- Boost-users - lists.boost.org

[serialization] custom allocation/deletion
by Brian Budge 07 Jun '12

07 Jun '12

Hi all - Is there a way to use custom allocation while loading from an archive? I'm thinking like passing an allocator along with the archive during deserialization? Adding to this, is it possible to add a custom deleter to a shared_ptr during deserialization? I am thinking of using this with boost mpi, and if I send a shared_ptr over the wire with some kind of deleter, the same deleter object can't be used on the other side since it's in a different address space. Thanks, Brian

2 5

signal_set_service.ipp(247) error SIG_ERR undeclared
by Christopher Pisz 07 Jun '12

07 Jun '12

signal_set_service.ipp(247) error SIG_ERR undeclared I am getting this error when trying to compile a precompiled header that includes boost\asio.hpp I am using boost version 1.49.0 This did not occur with 1.40.0 Any ideas?

1 0

[pool] Questions about memory pool
by Junchao Zhang 07 Jun '12

07 Jun '12

Hello, I'm new to boost memory pool. I have two questions: 1) My program has multiple iterations. In each iteration, I need to allocate chunks(objects) from a pool. I don't need to allocate array of chunks. I don't free objects until the end of an iteration. Then what is the most efficient way to do that? I wrote the following code, but I'm not sure it is right. boost::pool<> p(sizeof(MyType)); for (...) { ... // many calls to p.malloc(); ... p.release_memory(); // Is it OK??? } Also, I was wondering, to improve locality, how to reuse the memory in the next iteration, instead of deallocating/allocating memory again and again. 2) How to inquiry a pool to know have many objects have been allocated from the pool? For example, if malloc() 2 times, free() 1 time, then the count is 1. Does boost pool have this interface? Thanks! -- Junchao Zhang

1 0

[MSM] cannot use state machine level internal_transition_table within the state machine which has Completion (anonymous) transitions in its transition_table
by James Zhang 06 Jun '12

06 Jun '12

Hi, I'm trying to setup a MSM state machine, according to : https://groups.google.com/group/boost-list/browse_thread/thread/bd9854b58a3… I can setup a state machine level internal_transition_table to handle the state-independent events. but the build failed if the transition_table has Completion (anonymous) transitions. I did following test: 1. if I remove the internal_transition_table, the build succeed. 2. if I give an event to the Rows, then the build succeed tool Row < Initialized , none , Synchronized >, Row < Synchronized , none , WaitResponse , sendPoll >, could anybody give me some clues about this? thanks. following is the code: #include <iostream> // back-end #include <boost/msm/back/state_machine.hpp> //front-end #include <boost/msm/front/state_machine_def.hpp> #include <boost/msm/front/functor_row.hpp> //#include <boost/msm/front/euml/common.hpp> // for And_ operator //#include <boost/msm/front/euml/operator.hpp> using namespace std; namespace msm = boost::msm; using namespace msm::front; namespace mpl = boost::mpl; // for And_ operator //using namespace msm::front::euml; namespace { // events struct evt_empty {}; struct evt_response{}; // front-end: define the FSM structure struct mystatemachine_ : public msm::front::state_machine_def<mystatemachine_> { // The list of FSM states struct Initialized : public msm::front::state<> { // every (optional) entry/exit methods get the event passed. template <class Event,class FSM> void on_entry(Event const&,FSM& ) { std::cout << "entering: Initialized" << std::endl; } template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: Initialized" << std::endl;} }; struct Synchronized : public msm::front::state<> { // every (optional) entry/exit methods get the event passed. template <class Event,class FSM> void on_entry(Event const&,FSM& ) { std::cout << "entering: Synchronized" << std::endl; } template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: Synchronized" << std::endl;} }; struct WaitResponse : public msm::front::state<> { // every (optional) entry/exit methods get the event passed. template <class Event,class FSM> void on_entry(Event const&,FSM& ) { std::cout << "entering: WaitBSPResponse" << std::endl; } template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: WaitBSPResponse" << std::endl;} }; // the initial state of the sas SM. Must be defined typedef Initialized initial_state; // actions struct sendPoll { template <class EVT,class FSM,class SourceState,class TargetState> void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) { cout << "send sync poll" << endl; } }; // Transition table for sas struct transition_table : mpl::vector< // Start Event Next Action Guard // +----------------------+--------------------+----------------------+---------------+--------------------+ Row < Initialized , none , Synchronized >, Row < Synchronized , none , WaitResponse , sendPoll >, Row < WaitResponse , evt_response , WaitResponse , sendPoll , none > // +----------------------+--------------------+----------------------+---------------+--------------------+ > {}; struct internal_guard { template <class EVT,class FSM,class SourceState,class TargetState> bool operator()(EVT const& evt ,FSM&fsm,SourceState& ,TargetState& ) { std::cout << "Empty::internal_transition_table guard " <<std::endl; return true; } }; struct internal_action { template <class EVT,class FSM,class SourceState,class TargetState> void operator()(EVT const& ,FSM& fsm,SourceState& ,TargetState& ) { std::cout << "Empty::internal_transition_table action\n" <<std::endl; } }; struct internal_transition_table : mpl::vector< // Start Event Next Action Guard Internal < evt_empty , internal_action ,internal_guard > // +---------+-------------+---------+---------------------+----------------------+ > {}; // Replaces the default no-transition response. template <class FSM,class Event> void no_transition(Event const& e, FSM&,int state) { std::cout << "no transition from state " << state << " on event " << typeid(e).name() << std::endl; } }; // Pick a back-end typedef msm::back::state_machine<mystatemachine_> MyStateMachine; // // Testing utilities. // static char const* const state_names[] = { "initialized", "synchronized", "waitBSPResponse" }; void pstate(MyStateMachine const& p) { std::cout << " -> " << state_names[p.current_state()[0]] << std::endl; } void test() { MyStateMachine sm; sm.start(); sm.process_event(evt_empty()); pstate(sm); } }

