Re: Memory Allocation : Static or Dynamic?

On  8 May 2008 at 16:58, swornavidhya.mahadevan@[EMAIL PROTECTED]
 wrote:
> Which allocation (Static / Dynamic) is suitable for the situation when
> we are trying to allocate for a overloaded memory when the memory is
> full and no space to allocate.
> What will happen if both the allocation is impossible.

Definitely use dynamic allocation if there's a serious risk of running
out of memory (and as a general principle, don't allocate large arrays
on the stack). If malloc() fails, you can detect this (it will return a
null pointer) and attempt to recover or exit cleanly. If you run out of
static memory for your automatic variables, the most likely outcome is
that the heap will become corrupted without warning. If you're lucky,
your program will quickly segfault; if your unlucky, you could go on for
hours processing corrupted data.

What's going on is that in your process's virtual address space, memory
is arranged like this:

-----------------------
|                     |
|       STACK         |
|  (grows downwards)  |
|                     |
-----------------------
|                     |
|     FREE MEMORY     |
| (available for the  |
|   stack or heap)    |
|                     |
-----------------------
|                     |
|        HEAP         |
|   (grows upwards)   |
|                     |
-----------------------

So if you run out of free memory and overflow the stack, you can see
that bad things will happen.