| <html> |
| <head> |
| <script src="/js-test-resources/js-test.js"></script> |
| </head> |
| <body> |
| <p id="description"></p> |
| <div id="console"></div> |
| <script> |
| description("Verifies the minimum resolution is 5 microseconds."); |
| |
| function testTimeResolution(highResTimeFunc) { |
| var t0 = highResTimeFunc(); |
| var t1 = highResTimeFunc(); |
| while (t0 == t1) { |
| t1 = highResTimeFunc(); |
| } |
| |
| var expectedResolutionMilliseconds = 0.005; |
| var integerMultipleOfResolution = (t1 - t0) / expectedResolutionMilliseconds; |
| shouldBeNearZeroOrOne = integerMultipleOfResolution % 1; |
| shouldBe("shouldBeNearZeroOrOne < 1e-10 || Math.abs(shouldBeNearZeroOrOne - 1) < 1e-10", "true"); |
| } |
| |
| function timeByPerformanceNow() { |
| return performance.now(); |
| } |
| |
| function timeByUserTiming() { |
| performance.mark('timer'); |
| var t = performance.getEntriesByName('timer')[0].startTime; |
| performance.clearMarks('timer'); |
| return t; |
| } |
| |
| testTimeResolution(timeByPerformanceNow); |
| testTimeResolution(timeByUserTiming); |
| </script> |
| </body> |
| </html> |
