- Boost - lists.boost.org

[fiber] design fault with multithreading
by Tatsuyuki Ishi 27 Sep '16

27 Sep '16

The current design doesn't allow a work-stealing algorithm to distribute work perfectly. Unfortunately, the use of sleep queue and remote ready queue made it insufficient for schedulers like shared_work. Instead here, I'd like to propose it as non-pure virtual function in the algorithm class. This allows schedulers to override the queues, and enables the use of underlying implementation's timer manager, which is included in Asio. Friendly notice: please use "Reply All" when replying to me.

1 0

Boost should not be saying "_FPOSOFF"
by Billy O'Neal (VC LIBS) 27 Sep '16

27 Sep '16

Hello, Boost folks. :) I tried to remove this undocumented internal macro from our STL because we used it in only one place, but this broke Boost: #define _FPOSOFF(fp) ((long long)(fp)) ...patience... ...found 722 targets... ...updating 18 targets... common.mkdir build\boost\bin.v2\libs common.mkdir build\boost\bin.v2\libs\iostreams common.mkdir build\boost\bin.v2\libs\iostreams\build common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99 common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\debug common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\file_descriptor.obj file_descriptor.cpp d:\src\vc\wcfb01\qa\vc\FE\3rdpartycomp\boost_1_60_0\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\file_descriptor.cpp(265): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data libs\iostreams\src\file_descriptor.cpp(289): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\file_descriptor.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\file_descriptor.obj... compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\mapped_file.obj mapped_file.cpp d:\src\vc\wcfb01\qa\vc\FE\3rdpartycomp\boost_1_60_0\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\mapped_file.cpp(59): warning C4244: 'return': conversion from 'const boost::iostreams::stream_offset' to '::size_t', possible loss of data libs\iostreams\src\mapped_file.cpp(325): warning C4244: 'argument': conversion from 'boost::iostreams::stream_offset' to 'SIZE_T', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\mapped_file.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\mapped_file.obj... ...skipped <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi>libboost_iostreams-vc-mt-gd-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi>file_descriptor.obj... ...skipped <pstage\lib>libboost_iostreams-vc-mt-gd-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi>libboost_iostreams-vc-mt-gd-1_60.lib... common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\release common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\file_descriptor.obj file_descriptor.cpp .\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\file_descriptor.cpp(265): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data libs\iostreams\src\file_descriptor.cpp(289): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\file_descriptor.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\file_descriptor.obj... compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\mapped_file.obj mapped_file.cpp .\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\mapped_file.cpp(59): warning C4244: 'return': conversion from 'const boost::iostreams::stream_offset' to '::size_t', possible loss of data libs\iostreams\src\mapped_file.cpp(325): warning C4244: 'argument': conversion from 'boost::iostreams::stream_offset' to 'SIZE_T', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\mapped_file.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\mapped_file.obj... ...skipped <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi>libboost_iostreams-vc-mt-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi>file_descriptor.obj... ...skipped <pstage\lib>libboost_iostreams-vc-mt-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi>libboost_iostreams-vc-mt-1_60.lib... ...failed updating 4 targets... ...skipped 4 targets... ...updated 10 targets... failed Billy3

8 18

[iterator] Is there any interest in Null Iterator Adaptor ?
by Rahman Salim Zengin 27 Sep '16

27 Sep '16

Hi! It would be pleasure for me to hear about your precious thoughts. https://github.com/rszengin/null_iterator Best regards.

3 5

Re: [boost] [fiber] Suggestions regarding asio
by Tatsuyuki Ishi 27 Sep '16

27 Sep '16

It would be better if you used "Reply to All", since I disabled the delivery from the list. > When considering using multiple threads with an io_service passed to a custom Boost.Fiber scheduler, I keep bumping into the problem that a given fiber scheduler instance must always run on its original thread -- but I know of no way to give an Asio handler "thread affinity." How do we get processor cycles to the scheduler on the thread whose fibers it is managing? Since we only poll on one master thread, we can easily get affinity. Maybe pseudocode is easier: * We have two class, one for main polling, others waiting for job. * The first one, polls from asio using the same way as the example (poll, or run_one). while(true) { if(!run_one()) stop_other_threads(); // No more work in asio, give up waiting poll(); // flush the queue // Now we should have some fibers in the queue. yield(); // continue execution } * Other threads, uses condvar to wait on the ready queue. awakened(){queue.push_back(f); cv.notify_[one,all](); iosvc.post([]{});} pick_next(){while(!jobs_available){cv.wait();} return job;}

5 7

Code complexity
by Vard Antinyan 27 Sep '16

27 Sep '16

Dear Boost developers, We have undertaken a task to assess code complexity triggers and generate recommendations for developing simple and understandable code. Our intension is to share the results with you, developers, so everyone can learn the triggers behind complex software. We need your help for rigorous results. My request to you is - if you get 5-10 min. time, would you please consider to answer the questions of this survey on code complexity? https://goo.gl/forms/h9WXZ8VSEw7BUyHg1 You are welcome to learn preliminary results through this link: https://www.facebook.com/SoftwareCodeQuality/photos/?tab=album&album_id=163… The results will be shared in a public webpage and everyone possible will be invited to learn and discuss them. Your knowledge and experience is vital for achieving substantial and generalizable results, and your effort is much appreciated! Sincerely Vard Antinyan PhD candidate in University of Gothenburg, Sweden Tel: 0046317725707

