www.boost.org/doc/libs/1_44_0/doc/html/boost_asio/example/serializati on/connection.hpp s11n_example::connection is an active object and have completion callback... but it's much simpler then ma::echo::server::session_manager - I try to suggest "samples" that can help to build such a kind of complex active objects. http://www.drdobbs.com/go-parallel/blog/archives/2009/09/parallelism_sho.htm l > We are surrounded by parallelism even more so that serial activities. > Social and biological systems are immersed in parallelism and these > systems have worked out the kinks over millions of years. > In biological systems, independent units perform simple computations > or activities independently and in parallel. and > IMPLICATIONS FOR COMPLEX REALTIME SYSTEMS: > Complex real-time systems would be a sea of state machine objects > interacting with each other. There will be low level state machines > which would work together to implement high level state machine behavior. Here's the place for active object pattern. Thanks for that attention that you have given to my question. Marat Abrarov. > -----Original Message----- > Date: Sun, 7 Nov 2010 12:58:06 +0800 > From: Dean Michael Berris <mikhailberis(a)gmail.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Does anybody interested in active object > pattern? > Message-ID: > <AANLkTi=PTkqO2ngdYcNNbp12hNnS=8=PxK3YsccajpFV(a)mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > On Sat, Nov 6, 2010 at 10:56 PM, Marat Abrarov <abrarov(a)mail.ru> wrote: > > > > Does anybody interested in active object pattern for massive parallelism > by means of C++? (Intel TBB doesn't offer a > > similar approach) > > > > I'm not sure how you think active objects help for massive parallelism > because the active object pattern implies that you're serializing > operations on a single object. > > I've used Boost.Asio to implement Active Objects but only in cases > where it makes sense -- like for example a concurrent accumulator or a > concurrent resource handle (log sink for example). You'd be better of > doing data parallelism with Boost.MPI and/or Boost.Asio's io_service > run on multiple threads, and having independent tasks multiplexed > across a number of processors (either through processes or threads). > > I remember reading about Microsoft's efforts (through Herb Sutter) to > introduce an "active" extension to Microsoft Visual C++, where you can > easily make classes that instantiate to active objects. I'm not sure > where that effort is now though. > > HTH > > -- > Dean Michael Berris > deanberris.com >

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[GIL] Adding base_channel_type metafunction
by Nathan Crookston 08 Nov '10

08 Nov '10

All, Several months ago I submitted a patch to prevent warnings when performing certain channel conversions [1]. After some discussion with Christian a part of the patch was removed in favor of using the unsigned_integral_max_value metafunction. After tweaking my specializations of that metafunction my code compiled fine. Recently I modified my code to use GIL more extensively. I'm pleased with the reduced code footprint (a 5000 line file was reduced to ~150 lines), but unfortunately there are more warnings due to unsafe conversions with my now-more-extensive testing. Attached is a file which adds a base_channel_type metafunction which correctly determines the type which the channel constructor is expecting. I believe this is more correct than using unsigned_integral_max_value as the value_type of *max_value is not the same as the channel type for, e.g., 8-bit unsigned channels. Something like this metafunction has also been requested recently [2]. The following demonstrates its use for the built-in channel type models I'm aware of: ///////////BEGIN CODE//////////////////// #include <boost/cstdint.hpp> #include <boost/gil/gil_all.hpp> #include <boost/static_assert.hpp> #include <boost/type_traits/is_same.hpp> namespace gil = boost::gil; typedef gil::packed_image3_type<boost::uint16_t, 7,7,2, gil::bgr_layout_t>::type bgr772_image_t; typedef gil::kth_element_type<bgr772_image_t::value_type,0>::type b7_element_type; typedef gil::base_channel_type<b7_element_type>::type b7_type; BOOST_STATIC_ASSERT((boost::is_same<b7_type, boost::uint8_t>::value)); typedef gil::base_channel_type<gil::channel_type<gil::gray32f_pixel_t>::type>::type gray32f_type; BOOST_STATIC_ASSERT((boost::is_same<gray32f_type, float>::value)); typedef gil::base_channel_type<gil::channel_type<gil::rgb8_pixel_t>::type>::type rgb8_type; BOOST_STATIC_ASSERT((boost::is_same<rgb8_type, boost::uint8_t>::value)); int main() {} /////////END CODE///////////////// Adding the metafunction and using it to cast values prior to channel construction has removed the warnings from my testing. The diff file also contains changes to channel_algorithm.hpp to suppress warnings using the supplied metafunction. I'd be happy to write additional test cases, trac tickets, etc. The changes have been tested with g++3.4, g++4.3 and VC8 (VS2005). Thanks, Nate [1] <http://lists.boost.org/boost-users/2010/06/60066.php> [2] <http://lists.boost.org/Archives/boost/2010/07/169159.php>

