Code:
# include <stdio.h>
# include <math.h>
# include <stdlib.h>
# include <malloc.h>
}
[code]...
I am compiling it on a 64 BIT ubuntu machine having 64GB ram using gcc 4.6 compiler. I am getting the following output Error allocating memory. But (914*866*2724) is approximately 8 GB, Whats wrong with the code?
I have created a database for music cds:
Code:
#include<stdio.h>
#include<stdlib.h>
#define array
typedef struct cd_database
[Code]....
When I am using malloc instead of arrays the code is not working properly after exit. I have tried alot but can't came up with a way
I wrote the following C++ constructor, and I get an error - BUFFER too small on strcpy_s
Trace::Trace(const char *str) {
if (str) {
int len = strlen(str);
this->m_name = new char[len+1]; // asking for 'len+1' memory elements of char
strcpy_s(m_name, len, str); // **** I get here an error "BUFFER TOO SMALL" ****
[Code] .....
m_name is a private data member of type char* .
What i'm interested in is the behavour of a struct/union constructed like this:
Code:
typedef struct {
uint64_t num1;
uint64_t num2;
} st_a;
typedef struct {
uint64_t num1;
uint32_t num2;
[Code] .....
What kind of behavour could I expect from object, in the following cases:
1. newsomestruct(0)->u.a.num1 = 2;
2. newsomestruct(1)->u.b.num1 = 2;
3. newsomestruct(0)->u.a.num2 = 2;
4. newsomestruct(1)->u.b.num2 = 2;
5. newsomestruct(0)->u.b.num1 = 2;
6. newsomestruct(1)->u.a.num1 = 2;
7. newsomestruct(0)->u.b.num2 = 2;
8. newsomestruct(1)->u.a.num2 = 2;
9. Code:
somestruct* ss1 = newsomestruct(0);
somestruct* ss2 = newsomestruct(1);
* ss1 = * ss2; 10. Code: somestruct* ss1 = newsomestruct(0);
somestruct* ss2 = newsomestruct(1);
* ss2 = * ss1;
This is what I'd expect, but I can't find any evidence online in C standards or elsewhere:
1. Works as expected, sets the value of a.num1 to 2.
2. Works as expected, sets the value of b.num1 to 2.
3. Works as expected, sets the value of a.num2 to 2.
4. Works as expected, sets the value of b.num2 to 2.
5. Works as expected, sets the value of b.num1 to 2.
6. Works as expected, sets the value of a.num1 to 2.
7. Works as expected, sets the value of b.num1 to 2.
8. Crashes/Memory Corruption, attempted to alter memory outside struct.
9. Works as expected, * ss1 == * ss2
10. Crashes/Memory Corruption, attempted to alter memory outside struct.
I've tested simular code on my machine (Xubuntu 14.04LTS compiled with gcc on -O3) and it appears to be reliable, given that you stick with acessing the type tagged in the struct or the common initial union struct members (in this case num1).
Do you have to allocate memory(malloc) for an array of structs? Example:
Code:
typedef struct{
char * name;
}First;
struct name{
First fname;
};
struct name Names[10];
I'm making some multi-threaded program, but thats not my problem as i've done that already. I have a class with user-functions containing a structure which then contains a two dimensional array for each user with 25 elements. So I dont want to limit the user and make the array for example with just 10 rows, but allocate the needed memory to match the amount of 'users' a potential user of my program would want. The problem is, that i know how i should allocate it using 'new int' but it just doesnt work ! It gives an error:
Error: no operator "=" matches these operands
UserStuff.h:
struct userDataStruct {
bool* isAdmin;
[Code]...
Then, in some completely other class function inside the file mentioned above: (I know i could do a function in CUsers class which could allocate the memory, but I have this function which is used for some other things and it already has the amount of max users
void OtherClass::somefunction(maxusers)
{
// This gives an error: Error: no operator "=" matches these operands
curUsers->uData.userNumbers = new int*[maxusers]; //maxusers is the int variable of max users specified by the client
// However this doesn't
for( int i = 0 ; i < maxusers ; i++ )
curUsers->uData.userNumbers[i] = new int[25]; // 25 columns, this doesnt give any error
}
I'm not really sure what I'm doing wrong. Doing this in some function from CUsers class works (without curUsers-> or with, doesn't give any error) but doing it from some other class's function doesnt.
I want to be able to dynamically allocate and index an array like the following: vv2d[1][2].x and vv2d[1][2].y. In order to accomplish that I have chosen to use a std::vector of a std::vector of a 2D point class.
Code:
/// Here is my templated version of a 2d point class which I have adopted from
/// one by Alexander Chernosvitov, Function Graphics, 2001 (see ogview.h)
/// http://www.codeguru.com/cpp/g-m/opengl/article.php/c5581/Function-graphics-in-3D.htm
template <typename T>
[Code]....
