Multithreading Modes

Graphic Components > Using JViews TGO in SWT Applications > Multithreading Modes

Multithreading Modes

INDEX

You can handle the SWT - Swing event threads of the user interface in two different modes:

Two-thread mode

The SWT events are handled in the SWT event thread and AWT/Swing events are handled in the AWT/Swing event thread. This is the default mode.

If your application uses this mode, you must be careful to:

Make API calls on SWT widgets only in the SWT event thread. Otherwise, you will get SWTExceptions of type ERROR_THREAD_INVALID_ACCESS.
Make API calls on JComponents, which include IlpNetwork, IlpEquipment, IlpTree, and IlpTable, only in the AWT/Swing event thread. Otherwise, you risk deadlocks.

You can switch between the two threads by using the SWT method Display.asyncExec() and the AWT method EventQueue.invokeLater().

Single-thread mode

The SWT and AWT/Swing events are handled in the same thread. This mode is enabled by calling IlvEventThreadUtil.setAWTThreadRedirect(Display) or IlvEventThreadUtil.enableAWTThreadRedirect() early during initialization.

This mode reduces the risk of producing deadlocks. If you are using JComponents other than IlpNetwork, IlpEquipment, IlpTree, and IlpTable in your application, your JComponents must use the method IlvSwingUtil.isDispatchThread() rather than EventQueue.isDispatchThread() or SwingUtilities.isEventDispatchThread().

   // Switch single-event-thread mode during a static initialization.
      static {
          IlvEventThreadUtil.enableAWTThreadRedirect();
      }

This mode is incompatible with AWT/Swing Dialogs. If you use single-thread mode, you cannot use AWT Dialogs, Swing JDialogs, or modal JInternalFrames in your application. There are also some other limitations. See the class IlvEventThreadUtil for a precise description of the limitations.

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