[albireo-dev] Re: resize/relayout problem again

[Bruno Haible <haible@xxxxxxx>]

> There is still a race condition in it (I got a wrong display once in 40 times)

This should fix the race condition.

Bruno


Index: src/org/eclipse/albireo/core/SwingControl.java
===================================================================
RCS file: /cvsroot/technology/org.eclipse.albireo/org.eclipse.albireo.core/src/org/eclipse/albireo/core/SwingControl.java,v
retrieving revision 1.76
diff -c -3 -r1.76 SwingControl.java
*** src/org/eclipse/albireo/core/SwingControl.java	30 Apr 2008 15:45:10 -0000	1.76
--- src/org/eclipse/albireo/core/SwingControl.java	30 Apr 2008 17:44:59 -0000
***************
*** 699,704 ****
--- 699,705 ----
       * the specified sizes, and the OR of the preconditions.
       */
      class SetAWTSizeQueue implements Runnable {
+         // True while a request is pending.
          private boolean pending /* = false */;
          // If pending:
          // The AWT time of the notification that triggered this request
***************
*** 708,713 ****
--- 709,716 ----
          // The size to which the frame shall be resized.
          private int width;
          private int height;
+         // True while processing the last request (after it was dequeued).
+         private boolean processing /* = false */;
          /**
           * Creates an empty queue.
           */
***************
*** 726,731 ****
--- 729,740 ----
              assert Display.getCurrent() != null;     // On SWT event thread
              if (verboseSizeLayout)
                  System.err.println("SWT thread: Preparing to set size: " + width + " x " + height + " for " + swingComponent);
+             // During the processing of a request, lastValidatedAWTTime is
+             // unreliable: it gets incremented to a value past the
+             // currentAWTTime, but this does not mean that we should drop this
+             // request.
+             if (processing)
+                 onBehalfAWTTime = null;
              boolean wasPending = this.pending;
              // Shortcut to avoid posting a Runnable that has no effect.
              // (lastValidatedAWTTime can only increase until the Runnable is
***************
*** 767,772 ****
--- 776,782 ----
                  // time at which the rootpane was last validated.
                  if (onBehalfAWTTime == null
                      || lastValidatedAWTTime - onBehalfAWTTime.intValue() < 0) {
+                     processing = true;
                      return new Dimension(width, height);
                  }
              }
***************
*** 774,781 ****
          }
          // Implementation of Runnable.
          public void run() {
!             Dimension size = dequeue();
!             if (size != null) {
                  // Set the frame's (and thus also the rootpane's) size.
                  if (verboseSizeLayout)
                      System.err.println("SWT->AWT thread: Setting size: " + size.width + " x " + size.height + " for " + swingComponent);
--- 784,795 ----
          }
          // Implementation of Runnable.
          public void run() {
!             assert EventQueue.isDispatchThread();    // On AWT event thread
!             assert !processing;
!             for (;;) {
!                 Dimension size = dequeue();
!                 if (size == null)
!                     break;
                  // Set the frame's (and thus also the rootpane's) size.
                  if (verboseSizeLayout)
                      System.err.println("SWT->AWT thread: Setting size: " + size.width + " x " + size.height + " for " + swingComponent);
***************
*** 783,789 ****
--- 797,813 ----
                      frame.setBounds(0, 0, Math.max(size.width, 0), Math.max(size.height, 0));
                      frame.validate();
                  }
+                 // Test if another request was enqueued (from the SWT thread)
+                 // while we were processing this one.
+                 synchronized(this) {
+                     processing = false;
+                     if (!pending)
+                         break;
+                 }
+                 // While this thread was resizing the frame, the SWT thread
+                 // enqueued another request.
              }
+             assert !processing;
          }
      }
      private SetAWTSizeQueue setAWTSizeQueue = new SetAWTSizeQueue();