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Memory Access Error Vector

vivienneanthony (73)
Hello,

I'm gettin a memory error. I'm not sure what's wrong.

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Program received signal SIGSEGV, Segmentation fault.
0x0000000000401e8d in std::__copy_move<true, true, std::random_access_iterator_tag>::__copy_m<AdaptiveFieldCell*> (
    __first=<error reading variable: Cannot access memory at address 0x7fffff7feff8>, 
    __last=<error reading variable: Cannot access memory at address 0x7fffff7feff0>, 
    __result=<error reading variable: Cannot access memory at address 0x7fffff7fefe8>) at /usr/include/c++/5/bits/stl_algobase.h:373
373             __copy_m(const _Tp* __first, const _Tp* __last, _Tp* __result)


Vivienne





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#ifndef ADAPTIVEFIELD_H
#define ADAPTIVEFIELD_H

using namespace std;

class AdaptiveFieldCell;


class AdaptiveField
{
    friend class AdaptiveFieldCell;

public:
    AdaptiveField();
    virtual ~AdaptiveField();

    bool Generate(double radius, float resolution, bool generateGeometry);          // Create

    unsigned int GetMaxLod(){return m_MaxLOD;};
    double GetFieldSize(){return m_FieldSize;};

protected:
private:

    float m_FixedClamp;                             // fixed clamp - Perlin clamp level

    unsigned int m_MaxLOD;                          // Maximum LOD

    double m_FieldSize;                             // field size - can be number of polys (resolution)

    vector<AdaptiveFieldCell *> m_PatchRegion;    // Adaptive field;

    unsigned int m_Iteration;                      // Used this passed for interation

};

#endif // ADAPTIVEFIELD_H


// field  size is the physical size
// m_field size is the sizw



#include <memory>
#include <vector>
#include <cmath>

#include "../include/AdaptiveField.h"
#include "../include/AdaptiveFieldCell.h"

AdaptiveField::AdaptiveField()
{
 m_PatchRegion.resize(8);

}

AdaptiveField::~AdaptiveField()
{

}

// Generate each area field
bool AdaptiveField::Generate(double radius, float resolution, bool generateGeometry)
{
    // generate maxLOD;
    m_MaxLOD = (unsigned int)log2((float)(2.0f * 3.14 * radius) / 4/.0f);

    // override
    m_MaxLOD = 2;

    // radius is twice -- use for simplex
    m_FieldSize = radius*2;

    // default interation
    m_Iteration=1;

    // resize

    // Generate - translation would be x,y,z but flat
    for(unsigned int x=0; x<2; x++)
    {
        for(unsigned int y=0; y<2; y++)
        {
            for(unsigned int z=0; z<2; z++)
            {
                // Generate Cell
                AdaptiveFieldCell * newPatch = new AdaptiveFieldCell();

                newPatch->SetField(this);

                // Set locatoin
                newPatch->SetLocation(x,y,z);

                // add a new patch recursively till the final
                m_PatchRegion.push_back(newPatch);

                // Generate patch
                newPatch->Generate(m_Iteration+1);
            }
        }
    }

    return false;
}





#ifndef ADAPTIVEFIELDCELL_H
#define ADAPTIVEFIELDCELL_H

using namespace std;

class AdaptiveField;

struct bVector3
{
    bool x_;
    bool y_;
    bool z_;
};

struct uVector3
{
    unsigned int x;
    unsigned int y;
    unsigned int z;
};


// maybe can be similiar to terrainpatch
class AdaptiveFieldCell
{


public:
    AdaptiveFieldCell();
    virtual ~AdaptiveFieldCell();

    // Generate new cell
    virtual bool Generate(unsigned int interation);

    // Save root location
    void SetLocation(unsigned int x, unsigned int y, unsigned int z)
    {
        m_Location.x = x;
        m_Location.y = y;
        m_Location.z = z;
    };

    void SetField(AdaptiveField * passedField)
    {
        m_ParentField = passedField;
    };


protected:
private:
    vector <AdaptiveFieldCell *> m_PatchRegion;              // not set based on interation can be 8 or 1;

    bool m_IsLeaf;                                             // Final
    bool m_IsSolid;                                            // Solid

    AdaptiveField  * m_ParentField;                             // Parent Field;

    unsigned int m_Iteration;                                   // iteration

    uVector3 m_Location;                                        // Location

};

#endif // ADAPTIVEFIELDCELL_H



#include <memory>
#include <vector>
#include <iostream>

#include "../include/AdaptiveField.h"
#include "../include/AdaptiveFieldCell.h"

AdaptiveFieldCell::AdaptiveFieldCell()
{
    // Create region here
    // m_PatchRegion = new vector<AdaptiveFieldCell *>;

     m_PatchRegion.resize(8);

}

AdaptiveFieldCell::~AdaptiveFieldCell()
{

}


bool AdaptiveFieldCell::Generate(unsigned int interation=1)
{

    // if interaction
    if(interation>m_ParentField->GetMaxLod())
    {
        m_IsLeaf=true;

        m_Iteration = m_ParentField->GetMaxLod();
    }
    else
    {
        m_IsLeaf=false;

        m_Iteration = interation;
    }

    // if generate patch
    if(m_IsLeaf==false)
    {

        m_PatchRegion.resize(8);for(unsigned int x=0; x<2; x++)
        {
            for(unsigned int y=0; y<2; y++)
            {
                for(unsigned int z=0; z<2; z++)
                {
                    // Generate Cell
                    AdaptiveFieldCell * newPatch = (AdaptiveFieldCell *) new AdaptiveFieldCell;

                    // Set Location
                    newPatch->SetLocation(x,y,z);

                    // set field
                    newPatch->SetField(m_ParentField);

                    // add a new patch recursively till the final
                    m_PatchRegion.push_back(newPatch);


                    // Generate patch
                    newPatch->Generate(m_Iteration++);
                }
            }
        }
    }

    // if generate patch
    if(m_IsLeaf==true)
    {
        // Bit manipulation
        float sizecell=m_ParentField->GetFieldSize()/(1<<m_Iteration);

        cout << sizecell << endl;

    }

    return false;
}
Last edited on
jonnin (11333)
chop down main(). First construct an object, does that crash? Then do the first thing to it... until you can isolate what command / member function / etc is crashing.

Then look at the memory access in the offending function or tell us and someone can find the memory bug. Its too much code to comb through looking for a bad pointer.
Thomas1965 (4571)
Can you show us your main function?
I tried the following and got a stack overflow in AdaptiveFieldCell::Generate. looks like an endless recursion.
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int main()
{
  AdaptiveField field;
  field.Generate(1.5, 1.0, true);
  return 0;
}



OUTPUT
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
adaptivefieldcell.cpp(25) : Entering bool __thiscall AdaptiveFieldCell::Generate
(unsigned int) - interation = 2
elbanono (2)
Looks like the line 
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                    // Generate patch
                    newPatch->Generate(m_Iteration++);
Does not what you expect: it calls newPatch->Generate() with the initial value of m_Iteration, and not the incremented value. Maybe writing newPatch->Generate(++m_Iteration); would work better
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