- Boost-users - lists.boost.org

Re: [Boost-users] Race in boost::condition_variable::wait
by Éric Malenfant 24 Dec '15

24 Dec '15

Not sure I understand your question. Unless I'm missing something, the guard in condition_variable::wait does not release the mutex, it is simply there to ensure that it is reacquired on exit. The mutex is released by pthread_cond_wait (atomically with the wait on the condition). Éric Malenfant Le 2015-12-22 8:30 PM, "Chris Stankevitz" <chrisstankevitz(a)gmail.com> a écrit : Hi, Regarding boost::condition_variable::wait (listed below with an obvious modification), It seems to me that there is a race condition because the following operations are not atomic: 1) unlocking of "m" 2) waiting on "cond". Can someone explain to me why boost::condition_variable::wait is not racing the user code in the example below? Thank you, Chris === inline void condition_variable::wait(unique_lock<mutex>& m) { int res=0; { thread_cv_detail::lock_on_exit<unique_lock<mutex> > guard; detail::interruption_checker check_for_interruption(&internal_mutex,&cond); guard.activate(m); #ifdef ENCOURAGE_DEADLOCK boost::this_thread::sleep_for(boost::chrono::seconds(100)); #endif do { res = pthread_cond_wait(&cond,&internal_mutex); } while (res == EINTR); } } === #define ENCOURAGE_DEADLOCK #include <boost/thread.hpp> int main() { boost::mutex Mutex; boost::condition_variable Condition; bool Quit = false; boost::thread Thread([&] { boost::unique_lock<boost::mutex> Lock(Mutex); while (!Quit) { Condition.wait(Lock); } }); boost::this_thread::sleep_for(boost::chrono::seconds(1)); boost::lock_guard<boost::mutex> Lock(Mutex); Quit = true; Condition.notify_all(); return 0; } _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[boost][iterator] Regarding Ticket #11847
by Gagan Kumar 24 Dec '15

24 Dec '15

Hi, I am new and I wanted to contribute. The ticker #11847 says,"reference typedef no longer available in parent class of iterator_facade" but actually I think reference is available in class iterator_facade itself(boost/iterator/iterator_facade.hpp). But still we are not able to use reference in class simple_iterator : public boost::iterator_facade<simple_iterator<T>, T, boost::forward_traversal_tag> and then after a while I saw this http://stackoverflow.com/questions/1643035/propagating-typedef-from-based-t… >From my side I can only solve this kind of problem by using typename boost::iterators::iterator_facade<simple_iterator<T>, T, boost::iterators::forward_traversal_tag>::reference; or using alternative of reference as T& dereference() const { return *m_iter; } //T& instead of reference, as stated in Ticket Can somebody please tell me or guide me to a better way to solve this problem. Regards Gagan Kumar

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Boost 1.60.0 has been released
by Marshall Clow 23 Dec '15

23 Dec '15

Release 1.60.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains one new library and numerous enhancements and bug fixes for existing libraries. New Libraries * VMD: Variadic Macro Data library, from Edward Diener For details, including download links, see http://www.boost.org/users/news/version_1.60.0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.60.0/ Tom Kent has made pre-built windows binaries, and they are available at: https://sourceforge.net/projects/boost/files/boost-binaries/1.60.0/ To install this release on your system, see http://www.boost.org/doc/libs/release/more/getting_started/index.html Thanks, --The Boost release team Vladimir Prus Rene Rivera Marshall Clow Eric Niebler Daniel James Beman Dawes

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Race in boost::condition_variable::wait
by Chris Stankevitz 23 Dec '15

