Open Radar

 
Summary:
Opening the site https://brendeneich.com in a UIWebView causes the app to be killed by jetsam. No memory warnings are sent to the app.

1) Jetsam is killing the app with no warning
2) Jetsam shouldn't be killing the app at all, the memory pressure isn't high enough

Steps to Reproduce:
Create a UIWebView-based app, and on a non-simulator, open brendeneich.com. The app will be killed with no warning by Jetsam.

Or, download Brave Browser, Dolphin or Puffin Browsers, they are all UIWebView browsers.

Expected Results:
1) Don't kill, there isn't enough memory pressure
2) If killed, send a warning so we can stop loading the web view

Actual Results:
App killed by Jetsam.

(NOTE: not reproducible in simulator

Version:
iOS 9.2.1

Notes:
Attempted to monitor memory pressure, but no memory pressure warnings happen:

dispatch_source_t source = dispatch_source_create(DISPATCH_SOURCE_TYPE_MEMORYPRESSURE, 0, DISPATCH_MEMORYPRESSURE_WARN|DISPATCH_MEMORYPRESSURE_CRITICAL, dispatch_get_main_queue());
        dispatch_source_set_event_handler(source, ^{
            dispatch_source_memorypressure_flags_t pressureLevel = dispatch_source_get_data(source);
            [NSNotificationCenter.defaultCenter postNotificationName:UIApplicationDidReceiveMemoryWarningNotification object:nil userInfo:@{@"pressure": @(pressureLevel)}];
        });
        dispatch_resume(source);


Configuration:
iPhone 5c, iPad Air