track C++ memory allocations

Question

I am looking for a way to track memory allocations in a C++ program. I am not interested in memory leaks, which seem to be what most tools are trying to find, but rather creating a memory usage profile for the application. Ideal output would be either a big list of function names plus number of maximum allocated bytes over time or better yet, a graphical representation of the heap over time. Horizontal axis is time, vertical axis heap space. Every function would get it's own color and draw lines according to allocated heap bytes. Bonus points for identifying allocated object types as well.

The idea is to find memory bottlenecks/to visualize what functions/threads consume the most memory and should be targetted for further optimization.

I have briefly looked at Purify, BoundsChecker and AQTime but they don't seem to be what I'm after. Valgrind looks suitable, however, I'm on Windows. Memtrack looks promising, but requires significant changes to the source code.

My google skills must have failed me, cause it doesn't seem to be such an uncommon request? All the needed information to create a tool like that should be readily available from the program's debug symbols plus runtime API calls - no?

Answer 1

Use Valgrind and its tool Massif. Its example output (a part of it):

99.48% (20,000B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->49.74% (10,000B) 0x804841A: main (example.c:20)
| 
->39.79% (8,000B) 0x80483C2: g (example.c:5)
| ->19.90% (4,000B) 0x80483E2: f (example.c:11)
| | ->19.90% (4,000B) 0x8048431: main (example.c:23)
| |   
| ->19.90% (4,000B) 0x8048436: main (example.c:25)
|   
->09.95% (2,000B) 0x80483DA: f (example.c:10)
  ->09.95% (2,000B) 0x8048431: main (example.c:23)

So, you will get detailed information:

• WHO allocated the memory (functions: g(), f(), and main() in above example); you also get complete backtrace leading to allocating function,
• to WHICH data structure the memory did go (no data structures in above example),
• WHEN it happened,
• what PERCENTAGE of all allocated memory it is (g: 39.7%, f: 9.95%, main: 49.7%).

Here is Massif manual

You can track heap allocation as well as stack allocation (turned off by default).

PS. I just read that you're on Windows. I will leave the answer though, because it gives a picture of what you can get from a possible tool.