Added session#kill to stop running more statements and reset the session to a clean state

Author: Zhen

driver/src/main/java/org/neo4j/driver/internal/InternalSession.java

@@ -98,6 +98,14 @@ public StatementResult run( Statement statement )
         return cursor;
     }
 
+    public void kill()
+    {
+        ensureNoUnrecoverableError();
+        ensureConnectionIsOpen();
+
+        connection.resetAndFlushAsync();
+    }
+
     @Override
     public boolean isOpen()
     {

driver/src/main/java/org/neo4j/driver/internal/net/ConcurrencyGuardingConnection.java

@@ -201,6 +201,12 @@ public boolean hasUnrecoverableErrors()
         return delegate.hasUnrecoverableErrors();
     }
 
+    @Override
+    public void resetAndFlushAsync()
+    {
+        delegate.resetAndFlushAsync();
+    }
+
     private void markAsAvailable()
     {
         inUse.set( false );

driver/src/main/java/org/neo4j/driver/internal/net/SocketConnection.java

@@ -206,4 +206,11 @@ public boolean hasUnrecoverableErrors()
     {
         throw new UnsupportedOperationException( "Unrecoverable error detection is not supported on SocketConnection." );
     }
+
+    @Override
+    public void resetAndFlushAsync()
+    {
+        reset();
+        flush();
+    }
 }

driver/src/main/java/org/neo4j/driver/internal/net/pooling/PooledConnection.java

@@ -211,6 +211,19 @@ public boolean hasUnrecoverableErrors()
         return unrecoverableErrorsOccurred;
     }
 
+    @Override
+    public void resetAndFlushAsync()
+    {
+        try
+        {
+            delegate.resetAndFlushAsync();
+        }
+        catch( RuntimeException e )
+        {
+            onDelegateException( e );
+        }
+    }
+
     public void dispose()
     {
         delegate.close();

driver/src/main/java/org/neo4j/driver/internal/spi/Connection.java

@@ -106,4 +106,9 @@ public interface Connection extends AutoCloseable
 
 
     boolean hasUnrecoverableErrors();
+
+    /**
+     * Asynchronously sending reset and flush to the socket output channel.
+     */
+    void resetAndFlushAsync();
 }

driver/src/main/java/org/neo4j/driver/v1/Session.java

@@ -58,7 +58,10 @@ public interface Session extends Resource, StatementRunner
      */
     Transaction beginTransaction();
 
-
+    /**
+     * Stop running more statements in this session and rest the session to a clean state.
+     */
+    void kill();
     /**
      * Signal that you are done using this session. In the default driver usage, closing
      * and accessing sessions is very low cost, because sessions are pooled by {@link Driver}.

driver/src/test/java/org/neo4j/driver/v1/util/TestNeo4jSession.java

@@ -100,6 +100,12 @@ public Transaction beginTransaction()
         return realSession.beginTransaction();
     }
 
+    @Override
+    public void kill()
+    {
+        realSession.kill();
+    }
+
     @Override
     public StatementResult run( String statementText, Map<String,Object> statementParameters )
     {