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cross platform high resolution timer
by Sean Farrow 24 Nov '10

24 Nov '10

Hi: Does boost contain a cross platform high resultion timm that allows a function to run every resolution. Something that is equivalent to the win32 multimedia timer. Any help appreciated. Sean.

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[Interprocess] Different outputs under bash and gdb
by Aditya Gadre 24 Nov '10

24 Nov '10

Dear all, I have a question about proper use of Boost.Interprocess for sharing custom C++ classes. I recently started using Boost.Interprocess and have been successful in sharing boost::array, std::vector<float>, std::vector< boost::array<float, 2> > etc using boost::interprocess::managed_shared_memory and boost::interprocess::allocator. Currently, I am trying to share a custom matrix class that is used to hold data in a tabular format. The Matrix class (attached header file Matrix.hpp) is a simple wrapper class that uses std::vector to store objects and provides functions to find items using linear and matrix indexing. I have modified a boost::interprocess example program to try out sharing the Matrix class (attached file test_matrix_shm.cpp). The parent process creates a managed memory segment along with a Matrix in the shared memory. The child process accesses the shared memory and successfully finds the Matrix object. However, when I run the program under bash, the output of the child process shows wrong data. However, if I run the same program under gdb, then every time the child process shows correct Matrix data as was set by the parent process (please find sample outputs below). I am really not sure what would cause this behavior. I would appreciate any input in this regard. * bash output * parent process Matrix size = 2 x 2 0 1 2 3 child process Matrix size = 2 x 2 -1.2522e-41 -1.25486e-41 -1.2571e-41 -1.25949e-41 child returning parent returning * gdb output * GNU gdb (GDB) SUSE (7.1-3.12) (gdb) run Starting program: test_matrix_shm parent process Matrix size = 2 x 2 0 1 2 3 Detaching after fork from child process 2548. child process Matrix size = 2 x 2 0 1 2 3 child returning parent returning Program exited normally. Thanks - Aditya

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[boost::asio] link errors using boost 1.44.0 on 32-bit
by Samir Kharchi 24 Nov '10

24 Nov '10

Hi, I am mainly using boost::asio and I get a link error when I try to build my project on 32-bit release VC8.0 saying (The according 32-Bit libs are correctly included): error LNK2019: Verweis auf nicht aufgelöstes externes Symbol ""class boost::system::error_category const & __cdecl boost::system::system_category(void)" (?system_category@system@boost@@YAABVerror_category@12@XZ)" in Funktion ""class boost::system::error_category const & __cdecl boost::system::get_system_category(void)" (?get_system_category@system@boost@@YAABVerror_category@12@XZ)". error LNK2001: Nicht aufgelöstes externes Symbol ""class boost::system::error_category const & __cdecl boost::system::system_category(void)" (?system_category@system@boost@@YAABVerror_category@12@XZ)". However, compiling my project in 64-Bit release works just fine (according 64-bi libs included) and I don´t get these errors. Anybody knows what´s going on here? :-/ I searched the boost list for previous problems but none of the topics I found helped. Thank you in advance Samir

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undefined references '__sync_fetch_and_add_4 ' for Boost_1_39_0 on Alpha platform
by Yan Wu 24 Nov '10

24 Nov '10

Hi, I got an error when building OpenOffice.org on Alpha EV6 platform, the error log is as following: Compiling: comphelper/unxlngaxp.pro/misc/comphelp4gcc3_version.c Making: comphelper.lib Making: libcomphelp4gcc3.so ../unxlngaxp.pro/slo/enumberablemap.o: In function 'comphelper::EnumerableMap::initialize(com::sun::star::uno::Sequence<com::sun::star::uno::Any> const&)': '__sync_fetch_and_add_4' undefined reference ./unxlngaxp.pro/slo/enumberablemap.o: In function 'comphelper::EnumerableMap::initialize(com::sun::star::uno::Sequence<com::sun::star::uno::Any> const&)': '__sync_fetch_and_add_4'undefined reference ../unxlngaxp.pro/slo/enumberablemap.o: In function 'comphelper::EnumerableMap::initialize(com::sun::star::uno::Sequence<com::sun::star::uno::Any> const&)': '__sync_fetch_and_add_4'undefined reference ../unxlngaxp.pro/slo/enumberablemap.o: In function 'comphelper::EnumerableMap::initialize(com::sun::star::uno::Sequence<com::sun::star::uno::Any> const&)': '__sync_fetch_and_add_4'undefined reference ../unxlngaxp.pro/slo/enumberablemap.o: In function 'comphelper::EnumerableMap::initialize(com::sun::star::uno::Sequence<com::sun::star::uno::Any> const&)': '__sync_fetch_and_add_4'undefined reference ../unxlngaxp.pro/slo/enumberablemap.o: more undefined references to '__sync_fetch_and_add_4' follow collect2: ld returned 1 exit status dmake: Error code 1: while making '../unxlngaxp.pro/lib/libcomphelp4gcc3.so' The <boost/shared_ptr.hpp> of Boost_1_39_0 is used here. Is this a bug on Boost_1_39_0 ? and is there already a fix for it? Best Regards, Yan

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boost thread query
by Sean Farrow 24 Nov '10

24 Nov '10

Hi: I have two threads that are started by a class created by the applications main thread. Can the thread function be a private member of that class or does it need to be public? When the application exits I need the threads to be notified and exit. What is the best way of handling this? I need this to be cross platform but in windows I would have used a waitforSingleObject and signalled the event when the main thread wants to exit. Could I use a condition for this, and do a do while loop waiting on the condition to be notified, if I do this do I need a mutex just for the condition? Any help appreciated. Cheers Sean.

