Change to avoid assertion when delivery is concurrent with session detachment:

    * in SessionState::getHandler() doesn't assert and just return pointer
    * do assertion internally in SessionState where getHandler was relied
      for this before
    * in SemanticHandler::deliver() get handler and check it; if null then
      dump the message and print an error



git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@594233 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 16 insertions, 11 deletions

diff --git a/cpp/src/qpid/broker/SemanticHandler.cpp b/cpp/src/qpid/broker/SemanticHandler.cpp
index 69dd1fd67e..d6e13e0a55 100644
--- a/cpp/src/qpid/broker/SemanticHandler.cpp
+++ b/cpp/src/qpid/broker/SemanticHandler.cpp
@@ -29,6 +29,7 @@
 #include "qpid/framing/ExecutionCompleteBody.h"
 #include "qpid/framing/ExecutionResultBody.h"
 #include "qpid/framing/ServerInvoker.h"
+#include "qpid/log/Statement.h"
 
 #include <boost/format.hpp>
 #include <boost/bind.hpp>
@@ -166,10 +167,13 @@ void SemanticHandler::handleContent(AMQFrame& frame)
 DeliveryId SemanticHandler::deliver(QueuedMessage& msg, DeliveryToken::shared_ptr token)
 {
     Mutex::ScopedLock l(outLock);
-    MessageDelivery::deliver(
-        msg, session.getHandler().out,
-        ++outgoing.hwm, token,
-        session.getConnection().getFrameMax());
+    SessionHandler* handler = session.getHandler();
+    if (handler) {
+        uint32_t maxFrameSize = handler->getConnection().getFrameMax();
+        MessageDelivery::deliver(msg, handler->out, ++outgoing.hwm, token, maxFrameSize);
+    } else {
+        QPID_LOG(error, "Dropping message as session is no longer attached to a channel.");        
+    }
     return outgoing.hwm;
 }
 
diff --git a/cpp/src/qpid/broker/SessionState.cpp b/cpp/src/qpid/broker/SessionState.cpp
index 45d78c9307..d5b6f5ba8a 100644
--- a/cpp/src/qpid/broker/SessionState.cpp
+++ b/cpp/src/qpid/broker/SessionState.cpp
@@ -55,17 +55,18 @@ SessionState::~SessionState() {
     factory.erase(getId());
 }
 
-SessionHandler& SessionState::getHandler() {
-    assert(isAttached());
-    return *handler;
+SessionHandler* SessionState::getHandler() {
+    return handler;
 }
 
 AMQP_ClientProxy& SessionState::getProxy() {
-    return getHandler().getProxy();
+    assert(isAttached());
+    return getHandler()->getProxy();
 }
 
 Connection& SessionState::getConnection() {
-    return getHandler().getConnection();
+    assert(isAttached());
+    return getHandler()->getConnection();
 }
 
 void SessionState::detach() {
diff --git a/cpp/src/qpid/broker/SessionState.h b/cpp/src/qpid/broker/SessionState.h
index eed088af31..d710079cd4 100644
--- a/cpp/src/qpid/broker/SessionState.h
+++ b/cpp/src/qpid/broker/SessionState.h
@@ -62,9 +62,9 @@ class SessionState : public framing::SessionState,
 
     void detach();
     void attach(SessionHandler& handler);
+
     
-    /** @pre isAttached() */
-    SessionHandler& getHandler();
+    SessionHandler* getHandler();
 
     /** @pre isAttached() */
     framing::AMQP_ClientProxy& getProxy();