8260163: IrresponsiveScriptTest.testInfiniteLoopInScript unit test fa…

…ils on Windows

Reviewed-by: kcr

modules/javafx.web/src/main/native/Source/WTF/wtf/generic/WorkQueueGeneric.cpp

@@ -72,6 +72,19 @@ void WorkQueue::dispatch(Function<void()>&& function)
 void WorkQueue::dispatchAfter(Seconds delay, Function<void()>&& function)
 {
     RefPtr<WorkQueue> protect(this);
+#if OS(WINDOWS) && PLATFORM(JAVA)
+    // From empirical testing, we've seen CreateTimerQueueTimer() sometimes fire up to 5+ ms early.
+    // This causes havoc for clients of this code that expect to not be called back until the
+    // specified duration has expired. Other folks online have also observed some slop in the
+    // firing times of CreateTimerQuqueTimer(). From the data posted at
+    // http://omeg.pl/blog/2011/11/on-winapi-timers-and-their-resolution, it appears that the slop
+    // can be up to about 10 ms. To ensure that we don't fire the timer early, we'll tack on a
+    // slop adjustment to the duration, and we'll use double the worst amount of slop observed
+    // so far.
+    const Seconds slopAdjustment { 20_ms };
+    if (delay)
+        delay += slopAdjustment;
+#endif
     m_runLoop->dispatchAfter(delay, [protect, function = WTFMove(function)] {
 #if PLATFORM(JAVA)
         AttachThreadAsDaemonToJavaEnv autoAttach;

modules/javafx.web/src/test/java/test/javafx/scene/web/IrresponsiveScriptTest.java

@@ -32,12 +32,10 @@
 import javafx.scene.web.WebEvent;
 import netscape.javascript.JSException;
 import org.junit.Assume;
-import org.junit.Ignore;
 import org.junit.Test;
 
 public class IrresponsiveScriptTest extends TestBase {
 
-    @Ignore("JDK-8260163")
     @Test public void testInfiniteLoopInScript() {
         try {
             // This infinite loop should get interrupted by Webkit in about 10s.