Fix problems accessing IExpressions2 outside executor thread (bug 306553)

dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/viewmodel/DsfCastToTypeSupport.java

@@ -13,10 +13,13 @@ package org.eclipse.cdt.dsf.debug.internal.ui.viewmodel;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ExecutionException;
 
 import org.eclipse.cdt.debug.core.model.ICastToArray;
 import org.eclipse.cdt.debug.core.model.ICastToType;
+import org.eclipse.cdt.dsf.concurrent.DataRequestMonitor;
 import org.eclipse.cdt.dsf.concurrent.IDsfStatusConstants;
+import org.eclipse.cdt.dsf.concurrent.Query;
 import org.eclipse.cdt.dsf.datamodel.AbstractDMEvent;
 import org.eclipse.cdt.dsf.datamodel.DMContexts;
 import org.eclipse.cdt.dsf.debug.service.IExpressions.IExpressionChangedDMEvent;
@@ -57,8 +60,51 @@ public class DsfCastToTypeSupport  {
 			this.memento = createCastedExpressionMemento(exprDMC);
     	}
 		
+	    public class TestExpressions2Query extends Query<Boolean> {
+
+	        public TestExpressions2Query() {
+	            super();
+	        }
+
+	        @Override
+	        protected void execute(final DataRequestMonitor<Boolean> rm) {
+	            /*
+	             * We're in another dispatch, so we must guard against executor
+	             * shutdown again.
+	             */
+	            final DsfSession session = DsfSession.getSession(
+	            		dmvmProvider.getSession().getId());
+	            if (session == null) {
+	                cancel(false);
+	                rm.done();
+	                return;
+	            }
+
+                DsfServicesTracker tracker = new DsfServicesTracker(
+                		DsfUIPlugin.getBundleContext(), dmvmProvider.getSession().getId());
+                IExpressions2 expressions2 = tracker.getService(IExpressions2.class);
+                rm.setData(expressions2 != null);
+                rm.done();
+                tracker.dispose();
+	        }
+	    }
+
 		private boolean isValid() {
-			return (serviceTracker.getService(IExpressions2.class) != null && exprDMC != null); 
+	        TestExpressions2Query query = new TestExpressions2Query();
+	        dmvmProvider.getSession().getExecutor().execute(query);
+
+			try {
+				/*
+				 * Return value is irrelevant, any error would come through with an
+				 * exception.
+				 */
+				return query.get();
+			} catch (InterruptedException e) {
+				assert false;
+				return false;
+			} catch (ExecutionException e) {
+				return false;
+			}
 		}
 		
 		private void throwIfNotValid() throws DebugException {

dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/ui/viewmodel/expression/ExpressionVMProvider.java

@@ -248,12 +248,10 @@ public class ExpressionVMProvider extends AbstractDMVMProvider
         VariableVMNode variableNode =  new VariableVMNode(this, getSession(), syncvarDataAccess);
         addChildNodes(variableNode, new IExpressionVMNode[] {variableNode});
         
-        /* Wire up the casting support if the IExpressions2 service is available. */
+        /*
-        DsfServicesTracker tracker = new DsfServicesTracker(DsfUIPlugin.getBundleContext(), getSession().getId());
+         * Hook up IExpressions2 if it exists.
-        IExpressions2 expressions2 = tracker.getService(IExpressions2.class);
+         */
-        if (expressions2 != null) {
+        hookUpCastingSupport(syncvarDataAccess, variableNode);
-        	variableNode.setCastToTypeSupport(new DsfCastToTypeSupport(getSession(), this, syncvarDataAccess));
-        }
 
         /*
          *  Tell the expression node which sub-nodes it will directly support.  It is very important
@@ -274,6 +272,25 @@ public class ExpressionVMProvider extends AbstractDMVMProvider
         setRootNode(rootNode);
     }
 
+	private void hookUpCastingSupport(final SyncVariableDataAccess syncvarDataAccess,
+			final VariableVMNode variableNode) {
+		 try {
+            getSession().getExecutor().execute(new DsfRunnable() {
+                public void run() {
+                    DsfServicesTracker tracker = new DsfServicesTracker(DsfUIPlugin.getBundleContext(), getSession().getId());
+                    IExpressions2 expressions2 = tracker.getService(IExpressions2.class);
+                    if (expressions2 != null) {
+                    	variableNode.setCastToTypeSupport(new DsfCastToTypeSupport(
+                    			getSession(), ExpressionVMProvider.this, syncvarDataAccess));
+                    }
+                    tracker.dispose();
+                }
+            });
+        } catch (RejectedExecutionException e) {
+            // Session disposed, ignore.
+        }
+	}
+    
     /**
      * Finds the expression node which can parse the given expression.  This 
      * method is used by the expression content and model proxy strategies.

dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/ui/viewmodel/variable/VariableVMProvider.java

@@ -101,17 +101,33 @@ public class VariableVMProvider extends AbstractDMVMProvider
         addChildNodes(rootNode, new IVMNode[] { subExpressioNode });
         
         // Wire up the casting support if the IExpressions2 service is available.
-        DsfServicesTracker tracker = new DsfServicesTracker(DsfUIPlugin.getBundleContext(), getSession().getId());
+        hookUpCastingSupport(varAccess, subExpressioNode);
-        IExpressions2 expressions2 = tracker.getService(IExpressions2.class);
-        if (expressions2 != null) {
-        	subExpressioNode.setCastToTypeSupport(new DsfCastToTypeSupport(getSession(), this, varAccess));
-        }
 
         // Configure the sub-expression node to be a child of itself.  This way the content
         // provider will recursively drill-down the variable hierarchy.
         addChildNodes(subExpressioNode, new IVMNode[] { subExpressioNode });
     }
 
+	private void hookUpCastingSupport(final SyncVariableDataAccess syncvarDataAccess,
+			final VariableVMNode variableNode) {
+		 try {
+            getSession().getExecutor().execute(new DsfRunnable() {
+                public void run() {
+                    DsfServicesTracker tracker = new DsfServicesTracker(DsfUIPlugin.getBundleContext(), getSession().getId());
+                    IExpressions2 expressions2 = tracker.getService(IExpressions2.class);
+                    if (expressions2 != null) {
+                    	variableNode.setCastToTypeSupport(new DsfCastToTypeSupport(
+                    			getSession(), VariableVMProvider.this, syncvarDataAccess));
+                    }
+                    tracker.dispose();
+                }
+            });
+        } catch (RejectedExecutionException e) {
+            // Session disposed, ignore.
+        }
+	}
+    
+
     @Override
     public IColumnPresentation createColumnPresentation(IPresentationContext context, Object element) {
         return new VariableColumnPresentation();