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the name of installed Boost libraries, with or without '-gcc'
by weining hao 07 Nov '10

07 Nov '10

Hi, I have installed boost 1.33-1 in SLES (SUSE Linux Enterprise Server) 11 manually by bjam 3.12, and in SLES10 sp2 via YAST2 (with the defalut bjam 3.1.4). I found that the installed libraries in SLES 11 are always with the postfix '-gcc', which is not appeared in the libraries in SLES 10 sp2 (For example, "libboost_filesystem-gcc.o" in SLES 11, but "libboost_filesystem.o" in SLES10 sp2). The '-gcc' also exists in the library name in SLES 9.3. Is it configurable to be with or without '-gcc', and in which file? Is it related to the SLES version, or bjam version? It is appreciated that you give some hints! Best regards, Weining

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Does anybody interested in active object pattern?
by Marat Abrarov 07 Nov '10

07 Nov '10

Hello, Boost C++ Libraries' community. I'm trying to develop the idea of (most effective) building active objects by means of Boost C++ Libraries (not as libpoet does). I chose for this Boost.Asio as the only library supports flexible "custom memory allocation" mechanism. Here is my project: https://sourceforge.net/projects/asio-samples/ And here is short description of the concept: https://think-async.com/Asio/Examples This project isn't a library and won't be it. It is something like advanced examples for Boost.Asio. And I hope this "advanced examples" are very close to production-level code. Does anybody interested in active object pattern for massive parallelism by means of C++? (Intel TBB doesn't offer a similar approach) Regards, Marat Abrarov.

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[iostreams] compressing and decompressing in memory
by Brian Budge 07 Nov '10

07 Nov '10

I've been searching around for examples for how to compress and decompress using the zip or gzip iostreams compressors into/out of memory buffers. Has anyone tried this? Would you use basic_array for this? Thanks, Brian

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sizeof(boost::fusion:map)
by Robert Lupton the Good 06 Nov '10

06 Nov '10

I was very excited to find the boost::fusion library, expecting that I could use it to implement structs with introspection. I still think I can, but I was disappointed to see that I'm paying a size penalty. I'd have expected all the book-keeping to be handled at compile time. The following code prints sizeof(Foo) = 12 sizeof(FooS) = 4 with g++ 4.2 or 4.4 on an os/x 10.6 or Centos box. Here Foo is boost::fusion::map<boost::fusion::pair<Name, int> > Where are the extra 8 bytes going? With more complex boost::fusion objects I see an overhead of up to 16 bytes. gdb indicates that foo.data.vec has the desired size, but foo.data is larger, and foo is larger still; however, it doesn't indicate any data members --- is this some sort of alignment issue? Is there a way to generate a "packed boost::fusion::map" without this space overhead? R #include <iostream> #include "boost/fusion/container.hpp" struct Name {}; int main() { typedef boost::fusion::map<boost::fusion::pair<Name, int> > Foo; struct FooS { int age; }; std::cout << "sizeof(Foo) = " << sizeof(Foo) << " sizeof(FooS) = " << sizeof(FooS) << std::endl; }

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boost regex no debug info and std::bad_cast
by justin 06 Nov '10

06 Nov '10

Hi, I'm trying to use boost/regex.hpp on OS X 10.6.4 10F569. $ g++ -v Using built-in specs. Target: i686-apple-darwin10 Configured with: /var/tmp/gcc/gcc-5664~89/src/configure --disable-checking --enable-werror --prefix=/usr --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin10 --program-prefix=i686-apple-darwin10- --host=x86_64-apple-darwin10 --target=i686-apple-darwin10 --with-gxx-include-dir=/include/c++/4.2.1 Thread model: posix gcc version 4.2.1 (Apple Inc. build 5664) BOOST BUILD $ ./bootstrap.sh --prefix=$BOOST_INSTALL $ ./bjam debug define=_GLIBCXX_DEBUG install --prefix=$BOOST_INSTALL MAKEFILE $ g++ -Wall -g -I~/Development/BOOST/boost_1_44_0 ~/Development/BOOST/BOOST_INSTALL/lib/libboost_regex.a example.cpp -o example example.cpp #include <iostream> #include <iterator> #include <algorithm> #include <boost/regex.hpp> int main() { std::string s("table.dat"); boost::regex expression("table.dat"); boost::regex_match(s, expression); return 0; } Problems (2): 1. $ ./example terminate called after throwing an instance of 'std::bad_cast' what(): std::bad_cast Abort trap 2. $ gdb example This GDB was configured as "x86_64-apple-darwin"...Reading symbols for shared libraries ... done warning: Could not find object file "/var/folders/Hk/HkJ3ILZ4GcOnWEOL-4iWEE+++TI/-Tmp-//ccC7Ee4y.o" - no debug information available for "example.cpp". Any help is appreciated, Justin -- View this message in context: http://boost.2283326.n4.nabble.com/boost-regex-no-debug-info-and-std-bad-ca… Sent from the Boost - Users mailing list archive at Nabble.com.