Boundary violation occurs as soon as vv2d[1][0].x is encountered. I believe the problem is my inability to dynamically allocate the size of the (primary) typedef vector. However, eliminating the typedef for the following does not change the result. Further examination shows the vv2d[1][0] size and capacity to be 0.
Code:
vector<vector<CPoint2D<double>>> vv2d;
vv2d.resize(3);
vv2d[0].resize(3);
I have to allocate memory for an array of structures, and my structure looks as following:
Code:
typedef struct {
char *name;
Uint *start_pos;
Uint len;
}
example_struct;
And now I want to allocate memory, for a variable number (so an array) of example_struct, so I first do:
Code:
example struct *all_struct;
int total_num = 3;
//will be set somehow, but for the example I set it on 3 all_struct = malloc (sizeof(example_struct) * total_num);
And now, as far as I now, I will have to allocate for each field of the structure memory, in order to be able to use it later. But I have problem at this point, a problem of understanding:
- I just allocated memory for 3 structures, but don't I have to allocate then memory for each structure separately, or can I just now allocate the fields like this:
Code: all_struct[0].name = malloc.....
But if yes, why the hell this works...
I have an integer pointer and i want its address without allocating memory,
main() {
int *a;
cout<<a;
}
This is giving 00000000 and its but obvious. Now if i use address of a (&a) along with *a,
main() {
int *a;
cout<<a;
cout<<&a;
}
'cout<<a' gives me a constant address but 'cout<<&a' gives me different address.
what is the reason behind & and why behaviour of 'cout<<a' changes when using with &.
I am writing a very basic database in C++ and I am accessing the data from a web browser. I am using the opensource Mongoose web server code....
I have an issue...
The way the DB works is this: on starting, the DB loads a json file of all of the data into it. I have a class called DatabaseLoader that does this - it is the class that gets rewritten depending on the data structure of the json.
This is passed to vectors (vector<Node*> and vector<Edge*>) as references from Graph object.
Once the DatabaseLoader has finished it can be destroyed and any memory allocated objects it created (except the ones in those two vectors).
From then on, the Graph object is in charge of all of the elements in the database that are stored in the two vectors. When the user browses to htpp://127.0.0.1:8000 they see the json representing each object in the vectors.
All good so far....
However, when I repeatedly hit refresh in my browser (and call me insane...) at quite a fast speed I get this error:
Code:
main(29855,0x7fff76763310) malloc: *** error for object 0x7f98b2829408: incorrect checksum for freed object - object was probably modified after being freed.
*** set a breakpoint in malloc_error_break to debug
[1] 29855 abort ./main testing.json
It seems to me this would be if I tried to "delete" and object twice, or if one of my objects was overwriting memory somewhere. However I am not recreating anything, I am just looping over the vectors and printing out the content. When I refresh slowly, I dont see this happen - i did it quite a lot of times, but when I do it fast I think it is happening.
So is there any possibility of me hitting the c++ web server to quickly and it is trying to process the data twice, causing some sort of memory error - i.e do I need to implement threading or something??
I can paste code, but there is quite a lot now....
My Application is C# winform
I am facing below error at the time of form close and end of Dispose() method .
The instruction at "0xXXXXXXXX" referenced memory at "0xXXXXXXXX", The memory could not be "written". Click on OK to terminate that program.
how to avoid / catch this error .
It is been several days that I am stucked with the segmentation error and I do not know anymore what to do I try to do a loop over my function but it is working only for my first iteration. Here the code:
#include <iostream>
#include <cstdio>
#include <cstdlib>
[Code].....
I would like to iterate over solvep (since h is changing at each iteration..I usually add other fct but now I try to debug why the loop is not working.).The first iteration is working fine but not the other iterations.
I am getting "driver could not be loaded due to system error 8" error while connecting to SQL Server 2005 from VC++. Its also throwing out of memory error. Basically i am developing and ISAPI dll. I use the following code to connect to DB.
CDatabase DBConnection;
if(! DBConnection.IsOpen()) {
DBConnection.OpenEx("Driver={SQL Server};Server=10.120.110.30;Database=Test;Trusted_Connection=yes;", CDatabase:penReadOnly | CDatabase::noOdbcDialog);
[Code] .....
for CDatabaseConnection, i can see 2 different method to open the connection, OpenEx and Open. Whats the difference between OpenEx and Open?
Trying to append a comma to a string. Getting "Segmentation Error" on Solaris when the function is entered the second time.
Code:
// Appends a comma to the given string
void appendComma(char* instring) {
if (instring == NULL) {
instring = realloc(NULL, strlen(","));
strcpy(instring,",");
[Code] .....
I am allocating space only for two characters but it fits all of them, if you run this it will print the whole string literal "hello my friend". How is that possible?
I am using gcc 4.6.3., I know about strncpy().
#include<iostream>
#include<cstring>
using namespace std;
int main(){
char* str = new char[2];
strcpy(str, "hello my friend");
cout << str << endl;
return 0;
}
decalration won't allocate storage, while definition will. This is a test program:
#include <iostream>
using namespace std;
extern int ei;
int i;
[Code].....