23 Dec '15

Hi, Regarding boost::condition_variable::wait (listed below with an obvious modification), It seems to me that there is a race condition because the following operations are not atomic: 1) unlocking of "m" 2) waiting on "cond". Can someone explain to me why boost::condition_variable::wait is not racing the user code in the example below? Thank you, Chris === inline void condition_variable::wait(unique_lock<mutex>& m) { int res=0; { thread_cv_detail::lock_on_exit<unique_lock<mutex> > guard; detail::interruption_checker check_for_interruption(&internal_mutex,&cond); guard.activate(m); #ifdef ENCOURAGE_DEADLOCK boost::this_thread::sleep_for(boost::chrono::seconds(100)); #endif do { res = pthread_cond_wait(&cond,&internal_mutex); } while (res == EINTR); } } === #define ENCOURAGE_DEADLOCK #include <boost/thread.hpp> int main() { boost::mutex Mutex; boost::condition_variable Condition; bool Quit = false; boost::thread Thread([&] { boost::unique_lock<boost::mutex> Lock(Mutex); while (!Quit) { Condition.wait(Lock); } }); boost::this_thread::sleep_for(boost::chrono::seconds(1)); boost::lock_guard<boost::mutex> Lock(Mutex); Quit = true; Condition.notify_all(); return 0; }

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Not for publishing
by Soul Studios 23 Dec '15

23 Dec '15

To whoever it is that's been blocking my posts to the mailing list - with the exception of this email, please stop. I have chronic fatigue syndrome, and I feel like I'm fighting an uphill battle against the lack of documentation around actually doing documentation for boost. I would've understood if I'd said anything reasonably offensive, but I don't think I did.

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Software Freedom Conservancy Support
by Jon Kalb 23 Dec '15

23 Dec '15

This is not a technical message, but instead focuses on Boost Administration. Software Freedom Conservancy in a Financial Fight for its Life Software Freedom Conservancy, the non-profit home of Boost is facing an existential threat. Historically, Conservancy has been funded by corporate donations. This works great when it works, but a management shake-up, change in priorities, or a bad quarter at a large donor can derail the organization¹s programs. It has become obvious that Conservancy must move to a Supporter-driven funding model, where individuals who believe in Conservancy¹s mission of supporting open source projects, such as Boost, make a personal commitment to support that effort. Conservancy's fundraiser, found at https://sfconservancy.org/supporter/, is centered around asking individuals who care about the work that Conservancy does to donate $120/year, or just $10/month, to support the organization. Conservancy seeks about 2,500 Supporters to continue its current work, and 750 Supporters to continue a ³bare minimum² of services to its projects. What does this mean to Boost? Boost receives a myriad of important services (see https://sfconservancy.org/members/services/ ) from Conservancy. We¹ve relied on Conservancy since 2007 to provide them. Here are some of the things that Conservancy does for Boost that are in the ³bare minimum² category: * Dealing with all the financial and contractual details regarding our annual C++ Now conference. It was BoostCon that brought Boost and Conservancy together. C++Now 2016 will the the tenth annual BoostCon and it is a tribute to what we¹ve accomplished working together. * Handle our Google Summer of Code payments and travel, including handling all financial transactions with Google to receive and then disperse the money. * Coordinating travel reimbursements for Boost contributors (both developers and students) to attend conferences. * Receiving and tracking all donations to Boost. * Keeping the non-profit status for us so that we don't have to form our own org and file our own paperwork. As the Chair of the Boost Steering Committee, I cannot overstate how important this is to our existence as an organization. Here are some of the services Boost has received in the wider category: * Dealing with questions from the community (including license-governing bodies like OSI) about Boost's license. * Discussing the issue of copyright governance and contributions with large corporations who want their employees to contribute to Boost but need legal assurances or have questions relating to Boost's license or contribution policies. * Reviewing and handling licensing terms of third-party software that relate to Boost in some way, and giving us feedback and answers about issues related to it. * General legal consulting on issues that we run into as an open source non-profit. As you can see, Boost really relies on the important work of Conservancy. Support from Boost Boost, like all of Conservancy¹s projects, contributes 10% of our revenue to Conservancy¹s general fund. (The other 90% is maintained and administered by Conservancy at the direction of the Boost Steering Committee to advance the Boost project.) But that 10% of revenue from all Conservancy¹s member projects doesn¹t add up to enough to even employee one full time person, let alone the already overworked staff of three that Conservancy has. Donors must make up the difference. When Conservancy launched its fundraising effort, I sent out a request to past BoostCon/C++Now attendees asking for support and I¹m proud and delighted to say that a number of Boost community members have already stepped up. One told me that her company will be matching her support. Boost is one of Conservancy¹s oldest and largest projects, so it is right that Boost community members make up a fair proportion of its supporters. I encourage you to choose Conservancy as one of your charitable gifts this holiday season. (Conservancy is a 501(c)(3) charity incorporated in New York, and donations are typically deductible on U.S. taxes.) Please visit: https://sfconservancy.org/supporter/ If you are able to join the others from the Boost community that are making this gift, please let me know. I¹d like to personally thank you. Jon Kalb Chair, Boost Steering Committee

