WebCore/manual-tests/input-starved-by-timers.html
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/manual-tests/input-starved-by-timers.html	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,51 @@
+<html>
+<head>
+<script>
+function log(m) {
+    document.getElementById("log").innerHTML += m + "<br>";
+}
+
+var multiplyFactor = 2;   // Create this many timers in every timer callback.
+var targetLatency = 10000; // Multiply timers until it takes this much to fire all their callbacks.
+var timerCount = 1;
+
+function timerCallback(creationTimestamp) {
+    --timerCount;
+
+    if (!multiplyFactor) {
+        if (timerCount == 0)
+            log("No more timers - UI should be responsive now.");
+        return;
+    }
+
+    // Create more timers. Capture the current time so when callbacks are fired,
+    // we can check how long it actually took (latency caused by a long timer queue).
+    var timestamp = new Date().getTime();
+    for (i = 0; i < multiplyFactor; ++i) {
+        setTimeout(function() { timerCallback(timestamp); }, 0);
+        ++timerCount;
+    }
+
+    // Once the timer queue gets long enough for the timer firing latency to be over the limit,
+    // stop multplying them and keep the number of timers constant.
+    if (multiplyFactor > 1 && new Date().getTime() - creationTimestamp > targetLatency)
+        multiplyFactor = 1;
+}
+
+function runTest() {
+    log("Freezing UI...");
+    setTimeout(function() { timerCallback(new Date().getTime()); }, 0);
+    setTimeout("multiplyFactor = 0; log('Finishing. Started to drain timers.');", 10000);
+}
+
+</script>
+</head>
+<body onload="runTest()">
+This test will create enough timers to freeze browser UI. After 10 seconds, it
+will start drain the timers so the UI becomes responsive again in a few seconds.
+You don't need to kill the browser.<br>If the bug is fixed, there will be no
+UI freeze. Refresh the page to repeat the experiment.<br>Try to click at this
+button (or browser's menu) while UI is frozen: <button onclick="log('clicked')">Click Me</button> <hr>
+<div id="log"></div>
+</body>
+</html>