| <!DOCTYPE html> |
| <head> |
| <script src="../resources/js-test.js"></script> |
| <script src="resources/netinfo_common.js"></script> |
| </head> |
| <body> |
| <script> |
| |
| description('Tests that unused listeners are collected.'); |
| |
| shouldBe('typeof window.internals.observeGC', '"function"', |
| 'this test requires window.internals'); |
| |
| let callback = function(e) { |
| testFailed("Should not get here."); |
| }; |
| |
| // Add a listener. |
| var callbackObserver; |
| // Do not pass the object directly to observeGC function. It may |
| // remain live on this function's stack preventing GC from collecting |
| // it. Accessing the object inside an inner function will prevent any |
| // unneeded references on this function's stack. (http://crbug.com/595672/) |
| (function() { |
| callbackObserver = internals.observeGC(callback); |
| connection.addEventListener('typechange', callback); |
| })(); |
| |
| gc(); |
| shouldBeFalse('callbackObserver.wasCollected'); |
| |
| // Remove the listener and its callback reference. |
| // Access objects in an inner function to avoid references to objects |
| // remaining live on this function's stack frame (http://crbug.com/595672/). |
| (() => {connection.removeEventListener('typechange', callback);})(); |
| callback = null; |
| gc(); |
| shouldBeTrue('callbackObserver.wasCollected'); |
| finishJSTest(); |
| |
| </script> |
| </body> |
| </html> |
