Smart Pointers

[Sreeram]

Hello,

I am having a doubt about smart pointer. I wrote a smart ptr class
with limited functionalities . I want to do like this!

CSmartPtr <CSomeClass> test = new CSomeClass;
// here i need to call a function which will start a thread and
returns once it starts the thread. Here i should able to increment the
refcount of smart pointer and should decrement once the thread
finishes executing. What i
should do here? Can anybody please advice me?

The code will looks like this.

while (bDone) // loop forever
{
// do some process here.
if (accepted)
{
CSmartPtr <CSomeClass> test = new CSomeClass;
// call the thread starter function of the "CSomeClass ".
}
}

Thanks,
Sreeram

Note: Please send a copy of the answer to sreeram0425@net scape.net.
Because i can acess this newsgroup only through google which will post
the answer after 8 or 10hours. Thanks!

[tom_usenet]

Re: Smart Pointers

On 3 Dec 2003 05:12:20 -0800, sreeram0425@net scape.net (Sreeram)
wrote:
[color=blue]
>Hello,
>
> I am having a doubt about smart pointer. I wrote a smart ptr class
>with limited functionalities . I want to do like this!
>
> CSmartPtr <CSomeClass> test = new CSomeClass;[/color]

Better would be:

CSmartPtr<CSome Class> test(new CSomeClass);

The constructor should be explicit to prevent dangerous implicit
conversions.
[color=blue]
> // here i need to call a function which will start a thread and
>returns once it starts the thread. Here i should able to increment the
>refcount of smart pointer and should decrement once the thread
>finishes executing. What i
>should do here? Can anybody please advice me?[/color]

First, you need to ensure that your increment and decrement functions
are atomic. Second, you need to block until the created thread has had
a chance to create its own copy of the smart pointer. e.g.

CSmartPtr<CSome Class> test(new CSomeClass);
startThread(&te st);
waitForThreadSt arted();

and the thread function should do:

void threadFunc(void * p)
{
CSmartPtr<CSome Class>* tempptr =
reinterpret_cas t<CSmartPtr<CSo meClass>*>(p);
CSmartPtr<CSome Class> ptr = *tempptr; //create local reference
notifyLaunchThr ead();
//carry on.

//at exit, reference is released.
}

Details will vary depending on your threading library...

Tom

C++ FAQ: http://www.parashift.com/c++-faq-lite/
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html