Re: problem with new

[Eljay Love-Jensen <eljay at adobe dot com>]

Hi Arun,

The kind of error you are seeing is often -- but not always -- indicative 
of heap corruption, in my experience.

You can get heap corruption by double-deleting a pointer.

You can get heap corruption by using new[] to allocate, but using delete to 
deallocate.

You can get heap corruption by using new to allocate, but using delete to 
deallocate.

You can get heap corruption by deleting a pointer that was not new'd (not 
including NULL).

You can get heap corruption by memory overruns or memory underruns.

You can get heap corruption if you new a pointer from one heap, and attempt 
to delete that pointer in a different heap.

You can get heap corruption by a wild pointer.

(I've tried to list these in the order of the most common to least common.)

Unfortunately, when you actually experience the SEGV may be far from the 
code that caused the heap to be mucked up.

Fortunately, there are alternative heaps that keep meticulous track of your 
heap and perform consistency checks and diagnostic information (often able 
to be triggered programmatically).  They tend to be significantly slower, 
but they can help find heap problems sooner.  I don't have any links, but 
I'm sure Google can find something.

Also, there are tools that can aid in tracking down these kinds of problems 
-- such as electric fence, valgrind, Rational Purify, Parasoft Insure++,

q.v.:
http://www.cs.utexas.edu/users/jpmartin/memCheckers.html
http://users.actcom.co.il/~choo/lupg/tutorials/unix-memory/unix-memory.html

HTH,
--Eljay