testing/web-platform/tests/requestidlecallback/callback-timeout-when-busy.html

   1 <!DOCTYPE html>
   2 <title>window.requestIdleCallback deals with timeouts correctly</title>
   3 <meta name="timeout" content="long">
   4 <link rel="author" title="Ross McIlroy" href="mailto:rmcilroy@chromium.org" />
   5 <script src="/resources/testharness.js"></script>
   6 <script src="/resources/testharnessreport.js"></script>
   7 <script>
   8
   9 async_test(function() {
  10   // Check whether requestIdleCallback with a timeout works when the event loop
  11   // is busy.
  12   var busy_loop_iterations_remaining = 10;  // Should take 20 * 40 = 400ms
  13   var idle_callback_scheduled;
  14   var idle_callback = this.step_func_done(function(deadline) {
  15     assert_false(deadline.didTimeout, "IdleDeadline.didTimeout MUST be false if requestIdleCallback wasn't scheduled due to a timeout");
  16     assert_equals(busy_loop_iterations_remaining, 0, "Busy event loop should be finished by the time we get scheduled");
  17   });
  18
  19   var busy_loop_iterations_remaining = 10;  // Should take 20 * 40 = 400ms
  20   step_timeout(this.step_func(function busyLoop() {
  21     var start_time = performance.now();
  22     if (!idle_callback_scheduled) {
  23       idle_callback_scheduled = start_time;
  24       requestIdleCallback(idle_callback);
  25     }
  26
  27     // Use up more than a frames worth of budget.
  28     while (performance.now() - start_time < 40) {
  29     }
  30     if (busy_loop_iterations_remaining > 0) {
  31       busy_loop_iterations_remaining--;
  32       step_timeout(busyLoop);
  33     }
  34   }));
  35 }, 'requestIdleCallback not scheduled when event loop is busy.');
  36
  37 async_test(function() {
  38   // Check whether requestIdleCallback with a timeout works when the event loop
  39   // is busy.
  40   var busy_loop_iterations_remaining = 10;  // Should take 20 * 40 = 400ms
  41   var timeout = 200;
  42   var idle_callback_scheduled;
  43   var idle_callback = this.step_func_done(function(deadline) {
  44     var time_delta = performance.now() - idle_callback_scheduled;
  45     assert_true(time_delta >= timeout, "Should only have been run after timeout");
  46     assert_true(deadline.timeRemaining() == 0, "IdleDeadline.timeRemaining MUST be equal to zero if requestIdleCallback was scheduled due to a timeout");
  47     assert_true(deadline.didTimeout, "IdleDeadline.didTimeout MUST be true if requestIdleCallback was scheduled due to a timeout");
  48     assert_true(busy_loop_iterations_remaining > 0, "Busy event loop should still be going");
  49   });
  50
  51   step_timeout(this.step_func(function busyLoop() {
  52     var start_time = performance.now();
  53     if (!idle_callback_scheduled) {
  54       idle_callback_scheduled = start_time;
  55       requestIdleCallback(idle_callback, { timeout: timeout });
  56     }
  57
  58     // Use up more than a frames worth of budget.
  59     while (performance.now() - start_time < 40) {
  60     }
  61     if (busy_loop_iterations_remaining > 0) {
  62       busy_loop_iterations_remaining--;
  63       step_timeout(busyLoop);
  64     }
  65   }));
  66 }, 'requestIdleCallback scheduled with timeout when event loop is busy.');
  67
  68 </script>
  69 <h1>Test of requestIdleCallback timeout behavior</h1>
  70 <div id="log"></div>