david-grs / mtrace

simple c++ hooks around malloc/realloc/free

mtrace

A C++ wrapper around malloc/free/realloc GNU libc hooks.

Example

    mtrace<malloc_chrono> mt;

    {
        auto uptr = std::make_unique<int>(5);
        std::cout << "after unique_ptr ctor: malloc=" << std::get<0>(mt).malloc_time().count() << "ns "
                  << " free=" << std::get<0>(mt).free_time().count() << "ns" << std::endl;
    }

    std::cout << "after unique_ptr dtor: malloc=" << std::get<0>(mt).malloc_time().count() << "ns "
              << " free=" << std::get<0>(mt).free_time().count() << "ns" << std::endl;

Output:

    after unique_ptr ctor: malloc=5100ns free=0ns
    after unique_ptr dtor: malloc=5100ns free=1131ns

Note

Be aware that this class is not thread-safe. This is the reason why these hooks are marked as deprecated in the glibc ; it is very unlikely that they get removed, but they should not be used in a multithreading environment, as a race condition might occured in the set/get of the hooks.

If you want to hook malloc/free/realloc in a multithreaded environment, you should replace these symbols directly (they are weak symbols in the GNU libc), and not use this class.