Memory leaks

This is a discussion on Memory leaks within the C++ Programming forums, part of the General Programming Boards category; What are some of the common problems that cause memory leaks? would the char* in this cause one? unsigned int ...

  1. #1
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    Memory leaks

    What are some of the common problems that cause memory leaks?

    would the char* in this cause one?

    unsigned int loadtex(char*name) {
    unsigned int img,texture;
    ilGenImages(1, &img); ilBindImage(img); ilLoad(IL_JPG,name); texture = ilutGLBindMipmaps();
    ilDeleteImages(1, &img);
    return texture;
    }

  2. #2
    Skunkmeister Stoned_Coder's Avatar
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    difficult to say without knowing how the memory that the char* points to was allocated.

    Memory leaks occur when you use malloc() and forget to call free(), or similarly when you call new and forget to call delete.

    for instance....

    char* name="whatever.foo";
    // your code here
    // no memory leaks

    name was statically allocated and memory taken care of by your compiler.

    char* name=new char[ 13 ];
    strcpy (name,"whatever.foo");
    // call your func
    // if you then do this.....
    delete [] name;
    // there is no memory leak

    hth
    Free the weed!! Class B to class C is not good enough!!
    And the FAQ is here :- http://faq.cprogramming.com/cgi-bin/smartfaq.cgi

  3. #3
    Guest Sebastiani's Avatar
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    Consider this:

    Code:
    char *DoSomething(const char *in)
    {
    char *out = malloc(strlen(in));
    return out;
    }
    
    int main()
    {
    char *in = malloc(100);  // ...hmm...one allocation...
    char withThisString[] = "A day in the life of a programmer";
    int x = 100;
    
    while(x-- > 0)
    {
    in = DoSomething(withThisString);
    //...now, 'out' gets malloc'd every loop!...
    <<  Memory Leak, 10 K of memory... <<
    }
    
    free(in);  //<--Which is free'd here? 
    
    return 0;
    <<  Memory Leak ??  <<
    }

  4. #4
    It's full of stars adrianxw's Avatar
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    Another "popular", (i.e. common), cause of, (diificult to find), memory leaks is using non thread safe stdlib calls in a multithreaded environment.
    Wave upon wave of demented avengers march cheerfully out of obscurity unto the dream.

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