Prevent pool from closing multiple times

README.rst

@@ -30,6 +30,18 @@ Quick Example
         session.write_transaction(add_friends, "Arthur", "Merlin")
         session.read_transaction(print_friends, "Arthur")
 
+Logging
+=============
+The driver provides a built-in logging. The following example code enables debug logging and prints out logs at stdout:
+
+.. code-block:: python
+
+    from neo4j.util import watch
+    import logging
+    from sys import stdout
+
+    watch("neo4j.bolt", logging.DEBUG, stdout)
+
 
 Installation
 ============

neo4j/bolt/connection.py

@@ -507,10 +507,16 @@ def close(self):
         """ Close all connections and empty the pool.
         This method is thread safe.
         """
-        with self.lock:
-            self._closed = True
-            for address in list(self.connections):
-                self.remove(address)
+        if self._closed:
+            return
+        try:
+            with self.lock:
+                if not self._closed:
+                    self._closed = True
+                    for address in list(self.connections):
+                        self.remove(address)
+        except TypeError as e:
+            pass
 
     def closed(self):
         """ Return :const:`True` if this pool is closed, :const:`False`

neo4j/v1/api.py

@@ -41,6 +41,7 @@
 RETRY_DELAY_MULTIPLIER = 2.0
 RETRY_DELAY_JITTER_FACTOR = 0.2
 
+
 def last_bookmark(b0, b1):
     """ Return the latest of two bookmarks by looking for the maximum
     integer value following the last colon in the bookmark string.
@@ -141,10 +142,7 @@ class Driver(object):
     #: Indicator of driver closure.
     _closed = False
 
-    _lock = None
-
     def __init__(self, pool, **config):
-        self._lock = RLock()
         self._pool = pool
         self._max_retry_time = config.get("max_retry_time", default_config["max_retry_time"])
 
@@ -185,18 +183,14 @@ def close(self):
         """ Shut down, closing any open connections that were spawned by
         this Driver.
         """
-        if self._lock is None:
-            return
-        with self._lock:
-            if not self._closed:
-                self._closed = True
-                if self._pool is not None:
-                    self._pool.close()
-                    self._pool = None
+        if not self._closed:
+            self._closed = True
+            if self._pool is not None:
+                self._pool.close()
+                self._pool = None
 
     def closed(self):
-        with self._lock:
-            return self._closed
+        return self._closed
 
 
 class Session(object):