Re: [Boost-users] [BGL] Free graph - double free or corruption

Subject: Re: [Boost-users] [BGL] Free graph - double free or corruption
From: Matthieu BOUSSARD (mboussar_at_[hidden])
Date: 2010-01-03 21:42:19

The planner computes a behaviour, which I'm using to select the next 
action. Then I delete the solver (delete(solver)) and create a new one 
(new solver). I used valgrind to check memory leaks, and it seems that 
the states are not freed.
I've set the environmment variable MALLOC_CHECK_  to 0 ignoring the 
double free error and use the following destructor
~Sampling_solver(){
        for(state_vertex_map_t::iterator 
it=name_vertex_map.begin();it!=name_vertex_map.end();it++){
           free(it->first);
       }
}
Then the memory leak desapears and the application (seems to) works 
fine. So I should really free the state in the destructor, but how?
And yes, for once performance is critical, but if I don't have too much 
work to do for using the shared_ptr, I'll try.

Matthieu

Jeremiah Willcock a écrit :
> On Mon, 4 Jan 2010, Matthieu BOUSSARD wrote:
>
>> Yes, the planner object contains the graph. Since the graph is 
>> declare inside the object I don't have to destroy it explicitely. 
>> right ?
>>
>> The following code is one thing I've tried, the first one I tried was 
>> to iterate on the  and freeing the states, but didn't work... So 
>> here, first romove from the graph and the free the state. If no other 
>> solution I'll try to switch to boost::shared_ptr<state_t> but I'd 
>> like to understand what's going on.
>> thamk you for your quick answer !
>>
>> class Sampling_solver{
>> public:
>>   int   nbsample;
>>   Graph g;
>>   vertex_name_map_t  v_name_map  ;
>>   vertex_prop_map_t  v_prop_map  ;
>>   edge_weight_map_t  e_weight_map;
>>   edge_name_map_t    e_name_map  ;
>>   state_vertex_map_t name_vertex_map;
>>
>>   Sampling_solver(Model *m);
>>   ~Sampling_solver(){
>>       graph_traits<Graph>::vertex_iterator vi, vi_end, next;
>>       tie(vi, vi_end) = vertices(g);
>>       for (next = vi; vi != vi_end; vi = next) {
>>           ++next;
>>           remove_vertex(*vi, g);
>>           free(v_name_map[*vi]);
>>       }
>>       g.clear();
>>   };
>
> Are you sure the solver object outlives the graph (and all copies of 
> properties obtained from the graph)?  Do you destroy the solver then 
> use the results of the algorithm (that are state objects destroyed by 
> the solver's destructor)?  In any case, shared_ptr is a much simpler 
> way to deal with the problem if performance is not critical.
>
> -- Jeremiah Willcock
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>

-- 
Matthieu BOUSSARD
Toyohashi University of Technology
Department of Information and Computer Sciences
Active Intelligent Systems Laboratory (Miura Laboratory)
Toyohashi - Japan