[452962] Have Saver registration done in a single place and correctly

- Have Saver registration/unregistration for both
ResourceSetListener and Lifecycle in constructor/dispose().
- Add SaverTest to check that in case of rollback a save in postcommit
is
disarmed to avoid a save for the next executed command.
- SaverTest is minimalist and can be run in standalone, it's for that
SessionResourcesSynchronizer/DAnalysisSelectorService/DAnalysisSessionImpl
and some others classes are changed.
- To avoid "IllegalStateException: Cannot activate read/write
transaction in read-only transaction context" when calling the
SavingPolicy in postcommit and this SavingPolicy execute an EMF Command,
have Saver call the SavingPolicy in
TransactionalEditingDomainListener.transactionClosed().
Have WorkspaceBackEnd cleaned correctly on session close.

Bug: 452962
Change-Id: Ibca4ebdb0a85eaf1ab9c0583b49a6f8630174cc4
Signed-off-by: Esteban Dugueperoux <esteban.dugueperoux@obeo.fr>

6 files changed, 262 insertions, 84 deletions

diff --git a/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/resource/AbstractResourceSyncBackend.java b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/resource/AbstractResourceSyncBackend.java
index b58beb0333..f48950d645 100644
--- a/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/resource/AbstractResourceSyncBackend.java
+++ b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/resource/AbstractResourceSyncBackend.java
@@ -43,16 +43,19 @@ public abstract class AbstractResourceSyncBackend {
         this.client = client;
     }
 
-
     /**
      * initialize and prepare the backend.
      */
-    public abstract void install();
+    public void install() {
+
+    }
 
     /**
      * de-initialize the backend.
      */
-    public abstract void uninstall();
+    public void uninstall() {
+        observedSet = null;
+    }
 
     /**
      * Specify which {@link ResourceSet} the backend should notify about.
diff --git a/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/internal/resource/WorkspaceBackend.java b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/internal/resource/WorkspaceBackend.java
index 1a1d5f2ad3..1777318436 100644
--- a/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/internal/resource/WorkspaceBackend.java
+++ b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/internal/resource/WorkspaceBackend.java
@@ -57,6 +57,7 @@ public class WorkspaceBackend extends AbstractResourceSyncBackend {
             workspace.removeResourceChangeListener(listener);
             listener = null;
         }
+        super.uninstall();
     }
 
     public ResourceSet getObservedSet() {
diff --git a/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/suite/common/AllCommonPluginTests.java b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/suite/common/AllCommonPluginTests.java
index 8f194d8f0d..f1a4be8e31 100644
--- a/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/suite/common/AllCommonPluginTests.java
+++ b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/suite/common/AllCommonPluginTests.java
@@ -59,6 +59,7 @@ import org.eclipse.sirius.tests.unit.common.OperationCanceledExceptionSessionTes
 import org.eclipse.sirius.tests.unit.common.PreferencesTests;
 import org.eclipse.sirius.tests.unit.common.RefreshEditorsPrecommitListenerTests;
 import org.eclipse.sirius.tests.unit.common.RestoreSessionFromEditorInputTests;
+import org.eclipse.sirius.tests.unit.common.SaverTest;
 import org.eclipse.sirius.tests.unit.common.SiriusCrossReferenceAdapterTests;
 import org.eclipse.sirius.tests.unit.common.TransientSessionTests;
 import org.eclipse.sirius.tests.unit.common.WorkspaceResourceSyncTestCase;
@@ -265,6 +266,7 @@ public class AllCommonPluginTests extends TestCase {
         suite.addTestSuite(TransientSessionTests.class);
         suite.addTestSuite(RestoreSessionFromEditorInputTests.class);
         suite.addTestSuite(SiriusCrossReferenceAdapterTests.class);
+        suite.addTestSuite(SaverTest.class);
     }
 
     /**
@@ -280,7 +282,8 @@ public class AllCommonPluginTests extends TestCase {
         suite.addTest(new JUnit4TestAdapter(DiagramMigrationTestCampaign10.class));
         // This one takes too long (12 minutes) to be part of the Gerrit suite.
         suite.addTestSuite(AcceleoMTInterpreterOnPackageImportTests.class);
-        // The ones below are "blacklisted" for now because they caused at least one false-negative Gerrit Verification job
+        // The ones below are "blacklisted" for now because they caused at least
+        // one false-negative Gerrit Verification job
         suite.addTestSuite(SessionManagerListener2Tests.class);
 