Others are all fine in this program except ei.
compiler error: undefined reference to ei.
I understand ei is only declared so there is no memory address, but when I do ei=1, then ei completed it's definition, why still cannot use pei to get it's address?
Working on this one from the Jumping into c++ book. The book asks that I create a multidimensional array at run time based on user input and fill it with a multiplication table
My code compiles fine but throws an uninitiated error for p when I try and run it.
Code:
void multiDimentionalMultiplication(int x, int y, int z){
int ***p;
**p = new int[x];
std::cout << "Allocating array.
[code]....
I am trying to figure out the syntax to dynamically allocate a single dimension of a triple dimensional array. Basically i have a 2D array of structs. but each struct is an array (basically rows of the information). The rows of this structure need to be allocated dynamically, but the height and width of the overarching structure are static.
Basically: Struct * ts_FieldInfo[100][100] = new Struct[Class.returndataitems()];
#include <iostream>
using namespace std;
int main() {
int elm = 0;
int size = 0;
int *array;
[Code] ....
so I have this code that dynamically allocates a pointer array increasing and removing elements of the array as its operated on.then it sorts and prints out the array when the user is finished operation on the array. i get this error message when running the program though.
"Unhandled exception at 0x0F474F98 (msvcr110d.dll) in Lab10_VarArray.exe: 0xC0000005: Access violation reading location 0xCCCCCCC0."
this is my code
#include <iostream>
#include <cstdlib>
#include "Header.h"
using std::cout; using std::endl; using std::cin;
int main(void) {
char op='x';
[Code]...
This is a homework assignment where I have to read a file into a dynamically allocated 2d array. The file format is
10
Jim 3.6
Jake 4.0
Will 3.0
Sara 3.4
Mike 2.5
Ellen 2.9
Melissa 3.9
Eric 3.8
John 3.5
Beth 3.9
where 10 is the number of students followed by the students and the gpa's. There is more to the program but I have not implemented it yet because I am getting a segmentation fault. The output I am getting when I print the array is
Jim 3.6
Jake 4.0
Will 3.0
Sara 3.4
Segmentation fault
I can see where the problem lies. If I raise value for row when I am allocating the rows of the array, all of the names print. I just do not see why I need to. From my understanding the row * sizeof(char*) should give me enough room for 10 entrie.
Code:
#include <stdio.h>
#include <stdlib.h>
void sort();
int main()
[Code] .....
I'm trying to dynamically allocate a standard array at runtime in the function of a class where the array is "owned" by the calling class. The calling class knows nothing about the array before it makes the call to create the array other than the datatype of the array. But the full array of data needs to be returned.
It appears that the pointer being passed makes a copy of the pointer on the stack and then when the function returns it pops it off the stack and the array is a memory leak because the pointer is once again a nullptr as it was before being passed and the array has not been deallocated with delete yet (as it should not have been).
(Edit:Unexpected value of MyArray being a nullptr instead of pointing to an array after returning from line 09.)
class Class1 {
void FunctionA() {
Class2 OwnedClass;
int* MyArray = nullptr;
int SizeOfMyArray = 0;
[Code] ....
I have an abstract based class and three derived classes. I also have a templated hash table class(using chaining as my collision resolution method, an array of stl lists), and a class to parse commands from a file, this also holds the instantiation of the hash table. My question is that since my command parsing class's constructor instantiates the hash table in the main driver(unable to modify) how can I make this dynamically allocated using data from the file?
template<class T>
class hashTable{
public:
hashTable(int size);
~hashTable();
[Code] .....
I'm trying extremely hard to understand pointers and I have the basic concept down.. I feel as though my knowledge of dynamically allocated pointers and pointers in general is not enough to understand the logic behind what I'm trying to do. The problem is that the donations array must be able to accept any number of donations. I've made it do just that, but there is also an array of pointers which must each point to the same element in the donations array. The program works if I assign int *arrPtr[100] for example, but it does not work if I try to dynamically allocate it to accept the same number of elements for donations entered by the user. Here it's the snippet
#include <iostream>
using namespace std;
//Function Prototypes
[Code]....
Cannot manage to find the error source when i try running the program, the first part of the program runs just fine its when i try to get the temperature one that i get the error
#include <iostream>
#define pi 3.141592
using namespace std;
int main() {
double r, h; //declare variables for radious and height
double Surfacearea;
[code]....
I've just recently started to learn C++, and I'm encountering some errors I can't seem to figure out.
InventoryItem.h:
Code:
#pragma once
class InventoryItem {
public:
InventoryItem(string name, int amount);
~InventoryItem(void);
string getName(void);
int getAmount(void);
[code].....
Errors:
Code:
1>d:c++consoleapplicationconsoleapplicationinventoryitem.h(6): error C2061: syntax error : identifier 'string'
1>d:c++consoleapplicationconsoleapplicationinventoryitem.h(8): error C2146: syntax error : missing ';' before identifier 'getName'
[Code] .....