3 2

1.50.0 beta 1 Beta release available
by Beman Dawes 06 Jun '12

06 Jun '12

Boost release 1.50.0 beta 1 is now available from SourceForge See http://sourceforge.net/projects/boost/files/ This release contains 4 new libraries (Algorithm, Functional/OverloadedFunction, LocalFunction, Utility/IdentityType) and numerous enhancements and bug fixes for existing libraries. For details of what's in the release, see http://beta.boost.org/users/history/version_1_50_0.html. Note that the links to files on this web page are for the final release - use the SourceForge link above to get the beta files. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

2 1

(no subject)
by Avishay Ben Shabtai 05 Jun '12

05 Jun '12

> > > Hi > > > > I am having compilation error when calling copy_graph. > > The compilation error is regarding vertex_all for default copy of > vertices. > > Where can I find info regarding this property and how to resolve the > issue? > > What graph type are you using? If it is custom, you might have an easier > time passing in your own vertex and edge copying functions, which avoids > the need to have vertex_all or edge_all properties. See > <URL:http://www.boost.org/doc/libs/1_49_0/libs/graph/doc/copy_graph.html> > for information on those parameters. > > -- Jeremiah Willcock I don't understand what is custom graph but my graph definition is: typedef boost::adjacency_list<boost::listS //container class of the edges. ,boost::vecS ,boost::bidirectionalS ,MCVertexProp ,boost::property<boost::edge_weight_t,MCEdgeWeight>s ,MCGraphProp> MCBaseGraph; do i need to declare vertex_all as property and if so what is its type?

2 11

[Boost.Random] Discrete distribution behavior
by sguazt 05 Jun '12

05 Jun '12

Dear Booster, I have a problem in understanding how the boost::random::discrete_distribution works. As far as I know, given the following events: x1, x2 and x2 and weights: 1, 4, and 5, * the associated PDF of the discrete distribution would be: \Pr{X=x1}=1/10 \Pr{X=x2}=4/10 \Pr{X=x3}=5/10 * and the CDF would be: \Pr{X<=x1}=1/10 \Pr{X<=x2}=5/10 \Pr{X<=x3}=1 So, if my random generator generates the value 0.814724, the discrete random variate would return the event x3 (if I'm not wrong). Instead, it seems that boost::random::discrete_distribution does not work in this way. To test it I have implemented a small program (see attachment). Moreover, I have also implemented a naive version of discrete distribution (called my::discrete_distribution), which simply draws a uniform [0,1] random number and select the first event whose CDF is greater than or equal to the drawn value. I have also added some debug prints in other boost classes (just to get the value of the generated random numbers). I run it in Linux with Boost devel version + GCC 4.6.3 (with flags: -Wall -ansi -pedantic) Here's the output: Testing Boost... [boost::random::mersenne_twister] 3499211612 [boost::random::mersenne_twister] 581869302 [boost::random::discrete_distribution] test=0.814724 - result=0 Random Event: 1 [boost::random::mersenne_twister] 3890346734 [boost::random::mersenne_twister] 3586334585 [boost::random::discrete_distribution] test=0.905792 - result=2 Random Event: 2 [boost::random::mersenne_twister] 545404204 [boost::random::mersenne_twister] 4161255391 [boost::random::discrete_distribution] test=0.126987 - result=2 Random Event: 2 Testing My own version... [boost::random::mersenne_twister] 3499211612 [my::discrete_distribution::rand] RNG: 0.814724 Random Event: 2 [boost::random::mersenne_twister] 581869302 [my::discrete_distribution::rand] RNG: 0.135477 Random Event: 1 [boost::random::mersenne_twister] 3890346734 [my::discrete_distribution::rand] RNG: 0.905792 Random Event: 2 As you can see, the sequence of Random Event is different. Looking at the output of my::distribution, it seems it is working OK. Can you help me in understanding what is going on? Thank you very much for the help!! Best, -- Marco

3 4

accumulator operations
by Olaf Peter 04 Jun '12

04 Jun '12

Hi, I like to collects some stats. There are several data slices where I can partially/separated collect them (each of them). Finaly I like to combine these stats to a single one to get summarized informations. How to? May this work: accumulator_set<..> acc1; accumulator_set<..> acc2; ... accumulator_set<..> acc_all; ... acc1(42); ... acc_all += acc1; ... acc_all += acc2; Because did not found informations about. The same problem woulde be probably for a threaded implementation too. Thanks, Olaf

4 4

[uBlas] Linkage problems in assignment.hpp
by Jérémy Coulon 04 Jun '12

04 Jun '12

Hi, I upgraded to Boost v1.49 recently. I am affected by the following bug : https://svn.boost.org/trac/boost/ticket/6010 According to trac, the bug should be fixed in 1.48, right ? Then why is it still there in 1.49 ? Jeremy

1 1

[BGL] copy_graph compilation issue
by Avishay Ben Shabtai 04 Jun '12

04 Jun '12

Hi I am having compilation error when calling copy_graph. The compilation error is regarding vertex_all for default copy of vertices. Where can I find info regarding this property and how to resolve the issue? Sent from my iPad

2 1