2 1

(Boost) Synapse update
by Emil Dotchevski 27 Sep '16

27 Sep '16

(Synapse is not part of Boost. I appreciate feedback as well as looking for someone willing to volunteer as review manager when Synapse is submitted for formal review.) Synapse is a signal-programming library similar to the Qt signal/slot system and Boost Signals 2. The difference is that Synapse is non-intrusive: any object of any static type whatsoever can serve as an emitter. I've just updated Synapse with support for interthread communication. It is available on github: http://zajo.github.io/boost-synapse/index.html. Thanks, Emil

3 5

Need help with errors while building boost for clang on android NDK
by Robert Dailey 26 Sep '16

26 Sep '16

I'm using NDK r11 and I'm setting up project-config.jam to build boost using clang + llvm STL. I'm running into a few errors that I do not know how to solve. I will post my config file at the bottom. First problem is that boost does not know where to find tools 'ar' and 'ranlib': clang-linux.archive bin.v2\libs\container\build\clang-linux-android\release\link-static\runtime-link-static\target-os-linux\threading-multi\libboost_container-clang-mt-s-1_61.a '"ar"' is not recognized as an internal or external command, operable program or batch file. '"ranlib"' is not recognized as an internal or external command, operable program or batch file. How can I explicitly specify the NDK path to these executables? Second problem is related to some assembler stuff, I think. I get these errors while compiling boost thread: clang-linux.compile.asm bin.v2\libs\context\build\clang-linux-android\release\link-static\runtime-link-static\target-os-linux\threading-multi\asm\make_i386_ms_pe_gas.o libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:1: error: unknown directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:22: error: unknown directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:36: error: expected identifier in directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:40: error: unknown directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:136:1: error: unknown directive .def __exit; .scl 2; .type 32; .endef ^ How can I solve this? I have no idea at this point. I'm invoking the build using: b2 --without-python threading=multi link=static runtime-link=static toolset=gcc-android target-os=linux threadapi=pthread --stagedir=android stage And my project-config.jam looks like: import option ; option.set keep-going : false ; androidNDKRoot = E:/android/ndk ; androidAbiVer = 4.9 ; androidPlatform = windows-x86_64 ; using clang : android : $(androidNDKRoot)/toolchains/llvm/prebuilt/$(androidPlatform)/bin/clang++ : <compileflags>--sysroot=$(androidNDKRoot)/platforms/android-15/arch-arm <compileflags>-Os <compileflags>-fno-strict-aliasing <compileflags>-O2 <compileflags>-DNDEBUG <compileflags>-g <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++abi/libcxxabi/include <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++/libcxx/include <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a <compileflags>-I$(androidNDKRoot)/sources/android/support/include <compileflags>-DANDROID <compileflags>-D__ANDROID__ <compileflags>-D__arm__ <compileflags>-D_REENTRANT ;

1 1

[Math/Special Functions] Is there any interest in the Lambert W function?
by Balázs Cziráki 26 Sep '16

26 Sep '16

Greetings! I'm working on a C++ implementation of the Lambert W (a.k.a. product logarithm or Omega function) and I wanted to ask the Boost developer community if there is interest in adding it to the library. The current version can be found on GitHub: https://github.com/CzB404/lambert_w/ I've successfully tested it with Cygwin GCC v5.4, v6.2 and with MinGW GCC that is supplied with Code::Blocks, and also on Visual Studio 2015. A test on a Linux based OS (probably Ubuntu) is also going to happen. Any suggestions or constructive criticism is welcome. Best regards, Balázs Cziráki

4 5

[range] sub_range of istream_range
by Andrew Hundt 26 Sep '16

26 Sep '16

I’m trying to iterate through a file using sub_ranges of an istream_range of an ifstream. However, it seems if I construct sub ranges of various subsets of the full istream_range, try to adjust the limits with advance_begin and advance_end, and then access them I get null dereferences. Any thoughts? I can produce an example if needed. Cheers! Andrew Hundt

1 0

markable -- informal review request
by Andrzej Krzemienski 24 Sep '16

24 Sep '16

Hi Everyone, I would like to ask your opinion, suggestions, and perhaps an informal review of the 'markable' library. An alternative to boost::optional when performance really matters. It is the second incarnation of the 'compact_optional' library that I have presented last year. The main differences from the previous version: * name change: it is called 'markable' so that it is not confused with 'optional'. It uses "mark values" and mark policies" * it has the ability to mark an empty state even for the types with strong invariants, by marking a bit pattern rather than any proper value of T (an idea by Matt Calabrese) An example use case: typedef markable<mark_int<int, -1>> opt_int; opt_int oi; opt_int o2 (2); assert (!oi.has_value());assert (o2.has_value());assert (o2.value() == 2); static_assert (sizeof(opt_int) == sizeof(int), ""); The github repository: https://github.com/akrzemi1/markable And documentation therein: https://github.com/akrzemi1/markable/tree/master/documentation Any comments, suggestions or critique are most welcome. Regards, &rzej;

4 8