Moves AvailabilityGuard#shutdown() call back to first thing in db shu…

…tdown

Because it acts as a flag signalling to others that the db is shutting
down. This was otherwise a problem in some loops that would continue
until a database was shutting down.

community/kernel/src/main/java/org/neo4j/kernel/DatabaseAvailability.java

@@ -93,6 +93,5 @@ private void awaitTransactionsClosedWithinTimeout()
     public void shutdown()
             throws Throwable
     {
-        availabilityGuard.shutdown();
     }
 }

community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelTransactions.java

@@ -29,7 +29,6 @@
 import org.neo4j.collection.pool.LinkedQueuePool;
 import org.neo4j.collection.pool.MarshlandPool;
 import org.neo4j.function.Factory;
-import org.neo4j.graphdb.DatabaseShutdownException;
 import org.neo4j.graphdb.TransactionFailureException;
 import org.neo4j.kernel.AvailabilityGuard;
 import org.neo4j.kernel.api.KernelTransaction;
@@ -301,10 +300,6 @@ Set<KernelTransactionImplementation> getAllTransactions()
 
     private void assertRunning()
     {
-        if ( availabilityGuard.isShutdown() )
-        {
-            throw new DatabaseShutdownException();
-        }
         if ( stopped )
         {
             throw new IllegalStateException( "Can't start new transaction with stopped " + getClass() );
@@ -322,7 +317,7 @@ private void assertCurrentThreadIsNotBlockingNewTransactions()
 
     private class KernelTransactionImplementationFactory implements Factory<KernelTransactionImplementation>
     {
-        private Set<KernelTransactionImplementation> transactions;
+        private final Set<KernelTransactionImplementation> transactions;
 
         KernelTransactionImplementationFactory( Set<KernelTransactionImplementation> transactions )
         {
@@ -345,7 +340,7 @@ public KernelTransactionImplementation newInstance()
 
     private class GlobalKernelTransactionPool extends LinkedQueuePool<KernelTransactionImplementation>
     {
-        private Set<KernelTransactionImplementation> transactions;
+        private final Set<KernelTransactionImplementation> transactions;
 
         GlobalKernelTransactionPool( Set<KernelTransactionImplementation> transactions,
                 Factory<KernelTransactionImplementation> factory )

community/kernel/src/main/java/org/neo4j/kernel/impl/factory/ClassicCoreSPI.java

@@ -154,6 +154,7 @@ public void shutdown()
     {
         try
         {
+            platform.availabilityGuard.shutdown();
             msgLog.log( "Shutdown started" );
             platform.life.shutdown();
         }

community/kernel/src/main/java/org/neo4j/kernel/impl/factory/GraphDatabaseFacade.java

@@ -105,6 +105,7 @@
 import org.neo4j.storageengine.api.EntityType;
 
 import static java.lang.String.format;
+
 import static org.neo4j.collection.primitive.PrimitiveLongCollections.map;
 import static org.neo4j.helpers.collection.Iterators.emptyIterator;
 import static org.neo4j.kernel.api.security.SecurityContext.AUTH_DISABLED;