May 2015 - Boost-users - lists.preview.boost.org

[interprocess] Determine size of managed_shared_memory
by Kai Benndorf 12 Oct '19

12 Oct '19

Hi all, I want to create a managed_shared_memory in exactly the size I needed. Therefore I do something like this: size = sizeof( common_managed_shared_memory ); size += sizeof( MyClassInSharedMem ); managed_shared_memory segment(create_only, "name", size ); MyClassInSharedMem allocates itself some memory by segment->allocate(). I added this also to the size, but get a boost::interprocess::bad_alloc exception on allocating this additional memory. Are there some magic bytes I forgot to add? Many thanks in advance Kai

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[Range, Phoenix] What am I missing...
by Robert Jones 25 Apr '17

25 Apr '17

Hi Folks Can anyone explain the output of this program... #include <iostream> #include <boost/range/algorithm/copy.hpp> #include <boost/range/counting_range.hpp> #include <boost/range/adaptor/reversed.hpp> #include <boost/range/adaptor/transformed.hpp> #include <boost/phoenix/bind/bind_function.hpp> #include <boost/phoenix/core/argument.hpp> int f( int i ) { return i * 2; } int main( ) { using boost::adaptors::reversed; using boost::adaptors::transformed; using boost::counting_range; using boost::copy; using boost::phoenix::arg_names::_1; copy( counting_range( 1, 5 ) | reversed | transformed( f ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; copy( counting_range( 1, 5 ) | reversed | transformed( bind( f, _1 ) ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; } Which is... 8 6 4 2 1768406272 1768406272 1768406272 1768406272 I'm using Gcc 4.6.2 & Boost 1.53 Thx All.

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[statechart] Passing parameters from event to State Local Storage
by Christophe Bourez 16 Nov '16

16 Nov '16

I need to maintain a parameter into the state local storage. This parameter is initially contained in the event that causes the transition to the target state. I give hereafter a small illustrative example. typename sc = boost::statechart; class EvTest : public sc::event<EvTest> { public: EvTest(std::size_t val) : value(val) {} std::size_t getValue() const { return this->value; } private: std::size_t value; }; class MyStateMachine; class StSource; class StTarget; class StSource : public sc::simple_state<StSource, MyStateMachine> { public: typedef sc::custom_reaction<EvTest> reactions; sc::result react(const EvTest &event) { // How to pass event.getValue() to the target state ? transit<StTarget>(); } }; class StTarget : public sc::simple_state<StTarget, MyStateMachine> { public: StTarget(std::size_t val) : val(value) {} private: std::size_t value; }; Thanks, Christophe

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Re: [Boost-users] Crashing Issue
by swati upadhyaya 04 Nov '15

04 Nov '15

hi I am using like this where RunningThreads_ is vector containing boost thread object pointer(handler).I am using interrupt() for the interruption of thread interruption_point() catching that interruption then joining.everytime its crashing in join() for me but for others who have the same configuration its working fine all of us has windos 8. For me also it was working last week but this week the same piece of code is crashing. :( RunningThreads_[i].handle->interrupt(); RunningThreads_[i].handle->join(); delete RunningThreads_[i].handle; On Thu, Feb 5, 2015 at 9:31 AM, swati upadhyaya <swatiupadhyaya(a)gmail.com> wrote: > RunningThreads_[i].handle->interrupt(); > LOG4CPLUS_INFO(root, "Thread Interrupted for " << > RunningThreads_[i].app_name << " successful"); > RunningThreads_[i].handle->join(); > LOG4CPLUS_INFO(root, "Waiting for thread to exit " << > RunningThreads_[i].app_name << " successful"); > delete RunningThreads_[i].handle; > LOG4CPLUS_INFO(root, "Thread handle for " << > RunningThreads_[i].app_name << " successfully deleted"); > //RunningThreads_.erase(i); > > On Wed, Feb 4, 2015 at 12:10 AM, Vicente J. Botet Escriba < > vicente.botet(a)wanadoo.fr> wrote: > >> Le 03/02/15 09:10, swati upadhyaya a écrit : >> >> In my code join() timed_joined() is crashing, I am using these API >> after interrupt(),Same piece of code is working for others but in my system >> its crashing, >> Is there some dependency problem I am using >> Boost version: 1.55.0 >> OS: Windows 8 >> IDE: Visual Studio 2010 >> >> Hi, >> >> it could help if you post the example and the backtrace. >> >> Which version/OS/compiler use others for which this works? >> >> Vicente >> >> _______________________________________________ >> Boost-users mailing list >> Boost-users(a)lists.boost.org >> http://lists.boost.org/mailman/listinfo.cgi/boost-users >> > >

