Changeset 248996 in webkit

Timestamp:

Aug 21, 2019, 10:51:53 PM (7 years ago)

Author:

rniwa@webkit.org

Message:

Layout Test perf/clone-with-focus.html is a Flaky Failure
​https://bugs.webkit.org/show_bug.cgi?id=201012

Reviewed by Antti Koivisto.

The flakiness was observed when the time to clone elements without focus is 0ms
but the time to clone elements with focus is 1ms or greater.

The test tries to make sure the time to clone elements with foucs is less than 2x
of the time to clone elements without focus. When the time to clone without focus
is 0ms, any difference is always more than 2x larger.

Fixed the test by increasing the number of elements until the time to clone without
focus takes at least 5ms.

• perf/clone-with-focus.html:

Location:

trunk/LayoutTests

Files:

• ChangeLog (modified) (1 diff)
• perf/clone-with-focus.html (modified) (3 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2019-08-21  Ryosuke Niwa  <rniwa@webkit.org>
+
+        Layout Test perf/clone-with-focus.html is a Flaky Failure
+        https://bugs.webkit.org/show_bug.cgi?id=201012
+
+        Reviewed by Antti Koivisto.
+
+        The flakiness was observed when the time to clone elements without focus is 0ms
+        but the time to clone elements with focus is 1ms or greater.
+
+        The test tries to make sure the time to clone elements with foucs is less than 2x
+        of the time to clone elements without focus. When the time to clone without focus
+        is 0ms, any difference is always more than 2x larger.
+
+        Fixed the test by increasing the number of elements until the time to clone without
+        focus takes at least 5ms.
+
+        * perf/clone-with-focus.html:
+
 2019-08-21  Myles C. Maxfield  <mmaxfield@apple.com>
 

trunk/LayoutTests/perf/clone-with-focus.html

@@ -18 +18 @@
             if (focusInput)
                 inputElement.focus();
-                
-            var startTime = Date.now();
+
+            var startTime = performance.now();
             for (var i = 0; i < numberOfElements; i++) {
                 var clone = templateElement.cloneNode(true);
@@ -25 +25 @@
                 listElement.appendChild(clone);
             }
-            var endTime = Date.now();
-            
+            var endTime = performance.now();
+
             if (focusInput)
                 inputElement.blur();
-                
-            while (listElement.firstChild != listElement.lastChild)
-                listElement.removeChild(listElement.lastChild);
-            
+
+            const originalItem = listElement.firstChild;
+            listElement.textContent = '';
+            listElement.appendChild(originalItem);
+
             return endTime - startTime;
         }
@@ -43 +44 @@
         }
 
-        var timeWithoutFocus = test(1000, false);
-        var timeWithFocus = test(1000, true);
+        const start = performance.now();
+        let factor = 0;
+        while (test(1000 * factor, false) < 5)
+            factor++;
+
+        var timeWithoutFocus = test(1000 * factor, false);
+        var timeWithFocus = test(1000 * factor, true);
 
         if (Math.abs(timeWithFocus - timeWithoutFocus) <= timeWithoutFocus) {