PYTHON-2206 Rename pool_id to generation to better match CMAP spec

Author: ShaneHarvey

pymongo/client_session.py

@@ -838,13 +838,13 @@ def _start_retryable_write(self):
 
 
 class _ServerSession(object):
-    def __init__(self, pool_id):
+    def __init__(self, generation):
         # Ensure id is type 4, regardless of CodecOptions.uuid_representation.
         self.session_id = {'id': Binary(uuid.uuid4().bytes, 4)}
         self.last_use = monotonic.time()
         self._transaction_id = 0
         self.dirty = False
-        self.pool_id = pool_id
+        self.generation = generation
 
     def mark_dirty(self):
         """Mark this session as dirty.
@@ -876,10 +876,10 @@ class _ServerSessionPool(collections.deque):
     """
     def __init__(self, *args, **kwargs):
         super(_ServerSessionPool, self).__init__(*args, **kwargs)
-        self.pool_id = 0
+        self.generation = 0
 
     def reset(self):
-        self.pool_id += 1
+        self.generation += 1
         self.clear()
 
     def pop_all(self):
@@ -902,7 +902,7 @@ def get_server_session(self, session_timeout_minutes):
             if not s.timed_out(session_timeout_minutes):
                 return s
 
-        return _ServerSession(self.pool_id)
+        return _ServerSession(self.generation)
 
     def return_server_session(self, server_session, session_timeout_minutes):
         self._clear_stale(session_timeout_minutes)
@@ -912,7 +912,8 @@ def return_server_session(self, server_session, session_timeout_minutes):
     def return_server_session_no_lock(self, server_session):
         # Discard sessions from an old pool to avoid duplicate sessions in the
         # child process after a fork.
-        if server_session.pool_id == self.pool_id and not server_session.dirty:
+        if (server_session.generation == self.generation and
+                not server_session.dirty):
             self.appendleft(server_session)
 
     def _clear_stale(self, session_timeout_minutes):

pymongo/monitor.py

@@ -107,7 +107,7 @@ def __init__(
     def close(self):
         super(Monitor, self).close()
 
-        # Increment the pool_id and maybe close the socket. If the executor
+        # Increment the generation and maybe close the socket. If the executor
         # thread has the socket checked out, it will be closed when checked in.
         self._pool.reset()
 

pymongo/pool.py

@@ -488,9 +488,9 @@ def __init__(self, sock, pool, address, id):
         self.compression_settings = pool.opts.compression_settings
         self.compression_context = None
 
-        # The pool's pool_id changes with each reset() so we can close sockets
-        # created before the last reset.
-        self.pool_id = pool.pool_id
+        # The pool's generation changes with each reset() so we can close
+        # sockets created before the last reset.
+        self.generation = pool.generation
         self.ready = False
 
     def ismaster(self, metadata, cluster_time):
@@ -956,7 +956,7 @@ def __init__(self, address, options, handshake=True):
 
         # Keep track of resets, so we notice sockets created before the most
         # recent reset and close them.
-        self.pool_id = 0
+        self.generation = 0
         self.pid = os.getpid()
         self.address = address
         self.opts = options
@@ -985,7 +985,7 @@ def _reset(self, close):
         with self.lock:
             if self.closed:
                 return
-            self.pool_id += 1
+            self.generation += 1
             self.pid = os.getpid()
             sockets, self.sockets = self.sockets, collections.deque()
             self.active_sockets = 0
@@ -1022,10 +1022,10 @@ def reset(self):
     def close(self):
         self._reset(close=True)
 
-    def remove_stale_sockets(self, reference_pool_id):
+    def remove_stale_sockets(self, reference_generation):
         """Removes stale sockets then adds new ones if pool is too small and
-        has not been reset. The `reference_pool_id` argument specifies the
-        `pool_id` at the point in time this operation was requested on the
+        has not been reset. The `reference_generation` argument specifies the
+        `generation` at the point in time this operation was requested on the
         pool.
         """
         if self.opts.max_idle_time_seconds is not None:
@@ -1050,7 +1050,7 @@ def remove_stale_sockets(self, reference_pool_id):
                 with self.lock:
                     # Close connection and return if the pool was reset during
                     # socket creation or while acquiring the pool lock.
-                    if self.pool_id != reference_pool_id:
+                    if self.generation != reference_generation:
                         sock_info.close_socket(ConnectionClosedReason.STALE)
                         break
                     self.sockets.appendleft(sock_info)
@@ -1205,7 +1205,7 @@ def return_socket(self, sock_info, publish_checkin=True):
         else:
             if self.closed:
                 sock_info.close_socket(ConnectionClosedReason.POOL_CLOSED)
-            elif sock_info.pool_id != self.pool_id:
+            elif sock_info.generation != self.generation:
                 sock_info.close_socket(ConnectionClosedReason.STALE)
             elif not sock_info.closed:
                 sock_info.update_last_checkin_time()

pymongo/topology.py

@@ -435,10 +435,10 @@ def update_pool(self):
         servers = []
         with self._lock:
             for server in self._servers.values():
-                servers.append((server, server._pool.pool_id))
+                servers.append((server, server._pool.generation))
 
-        for server, pool_id in servers:
-            server._pool.remove_stale_sockets(pool_id)
+        for server, generation in servers:
+            server._pool.remove_stale_sockets(generation)
 
     def close(self):
         """Clear pools and terminate monitors. Topology reopens on demand."""

test/test_client.py

@@ -1462,7 +1462,7 @@ def test_reset_during_update_pool(self):
         self.addCleanup(client.close)
         client.admin.command('ping')
         pool = get_pool(client)
-        pool_id = pool.pool_id
+        generation = pool.generation
 
         # Continuously reset the pool.
         class ResetPoolThread(threading.Thread):
@@ -1488,7 +1488,7 @@ def run(self):
             while True:
                 for _ in range(10):
                     client._topology.update_pool()
-                if pool_id != pool.pool_id:
+                if generation != pool.generation:
                     break
         finally:
             t.stop()

test/test_topology.py

@@ -660,11 +660,11 @@ def _check_with_socket(self, *args, **kwargs):
         t = create_mock_topology(monitor_class=TestMonitor)
         server = wait_for_master(t)
         self.assertEqual(1, ismaster_count[0])
-        pool_id = server.pool.pool_id
+        generation = server.pool.generation
 
         # Pool is reset by ismaster failure.
         t.request_check_all()
-        self.assertNotEqual(pool_id, server.pool.pool_id)
+        self.assertNotEqual(generation, server.pool.generation)
 
     def test_ismaster_retry(self):
         # ismaster succeeds at first, then raises socket error, then succeeds.

test/utils.py

@@ -207,7 +207,7 @@ def __exit__(self, exc_type, exc_val, exc_tb):
 
 class MockPool(object):
     def __init__(self, *args, **kwargs):
-        self.pool_id = 0
+        self.generation = 0
         self._lock = threading.Lock()
         self.opts = PoolOptions()
 
@@ -219,7 +219,7 @@ def return_socket(self, *args, **kwargs):
 
     def _reset(self):
         with self._lock:
-            self.pool_id += 1
+            self.generation += 1
 
     def reset(self):
         self._reset()
@@ -230,7 +230,7 @@ def close(self):
     def update_is_writable(self, is_writable):
         pass
 
-    def remove_stale_sockets(self, reference_pool_id):
+    def remove_stale_sockets(self, reference_generation):
         pass