File input - receive bad alloc message

[Dr Lazarus]

I have written a small program designed to read file input and put this information into a multidimensional array. As it stands, the program reads just one file for now, the name of which I specify when calling readfile.open. However, I have now altered the program so that the readfile function accepts a c-style string (I need to do this so that in the future I can alter the name of the file by looping over variables). The program now crashes with the following message:

terminate called after throwing an instance of 'std::bad_alloc'
what(): std::bad_alloc

The program compiles fine; I am using g++ on red hat. Here is the program source code:

#include <cstdio>
#include <cstdlib>
#include <complex>
#include <math.h>
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
using namespace std;

complex<double> convert_complex(complex<double>);

ifstream:os_type size;
complex<double> *zbuff;

int main(int argc, char *argv[])
{
int srcdir, srccol, slice, sinkpar;
int i, j, k, kount;
int Nc = 3;
int spaceh = (24*24*24)/2;
srcdir = 0;

complex<double> Psi[4][Nc][spaceh][4]; // Complex array to store info in file //

string filename;
stringstream(filename) << "bqcd.567.00000.00.1.1.10.0.prop"; // Filename, potentially modifiable //

ifstream readfile;
readfile.open(filename.c_str(), ios::in | ios::binary | ios::ate);
size = readfile.tellg(); // Determine size of input file using the get pointer //
readfile.seekg(0, ios::beg); // Put pointer back to beginning of file //
zbuff = new complex<double>[size]; // < -- Execution stops here. zbuff is simple a one dimensional complex array //
readfile.read(reinterpret_cast <char *> (zbuff), size);


for(k = 0; k < spaceh; k++)
{
for(j = 0; j < Nc; j++)
{
for(i = 0; i < 4; i++)
{
Psi[i][j][k][srcdir] = convert_complex(zbuff[kount]); // Take info in 1-d array zbuff, change endianness of entry, place in correct element of 4-d array Psi //
kount++;
}
}
}

readfile.close();

cout << Psi[1][1][1][srcdir] << endl; // Test output from Psi //
cout << Psi[2][1][2][srcdir] << endl;
cout << Psi[0][0][0][srcdir] << endl;
cout << Psi[0][0][790][srcdir] << endl;

return 0;
}

complex<double> convert_complex(complex<double> in)
{
complex<double> out;
char *p_in = (char *) &in;
char *p_out = (char *) &out;
p_out[0] = p_in[15];
p_out[1] = p_in[14]; // Function to reverse byte order of a single entry of complex array zbuff //
p_out[2] = p_in[13];
p_out[3] = p_in[12];
p_out[4] = p_in[11];
p_out[5] = p_in[10];
p_out[6] = p_in[9];
p_out[7] = p_in[8];
p_out[8] = p_in[7];
p_out[9] = p_in[6];
p_out[10] = p_in[5];
p_out[11] = p_in[4];
p_out[12] = p_in[3];
p_out[13] = p_in[2];
p_out[14] = p_in[1];
p_out[15] = p_in[0];
return out;
}

As I said, the program works perfectly when the filename is given explicitly. Only when I pass the filename as a string does the program crash. Curiously, the crash does not occur at the filename line, but later on, when "new" is called. The bas alloc suggests I have run out of space for something. I don't see how that is possible, since nothing is particularly large here. zbuff is the largest creation here, but there were no complaints before I made this minor change, and I also intent to make zbuff considerably larger in the future!

Any help would be much appreciated.

Warren

[z05DSL3A]

A few things from just reading the code

ifstream:os_type size; ?
I'm not sure what this should be, but it doesn't look correct, possibly should be ifstream::off_type size; ifstream::pos_type size;

int Nc = 3;
int spaceh = (24*24*24)/2;
srcdir = 0;

complex<double> Psi[4][Nc][spaceh][4]; // Complex array to store info in file // 

Nc and spaceh should be const

It is possibly a rather large array to have on the stack.

I don't see where you initialise Kount

PS can you edit your post and put [code]before your code and [/code] after.

[Dr Lazarus]

size was declared as ifstream::pos_type size; must have been chopped up when I copied and pasted. I'll certainly alter the array dimensions to make them consts, thanks for pointing that out, and I'm just as puzzled about Kount too.

The array may be rather large, and I was worried about this too, but the program actually worked before I altered the method of passing readfile.open the filename. It seems odd that this would cause the program to crash, since the size of the c-style string provided should be exactly the same as when I provided the filename explicitly (in the previous, very similar version of my program).

[wmheric]

Oh by the way, why not replace lines 64-79 with a loop

[z05DSL3A]

Try inserting a line like std::cerr << "File size: " << size << std::endl;, in between lines 32 and 33 just as a sanity check, make sure the file size is not stupid;

I don't think

string filename;
stringstream(filename) << "bqcd.567.00000.00.1.1.10.0.prop"; // Filename, potentially modifiable //

ifstream readfile;
readfile.open(filename.c_str(), ios::in | ios::binary | ios::ate);

is doing what you intend, try:

string filename =  "bqcd.567.00000.00.1.1.10.0.prop"; // Filename, potentially modifiable //

ifstream readfile;
readfile.open(filename.c_str(), ios::in | ios::binary | ios::ate);