iOS Development: How can I induce low memory warnings on device?

Question

I'd like to test my app functions well in low memory conditions, but it's difficult to test. How can I induce low memory warnings that trigger the didReceiveMemoryWarning method in my views when the app is running on the device, not the simulator? Or what are some ways I can test my app under these possible conditions?

The reason I can't use the simulator is my app uses Game Center and invites don't work on the simulator.

Answer 1

You can call the private method :

[[UIApplication sharedApplication] performSelector:@selector(_performMemoryWarning)];

Just remember to use it on debug only, or else your app will get rejected.

Answer 2

iOS模拟器的Simulate Memory Warning菜单项允许您模拟内存警告。

Answer 3

Using Instruments, use the menu item: Instrument -> Simulate Memory Warning.

To use Instruments on your app from Xcode, use the Product -> Profile menu item.

Answer 4

我在Swift中重写了Enzo Tran的答案 ：

UIControl().sendAction(Selector(("_performMemoryWarning")), to: UIApplication.shared, for: nil)

Answer 5

将@ChikabuZ转换为swift 3：

UIControl().sendAction(Selector(("_performMemoryWarning")), to: UIApplication.shared, for: nil)

Answer 6

Theres a menu command that will invoke it.

Hardware > Simulate Memory Warning from the simulator.

Answer 7

To test on a device, just add some code that periodically allocates large chunks of memory without freeing it (ie leak on purpose). You can do this in a separate thread, or in response to a timer, or using whatever mechanism that best allows you to test and observe the behavior of your application.

You might also choose to create a separate app that does something similar and is designed to run in the background, if you'd like to easily reuse this and/or test with multiple applications.

Answer 8

如果有人出于某种原因试图在Swift 4中这样做 - 这里是如何分配1.2 GB的内存。

let d = Data.init(repeating: 100, count: 1200000000)

Answer 9

If someone, for whatever reason, tries to do this in Swift 3 - here is how to allocate 1.2 GB of ram.

   for i in 0...1200 {
      var p: [UnsafeMutableRawPointer] = []
      var allocatedMB = 0
      p.append(malloc(1048576))
      memset(p[allocatedMB], 0, 1048576);
      allocatedMB += 1;
   }

Answer 10

Swift 4:

UIApplication.shared.perform(Selector(("_performMemoryWarning")))

Can execute the above in response to an event/notification.