From 4a7f057af1bb23d75991993394f873df9ffb9b25 Mon Sep 17 00:00:00 2001
From: Matej Sekoranja <matej.sekoranja@cosylab.com>
Date: Wed, 16 Dec 2015 14:45:20 +0100
Subject: [PATCH] server channel destroy notification to the client

---
 src/remoteClient/clientContextImpl.cpp | 43 ++++++++++++++++++++++++--
 src/remoteClient/clientContextImpl.h   |  1 +
 src/server/responseHandlers.cpp        | 26 ++++++++++++++--
 3 files changed, 65 insertions(+), 5 deletions(-)

diff --git a/src/remoteClient/clientContextImpl.cpp b/src/remoteClient/clientContextImpl.cpp
index 15e8e31..135d371 100644
--- a/src/remoteClient/clientContextImpl.cpp
+++ b/src/remoteClient/clientContextImpl.cpp
@@ -3165,6 +3165,33 @@ namespace epics {
         };
 
 
+        class DestroyChannelHandler : public AbstractClientResponseHandler, private epics::pvData::NoDefaultMethods {
+        public:
+            DestroyChannelHandler(ClientContextImpl::shared_pointer const & context) :
+                    AbstractClientResponseHandler(context, "Destroy channel")
+            {
+            }
+
+            virtual ~DestroyChannelHandler() {
+            }
+
+            virtual void handleResponse(osiSockAddr* responseFrom,
+                                        Transport::shared_pointer const & transport, int8 version, int8 command,
+                                        size_t payloadSize, epics::pvData::ByteBuffer* payloadBuffer)
+            {
+                AbstractClientResponseHandler::handleResponse(responseFrom, transport, version, command, payloadSize, payloadBuffer);
+
+                transport->ensureData(4);
+                pvAccessID cid = payloadBuffer->getInt();
+                /*pvAccessID sid =*/ payloadBuffer->getInt();
+
+                // TODO optimize
+                ChannelImpl::shared_pointer channel = static_pointer_cast<ChannelImpl>(_context.lock()->getChannel(cid));
+                if (channel.get())
+                    channel->channelDestroyedOnServer();
+            }
+        };
+
 
         /**
          * PVA response handler - main handler which dispatches responses to appripriate handlers.
@@ -3200,7 +3227,7 @@ namespace epics {
                 m_handlerTable[CMD_AUTHNZ].reset(new AuthNZHandler(context.get())); /*  5 */
                 m_handlerTable[CMD_ACL_CHANGE].reset(new NoopResponse(context, "Access rights change")); /*  6 */
                 m_handlerTable[CMD_CREATE_CHANNEL].reset(new CreateChannelHandler(context)); /*  7 */
-                m_handlerTable[CMD_DESTROY_CHANNEL].reset(new NoopResponse(context, "Destroy channel")); /*  8 */ // TODO it might be useful to implement this...
+                m_handlerTable[CMD_DESTROY_CHANNEL].reset(new DestroyChannelHandler(context)); /*  8 */
                 m_handlerTable[CMD_CONNECTION_VALIDATED].reset(new ClientConnectionValidatedHandler(context)); /*  9 */
                 m_handlerTable[CMD_GET] = dataResponse; /* 10 - get response */
                 m_handlerTable[CMD_PUT] = dataResponse; /* 11 - put response */
@@ -3859,6 +3886,16 @@ namespace epics {
                         this->initiateSearch();
                     
                 }
+
+                void channelDestroyedOnServer() {
+                    if (isConnected())
+                    {
+                        disconnect(true, false);
+
+                        // should be called without any lock hold
+                        reportChannelStateChange();
+                    }
+                }
                 
                 #define STATIC_SEARCH_BASE_DELAY_SEC 5
                 #define STATIC_SEARCH_MAX_MULTIPLIER 10
@@ -4059,7 +4096,7 @@ namespace epics {
                     
                     if (issueCreateMessage)
                     {
-                        control->startMessage((int8)7, 2+4);
+                        control->startMessage((int8)CMD_CREATE_CHANNEL, 2+4);
                         
                         // count
                         buffer->putShort((int16)1);
@@ -4072,7 +4109,7 @@ namespace epics {
                     }
                     else
                     {
-                        control->startMessage((int8)8, 4+4);
+                        control->startMessage((int8)CMD_DESTROY_CHANNEL, 4+4);
                         // SID
                         m_channelMutex.lock();
                         pvAccessID sid = m_serverChannelID;
diff --git a/src/remoteClient/clientContextImpl.h b/src/remoteClient/clientContextImpl.h
index 36c9a38..06e7c02 100644
--- a/src/remoteClient/clientContextImpl.h
+++ b/src/remoteClient/clientContextImpl.h
@@ -48,6 +48,7 @@ namespace epics {
             virtual void connectionCompleted(pvAccessID sid/*,  rights*/) = 0;
             virtual void createChannelFailed() = 0;
             virtual std::tr1::shared_ptr<ClientContextImpl> getContext() = 0;
+            virtual void channelDestroyedOnServer() = 0;
 
             virtual pvAccessID getServerChannelID() = 0;
             virtual void registerResponseRequest(ResponseRequest::shared_pointer const & responseRequest) = 0;
diff --git a/src/server/responseHandlers.cpp b/src/server/responseHandlers.cpp
index 8cf4a22..c82f247 100644
--- a/src/server/responseHandlers.cpp
+++ b/src/server/responseHandlers.cpp
@@ -843,9 +843,31 @@ void ServerChannelRequesterImpl::channelCreated(const Status& status, Channel::s
 
 void ServerChannelRequesterImpl::channelStateChange(Channel::shared_pointer const & /*channel*/, const Channel::ConnectionState /*isConnected*/)
 {
-	// TODO should we notify remote side?
+    if(Transport::shared_pointer transport = _transport.lock())
+    {
+        ChannelHostingTransport::shared_pointer casTransport = dynamic_pointer_cast<ChannelHostingTransport>(transport);
+        if (!casTransport)
+            return;
 
-    // YES :)
+        ServerChannelImpl::shared_pointer channel;
+        {
+            Lock guard(_mutex);
+            channel= dynamic_pointer_cast<ServerChannelImpl>(_serverChannel.lock());
+        }
+
+        if (!channel)
+            return;
+
+        // destroy
+        channel->destroy();
+
+        // .. and unregister
+        casTransport->unregisterChannel(channel->getSID());
+
+        // send response back
+        TransportSender::shared_pointer sr(new ServerDestroyChannelHandlerTransportSender(channel->getCID(), channel->getSID()));
+        transport->enqueueSendRequest(sr);
+    }
 }
 
 string ServerChannelRequesterImpl::getRequesterName()