How to measure SDK storage in an iOS app

I have tried to measure the amount of memory using various methods - and each method returns a different value.

The first way looked at low caliber in Xcode during application launch. It shows 20.9 MB of usage:

Second way to use this code (it shows 38-39MB usage):

vm_size_t usedMemory(void) {
    struct task_basic_info info;
    mach_msg_type_number_t size = sizeof(info);
    kern_return_t kerr = task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)&info, &size);
    return (kerr == KERN_SUCCESS) ? info.resident_size : 0; // size in bytes
}

vm_size_t freeMemory(void) {
    mach_port_t host_port = mach_host_self();
    mach_msg_type_number_t host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);
    vm_size_t pagesize;
    vm_statistics_data_t vm_stat;

    host_page_size(host_port, &pagesize);
    (void) host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size);
    return vm_stat.free_count * pagesize;
}

void logMemUsage(void) {
    // compute memory usage and log if different by >= 100k
    static long prevMemUsage = 0;
    long curMemUsage = usedMemory();
    long memUsageDiff = curMemUsage - prevMemUsage;

//    if (memUsageDiff > 100000 || memUsageDiff < -100000) {
        prevMemUsage = curMemUsage;
        NSLog(@"Memory used %7.1f (%+5.0f), free %7.1f kb", curMemUsage/1000.0f, memUsageDiff/1000.0f, freeMemory()/1000.0f);
//    }
}

      

        
        
        
      

    

The third way is using tools that show roughly 19-20 MB of usage

The bottom line is what I need to figure out how to measure the SDK memory size. (Before adding SDK and after adding SDK or "Blackbox" SDK measurements)

How and why do the results differ from each other?

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