Fix NEWT EDTUtil Deadlock on EDTUtil.start()

DisplayImpl.runOnEDTIfAvail(..) issues EDTUtil.start()
while holding it's object-lock - if the EDT is not running,
then invokes the given task.

EDTUtil.start() impl. holds it's own edt-lock
while starting, then releases it's edt-lock while issuing a null-task.

If another thread injects a blocking task right in-between
which also acquires the display's object-lock it deadlocks.

Simply remove issuing the null-task, so EDTUtil.start()
can return immediatly (releasing edt-lock)
and allowing DisplayImpl.runOnEDTIfAvail(..)
also to release it's object-lock.

The other threads task then can be executed,
where the 'starting task' would come second - which is OK,
even though a rare occasion.

Above situation was triggered via AWT/NEWT reparenting w/ forced recreation
via TestParenting01dAWT.

+++

The null-task at EDTUtil.start() was remaining code to ensure
that the EDT completed starting, which is redundant.

1 files changed, 6 insertions, 5 deletions

diff --git a/src/test/com/jogamp/opengl/test/junit/newt/TestDisplayLifecycle01NEWT.java b/src/test/com/jogamp/opengl/test/junit/newt/TestDisplayLifecycle01NEWT.java
index b007f57f3..8989f3a89 100644
--- a/src/test/com/jogamp/opengl/test/junit/newt/TestDisplayLifecycle01NEWT.java
+++ b/src/test/com/jogamp/opengl/test/junit/newt/TestDisplayLifecycle01NEWT.java
@@ -3,14 +3,14 @@
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@@ -20,7 +20,7 @@
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@@ -69,7 +69,7 @@ public class TestDisplayLifecycle01NEWT extends UITestCase {
 
         //
         // Create native windowing resources .. X11/Win/OSX
-        // 
+        //
         GLWindow glWindow;
         if(null!=screen) {
             Window window = NewtFactory.createWindow(screen, caps);
@@ -209,6 +209,7 @@ public class TestDisplayLifecycle01NEWT extends UITestCase {
             Assert.assertNotNull(edtUtil);
             Assert.assertEquals(false,edtUtil.isRunning());
             edtUtil.start();
+            Assert.assertEquals(true,edtUtil.isRunning());
             edtUtil.invoke(true, null);
             Assert.assertEquals(true,edtUtil.isRunning());
             edtUtil.invokeStop(true, null);