[289584] Deadlock in CDOView

https://bugs.eclipse.org/bugs/show_bug.cgi?id=289584

1 files changed, 44 insertions, 29 deletions

diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOViewImpl.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOViewImpl.java
index 9051c2dafb..88696bcf74 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOViewImpl.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOViewImpl.java
@@ -713,49 +713,64 @@ public class CDOViewImpl extends Lifecycle implements InternalCDOView
     {
       return null;
     }
-
-    synchronized (objects)
+    // Since getObject could trigger a read (ONLY when we load a resource) we NEED to make sure the state lock is
+    // active.
+    // Always use in the following order
+    // 1- getStateLock().lock();
+    // 2- synchronized(objects)
+    // DO NOT inverse them otherwise deadlock could occured.
+
+    ReentrantLock stateLock = getStateLock();
+    stateLock.lock();
+    try
     {
-      if (id.equals(lastLookupID))
-      {
-        return lastLookupObject;
-      }
-
-      // Needed for recursive call to getObject. (from createObject/cleanObject/getResource/getObject)
-      InternalCDOObject localLookupObject = objects.get(id);
-      if (localLookupObject == null)
+      synchronized (objects)
       {
-        if (id.isMeta())
+        if (id.equals(lastLookupID))
         {
-          localLookupObject = createMetaObject((CDOIDMeta)id);
+          return lastLookupObject;
         }
-        else
+
+        // Needed for recursive call to getObject. (from createObject/cleanObject/getResource/getObject)
+        InternalCDOObject localLookupObject = objects.get(id);
+        if (localLookupObject == null)
         {
-          if (loadOnDemand)
+          if (id.isMeta())
+          {
+            localLookupObject = createMetaObject((CDOIDMeta)id);
+          }
+          else
           {
-            if (id.isTemporary())
+            if (loadOnDemand)
             {
-              throw new ObjectNotFoundException(id);
-            }
+              if (id.isTemporary())
+              {
+                throw new ObjectNotFoundException(id);
+              }
 
-            localLookupObject = createObject(id);
+              localLookupObject = createObject(id);
+            }
+            else
+            {
+              return null;
+            }
           }
-          else
+
+          // CDOResource have a special way to register to the view.
+          if (!CDOModelUtil.isResource(localLookupObject.eClass()))
           {
-            return null;
+            registerObject(localLookupObject);
           }
         }
 
-        // CDOResource have a special way to register to the view.
-        if (!CDOModelUtil.isResource(localLookupObject.eClass()))
-        {
-          registerObject(localLookupObject);
-        }
+        lastLookupID = id;
+        lastLookupObject = localLookupObject;
+        return lastLookupObject;
       }
-
-      lastLookupID = id;
-      lastLookupObject = localLookupObject;
-      return lastLookupObject;
+    }
+    finally
+    {
+      stateLock.unlock();
     }
   }