     }
diff --git a/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/SaverTest.java b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/SaverTest.java
new file mode 100644
index 0000000000..8545dfd3cf
--- /dev/null
+++ b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/SaverTest.java
@@ -0,0 +1,177 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Obeo. 
+ * All rights reserved. This program
+ * and the accompanying materials are made available under the terms of the
+ * Eclipse Public License v1.0 which accompanies this distribution, and is
+ * available at http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors: Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.tests.unit.common;
+
+import java.io.File;
+import java.util.Collection;
+import java.util.Map;
+
+import junit.framework.TestCase;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.emf.common.command.Command;
+import org.eclipse.emf.common.util.URI;
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.emf.transaction.RecordingCommand;
+import org.eclipse.emf.transaction.ResourceSetChangeEvent;
+import org.eclipse.emf.transaction.ResourceSetListener;
+import org.eclipse.emf.transaction.ResourceSetListenerImpl;
+import org.eclipse.emf.transaction.RollbackException;
+import org.eclipse.emf.transaction.TransactionalEditingDomain;
+import org.eclipse.sirius.business.api.helper.SiriusUtil;
+import org.eclipse.sirius.business.api.session.SavingPolicy;
+import org.eclipse.sirius.business.api.session.Session;
+import org.eclipse.sirius.business.api.session.SessionStatus;
+import org.eclipse.sirius.business.api.session.factory.SessionFactory;
+import org.eclipse.sirius.business.internal.resource.parser.AirDResourceFactory;
+import org.eclipse.sirius.business.internal.session.danalysis.DAnalysisSessionImpl;
+import org.eclipse.sirius.viewpoint.DAnalysis;
+
+/**
+ * Test for Bugzilla 445603.
+ * 
+ * @author <a href="mailto:esteban.dugueperoux@obeo.fr">Esteban Dugueperoux</a>
+ */
+public class SaverTest extends TestCase {
+
+    private File tempFile;
+
+    private Session session;
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+        Resource.Factory.Registry.INSTANCE.getExtensionToFactoryMap().put(SiriusUtil.SESSION_RESOURCE_EXTENSION, new AirDResourceFactory());
+        tempFile = File.createTempFile("test", "." + SiriusUtil.SESSION_RESOURCE_EXTENSION);
+        tempFile.delete();
+        URI sessionResourceURI = URI.createFileURI(tempFile.getCanonicalPath());
+        session = SessionFactory.INSTANCE.createSession(sessionResourceURI, new NullProgressMonitor());
+        session.open(new NullProgressMonitor());
+    }
+
+    /**
+     * Test that a session saving in middle of a EMF Transaction is done only
+     * after transaction closing.
+     */
+    public void testSaveInMiddleOfTransaction() {
+        // Make the session dirty
+        TransactionalEditingDomain domain = session.getTransactionalEditingDomain();
+        DAnalysis dAnalysis = (DAnalysis) session.getSessionResource().getContents().get(0);
+        Command updateDAnalysisCmd = new ChangeDAnalysisCmd(domain, dAnalysis);
+        domain.getCommandStack().execute(updateDAnalysisCmd);
+        assertEquals(SessionStatus.DIRTY, session.getStatus());
+
+        // Test that session is saved only after transaction closing
+        ResourceSetListener saverInMiddleOfTx = new SaverInMiddleOfTx(session, false);
+        domain.addResourceSetListener(saverInMiddleOfTx);
+        updateDAnalysisCmd = new ChangeDAnalysisCmd(domain, dAnalysis);
+        domain.getCommandStack().execute(updateDAnalysisCmd);
+        assertEquals(SessionStatus.SYNC, session.getStatus());
+        domain.removeResourceSetListener(saverInMiddleOfTx);
+
+        // Test also with a rollback
+        saverInMiddleOfTx = new SaverInMiddleOfTx(session, true);
+        domain.addResourceSetListener(saverInMiddleOfTx);
+
+        updateDAnalysisCmd = new ChangeDAnalysisCmd(domain, dAnalysis);
+        domain.getCommandStack().execute(updateDAnalysisCmd);
+        assertEquals(SessionStatus.SYNC, session.getStatus());
+        domain.removeResourceSetListener(saverInMiddleOfTx);
+
+        updateDAnalysisCmd = new ChangeDAnalysisCmd(domain, dAnalysis);
+        domain.getCommandStack().execute(updateDAnalysisCmd);
