Bug 262245 - [vm] AbstractVMProvider may install the same model proxy for multiple views, resulting in the viewer not working.

2 files changed, 12 insertions, 4 deletions

diff --git a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/ui/viewmodel/AbstractVMProvider.java b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/ui/viewmodel/AbstractVMProvider.java
index de4388e247e..d0a8b339867 100644
--- a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/ui/viewmodel/AbstractVMProvider.java
+++ b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/ui/viewmodel/AbstractVMProvider.java
@@ -637,12 +637,14 @@ abstract public class AbstractVMProvider implements IVMProvider, IVMEventListene
     public IModelProxy createModelProxy(Object element, IPresentationContext context) {
         
         // Iterate through the current active proxies to try to find a proxy with the same
-        // element and re-use it if found.  At the same time purge proxies that are no longer
+        // element and re-use it if found. Only disposed proxies can be re-used because
+        // multiple viewers cannot use the same proxy.  Also at this time purge other proxies 
+        // that are no longer installed.
         IVMModelProxy proxy = null;
         for (Iterator<IVMModelProxy> itr = getActiveModelProxies().iterator(); itr.hasNext();) {
             IVMModelProxy next = itr.next();
             if (next != null) {
-            	if (next.getRootElement().equals(element)) {
+            	if (next.getRootElement().equals(element) && next.isDisposed()) {
             		proxy = next;
             	} else if (next.isDisposed()) {
             		itr.remove();
diff --git a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/ui/viewmodel/update/AbstractCachingVMProvider.java b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/ui/viewmodel/update/AbstractCachingVMProvider.java
index 632a1dc2607..2df17ebf83d 100644
--- a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/ui/viewmodel/update/AbstractCachingVMProvider.java
+++ b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/ui/viewmodel/update/AbstractCachingVMProvider.java
@@ -819,11 +819,17 @@ public class AbstractCachingVMProvider extends AbstractVMProvider implements ICa
     @Override
     public IModelProxy createModelProxy(Object element, IPresentationContext context) {
         // Iterate through the current active proxies to try to find a proxy with the same
-        // element and re-use it if found.  At the same time purge proxies that are no longer
+        // element and re-use it if found.  Only disposed proxies can be re-used because
+        // multiple viewers cannot use the same proxy.
+        // 
+        // Unlike in the base class, do not remove proxies just because they were disposed 
+        // by the viewer.  These proxies can contain modification history for variables in 
+        // their cache.  The proxies will be removed once their cache entries are emptied.  
+        // See rootElementRemovedFromCache().
         IVMModelProxy proxy = null;
         for (Iterator<IVMModelProxy> itr = getActiveModelProxies().iterator(); itr.hasNext();) {
             IVMModelProxy next = itr.next();
-            if (next != null && next.getRootElement().equals(element)) {
+            if (next != null && next.getRootElement().equals(element) && next.isDisposed()) {
                 proxy = next;
                 break;
             }