Found one Java-level deadlock:
=============================
"SimulationThread":
waiting to lock monitor 0x00007fcea9011e98 (object 0x00000006fb511450, a java.lang.Object),
which is held by "AWT-EventQueue-0"
"AWT-EventQueue-0":
waiting to lock monitor 0x00007fcea922ac08 (object 0x00000007248daf68, a java.awt.Component$AWTTreeLock),
which is held by "SimulationThread"
Java stack information for the threads listed above:
===================================================
"SimulationThread":
at com.apple.laf.AquaFileSystemModel.getRowCount(AquaFileSystemModel.java:194)
- waiting to lock <0x00000006fb511450> (a java.lang.Object)
at javax.swing.JTable.getRowCount(JTable.java:2662)
at javax.swing.plaf.basic.BasicTableUI.createTableSize(BasicTableUI.java:1692)
at javax.swing.plaf.basic.BasicTableUI.getPreferredSize(BasicTableUI.java:1733)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1660)
at javax.swing.ScrollPaneLayout.preferredLayoutSize(ScrollPaneLayout.java:495)
at java.awt.Container.preferredSize(Container.java:1788)
- locked <0x00000007248daf68> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.getPreferredSize(Container.java:1773)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1662)
at java.awt.BorderLayout.preferredLayoutSize(BorderLayout.java:719)
- locked <0x00000007248daf68> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.preferredSize(Container.java:1788)
- locked <0x00000007248daf68> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.getPreferredSize(Container.java:1773)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1662)
at java.awt.BorderLayout.preferredLayoutSize(BorderLayout.java:719)
- locked <0x00000007248daf68> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.preferredSize(Container.java:1788)
- locked <0x00000007248daf68> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.getPreferredSize(Container.java:1773)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1662)
at javax.swing.BoxLayout.checkRequests(BoxLayout.java:483)
at javax.swing.BoxLayout.layoutContainer(BoxLayout.java:424)
- locked <0x00000006fb4fd310> (a javax.swing.BoxLayout)
at java.awt.Container.layout(Container.java:1503)
at java.awt.Container.doLayout(Container.java:1492)
at java.awt.Container.validateTree(Container.java:1688)
at java.awt.Container.validateTree(Container.java:1697)
at java.awt.Container.validateTree(Container.java:1697)
at java.awt.Container.validateTree(Container.java:1697)
at java.awt.Container.validateTree(Container.java:1697)
at java.awt.Container.validate(Container.java:1623)
- locked <0x00000007248daf68> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.validateUnconditionally(Container.java:1660)
- locked <0x00000007248daf68> (a java.awt.Component$AWTTreeLock)
at java.awt.Window.pack(Window.java:818)
at javax.swing.JFileChooser.createDialog(JFileChooser.java:805)
at javax.swing.JFileChooser.showDialog(JFileChooser.java:732)
at javax.swing.JFileChooser.showOpenDialog(JFileChooser.java:639)
at DesignScene.setupStart(DesignScene.java:40)
at DesignScene.act(DesignScene.java:62)
at greenfoot.core.Simulation.actWorld(Simulation.java:589)
at greenfoot.core.Simulation.runOneLoop(Simulation.java:524)
at greenfoot.core.Simulation.runContent(Simulation.java:215)
at greenfoot.core.Simulation.run(Simulation.java:205)
"AWT-EventQueue-0":
at java.awt.Component.invalidate(Component.java:2920)
- waiting to lock <0x00000007248daf68> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.invalidate(Container.java:1580)
at javax.swing.JComponent.revalidate(JComponent.java:4849)
at javax.swing.JTable.tableRowsInserted(JTable.java:4482)
at javax.swing.JTable.tableChanged(JTable.java:4407)
at javax.swing.table.AbstractTableModel.fireTableChanged(AbstractTableModel.java:296)
at javax.swing.table.AbstractTableModel.fireTableRowsInserted(AbstractTableModel.java:231)
at com.apple.laf.AquaFileSystemModel$DoChangeContents.run(AquaFileSystemModel.java:458)
- locked <0x00000006fb511450> (a java.lang.Object)
- locked <0x00000006fb677bb8> (a java.lang.Object)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:312)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
Found 1 deadlock.