234271 - Invalid thread access logged in the .log file

2 files changed, 23 insertions, 3 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Display.java b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Display.java
index d70bd53ba3..b882b4fd91 100755
--- a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Display.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Display.java
@@ -680,7 +680,27 @@ protected void checkSubclass () {
 
 protected void checkDevice () {
 	if (thread == null) error (SWT.ERROR_WIDGET_DISPOSED);
-	if (thread != Thread.currentThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
+	if (thread != Thread.currentThread ()) {
+		/*
+		* Bug in IBM JVM 1.6.  For some reason, under
+		* conditions that are yet to be full understood,
+		* Thread.currentThread() is either returning null
+		* or a different instance from the one that was
+		* saved when the Display was created.  This is
+		* possibly a JIT problem because modifying this
+		* method to print logging information when the
+		* error happens seems to fix the problem.  The
+		* fix is to use operating system calls to verify
+		* that the current thread is not the Display thread.
+		* 
+		* NOTE: Despite the fact that Thread.currentThread()
+		* is used in other places, the failure has not been
+		* observed in all places where it is called. 
+		*/
+		if (threadId != OS.GetCurrentThreadId ()) {
+			error (SWT.ERROR_THREAD_INVALID_ACCESS);
+		}
+	}
 	if (isDisposed ()) error (SWT.ERROR_DEVICE_DISPOSED);
 }
 
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Widget.java b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Widget.java
index 09250e4720..9fa412b94e 100755
--- a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Widget.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Widget.java
@@ -347,8 +347,8 @@ protected void checkWidget () {
 		* that the current thread is not the Display thread.
 		* 
 		* NOTE: Despite the fact that Thread.currentThread()
-		* is used in other places, the failure has only been
-		* observed here.
+		* is used in other places, the failure has not been
+		* observed in all places where it is called. 
 		*/
 		if (display.threadId != OS.GetCurrentThreadId ()) {
 			error (SWT.ERROR_THREAD_INVALID_ACCESS);