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boost.test: Run multiple tests
by Udo Steinbach 22 Dec '15

22 Dec '15

Hello, boost:test is a great tool. Now I have boost updated to v1.60 and can't run more than one tests at once. System is MinGW on Windows. Given suite_1 test_1_1 suite_1_2 test_1_2_1 and many more, all enabled by default, with v1.59 I could run these both test and exclude all others with --run_test=suite_1/test_1_1,suite_1/suite_1_2/test_1_2_1 respectively BOOST_TESTS_TO_RUN, but with v1.60 the result is "Test setup error: no test cases matching filter or all test cases were disabled". With --run_test=suite_1/test_1_1,suite1_2/test_1_2_1 only test_1_2_1 is executed. Same result with BOOST_TEST_RUN_FILTERS=suite_1/test_1_1,suite1_2/test_1_2_1 . With multiple --run_test= all is fine. But how do I execute multiple tests via variable? bye Udo -- Fahrradverkehr in Deutschland: http://radwege.udoline.de/ GPG: A245 F153 0636 6E34 E2F3 E1EB 817A B14D 3E7E 482E

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Johnson all pair shortest path and output in a C array
by Paolo Bolzoni 22 Dec '15

22 Dec '15

Dear list, I need to get the all pair shortest path in a C array, to pass it to a java program. However johnson all pair shortest path[1] requires a BasicMatrix[2] as output, so a simple array won't do. At the moment I used few classes (see Matrix and MatrixR[3]) as wrapper around a std::vector and it works fine, but I was wondering if I am missing a simpler solution. Is there? Yours faithfully, Paolo [1]http://www.boost.org/doc/libs/release/libs/graph/doc/johnson_all_pairs_sh… [2]http://www.boost.org/doc/libs/release/libs/graph/doc/BasicMatrix.html [3] struct Matrix { Matrix(std::vector<int64_t>& storage, size_t rows, size_t columns) : m_(storage), columns_(columns) { m_.clear(); m_.resize(rows * columns_, int64_t{0}); } int64_t& get(size_t row, size_t column) { return m_[row * columns_ + column]; } std::vector<int64_t>& m_; size_t columns_; }; struct MatrixR; struct MatrixRR { MatrixRR(MatrixR const& m, size_t column) : m_(m), column_(column) {} int64_t& operator[] (size_t row) const; MatrixR const& m_; size_t column_; }; struct MatrixR { MatrixR(Matrix& m) : m_(m) {} MatrixRR operator[] (size_t column) const { return MatrixRR(*this, column); } Matrix& m_; }; int64_t & MatrixRR :: operator[] (size_t row) const { return m_.m_.get(row, column_); }

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Re: [Boost-users] [container] Boost 1.60 Release link error
by Hickman, Steve (AdvTech) 22 Dec '15

