iOS Development: How can I induce low memory warnings on device?
IphoneIpadIosIphone Problem Overview
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.
Iphone Solutions
Solution 1 - Iphone
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.
Solution 2 - Iphone
Solution 3 - Iphone
Using Instruments, use the menu item: Instrument -> Simulate Memory Warning.
To use Instruments on your app from Xcode, use the Product -> Profile menu item.
Solution 4 - Iphone
I've re-written Enzo Tran's answer in Swift:
UIControl().sendAction(Selector(("_performMemoryWarning")), to: UIApplication.shared, for: nil)
Solution 5 - Iphone
If someone, for whatever reason, tries to do this in Swift 4 - here is how to allocate 1.2 GB of ram.
let d = Data.init(repeating: 100, count: 1200000000)
- This is helpful to trigger a warning alert in other apps
Solution 6 - Iphone
To test on a device, just add some code that periodically allocates large chunks of memory without freeing it (i.e. 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.
Solution 7 - Iphone
Converted @ChikabuZ to swift 3:
UIControl().sendAction(Selector(("_performMemoryWarning")), to: UIApplication.shared, for: nil)
Solution 8 - Iphone
Theres a menu command that will invoke it.
Hardware > Simulate Memory Warning
from the simulator.
Solution 9 - Iphone
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;
}
Solution 10 - Iphone
Swift 4:
UIApplication.shared.perform(Selector(("_performMemoryWarning")))
Can execute the above in response to an event/notification.