*** glibc detected *** corrupted double-linked list: 0xb7e15938 ***

[swong1]

Hi all. I have a C++ program that I wrote. The code compiles without any error or warning message. But when I execute it, I get the

*** glibc detected *** corrupted double-linked list: 0xb7e15938 ***
Aborted

message. This only happens when I chose certain input parameters. It works flawlessly under other conditions. Can someone please help me make sense of this error message? I want to know which part of my program is causing trouble.

[rock freak]

some source code may help out in finding out whats wrong!

look forward to helping you

[swong1]

Hi rock freak, thanks for your reply. I'll try to make it as plain as possible, I don't want to complicate things unnecessarily.

Okay, here's my main program:

#include <iostream>
#include "algo1.h"
#include "algo1p5.h"
#include "algo2a.h"
#include "algo2b.h"
#include "algo3.h"
using namespace std;

int main(int argc, char* argv[]) {

system("date");

if(argc != 4) {
cout << "Please enter the version of algorithm to use: 1, 1p5, 2a, 2b, 3\n"
<< "followed by the radius of droplet: 3, 4, 5, 6, 7, 8, 12, 16\n"
<< "followed by the temperature: e.g. 3.5\n";
exit(EXIT_FAILURE);
}

string algo = argv[1];
int radius = atoi(argv[2]);
double temperature = atof(argv[3]);

if(algo == "1") {
cout << "Algorithm 1: original Metropolis algorithm.\n";
algo1 simulation;
simulation.minimize(argv[1], radius, temperature);
}
else if(algo == "2a") {
cout << "Algorithm 2a: randomly select a neighbour's spin\n"
<< "with weighted probability.\n"
<< "4-cases modified Metropolis acceptance ratios.\n";
algo2a simulation;
simulation.minimize(argv[1], radius, temperature);
}
else if(algo == "1p5") {
cout << "Algorithm 1.5: randomly select a neighbour's spin\n"
<< "with equal probability.\n";
algo1p5 simulation;
simulation.minimize(argv[1], radius, temperature);
}
else if(algo == "2b") {
cout << "Algorithm 2b: same as 2a but without the modifying\n"
<< "factor in the acceptance probability.\n";
algo2b simulation;
simulation.minimize(argv[1], radius, temperature);
}
else if(algo == "3") {
cout << "Algorithm 3: randomly select a pixel and its neighbour\n"
<< "with Metropolis acceptance probability.\n";
algo3 simulation;
simulation.minimize(argv[1], radius, temperature);
}
else {
cout << "Please enter a valid version of algorithm: 1, 1p5 or 2a\n"
<< "and the droplet's radius: 3, 4, 5, 6, 7, 8, 12, 16\n";
exit(EXIT_FAILURE);
}
(error message seems to occur at this point)
system("date");

}

It's pretty standard fare. According to the run time input ('1', '1p5', '2a', '2b', '3'), the program will run slightly different version of the code. The funny thing is, I don't get the error message if I choose '1', but I get the error message if I choose all the other versions. I get the same error message even if I switch the sequence of the "if" statements.

"algo1" is the parent class while all others are derived from "algo1".

An example code for say, "algo1p5" looks like:

#ifndef ALGO1P5_H
#define ALGO1P5_H
#include "algo1.h"


// algo1p5 class is derived from algo1 class
class algo1p5 : public algo1 {

protected:
virtual void create_directories();
virtual void flip_spin_algorithm(const double, const float);

public:
algo1p5(int x = Ddim) : algo1(x) { }
algo1p5(int x, int y) : algo1(x, y) { }
~algo1p5() { for(int i=0; i<=NDROP; i++) delete droplet[i]; }

};

void algo1p5::create_directories() {

string cd_data = "cd data/algo1p5";
string cd_movies = "cd movies/algo1p5";
string mkdir_data = "mkdir data/algo1p5";
string mkdir_movies = "mkdir movies/algo1p5";

if(system(cd_data.c_str())) {
cout << "Creating data directory.\n";
system(mkdir_data.c_str());
}
if(system(cd_movies.c_str())) {
cout << "Creating movies directory.\n";
system(mkdir_movies.c_str());
}
}

void algo1p5::flip_spin_algorithm(const double kT, const float xy) {

int spin1, t_spin, spin;
int spin_count[NDROP + 1];
int coord1, coord2, nn, dET;
double maxdET = 50*Jij;
double dEJ, dEA;
double prob[int(maxdET)];

// This can only be done if Jij and Ja are integers
for(dET=0; dET<maxdET; dET++)
prob[dET] = exp(-dET*Jij/kT);

for(int attempt=0; attempt<xy; attempt++) {

dEJ = dEA = 0.0;
for(spin=0; spin<=NDROP; spin++)
spin_count[spin] = 0;

coord1 = MOD(ran3l(&ran_seed1), XY);
spin1 = lattice[coord1]->get_spin();

// Count the number of neighbours with 0 and non-0 spins
for(nn=1; nn<=NN4; nn++){
coord2 = MOD(coord1 + disp[nn], XY);
spin_count[lattice[coord2]->get_spin()]++;
}

// All neighbours have the same spin as the candidate spin
if(spin_count[spin1] == NN4)
continue;

else if(ran3f(&ran_seed3) > 0.5) { // equal probability
t_spin = abs(spin1 - 1);
dEJ = (2*spin_count[spin1] - NN4)*Jij;
dEA = (Ja[spin1]*(-2*(droplet[spin1]->get_area() -
droplet[spin1]->get_target_area()) + 1) +
Ja[t_spin]*(2*(droplet[t_spin]->get_area() -
droplet[t_spin]->get_target_area()) + 1));

// This is true only if Jij and Ja are integers
dET = int(dEJ + dEA);
if(dET <= 0 || ran3f(&ran_seed3) < prob[dET])
flip_spin_routine(coord1, spin1, t_spin);
}
}
}

#endif

I don't want to include unnecessary code for fear of complicating things. Hope this helps.

[swong1]

Used valgrind to check for memory allocation. It appears that I have attempted to free memory that has already been freed. I commented out the delete command in the destructor and everything is fine again. This is a novice mistake, the destructor of BOTH derived and parent class are called, so the delete command was executed twice. That is why the error only occurs when I run the derived class and not the parent class.
Thanks!