How to Get Memory Usage in Swift

How to get memory usage of my application and system in swift by programatically

For Swift 3.0 you can use the following function.

func report_memory() {
    var taskInfo = mach_task_basic_info()
    var count = mach_msg_type_number_t(MemoryLayout<mach_task_basic_info>.size)/4
    let kerr: kern_return_t = withUnsafeMutablePointer(to: &taskInfo) {
        $0.withMemoryRebound(to: integer_t.self, capacity: 1) {
            task_info(mach_task_self_, task_flavor_t(MACH_TASK_BASIC_INFO), $0, &count)
        }
    }

    if kerr == KERN_SUCCESS {
        print("Memory used in bytes: \(taskInfo.resident_size)")
    }
    else {
        print("Error with task_info(): " +
            (String(cString: mach_error_string(kerr), encoding: String.Encoding.ascii) ?? "unknown error"))
    }
}

Swift iOS memory usage increasing during runtime

Profile Memory Allocation

I made a test iOS application to show how you could profile memory allocation. After creating a new iOS project I added the following to the AppDelegate:

var test: [String] = []

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.

    while true {
        test.append("blasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdfblasdgpjsogfisogfihsofighäkneäijifdf")
    }
    return true
}

This should simulate your problem. Then we longpress the build button and choose profile.

We choose Allocations as profiling template.

We press the record button.

We once again select Allocations.

We select Call Trees.

And probably we already find the problematic stack trace on the right side.

Or you scan the call tree by yourself.

This should give you a starting point for further debugging to find the infinite loop :)

Programmatically retrieve memory usage on iPhone

To get the actual bytes of memory that your application is using, you can do something like the example below. However, you really should become familiar with the various profiling tools as well as they are designed to give you a much better picture of usage over-all.

#import <mach/mach.h>

// ...

void report_memory(void) {
  struct task_basic_info info;
  mach_msg_type_number_t size = TASK_BASIC_INFO_COUNT;
  kern_return_t kerr = task_info(mach_task_self(),
                                 TASK_BASIC_INFO,
                                 (task_info_t)&info,
                                 &size);
  if( kerr == KERN_SUCCESS ) {
    NSLog(@"Memory in use (in bytes): %lu", info.resident_size);
    NSLog(@"Memory in use (in MiB): %f", ((CGFloat)info.resident_size / 1048576));
  } else {
    NSLog(@"Error with task_info(): %s", mach_error_string(kerr));
  }
}

There is also a field in the structure info.virtual_size which will give you the number of bytes available virtual memory (or memory allocated to your application as potential virtual memory in any event). The code that pgb links to will give you the amount of memory available to the device and what type of memory it is.

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