+        assertEquals(SessionStatus.DIRTY, session.getStatus());
+    }
+
+    /**
+     * Test that a session saving in middle of a EMF Transaction is done only
+     * after transaction closing and with a {@link SavingPolicy} executing a EMF
+     * Command does not throw exception "IllegalStateException: Cannot activate
+     * read/write transaction in read-only transaction context".
+     */
+    public void testSaveInMiddleOfTransactionWithSavingPolicyExecutingAEMFCommand() {
+        ((DAnalysisSessionImpl) session).setSaveInExclusiveTransaction(false);
+        final SavingPolicy savingPolicy = session.getSavingPolicy();
+        session.setSavingPolicy(new SavingPolicy() {
+
+            @Override
+            public Collection<Resource> save(Iterable<Resource> resourcesToSave, Map<?, ?> options, IProgressMonitor monitor) {
+                TransactionalEditingDomain domain = session.getTransactionalEditingDomain();
+                DAnalysis dAnalysis = (DAnalysis) session.getSessionResource().getContents().get(0);
+                Command updateDAnalysisCmd = new ChangeDAnalysisCmd(domain, dAnalysis);
+                domain.getCommandStack().execute(updateDAnalysisCmd);
+                return savingPolicy.save(resourcesToSave, options, monitor);
+            }
+        });
+        // Make the session dirty
+        TransactionalEditingDomain domain = session.getTransactionalEditingDomain();
+        DAnalysis dAnalysis = (DAnalysis) session.getSessionResource().getContents().get(0);
+        Command updateDAnalysisCmd = new ChangeDAnalysisCmd(domain, dAnalysis);
+        domain.getCommandStack().execute(updateDAnalysisCmd);
+        assertEquals(SessionStatus.DIRTY, session.getStatus());
+
+        // Test that session is saved only after transaction closing
+        ResourceSetListener saverInMiddleOfTx = new SaverInMiddleOfTx(session, false);
+        domain.addResourceSetListener(saverInMiddleOfTx);
+        updateDAnalysisCmd = new ChangeDAnalysisCmd(domain, dAnalysis);
+        domain.getCommandStack().execute(updateDAnalysisCmd);
+        assertEquals(SessionStatus.SYNC, session.getStatus());
+        domain.removeResourceSetListener(saverInMiddleOfTx);
+    }
+
+    private static class ChangeDAnalysisCmd extends RecordingCommand {
+
+        private DAnalysis dAnalysis;
+
+        public ChangeDAnalysisCmd(TransactionalEditingDomain domain, DAnalysis dAnalysis) {
+            super(domain);
+            this.dAnalysis = dAnalysis;
+        }
+
+        @Override
+        protected void doExecute() {
+            dAnalysis.setVersion(dAnalysis.getVersion() + "Changed");
+        }
+    }
+
+    private static class SaverInMiddleOfTx extends ResourceSetListenerImpl {
+
+        private Session session;
+
+        private boolean rollback;
+
+        public SaverInMiddleOfTx(Session session, boolean rollback) {
+            this.session = session;
+            this.rollback = rollback;
+        }
+
+        @Override
+        public Command transactionAboutToCommit(ResourceSetChangeEvent event) throws RollbackException {
+            session.save(new NullProgressMonitor());
+            if (rollback) {
+                throw new RollbackException(Status.CANCEL_STATUS);
+            } else {
+                assertEquals(SessionStatus.DIRTY, session.getStatus());
+            }
+            return super.transactionAboutToCommit(event);
+        }
+    }
+
+    @Override
+    protected void tearDown() throws Exception {
+        session.close(new NullProgressMonitor());
+        session = null;
+        tempFile.delete();
+        tempFile = null;
+        super.tearDown();
+    }
+}
diff --git a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/session/danalysis/DAnalysisSessionImpl.java b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/session/danalysis/DAnalysisSessionImpl.java
index 71c5ff361e..8dc8288cde 100644
--- a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/session/danalysis/DAnalysisSessionImpl.java
+++ b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/session/danalysis/DAnalysisSessionImpl.java
@@ -13,7 +13,6 @@ package org.eclipse.sirius.business.internal.session.danalysis;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
@@ -142,7 +141,7 @@ public class DAnalysisSessionImpl extends DAnalysisSessionEObjectImpl implements
 
