Closing a program - what happens

I have written a small console application with this structure:

Code:

---

int main()
{
  AllocateSomeMemory();

  while(1)
  {
      Sleep(30);
      DoSomeThings();
  }
  DeallocateSomeMemory();
}

---

If I close the application, will the memory be deallocated? More precisely: will my code that deals with deallocating the memory be executed, or will the OS (WindowsXP) handle this for me? What is the 'correct' way to deal with a this (a loop that should run untill the application is closed)?

If I remember rightly all the memory is freed up after the program closes, it is just if you reallocate before deallocating then you cause a memory leak. I think I right though, I am not 100% sure.

You are correct bumfluff. The thing to watch for is pointer allocations on program close.
If for example you allocate a pointer variable space on the heap using "new" then you MUST call "delete" before the return 0 statement to ensure the memory is freed once more. You can if then wish assign that pointer to NULL to deter any possible memory leak, but that is a preference not an absolute.
As a side note, any allocations I do with new are deleted and NULLED out of habit. :)

http://c-faq.com/malloc/freeb4exit.html
Having said that, it's good practice to try and make your program leak-free from the outset.

> What is the 'correct' way to deal with a this (a loop that should run untill the application is closed)?
Write it as a windows application (with a winmain() and a message loop), and respond to the WM_CLOSE event in the appropriate manner.

Or have something like
while ( !done )
rather than
while ( 1 )
and a mechanism somewhere in your code to set that flag at the end of the program.

Thanks.

So it's only possible to let my code react to the close event in a windows application. I'll have to learn about that then.

MS-Windows specific: console program can call _onexit() to install an event handler which is supposed to get called whenever the program terminates for whatever reason.

Sorry to interject, but:

Is there any mechanism to release memory when a program crashes, or is it lost until the os reboots?

Do Windows, Linux, OS X differ in this regard?

Quote:

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Originally Posted by Ancient Dragon

MS-Windows specific: console program can call _onexit() to install an event handler which is supposed to get called whenever the program terminates for whatever reason.

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isn't there a standard atexit function?

> Do Windows, Linux, OS X differ in this regard?
Like my link said, all good operating systems free all the memory associated with a process when that process dies - for whatever reason.

The OS will simply deallocate all the virtual memory associated with the process.

Thanks, Salem. I didn't notice the link.

Guess it was too red...