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building boost for Android
by Igor R 06 Nov '10

06 Nov '10

Hello, Has anyone managed to build boost for this platform? Thanks.

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Boost.MPI 1.44.0 fails to build when BOOST_MPI_HOMOGENEOUS is set
by Riccardo Murri 06 Nov '10

06 Nov '10

Hello, I'm trying to build Boost.MPI from the 1.44.0 sources; if I uncomment the `#define BOOST_MPI_HOMOGENEOUS` line in `boost/mpi/config.hpp`, then build fails with errors like this one (full compile log attached): ./boost/mpi/detail/binary_buffer_iprimitive.hpp: In member function ‘void boost::mpi::binary_buffer_iprimitive::load(T&) [with T = boost::archive::class_id_optional_type]’: ./boost/archive/detail/iserializer.hpp:107: instantiated from ‘static void boost::archive::load_access::load_primitive(Archive&, T&) [with Archive = boost::mpi::packed_iarchive, T = boost::archive::class_id_optional_type]’ ./boost/archive/detail/iserializer.hpp:356: instantiated from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::load_primitive::invoke(Archive&, T&) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/iserializer.hpp:433: instantiated from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::invoke(Archive&, T&) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/iserializer.hpp:586: instantiated from ‘void boost::archive::load(Archive&, T&) [with Archive = boost::mpi::packed_iarchive, T = boost::archive::class_id_optional_type]’ ./boost/archive/detail/common_iarchive.hpp:66: instantiated from ‘void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/mpi/packed_iarchive.hpp:101: instantiated from ‘void boost::mpi::packed_iarchive::load_override(T&, int, mpl_::false_) [with T = boost::archive::class_id_optional_type]’ ./boost/mpi/packed_iarchive.hpp:118: instantiated from ‘void boost::mpi::packed_iarchive::load_override(T&, int) [with T = boost::archive::class_id_optional_type]’ ./boost/archive/detail/interface_iarchive.hpp:60: instantiated from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/common_iarchive.hpp:54: instantiated from ‘void boost::archive::detail::common_iarchive<Archive>::vload(boost::archive::class_id_optional_type&) [with Archive = boost::mpi::packed_iarchive]’ libs/mpi/src/request.cpp:120: instantiated from here ./boost/mpi/detail/binary_buffer_iprimitive.hpp:87: error: no matching function for call to ‘assertion_failed(mpl_::failed************ boost::serialization::is_bitwise_serializable<boost::archive::class_id_optional_type>::************)’ Boost 1.43.0 compiles just fine with BOOST_MPI_HOMOGENEOUS uncommented. I'm using GCC 4.4.5 on Ubuntu 10.10; OpenMPI 1.4.1 installed from the official Ubuntu package. Is this an issue with the sources? Best regards, Riccardo -- Riccardo Murri, Hadlaubstr. 150, 8006 Zürich (CH)

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Re: [Boost-users] boost regex no debug info and std::bad_cast
by justin 05 Nov '10

05 Nov '10

Different Code (example.cpp) #include <boost/lexical_cast.hpp> #include <iostream> using namespace::std; int main() { unsigned int x = 3; string s = boost::lexical_cast<string>(x); return 0; } Works $ g++ -Wall -g -I~/Development/BOOST/boost_1_44_0 example.cpp -o example Doesn't Work: including boost regex library $ g++ -Wall -g -I~/Development/BOOST/boost_1_44_0 ~/Development/BOOST/BOOST_INSTALL/lib/libboost_regex.a example.cpp -o example Seems to be a bug: https://svn.boost.org/trac/boost/ticket/4595 https://svn.boost.org/trac/boost/ticket/4595 Is this bug related to my previous question about using boost regex? Thanks -- View this message in context: http://boost.2283326.n4.nabble.com/boost-regex-no-debug-info-and-std-bad-ca… Sent from the Boost - Users mailing list archive at Nabble.com.

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