Remove terminated connection queues from the pool

It was previously possible for empty/terminated connection queues to stay in
the `SocketConnectionPool` when is was closed concurrently with sessions being
acquired. This was not critical because `SocketConnectionPool` is only closed
when the whole driver is closed but resulted in a flaky test.

This commit adds removal of terminated connection queues.

Author: lutovich

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

@@ -84,11 +84,7 @@ public PooledConnection get()
         };
         PooledConnection conn = connections.acquire( supplier );
 
-        if ( closed.get() )
-        {
-            connections.terminate();
-            throw poolClosedException();
-        }
+        assertNotClosed( address, connections );
 
         conn.updateTimestamp();
         return conn;
@@ -140,16 +136,21 @@ public void close()
         }
     }
 
-    private void assertNotClosed()
+    private void assertNotClosed( BoltServerAddress address, BlockingPooledConnectionQueue connections )
     {
         if ( closed.get() )
         {
-            throw poolClosedException();
+            connections.terminate();
+            pools.remove( address );
+            assertNotClosed();
         }
     }
 
-    private static RuntimeException poolClosedException()
+    private void assertNotClosed()
     {
-        return new IllegalStateException( "Pool closed" );
+        if ( closed.get() )
+        {
+            throw new IllegalStateException( "Pool closed" );
+        }
     }
 }

driver/src/test/java/org/neo4j/driver/internal/net/pooling/SocketConnectionPoolTest.java

@@ -265,7 +265,8 @@ public void closeWithConcurrentAcquisitionsEmptiesThePool() throws InterruptedEx
 
         for ( int i = 0; i < port.intValue(); i++ )
         {
-            assertFalse( pool.hasAddress( new BoltServerAddress( "localhost", i ) ) );
+            boolean hasAddress = pool.hasAddress( new BoltServerAddress( "localhost", i ) );
+            assertFalse( "Pool still has connection queues" + pool, hasAddress );
         }
         for ( Connection connection : createdConnections )
         {