pointer question

This is a discussion on pointer question within the C Programming forums, part of the General Programming Boards category; if two pointer variables point to the same memory location, what happens when one of the pointers is freed?...

  1. #1
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    pointer question

    if two pointer variables point to the same memory location, what happens when one of the pointers is freed?

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    pwns nooblars
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    Undefined behavior if you try to use the other one.

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    Gawking at stupidity
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    Quote Originally Posted by snugglebuns
    if two pointer variables point to the same memory location, what happens when one of the pointers is freed?
    It frees the memory and then you're left with 2 dangling pointers instead of just 1.
    If you understand what you're doing, you're not learning anything.

  4. #4
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    It's not the pointer that is freed. It is the memory that the pointer is pointing to that is freed. In this case, two pointers are pointing to it.
    It's like two men standing, pointing at a woman and then all of a sudden lighting strikes her and she's dead. You are left with two men pointing at nothing.

  5. #5
    ATH0 quzah's Avatar
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    No, then you have two men pointing at a smoking corpse...


    Quzah.
    Hope is the first step on the road to disappointment.

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    Supermassive black hole cboard_member's Avatar
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    Or just her teeth... she could have been blown sky high and landed in a nearby village.
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    - Mike McShaffry

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    "Hey Bob, look at that woman over there, she's smokin' hot!"
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    "Oh, wow... I guess I see it now..."


    p.s. is there any function to manually free memory on the stack?
    (Naturally, I tried free... that was a learning experience )

  8. #8
    Supermassive black hole cboard_member's Avatar
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    Methinks there is, but you'd have to write your function (or at least part of it) in inline assembly.
    Good class architecture is not like a Swiss Army Knife; it should be more like a well balanced throwing knife.

    - Mike McShaffry

  9. #9
    and the hat of wrongness Salem's Avatar
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    Or a pair of physics geeks saying, oh wow, check out that cool lightning.

    > p.s. is there any function to manually free memory on the stack?
    No, the compiler allocates and frees all automatic variables for you.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
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