Re: pointers are unique?

Hi BlueRaja,

Well, the thing is that I am building a P2P simulator. In P2Ps there
is not guarrantee that a node has always valid and active neighbours.
A node may disappear without notifying its neighbours. Therefore,
explicitly deleting all the pointers to a deleted object does not 100%
represent an actual P2P.

-- George

On Jun 20, 3:08 pm, BlueRaja <blueraja.ad...@gmail.com> wrote:
> If there is any possibility that there will still be references to an
> object elsewhere after it is deleted, it should not be deleted in the first
> place; this is not a problem with pointers but rather with the design of
> your program.
> You would have to give a more in-depth description of the program (and,
> especially, what should happen when a node is deleted) in order for us to
> give a recommendation of what to do with your garbage-pointers.
>
> -BlueRaja
>
> On 6/20/07, Saurabh Saha <saurs...@gmail.com> wrote:
>
>
>
> > Hi George
>
> > I completely agree with you but the doubt that I possess is how do you
> > plan to allocate the same memory area that you freed because as soon as you
> > free taht portion of the area, the area becomes a part of the free pool of
> > memory space that is available to be allocated with of course the garbage
> > values or values wrt the earlier object.
>
> > Now what exactly is the probability that a new node will take up exactly
> > the same area that you freed in the last node as now it is not about the
> > memory area but the picture is rather the free pool of memory in the heap.
>
> > Now allocation of memory to the new node is the OS's responsibility and
> > hence it takes care of it not the coder at the code level.Wat say????
>
> > Regards
> > Saurabh
>
> > On 6/20/07, gexarchakos <gexarcha...@gmail.com> wrote:
>
> > > Many thanks Saurabh,
>
> > > actually you are right, that's exactly what I meant. I think I agree
> > > with your points...
>
> > > I am building a network simulator and created a directional graph and
> > > initially I was using the pointers as IDs. But now I expand the
> > > simulator with dynamic insertion and deletion of nodes. This means
> > > that a new node may take the same memory space as an old deleted one.
> > > In this case, not updated pointers from other nodes to the old one
> > > will actually point to the new node. If no new node is inserted in the
> > > same memory space then these pointers will be broken, right?
>
> > > That was the problem that generated the question.
>
> > > Many thanks again,
> > > --George
>
> > > On Jun 20, 11:54 am, "Saurabh Saha" < saurs...@gmail.com> wrote:
> > > > Hi George
>
> > > > When u talk about deleting a memory address what exactly do u actually
> > > > mean-It does not mean u delete any memory area but rather it means
> > > that u
> > > > free portion of d dynamic memory which was allocated to the object at
> > > > runtime so I believe there is of course a possibility that the same
> > > memory
> > > > area can be taken up by another object unless of course the developer
> > > > forgets to de allocate the memory allocated thus resulting in a memory
> > > leak.
>
> > > > So talking about delete from the OS point of view does not quite mean
> > > that
> > > > whatever u delete from th UI is actually deleted but rather that the
> > > > reference entity pointing to d memory area gets allocated 2 Null
> > > permanently
> > > > and hence cannot point to d memory area it was earlier pointing to.
>
> > > > Correct me if i am wrong guys,.
>
> > > > Regards
> > > > Saurabh
>
> > > > On 6/20/07, gexarchakos <gexarcha...@gmail.com> wrote:
>
> > > > > Hello everyone,
>
> > > > > just a question on pointers:
> > > > > Assume that you dynamically allocate memory for an object. Sometime
> > > > > later, you dynamically delete it...
> > > > > Is there a possibility that another dynamically created object will
> > > > > take the same memory address as one previously deleted? In that
> > > case,
> > > > > pointers cannot work as IDs of objects, right?
>
> > > > > To me it makes sense if there is such a possibility. I'd like your
> > > > > opinion...
>
> > > > > Thanks,
> > > > > -- George

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