Method free

src/core/test/mem_alloc.cpp:59–66

    }

    void free(void* ptr) override {
        MGB_LOCK_GUARD(m_mtx);
        auto iter = m_addr2size.find(ptr);
        mgb_assert(iter != m_addr2size.end());
        ++m_nr_free;
        m_cur_usage -= iter->second;
        m_addr2size.erase(iter);
    }

    void get_mem_info(size_t& free, size_t& tot) override {
        tot = m_tot_size;