QPID-4163: Deadlock between LinkRegistry and TimerTask locks

Previously TimerTask::cancel was being called with locks held in this stack trace, causing a deadlock.

Moved call to cancel outside of the lock.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1364805 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 12 insertions, 10 deletions

diff --git a/cpp/src/qpid/broker/Link.cpp b/cpp/src/qpid/broker/Link.cpp
index 297c5e22a9..84dd163ac3 100644
--- a/cpp/src/qpid/broker/Link.cpp
+++ b/cpp/src/qpid/broker/Link.cpp
@@ -249,17 +249,19 @@ void Link::established(Connection* c)
 
     if (!hideManagement() && agent)
         agent->raiseEvent(_qmf::EventBrokerLinkUp(addr.str()));
-
-    Mutex::ScopedLock mutex(lock);
-    setStateLH(STATE_OPERATIONAL);
-    currentInterval = 1;
-    visitCount      = 0;
-    connection = c;
-
-    if (closing)
+    bool isClosing = false;
+    {
+        Mutex::ScopedLock mutex(lock);
+        setStateLH(STATE_OPERATIONAL);
+        currentInterval = 1;
+        visitCount      = 0;
+        connection = c;
+        isClosing = closing;
+    }
+    if (isClosing)
         destroy();
     else // Process any IO tasks bridges added before established.
-        connection->requestIOProcessing (boost::bind(&Link::ioThreadProcessing, this));
+        c->requestIOProcessing (boost::bind(&Link::ioThreadProcessing, this));
 }
 
 
diff --git a/cpp/src/qpid/broker/LinkRegistry.cpp b/cpp/src/qpid/broker/LinkRegistry.cpp
index 75c311c917..31b113c4d9 100644
--- a/cpp/src/qpid/broker/LinkRegistry.cpp
+++ b/cpp/src/qpid/broker/LinkRegistry.cpp
@@ -326,13 +326,13 @@ void LinkRegistry::notifyConnection(const std::string& key, Connection* c)
             if (l->second->pendingConnection(host, port)) {
                 link = l->second;
                 connections[key] = link->getName();
-                link->established(c);
                 break;
             }
         }
     }
 
     if (link) {
+        link->established(c);
         c->setUserId(str(format("%1%@%2%") % link->getUsername() % realm));
     }
 }