From 8c43c59c03e77f1281994b5a368cf56c62294c46 Mon Sep 17 00:00:00 2001
From: Oleg Zhurakousky <ozhurakousky@vmware.com>
Date: Thu, 11 Oct 2012 13:17:02 -0400
Subject: [PATCH] INT-2777 TransactionSynchronization

Ensured that bindings of the resource only happen if TransactionSynchronizationFactory is not null
Add documentation describing the expectation for the unbinding of the resource.

INT-2777 Polishing

Don't set up holder if it's not used.

Doc fixes.
---
 .../endpoint/SourcePollingChannelAdapter.java          |  7 +++----
 .../integration/mail/ImapIdleChannelAdapter.java       |  8 +++-----
 src/reference/docbook/transactions.xml                 | 10 ++++++++++
 src/reference/docbook/whats-new.xml                    |  8 --------
 4 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/spring-integration-core/src/main/java/org/springframework/integration/endpoint/SourcePollingChannelAdapter.java b/spring-integration-core/src/main/java/org/springframework/integration/endpoint/SourcePollingChannelAdapter.java
index f1a594b507..83d3dd55a2 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/endpoint/SourcePollingChannelAdapter.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/endpoint/SourcePollingChannelAdapter.java
@@ -103,11 +103,10 @@ public class SourcePollingChannelAdapter extends AbstractPollingEndpoint impleme
 		IntegrationResourceHolder holder = null;
 
 		if (TransactionSynchronizationManager.isActualTransactionActive()) {
-			holder = new IntegrationResourceHolder();
-			holder.addAttribute(IntegrationResourceHolder.MESSAGE_SOURCE, source);
-			TransactionSynchronizationManager.bindResource(source, holder);
-
 			if (transactionSynchronizationFactory != null){
+				holder = new IntegrationResourceHolder();
+				holder.addAttribute(IntegrationResourceHolder.MESSAGE_SOURCE, source);
+				TransactionSynchronizationManager.bindResource(source, holder);
 				TransactionSynchronizationManager.registerSynchronization(transactionSynchronizationFactory.create(source));
 			}
 		}
diff --git a/spring-integration-mail/src/main/java/org/springframework/integration/mail/ImapIdleChannelAdapter.java b/spring-integration-mail/src/main/java/org/springframework/integration/mail/ImapIdleChannelAdapter.java
index 43874d001a..dc4e6fca74 100755
--- a/spring-integration-mail/src/main/java/org/springframework/integration/mail/ImapIdleChannelAdapter.java
+++ b/spring-integration-mail/src/main/java/org/springframework/integration/mail/ImapIdleChannelAdapter.java
@@ -211,12 +211,10 @@ public class ImapIdleChannelAdapter extends MessageProducerSupport implements Be
 						MessageBuilder.withPayload(mailMessage).build();
 
 				if (TransactionSynchronizationManager.isActualTransactionActive()) {
-
-					IntegrationResourceHolder holder = new IntegrationResourceHolder();
-					holder.setMessage(message);
-					TransactionSynchronizationManager.bindResource(ImapIdleChannelAdapter.this, holder);
-
 					if (transactionSynchronizationFactory != null){
+						IntegrationResourceHolder holder = new IntegrationResourceHolder();
+						holder.setMessage(message);
+						TransactionSynchronizationManager.bindResource(ImapIdleChannelAdapter.this, holder);
 						TransactionSynchronizationManager.
 							registerSynchronization(transactionSynchronizationFactory.create(ImapIdleChannelAdapter.this));
 					}
diff --git a/src/reference/docbook/transactions.xml b/src/reference/docbook/transactions.xml
index fde979ddef..26e38766df 100644
--- a/src/reference/docbook/transactions.xml
+++ b/src/reference/docbook/transactions.xml
@@ -254,10 +254,20 @@ public interface TransactionSynchronizationProcessor {
         'payload'.
       </para>
       <important>
+       <para>
         It is important to understand that this is simply synchronizing the actions with a transaction, it does not
         make a resource that is not inherently transactional actually transactional. Instead, the transaction
         (be it JDBC or otherwise) is started before the poll, and committed/rolled back when the flow completes,
         followed by the synchronized action.
+       </para>
+       <para>
+        It is also important to understand that if you provide a custom <classname>TransactionSynchronizationFactory</classname>, 
+        it is responsible for creating a resource synchronization that will cause the bound resource to be unbound automatically, 
+        when the transaction completes. 
+        The default <classname>TransactionSynchronizationFactory</classname> does this by returning a subclass 
+        of <classname>ResourceHolderSynchronization</classname>, with the default
+        <emphasis>shouldUnbindAtCompletion()</emphasis> returning <code>true</code>.
+       </para>
       </important>
       <para>
         In addition to the <emphasis>after-commit</emphasis> and <emphasis>after-rollback</emphasis> expressions,
diff --git a/src/reference/docbook/whats-new.xml b/src/reference/docbook/whats-new.xml
index 91911c6f67..1eaeb7b8e5 100644
--- a/src/reference/docbook/whats-new.xml
+++ b/src/reference/docbook/whats-new.xml
@@ -119,14 +119,6 @@
 				For more information please see <xref linkend="file-writing-destination-exists"/>.
 			</para>
 		</section>
-		<section id="2.2-tx">
-			<title>Transaction Synchronization</title>
-			<para>
-				When running from a transactional poller,
-				mail inbound adapters can be configured to update the mailbox only
-				if the transaction commits.
-			</para>
-		</section>
 		<section id="2.2-shutdown">
 			<title>Orderly Shutdown</title>
 			<para>