Use dedicated Lock for session synchronization (#9156)

3 files changed, 55 insertions, 12 deletions

diff --git a/server/src/com/vaadin/server/AbstractCommunicationManager.java b/server/src/com/vaadin/server/AbstractCommunicationManager.java
index 00d508de4c..c2a5377e12 100644
--- a/server/src/com/vaadin/server/AbstractCommunicationManager.java
+++ b/server/src/com/vaadin/server/AbstractCommunicationManager.java
@@ -300,9 +300,12 @@ public abstract class AbstractCommunicationManager implements Serializable {
                 cleanStreamVariable(owner, variableName);
             }
         } catch (Exception e) {
-            synchronized (session) {
+            session.getLock().lock();
+            try {
                 handleChangeVariablesError(session, (Component) owner, e,
                         new HashMap<String, Object>());
+            } finally {
+                session.getLock().unlock();
             }
         }
         sendUploadResponse(request, response);
@@ -345,9 +348,12 @@ public abstract class AbstractCommunicationManager implements Serializable {
                 cleanStreamVariable(owner, variableName);
             }
         } catch (Exception e) {
-            synchronized (session) {
+            session.getLock().lock();
+            try {
                 handleChangeVariablesError(session, (Component) owner, e,
                         new HashMap<String, Object>());
+            } finally {
+                session.getLock().unlock();
             }
         }
         sendUploadResponse(request, response);
@@ -379,10 +385,13 @@ public abstract class AbstractCommunicationManager implements Serializable {
                 filename, type, contentLength);
         try {
             boolean listenProgress;
-            synchronized (session) {
+            session.getLock().lock();
+            try {
                 streamVariable.streamingStarted(startedEvent);
                 out = streamVariable.getOutputStream();
                 listenProgress = streamVariable.listenProgress();
+            } finally {
+                session.getLock().unlock();
             }
 
             // Gets the output target stream
@@ -403,10 +412,13 @@ public abstract class AbstractCommunicationManager implements Serializable {
                 if (listenProgress) {
                     // update progress if listener set and contentLength
                     // received
-                    synchronized (session) {
+                    session.getLock().lock();
+                    try {
                         StreamingProgressEventImpl progressEvent = new StreamingProgressEventImpl(
                                 filename, type, contentLength, totalBytes);
                         streamVariable.onProgress(progressEvent);
+                    } finally {
+                        session.getLock().unlock();
                     }
                 }
                 if (streamVariable.isInterrupted()) {
@@ -418,8 +430,11 @@ public abstract class AbstractCommunicationManager implements Serializable {
             out.close();
             StreamingEndEvent event = new StreamingEndEventImpl(filename, type,
                     totalBytes);
-            synchronized (session) {
+            session.getLock().lock();
+            try {
                 streamVariable.streamingFinished(event);
+            } finally {
+                session.getLock().unlock();
             }
 
         } catch (UploadInterruptedException e) {
@@ -427,20 +442,26 @@ public abstract class AbstractCommunicationManager implements Serializable {
             tryToCloseStream(out);
             StreamingErrorEvent event = new StreamingErrorEventImpl(filename,
                     type, contentLength, totalBytes, e);
-            synchronized (session) {
+            session.getLock().lock();
+            try {
                 streamVariable.streamingFailed(event);
+            } finally {
+                session.getLock().unlock();
             }
             // Note, we are not throwing interrupted exception forward as it is
             // not a terminal level error like all other exception.
         } catch (final Exception e) {
             tryToCloseStream(out);
-            synchronized (session) {
+            session.getLock().lock();
+            try {
                 StreamingErrorEvent event = new StreamingErrorEventImpl(
                         filename, type, contentLength, totalBytes, e);
                 streamVariable.streamingFailed(event);
                 // throw exception for terminal to be handled (to be passed to
                 // terminalErrorHandler)
                 throw new UploadException(e);
+            } finally {
+                session.getLock().unlock();
             }
         }
         return startedEvent.isDisposed();
@@ -551,7 +572,8 @@ public abstract class AbstractCommunicationManager implements Serializable {
         // The rest of the process is synchronized with the session
         // in order to guarantee that no parallel variable handling is
         // made
-        synchronized (session) {
+        session.getLock().lock();
+        try {
 
             // Finds the UI within the session
             if (session.isRunning()) {
@@ -592,6 +614,8 @@ public abstract class AbstractCommunicationManager implements Serializable {
             paintAfterVariableChanges(request, response, callback, repaintAll,
                     outWriter, uI, analyzeLayouts);
             postPaint(uI);
+        } finally {
+            session.getLock().unlock();
         }
 
         outWriter.close();
diff --git a/server/src/com/vaadin/server/VaadinPortlet.java b/server/src/com/vaadin/server/VaadinPortlet.java
index 45a952d48d..026873a04d 100644
--- a/server/src/com/vaadin/server/VaadinPortlet.java
+++ b/server/src/com/vaadin/server/VaadinPortlet.java
@@ -529,7 +529,8 @@ public class VaadinPortlet extends GenericPortlet implements Constants {
 
                 // Finds the window within the application
                 UI uI = null;
-                synchronized (application) {
+                application.getLock().lock();
+                try {
                     if (application.isRunning()) {
                         switch (requestType) {
                         case RENDER:
@@ -555,6 +556,8 @@ public class VaadinPortlet extends GenericPortlet implements Constants {
                         }
                         // if window not found, not a problem - use null
                     }
+                } finally {
+                    application.getLock().unlock();
                 }
 
                 // TODO Should this happen before or after the transaction
diff --git a/server/src/com/vaadin/server/VaadinSession.java b/server/src/com/vaadin/server/VaadinSession.java
index f0e3ec4895..c6b2d91f29 100644
--- a/server/src/com/vaadin/server/VaadinSession.java
+++ b/server/src/com/vaadin/server/VaadinSession.java
@@ -28,6 +28,8 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Logger;
 
 import javax.portlet.PortletSession;
@@ -76,6 +78,8 @@ public class VaadinSession implements HttpSessionBindingListener, Serializable {
             .findMethod(BootstrapListener.class, "modifyBootstrapPage",
                     BootstrapPageResponse.class);
 
+    private final Lock lock = new ReentrantLock();
+
     /**
      * An event sent to {@link #start(SessionStartEvent)} when a new Application
      * is being started.
@@ -929,15 +933,17 @@ public class VaadinSession implements HttpSessionBindingListener, Serializable {
             return uI;
         }
         Integer uiId = getUIId(request);
-
-        synchronized (this) {
+        getLock().lock();
+        try {
             uI = uIs.get(uiId);
 
             if (uI == null) {
                 uI = findExistingUi(request);
             }
 
-        } // end synchronized block
+        } finally {
+            getLock().unlock();
+        }
 
         UI.setCurrent(uI);
 
@@ -1290,4 +1296,14 @@ public class VaadinSession implements HttpSessionBindingListener, Serializable {
         return Collections.unmodifiableCollection(uiProviders);
     }
 
+    /**
+     * Gets the lock that should be used to synchronize usage of data inside
+     * this session.
+     * 
+     * @return the lock that should be used for synchronization
+     */
+    public Lock getLock() {
+        return lock;
+    }
+
 }