     // Session's configuration
 
-    private final Saver saver = new Saver(this);
+    private final Saver saver;
 
     private ReloadingPolicy reloadingPolicy;
 
@@ -192,7 +191,7 @@ public class DAnalysisSessionImpl extends DAnalysisSessionEObjectImpl implements
         Preconditions.checkNotNull(this.sessionResource, "A session must be inside a resource.");
         this.transactionalEditingDomain = Preconditions.checkNotNull(TransactionUtil.getEditingDomain(mainDAnalysis), "A session must be associated to an EditingDomain");
         this.mainDAnalysis = mainDAnalysis;
-
+        this.saver = new Saver(this);
         this.interpreter = new ODesignGenericInterpreter();
         this.representationsChangeAdapter = new RepresentationsChangeAdapter(this);
         this.controlledResourcesDetector = new ControlledResourcesDetector(this);
@@ -303,8 +302,7 @@ public class DAnalysisSessionImpl extends DAnalysisSessionEObjectImpl implements
         // resourceSet
         // code to remove when AirDCrossReferenceAdapter is deleted
         List<Adapter> adaptersToRemove = new ArrayList<Adapter>();
-        for (Iterator<Adapter> iterator = resourceSet.eAdapters().iterator(); iterator.hasNext(); ) {
-            Adapter next = iterator.next();
+        for (Adapter next : resourceSet.eAdapters()) {
             if (next instanceof SiriusCrossReferenceAdapter) {
                 ((SiriusCrossReferenceAdapter) next).disableResolveProxy();
                 adaptersToRemove.add(next);
@@ -984,6 +982,14 @@ public class DAnalysisSessionImpl extends DAnalysisSessionEObjectImpl implements
         return this.saver.deferSaveToPostCommit;
     }
 
+    /**
+     * Set to true to do saving in a read-only EMF Transaction, false otherwise.
+     * Note that if the {@link SavingPolicy} execute some EMF Command, this must
+     * be at false.
+     * 
+     * @param saveInExclusiveTransaction
+     *            specify if the saving is done in a read-only transaction
+     */
     public void setSaveInExclusiveTransaction(boolean saveInExclusiveTransaction) {
         this.saver.saveInExclusiveTransaction = saveInExclusiveTransaction;
     }
@@ -1212,7 +1218,6 @@ public class DAnalysisSessionImpl extends DAnalysisSessionEObjectImpl implements
             monitor.worked(1);
             this.representationNameListener = new RepresentationNameListener(this);
             monitor.worked(1);
-            saver.initialize();
 