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[boost.test] Floating point comparisons
by Anders Wang Kristensen 24 Nov '10

24 Nov '10

Hi, I'm using boost.test and BOOST_CHECK_CLOSE to verify that some matrices I compute are equal to some reference matices. This works fine as long as no entries are zero in either matrix (reference or computed). However, when an entry is zero, BOOST_CHECK_CLOSE always fails, which makes sense, since relative error is undefined in such cases. If either entry is zero, I can use BOOST_CHECK_SMALL instead with an absolute error: if (ref==0.0 || val==0.0) BOOST_CHECK_SMALL(ref - val, absolute_error); else BOOST_CHECK_CLOSE(ref, val, relative_error); But is this really the best way to do this? And if this is the standard way of doing this, shouldn't there be function in boost.test for automating this, like: BOOST_CHECK_NEAR(ref, value, relative_error, absolute_error); kinds regards, Anders (sorry if this post appears twice)

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[Build] System/integration testing?
by ajb＠spamcop.net 24 Nov '10

24 Nov '10

G'day. Boost.Build has fabulous facilities for unit testing, but I'm curious what is "best practice" for system testing. The simplest thing would be to run a shell script (portability isn't an issue here), passing it the path to all of the built binaries, but I'm sure someone must have already done something better than this. Thanks, Andrew Bromage

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boost interprocess: memory allocation container
by Carla Strembicke 23 Nov '10

23 Nov '10

Hello, I am using boost 1.44 and trying to create shared memory and utilizing the segment manager with a interprocess map. I continually get a compile error when call the segment manager construct call. I can't figure out what the problem is. I have tried copy/paste example but continue to get the same error. "/usr/local/boost_1_44_0/boost/interprocess/detail/named_proxy.hpp:123:131: error: no matching function for call to 'forward(std::less<int>()&)' Below is the snippet of code: string driver_share = _cc.share_name + "_drivers"; using namespace boost::interprocess; //Clean up before creating shared memory shared_memory_object::remove(driver_share.c_str()); managed_shared_memory segment(create_only, driver_share.c_str(),65536); typedef boost::process::pid_type key_type; typedef boost::posix_time::ptime value_type; typedef std::pair<key_type, value_type> pair_type; typedef boost::interprocess::allocator<pair_type, managed_shared_memory::segment_manager> mem_allocator; typedef boost::interprocess::map<key_type, value_type, std::less<key_type>, mem_allocator> driver_map; const mem_allocator alloc_instance(segment.get_segment_manager()); driver_map *dmap = segment.construct<driver_map>("DriverMap")( std::less<int>(), alloc_instance); My include files are as follows: #include <boost/thread/thread.hpp> #include <boost/date_time/posix_time/posix_time_types.hpp> #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/process/all.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/containers/map.hpp> #include <map> #include <functional> #include <iostream> using namespace boost; using namespace boost::posix_time; using namespace std; IF you know of any reason why I get this error that would be great.........I will continue to read the boost documentation. Regards carla Carla Strembicke Software Developer [cid:imagebf0008.jpg@2cac8a6e.ad7c4515] SUBNET Solutions Inc. www.SUBNET.com<http://www.subnet.com/> Making Substations More Intelligent T: 403.270.8885 F: 403.270.9631 #100, 4639 Manhattan Road SE, Calgary, Alberta, Canada; T2G 4B3 CONFIDENTIAL INFORMATION NOTICE: The information contained in this e-mail is privileged, confidential and intended solely for the use of the addressee named above. If the reader of this e-mail is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this e-mail is strictly prohibited. If you received this in error, please contact the sender and destroy all copies of this e-mail. Thank you.

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[boost-users] [ptr_container] Genericity on containers
by Eloi Du Bois 23 Nov '10

23 Nov '10

Hi, I would like to know why is'nt that working: boost::ptr_vector<B> p1; boost::ptr_vector<B> p2; std::vector<B> v1; boost::ptr_vector<A, boost::view_clone_allocator> pview; // add elements... p1 = p2; pview = p1; // p1 = v1; // don't work // pview = v1; // don't work It should be working, or would be interesting to get working. Thank you, Eloi Du Bois.

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Re: [Boost-users] Hybrid parallelism, no more + mpi+serialization, many questions
by Hicham Mouline 23 Nov '10

23 Nov '10

> Here's how I'd probably do this using a pull model: > <snip> > Brian Hi Brian, Thanks for the solution. I think I'll go first just with monothread mpi processes. Can I use MPI splitting the communicators following my tree's shape? Does MPI allow splitting world, and then splitting again, then again....? rds,

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