From befb12a08e60bb6eaf9331dae31cef4f6cb6e48f Mon Sep 17 00:00:00 2001
From: Alan Conway <aconway@apache.org>
Date: Thu, 22 Dec 2011 20:36:10 +0000
Subject: QPID-3603: Lifecycle and locking fixes for QueueReplicator

Separate bridge de-activation from destruction in QueueReplicator:
Only deactivate if destroyed by the WiringReplicator because of a
queue delete.  If destroyed for any other reason (e.g. broker
destruction) don't de-activate the bridge as required resources may
not exist.

Added missing locks in QueueReplicator functions.

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/qpid-3603@1222432 13f79535-47bb-0310-9956-ffa450edef68
---
 qpid/cpp/src/qpid/ha/QueueReplicator.cpp  | 8 ++++++--
 qpid/cpp/src/qpid/ha/QueueReplicator.h    | 8 +++++---
 qpid/cpp/src/qpid/ha/WiringReplicator.cpp | 5 +++++
 3 files changed, 16 insertions(+), 5 deletions(-)

(limited to 'qpid/cpp/src')

diff --git a/qpid/cpp/src/qpid/ha/QueueReplicator.cpp b/qpid/cpp/src/qpid/ha/QueueReplicator.cpp
index f567d61078..d99f5126f5 100644
--- a/qpid/cpp/src/qpid/ha/QueueReplicator.cpp
+++ b/qpid/cpp/src/qpid/ha/QueueReplicator.cpp
@@ -82,14 +82,18 @@ void QueueReplicator::activate() {
     );
 }
 
-QueueReplicator::~QueueReplicator() {
+QueueReplicator::~QueueReplicator() {}
+
+void QueueReplicator::deactivate() {
+    sys::Mutex::ScopedLock l(lock);
     queue->getBroker()->getLinks().destroy(
         link->getHost(), link->getPort(), queue->getName(), getName(), string());
 }
 
 // Called in a broker connection thread when the bridge is created.
-// shared_ptr to self is just to ensure we are still in memory.
 void QueueReplicator::initializeBridge(Bridge& bridge, SessionHandler& sessionHandler) {
+    sys::Mutex::ScopedLock l(lock);
+
     framing::AMQP_ServerProxy peer(sessionHandler.out);
     const qmf::org::apache::qpid::broker::ArgsLinkBridge& args(bridge.getArgs());
     framing::FieldTable settings;
diff --git a/qpid/cpp/src/qpid/ha/QueueReplicator.h b/qpid/cpp/src/qpid/ha/QueueReplicator.h
index ad820346d5..0a1453dc63 100644
--- a/qpid/cpp/src/qpid/ha/QueueReplicator.h
+++ b/qpid/cpp/src/qpid/ha/QueueReplicator.h
@@ -46,7 +46,7 @@ namespace ha {
  * Creates a ReplicatingSubscription on the primary by passing special
  * arguments to the consume command.
  *
- * THREAD UNSAFE: Only called in the connection thread of the source queue.
+ * THREAD SAFE: Called in different connection threads.
  */
 class QueueReplicator : public broker::Exchange,
                         public boost::enable_shared_from_this<QueueReplicator>
@@ -59,10 +59,12 @@ class QueueReplicator : public broker::Exchange,
     QueueReplicator(boost::shared_ptr<broker::Queue> q, boost::shared_ptr<broker::Link> l);
     ~QueueReplicator();
 
-    void activate();
+    void activate();            // Call after ctor
+    void deactivate();          // Call before dtor
 
     std::string getType() const;
-    bool bind(boost::shared_ptr<broker::Queue>, const std::string&, const framing::FieldTable*);
+    bool bind(boost::shared_ptr<broker::Queue
+              >, const std::string&, const framing::FieldTable*);
     bool unbind(boost::shared_ptr<broker::Queue>, const std::string&, const framing::FieldTable*);
     void route(broker::Deliverable&, const std::string&, const framing::FieldTable*);
     bool isBound(boost::shared_ptr<broker::Queue>, const std::string* const, const framing::FieldTable* const);
diff --git a/qpid/cpp/src/qpid/ha/WiringReplicator.cpp b/qpid/cpp/src/qpid/ha/WiringReplicator.cpp
index 416f516f7b..58cacb16f4 100644
--- a/qpid/cpp/src/qpid/ha/WiringReplicator.cpp
+++ b/qpid/cpp/src/qpid/ha/WiringReplicator.cpp
@@ -296,6 +296,11 @@ void WiringReplicator::doEventQueueDelete(Variant::Map& values) {
             values[USER].asString(),
             values[RHOST].asString());
         // Delete the QueueReplicator exchange for this queue.
+        boost::shared_ptr<broker::Exchange> ex =
+            broker.getExchanges().find(QueueReplicator::replicatorName(name));
+        boost::shared_ptr<QueueReplicator> qr =
+            boost::dynamic_pointer_cast<QueueReplicator>(ex);
+        if (qr) qr->deactivate();
         broker.getExchanges().destroy(QueueReplicator::replicatorName(name));
     }
 }
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