Workaround for Atmosphere race condition (#13528)

Change-Id: I39cb72ef9a1f6c6424dce7f9feff2cebbfe3fdfd

1 files changed, 40 insertions, 32 deletions

diff --git a/server/src/com/vaadin/server/communication/PushRequestHandler.java b/server/src/com/vaadin/server/communication/PushRequestHandler.java
index 7ac4c0e406..82e3961049 100644
--- a/server/src/com/vaadin/server/communication/PushRequestHandler.java
+++ b/server/src/com/vaadin/server/communication/PushRequestHandler.java
@@ -57,6 +57,12 @@ public class PushRequestHandler implements RequestHandler,
     private AtmosphereFramework atmosphere;
     private PushHandler pushHandler;
 
+    /**
+     * Atmosphere 2.x has a race condition when AtmosphereFramework init(config)
+     * is run from two threads at once. See http://dev.vaadin.com/ticket/13528
+     */
+    private static Object atmosphereInitRaceConditionWorkaroundLock = new Object();
+
     public PushRequestHandler(VaadinServletService service)
             throws ServiceException {
 
@@ -85,38 +91,40 @@ public class PushRequestHandler implements RequestHandler,
             }
         });
 
-        pushHandler = new PushHandler(service);
-        atmosphere.addAtmosphereHandler("/*", pushHandler.handler);
-        atmosphere.addInitParameter(ApplicationConfig.BROADCASTER_CACHE,
-                UUIDBroadcasterCache.class.getName());
-        atmosphere.addInitParameter(ApplicationConfig.PROPERTY_SESSION_SUPPORT,
-                "true");
-        atmosphere.addInitParameter(ApplicationConfig.MESSAGE_DELIMITER,
-                String.valueOf(PushConstants.MESSAGE_DELIMITER));
-
-        final String bufferSize = String
-                .valueOf(PushConstants.WEBSOCKET_BUFFER_SIZE);
-        atmosphere.addInitParameter(ApplicationConfig.WEBSOCKET_BUFFER_SIZE,
-                bufferSize);
-        atmosphere.addInitParameter(ApplicationConfig.WEBSOCKET_MAXTEXTSIZE,
-                bufferSize);
-        atmosphere.addInitParameter(ApplicationConfig.WEBSOCKET_MAXBINARYSIZE,
-                bufferSize);
-
-        // Disable Atmosphere's message about commercial support
-        atmosphere.addInitParameter("org.atmosphere.cpr.showSupportMessage",
-                "false");
-
-        try {
-            atmosphere.init(config);
-
-            // Ensure the client-side knows how to split the message stream
-            // into individual messages when using certain transports
-            AtmosphereInterceptor trackMessageSize = new TrackMessageSizeInterceptor();
-            trackMessageSize.configure(atmosphere.getAtmosphereConfig());
-            atmosphere.interceptor(trackMessageSize);
-        } catch (ServletException e) {
-            throw new ServiceException("Atmosphere init failed", e);
+        synchronized (atmosphereInitRaceConditionWorkaroundLock) {
+            pushHandler = new PushHandler(service);
+            atmosphere.addAtmosphereHandler("/*", pushHandler.handler);
+            atmosphere.addInitParameter(ApplicationConfig.BROADCASTER_CACHE,
+                    UUIDBroadcasterCache.class.getName());
+            atmosphere.addInitParameter(
+                    ApplicationConfig.PROPERTY_SESSION_SUPPORT, "true");
+            atmosphere.addInitParameter(ApplicationConfig.MESSAGE_DELIMITER,
+                    String.valueOf(PushConstants.MESSAGE_DELIMITER));
+
+            final String bufferSize = String
+                    .valueOf(PushConstants.WEBSOCKET_BUFFER_SIZE);
+            atmosphere.addInitParameter(
+                    ApplicationConfig.WEBSOCKET_BUFFER_SIZE, bufferSize);
+            atmosphere.addInitParameter(
+                    ApplicationConfig.WEBSOCKET_MAXTEXTSIZE, bufferSize);
+            atmosphere.addInitParameter(
+                    ApplicationConfig.WEBSOCKET_MAXBINARYSIZE, bufferSize);
+
+            // Disable Atmosphere's message about commercial support
+            atmosphere.addInitParameter(
+                    "org.atmosphere.cpr.showSupportMessage", "false");
+
+            try {
+                atmosphere.init(config);
+
+                // Ensure the client-side knows how to split the message stream
+                // into individual messages when using certain transports
+                AtmosphereInterceptor trackMessageSize = new TrackMessageSizeInterceptor();
+                trackMessageSize.configure(atmosphere.getAtmosphereConfig());
+                atmosphere.interceptor(trackMessageSize);
+            } catch (ServletException e) {
+                throw new ServiceException("Atmosphere init failed", e);
+            }
         }
     }