Re: [Boost-users] Mersenne twister problem

Subject: Re: [Boost-users] Mersenne twister problem
From: Matthias Troyer (troyer_at_[hidden])
Date: 2009-09-15 14:58:24

On Sep 15, 2009, at 10:50 AM, ruya wrote:

>
> SearchFunctor has a virtual destructor, the derivees have empty  
> destructor.
> MemHandler is just a helper does not store anything.

Here is my guess as to what happens: SPtr points to a SearchFunctor  
that has been deallocated. The generators were never deleted and can  
still be used, but the underlying engine got destroyed. Your code  
contains memory leaks, and could be simplified a lot.

Matthias

>
> class SearchFunctor{
>  protected:
>    typedef SmartPtr<SType> SPtr;
>    typedef typename SType::Domain Domain;
>    typedef typename SType::DPtr DPtr;
>    typedef typename Domain::MType MType;
>    typedef typename Domain::MPtr MPtr;
>    typedef typename Domain::EPtr EPtr;
>    typedef typename Domain::RPtr RPtr;
>    typedef vector<typename SType::MPtr> MVector;
>    typedef typename SType::DataType DataType;
>    typedef boost::mt19937 base_generator_type;
>    typedef boost::variate_generator<base_generator_type&,
> boost::uniform_real<> > GeneratorI;
>    typedef Private<MemP::ObjectType::_ACTIVE,MemP> MemHandler;
>  public:
>
>    virtual SPtr operator()( SPtr s, int iter ) = 0;
>
>    SearchFunctor(){
>      memh = MemHandler();
>      generator1 = base_generator_type(MASTER_SEED+13);
>      uni_dist1 = boost::uniform_real<>(0,1);
>      uniEmp = new GeneratorI(generator1, uni_dist1);
>      generator2 = base_generator_type(MASTER_SEED+17);
>      uni_dist2 = boost::uniform_real<>(0,1);
>      uniRes = new GeneratorI(generator2, uni_dist2);
>    }
>  protected:
>    virtual ~SearchFunctor(){}
>
>    base_generator_type generator1, generator2;
>    boost::uniform_real<> uni_dist1, uni_dist2;
>    GeneratorI* uniEmp;
>    GeneratorI* uniRes;
>    MemHandler memh;
>  };
>
>
>
> Matthias Troyer-2 wrote:
>>
>>
>> On Sep 14, 2009, at 9:40 AM, ruya wrote:
>>
>>>
>>> Hi
>>>
>>>
>>> Matthias Troyer-2 wrote:
>>>>
>>>> I would write this very differently, and can give you a better
>>>> version
>>>> that should have no problems, but could you please send me the
>>>> definition of GeneratorI first?
>>>>
>>> Sorry about that, the missing typedefs at SearchFunctor:
>>>
>>>   typedef boost::mt19937 base_generator_type;
>>>   typedef boost::variate_generator<base_generator_type&,
>>> boost::uniform_real<> > GeneratorI;
>>
>>
>> Another question: what does the destructor of your class look like?
>> Can you send the full class?
>>
>> Matthias
>>
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>>
>>
>
> -- 
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>
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