             final Collection<DAnalysis> allAnalyses = allAnalyses();
             if (allAnalyses.isEmpty()) {
@@ -1277,8 +1282,6 @@ public class DAnalysisSessionImpl extends DAnalysisSessionEObjectImpl implements
             monitor.worked(1);
             DViewOperations.on(this).updateSelectedViewpointsData(new SubProgressMonitor(monitor, 10));
             initLocalTriggers();
-
-            getTransactionalEditingDomain().addResourceSetListener(saver);
         } catch (OperationCanceledException e) {
             close(new SubProgressMonitor(monitor, 10));
             throw e;
@@ -1306,9 +1309,6 @@ public class DAnalysisSessionImpl extends DAnalysisSessionEObjectImpl implements
         if (!isOpen()) {
             return;
         }
-        if (saver != null && getTransactionalEditingDomain() != null) {
-            getTransactionalEditingDomain().removeResourceSetListener(saver);
-        }
         ViewpointRegistry.getInstance().removeListener(this.vsmUpdater);
         this.vsmUpdater = null;
         notifyListeners(SessionListener.CLOSING);
@@ -1400,10 +1400,9 @@ public class DAnalysisSessionImpl extends DAnalysisSessionEObjectImpl implements
         // Disable resolveProxy for SiriusCrossreferencerAdapter.
         // SiriusCrossreferencerAdapter on EObject are also on resource,
         // consequently we manage only the resource itself.
-        for (Iterator<Adapter> iterator = resource.eAdapters().iterator(); iterator.hasNext(); ) {
-            Adapter next = iterator.next();
-            if (next instanceof SiriusCrossReferenceAdapter) {
-                ((SiriusCrossReferenceAdapter) next).disableResolveProxy();
+        for (Adapter adapter : resource.eAdapters()) {
+            if (adapter instanceof SiriusCrossReferenceAdapter) {
+                ((SiriusCrossReferenceAdapter) adapter).disableResolveProxy();
             }
         }
     }
@@ -1419,10 +1418,9 @@ public class DAnalysisSessionImpl extends DAnalysisSessionEObjectImpl implements
         // Enable resolveProxy for SiriusCrossreferencerAdapter.
         // SiriusCrossreferencerAdapter on EObject are also on resource,
         // consequently we manage only the resource itself.
-        for (Iterator<Adapter> iterator = resource.eAdapters().iterator(); iterator.hasNext(); ) {
-            Adapter next = iterator.next();
-            if (next instanceof SiriusCrossReferenceAdapter) {
-                ((SiriusCrossReferenceAdapter) next).enableResolveProxy();
+        for (Adapter adapter : resource.eAdapters()) {
+            if (adapter instanceof SiriusCrossReferenceAdapter) {
+                ((SiriusCrossReferenceAdapter) adapter).enableResolveProxy();
             }
         }
     }
diff --git a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/session/danalysis/Saver.java b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/session/danalysis/Saver.java
index 9ec3b6366c..1e27288a9e 100644
--- a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/session/danalysis/Saver.java
+++ b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/session/danalysis/Saver.java
@@ -14,32 +14,33 @@ import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.emf.transaction.ResourceSetChangeEvent;
-import org.eclipse.emf.transaction.ResourceSetListenerImpl;
 import org.eclipse.emf.transaction.TransactionalEditingDomain;
+import org.eclipse.emf.transaction.TransactionalEditingDomain.Lifecycle;
 import org.eclipse.emf.transaction.TransactionalEditingDomainEvent;
-import org.eclipse.emf.transaction.TransactionalEditingDomainListener;
 import org.eclipse.emf.transaction.TransactionalEditingDomainListenerImpl;
 import org.eclipse.emf.transaction.impl.InternalTransaction;
 import org.eclipse.emf.transaction.impl.InternalTransactionalEditingDomain;
+import org.eclipse.emf.transaction.util.TransactionUtil;
 
 /**
- * Encapsulates the decision of *when* to actually save the session's state
- * when Session.save() is called. If Session.save() is called while a
- * transaction is in progress and deferSaveToPostCommit is true, the actual
- * saving will be performed after the current transaction has been
- * successfully commited. Otherwise it is performed immediatly.
+ * Encapsulates the decision of *when* to actually save the session's state when
+ * Session.save() is called. If Session.save() is called while a transaction is
+ * in progress and deferSaveToPostCommit is true, the actual saving will be
+ * performed after the current transaction has been successfully commited.
+ * Otherwise it is performed immediatly.
  * 
  * @author pcdavid
  */
-final class Saver extends ResourceSetListenerImpl {
+final class Saver extends TransactionalEditingDomainListenerImpl {
 
-    
     boolean deferSaveToPostCommit;
-    
+
     boolean saveInExclusiveTransaction;
-    
+
     AtomicBoolean domainDisposed = new AtomicBoolean(false);
+
+    private TransactionalEditingDomain domain;
+
     private final DAnalysisSessionImpl session;
 
     private AtomicBoolean saveOnPostCommit = new AtomicBoolean(false);
@@ -48,22 +49,7 @@ final class Saver extends ResourceSetListenerImpl {
 
     private IProgressMonitor savedMonitor;
 
-    /**
-     * Make sure the Saver's state is reset after the transaction is
-     * finished, even in case of rollback (in which case #resourceSetChanged
-     * will not have need called).
-     */
-    private TransactionalEditingDomainListener domainListener = new TransactionalEditingDomainListenerImpl() {
-        @Override
-        public void transactionClosed(TransactionalEditingDomainEvent event) {
-            disarm();
-        }
-
-        @Override
-        public void editingDomainDisposing(TransactionalEditingDomainEvent event) {
-            domainDisposed.set(true);
-        }
-    };
+    private AtomicBoolean isSaving = new AtomicBoolean();
 
