| <html> |
| <head> |
| <script src="../../resources/js-test.js"></script> |
| <script src="../../resources/testharness.js"></script> |
| <script src="../../resources/visibility.js"></script> |
| <script> |
| description('<a href="http://crbug.com/259680">Bug 259680</a>: JavaScript setInterval lagging behind'); |
| |
| var jsTestIsAsync = true; |
| var intervalDuration = 1000; |
| var testDuration = 4000; |
| var expectedNumFires = 4; |
| var numFires = 0; |
| var tolerance = 1; |
| |
| var intervalID; |
| var startTime; |
| |
| function timerFired() |
| { |
| ++numFires; |
| |
| var currentTime = new Date().getTime(); |
| if (currentTime >= startTime + testDuration) { |
| shouldBeCloseTo("numFires", expectedNumFires, tolerance); |
| |
| clearInterval(intervalID); |
| finishJSTest(); |
| return; |
| } |
| } |
| |
| function runTest() |
| { |
| assert_equals(document.visibilityState, "hidden"); |
| |
| if (!window.testRunner) { |
| debug('This test requires testRunner'); |
| return; |
| } |
| |
| startTime = new Date().getTime(); |
| intervalID = window.setInterval(timerFired, intervalDuration); |
| } |
| </script> |
| </head> |
| <body onload="setMainWindowHidden(true).then(runTest)"> |
| <p> |
| This test ensures that intervals on background pages whose duration is close to the timer alignment interval don't miss every other firing. |
| </p> |
| </body> |
| </html> |