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the stability of breadth_first_visit in BGL
by breadbread1984 14 Jul '15

14 Jul '15

I am wondering if breadth_first_visit can always get the same sequence of vertex no matter whether the graph is serialized and deserialized again. Thx

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Subgraph at distance n
by Rossano Schifanella 14 Jul '15

14 Jul '15

Hi all, which is the easiest way to extract from a graph G and a generic node source a subgraph with all the vertices/edges at distance at most n from source? Thanks a lot for your help. Best, Rossano

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Re: [Boost-users] [IPC Named Mutex]
by Lorenzo Trivelli 19 Jun '15

19 Jun '15

> >One thing you could try...in interprocess's win32_api.hpp, there is another implementation of get_last_bootup_time() which uses WMI instead of the event log (there were warnings in the source about WMI not supporting hibernation/clock changes correctly, so beware). If you define >BOOST_INTERPROCESS_BOOTSTAMP_IS_LASTBOOTUPTIME >it should use that other version...give that a try. (in visual studio Project Properties -> C/C++ -> Preprocessor -> Preprocessor Definitions: add a semi colon ';' then t Thanks Tom, I'll try to fallback to the "old" WMI version (which BTW worked in the 1.44 version I we used before) I'd also be glad to fix it by myself and so help boost developement, , but I do not completely understand the usage of the system boot time... If boost needs in some way a tmestamp to differentiate things, in my opinion there are plenty of them to use instead of the last boot time. Obviously it has been done for a reason, but I cannot understand why :-D Best regards Lorenzo

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threads and async questions and asnwers
by Victor Yankee 03 Jun '15

03 Jun '15

Hello List, I have a thread with a class and its method that raises a "question" signal and needs to wait with a timeout for an "answer" signal. There are several worker threads, some of which may be connected to the question signal. The answer signal will be raised by a worker thread only if it knows the answer; it is possible that no worker thread knows the answer so no answer signal will be raised (hence need for timeout). The question thread cannot know which worker thread to ask. What is a good way to achieve this using boost 1.58 and/or C++11? I am using g++ 4.9 on 64bit ubuntu 14.04. Thanks, Vic

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Re: [Boost-users] [MSM] Boost.MSM: statemachine to transition on templatized event-type
by Christophe Henry 01 Jun '15

01 Jun '15

Hi, > having tested Boost.MSM, I'm pretty happy with it. :) >It's interesting, in that it seems to handle all states in a static table. >No "new" operator etc. It's much faster without dynamic allocation. <snip> g_row<StateInitial, EventT, StateEven, &Machine_<EventT>::guardToEven>, >Unfortunately >gcc gives this error: >d.cpp:119:5: error: ‘g_row’ was not declared in this scope > g_row<StateInitial, EventT, StateEven, &Machine_<EventT>::guardToEven>, Short answer. Try: typename Machine_<EventT>::template g_row<StateFloat, EventT, StateFloat, &Machine_<EventT>::guardToFloat> Long answer: g_row is a type of state_machine_def and as your fsm is a template, it becomes a dependent type (=> typename) and a template one even (=> template). C++ is sometimes really annoying :( Longer answer. Give up this front-end, it's deprecated anyway. A better solution will be: #include <boost/msm/front/functor_row.hpp> using namespace boost::msm::front; struct GuardToOdd { template <class EVT,class FSM,class SourceState,class TargetState> bool operator()(EVT const& num,FSM& ,SourceState& ,TargetState& ) { const long long x = static_cast<long long>(num.getNum()); return ((x == num.getNum()) // is Integral type && ((x % 2) != 0)); } }; Row< StateFloat, EventT, StateOdd, none, GuardToOdd> HTH, Christophe

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{Boost-Test] How to specify order test suites are run.
by Merrill Cornish 01 Jun '15

01 Jun '15

I'm running Boost 1_58_0 on Windows 7.1, 64-bit, with MinGW 4.9.2, 64-bit. I've just started writing tests for my project and have one test suite working. I'm using BOOST_AUTO_TEST_CASE and BOOST_AUTO_TEST_SUITE. There will be many more test suites to come. They are not LOGICALLY dependent on each other, but if some fail, the other tests will be a waste of time. Therefore, I would like to be able to specify the order in which they are run. Is there a way to do that, or does choosing BOOST_AUTO_TEST_SUITE take it all out of my hands? Merrill Cornish

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