     /**
      * Create a new Saver for the specified session.
@@ -73,51 +59,40 @@ final class Saver extends ResourceSetListenerImpl {
      */
     public Saver(DAnalysisSessionImpl session) {
         this.session = session;
-    }
-
-    public void initialize() {
-        TransactionalEditingDomain ted = session.getTransactionalEditingDomain();
-        if (ted instanceof TransactionalEditingDomain.Lifecycle) {
-            TransactionalEditingDomain.Lifecycle lc = (TransactionalEditingDomain.Lifecycle) ted;
-            lc.addTransactionalEditingDomainListener(domainListener);
-        }
-    }
-
-    public void dispose() {
-        TransactionalEditingDomain ted = session.getTransactionalEditingDomain();
-        if (ted instanceof TransactionalEditingDomain.Lifecycle) {
-            TransactionalEditingDomain.Lifecycle lc = (TransactionalEditingDomain.Lifecycle) ted;
-            lc.removeTransactionalEditingDomainListener(domainListener);
+        domain = session.getTransactionalEditingDomain();
+        Lifecycle lifecycle = TransactionUtil.getAdapter(domain, Lifecycle.class);
+        if (lifecycle != null) {
+            lifecycle.addTransactionalEditingDomainListener(this);
         }
-        disarm();
-    }
-
-    @Override
-    public boolean isPostcommitOnly() {
-        return true;
     }
 
+    /**
+     * Do saving after transaction closing in case the SavingPolicy trigger
+     * another transaction by executing a EMF Command.
+     */
     @Override
-    public void resourceSetChanged(ResourceSetChangeEvent event) {
-        if (saveOnPostCommit.get()) {
-            saveNow(this.savedOptions, this.savedMonitor, true);
+    public void transactionClosed(TransactionalEditingDomainEvent event) {
+        if (!event.getTransaction().isReadOnly()) {
+            if (saveOnPostCommit.get()) {
+                saveNow(this.savedOptions, this.savedMonitor, saveInExclusiveTransaction);
+            }
         }
     }
 
     public void save(Map<?, ?> options, IProgressMonitor monitor) {
         boolean tip = transactionInProgress();
         if (tip && deferSaveToPostCommit) {
-            saveOnPostCommit(options, monitor);
+            saveAfterTransactionClosing(options, monitor);
         } else {
             saveNow(options, monitor, saveInExclusiveTransaction && !tip && !domainDisposed.get());
         }
     }
 
     /**
-     * Arm the trigger so that the saving is performed on the next
-     * post-commit.
+     * Arm the trigger so that the saving is performed after transaction
+     * closing.
      */
-    private void saveOnPostCommit(Map<?, ?> options, IProgressMonitor monitor) {
+    private void saveAfterTransactionClosing(Map<?, ?> options, IProgressMonitor monitor) {
         this.savedOptions = options;
         this.savedMonitor = monitor;
         this.saveOnPostCommit.set(true);
@@ -127,10 +102,23 @@ final class Saver extends ResourceSetListenerImpl {
      * Save immediately and disarm the trigger.
      */
     private void saveNow(Map<?, ?> options, IProgressMonitor monitor, boolean runExclusive) {
-        try {
-            session.doSave(options, monitor, runExclusive);
-        } finally {
-            disarm();
+        // This allows to have session saving thread safe, i.e. only one thread
+        // can do a save at a time
+        synchronized (isSaving) {
+            // In addition if the session saving or more specifically its
+            // SavingPolicy execute a EMF Command, and we have saveOnPostCommit
+            // at true, we risk a StackOverflow then to avoid that we check if
+            // we are already in a session saving call
+            if (!isSaving.get()) {
+                try {
+                    isSaving.set(true);
+                    session.doSave(options, monitor, runExclusive);
+                } finally {
+                    disarm();
+                    isSaving.set(false);
+
+                }
+            }
         }
     }
 
@@ -148,4 +136,12 @@ final class Saver extends ResourceSetListenerImpl {
         return false;
     }
 
-}
\ No newline at end of file
+    public void dispose() {
+        Lifecycle lifecycle = TransactionUtil.getAdapter(domain, Lifecycle.class);
+        if (lifecycle != null) {
+            lifecycle.removeTransactionalEditingDomainListener(this);
+        }
+        disarm();
+    }
+
+}