22 Dec '15

I'm using VS2012 on Win 7 64bit building 32bit executables. --- Steve H. From: Hickman, Steve (AdvTech) Sent: Monday, December 21, 2015 11:14 AM To: 'boost-users(a)lists.boost.org' <boost-users(a)lists.boost.org> Subject: [container] Boost 1.60 Release link error Getting a linker error with the Windows version of Boost on release only (not debug) using v 1.60. This did not show up with 1.58 (I skipped 1.59 so I have no comment on it). I'm using the prebuilt libraries: 8> Creating library D:\GITRepos\fd_x-current_feature\source\Devices\MockDevice\Test\Release\MockTest.lib and object D:\GITRepos\fd_x-current_feature\source\Devices\MockDevice\Test\Release\MockTest.exp 8>MockDevice.lib(Mock.obj) : error LNK2001: unresolved external symbol "public: void __thiscall boost::container::container_detail::has_member_function_named_construct<class boost::container::new_allocator<char> >::BaseMixin::construct(void)" (?construct@BaseMixin@?$has_member_function_named_construct@V?$new_allocator@D@container@boost@@@container_detail@container@boost@@QAEXXZ) 8>MockDevice.lib(Mock.obj) : error LNK2001: unresolved external symbol "public: void __thiscall boost::container::container_detail::has_member_function_named_construct<class boost::container::new_allocator<struct boost::container::container_detail::tree_node<struct std::pair<class boost::container::basic_string<char,struct std::char_traits<char>,class boost::container::new_allocator<char> > const ,struct boost::interprocess::ipcdetail::ref_count_ptr>,void *,0,1> > >::BaseMixin::construct(void)" (?construct@BaseMixin@?$has_member_function_named_construct@V?$new_allocator@U?$tree_node@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@std@@V?$new_allocator@D@container@boost@@@container@boost@@Uref_count_ptr@ipcdetail@interprocess@3@@std@@PAX$0A@$00@container_detail@container@boost@@@container@boost@@@container_detail@container@boost@@QAEXXZ) 8>D:\GITRepos\fd_x-current_feature\source\Devices\MockDevice\Test\Release\MockTest.exe : fatal error LNK1120: 2 unresolved externals Steve Hickman System Architect, Human Machine Collaboration Honeywell | Aerospace Office: 480-236-8367 steve.hickman(a)honeywell.com<mailto:steve.hickman@honeywell.com> https://in.honeywell.com/sites/aero/Pages/Home.aspx

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segfault using boost::thread_specific_ptr
by Michael P. Soulier 22 Dec '15

22 Dec '15

Hello, I’m trying to implement a thread-safe logger that uses a boost::thread_specific_ptr to a std::stringstream as a logging buffer. static boost::thread_specific_ptr<std::stringstream> tls_buffer; class MLoggerHandler { public: MLoggerHandler(boost::mutex& mutex, std::ostream& ostream); ~MLoggerHandler(); void setLevel(int level); template <class T> // For handling << from any object. MLoggerHandler& operator <<(T input) { std::cerr << "Adding to buffer" << std::endl; if (m_start) { *tls_buffer << localDateTime() << " " << input; <================= SEGFAULT m_start = false; } else { *tls_buffer << input; } std::cerr << "On buffer: " << tls_buffer->str() << std::endl; return *this; } // For handling std::endl std::ostream& operator <<(std::ostream& (*f)(std::ostream&)) { std::cerr << "Flushing buffer" << std::endl; m_start = true; std::ostream& rv = f(m_ostream); m_mutex.lock(); m_ostream << tls_buffer->str(); m_mutex.unlock(); tls_buffer->str(""); return rv; } private: // A flag to indicate the beginning of a new line. bool m_start = true; // A mutex passed in from the main logger for synchronization. boost::mutex& m_mutex; // The logging level. int m_level; // The output stream. std::ostream& m_ostream; // Return the current date and time as a localized string. const std::string localDateTime(); }; The initial idea, was to flush the buffer and write when a terminating std::endl was encountered. But, just trying to dereference the pointer and write to the std::stringstream is crashing. Do I need to initialize the std::stringstream, or is it initialized in constructor? Thanks, Mike

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