Simple C implementation to track memory malloc/free?

Question

programming language: C platform: ARM Compiler: ADS 1.2

I need to keep track of simple melloc/free calls in my project. I just need to get very basic id

Answer 1

I've been trying out some of the same techniques mentioned on this page and wound up here from a google search. I know this question is old, but wanted to add for the record...

1) Does your operating system not provide any tools to see how much heap memory is in use in a running process? I see you're talking about ARM, so this may well be the case. In most full-featured OSes, this is just a matter of using a cmd-line tool to see the heap size.

2) If available in your libc, sbrk(0) on most platforms will tell you the end address of your data segment. If you have it, all you need to do is store that address at the start of your program (say, startBrk=sbrk(0)), then at any time your allocated size is sbrk(0) - startBrk.

3) If shared objects can be used, you're dynamically linking to your libc, and your OS's runtime loader has something like an LD_PRELOAD environment variable, you might find it more useful to build your own shared object that defines the actual libc functions with the same symbols (malloc(), not MemAlloc()), then have the loader load your lib first and "interpose" the libc functions. You can further obtain the addresses of the actual libc functions with dlsym() and the RTLD_NEXT flag so you can do what you are doing above without having to recompile all your code to use your malloc/free wrappers. It is then just a runtime decision when you start your program (or any program that fits the description in the first sentence) where you set an environment variable like LD_PRELOAD=mymemdebug.so and then run it. (google for shared object interposition.. it's a great technique and one used by many debuggers/profilers)