From: Daniele Varrazzo <daniele.varrazzo@gmail.com>
Date: Thu, 6 Jan 2022 16:09:22 +0000 (+0100)
Subject: Don't look up other modules objects in __del__ methods
X-Git-Tag: pool-3.1~38
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f4ea31ca597926746d3fb3ca11697d3b2fa5fc70;p=thirdparty%2Fpsycopg.git

Don't look up other modules objects in __del__ methods

The modules might have been already cleaned up during interpreted
shutdown. See <https://bugs.python.org/issue46256#msg409847> for an
explanation.

The stdlib guards against the same thing happening too. However they
take a reference in the function closure, which is stronger than what we
do. Doing so, on our strictly typed codebase, is a tedious chore, so, if
this is enough (it should be, according to the OP), I'm happy this way.

Close #198.
---

diff --git a/docs/news.rst b/docs/news.rst
index 2b8b2fbbd..3e597a15c 100644
--- a/docs/news.rst
+++ b/docs/news.rst
@@ -24,6 +24,8 @@ Psycopg 3.0.8 (unreleased)
 
 - Decode connection errors in the ``client_encoding`` specified in the
   connection string, if available (:ticket:`#194`).
+- Fix possible warnings in objects deletion on interpreter shutdown
+  (:ticket:`#198`).
 
 
 Psycopg 3.0.7
diff --git a/psycopg/psycopg/connection.py b/psycopg/psycopg/connection.py
index d2bedf8e3..6af5a327b 100644
--- a/psycopg/psycopg/connection.py
+++ b/psycopg/psycopg/connection.py
@@ -5,13 +5,13 @@ psycopg connection objects
 # Copyright (C) 2020-2021 The Psycopg Team
 
 import logging
-import warnings
 import threading
 from types import TracebackType
 from typing import Any, Callable, cast, Dict, Generator, Generic, Iterator
 from typing import List, NamedTuple, Optional, Type, TypeVar, Tuple, Union
 from typing import overload, TYPE_CHECKING
 from weakref import ref, ReferenceType
+from warnings import warn
 from functools import partial
 from contextlib import contextmanager
 
@@ -146,7 +146,7 @@ class BaseConnection(Generic[Row]):
         if hasattr(self, "_pool"):
             return
 
-        warnings.warn(
+        warn(
             f"connection {self} was deleted while still open."
             f" Please use 'with' or '.close()' to close the connection",
             ResourceWarning,
diff --git a/psycopg/psycopg/pq/pq_ctypes.py b/psycopg/psycopg/pq/pq_ctypes.py
index a4d2775b5..83b288212 100644
--- a/psycopg/psycopg/pq/pq_ctypes.py
+++ b/psycopg/psycopg/pq/pq_ctypes.py
@@ -8,9 +8,9 @@ implementation.
 
 # Copyright (C) 2020-2021 The Psycopg Team
 
-import os
-import logging
 import sys
+import logging
+from os import getpid
 from weakref import ref
 from functools import partial
 
@@ -25,6 +25,9 @@ from .misc import PGnotify, ConninfoOption, PGresAttDesc
 from .misc import error_message, connection_summary
 from ._enums import Format, ExecStatus, Trace
 
+# Imported locally to call them from __del__ methods
+from ._pq_ctypes import PQclear, PQfinish, PQfreeCancel, PQstatus
+
 if TYPE_CHECKING:
     from . import abc
 
@@ -84,12 +87,12 @@ class PGconn:
         )
         impl.PQsetNoticeReceiver(pgconn_ptr, self._notice_receiver, None)
 
-        self._procpid = os.getpid()
+        self._procpid = getpid()
 
     def __del__(self) -> None:
         # Close the connection only if it was created in this process,
         # not if this object is being GC'd after fork.
-        if os.getpid() == self._procpid:
+        if getpid() == self._procpid:
             self.finish()
 
     def __repr__(self) -> str:
@@ -123,7 +126,7 @@ class PGconn:
     def finish(self) -> None:
         self._pgconn_ptr, p = None, self._pgconn_ptr
         if p:
-            impl.PQfinish(p)
+            PQfinish(p)
 
     @property
     def pgconn_ptr(self) -> Optional[int]:
@@ -203,7 +206,7 @@ class PGconn:
 
     @property
     def status(self) -> int:
-        return impl.PQstatus(self._pgconn_ptr)
+        return PQstatus(self._pgconn_ptr)
 
     @property
     def transaction_status(self) -> int:
@@ -743,7 +746,7 @@ class PGresult:
     def clear(self) -> None:
         self._pgresult_ptr, p = None, self._pgresult_ptr
         if p:
-            impl.PQclear(p)
+            PQclear(p)
 
     @property
     def pgresult_ptr(self) -> Optional[int]:
@@ -876,7 +879,7 @@ class PGcancel:
         """
         self.pgcancel_ptr, p = None, self.pgcancel_ptr
         if p:
-            impl.PQfreeCancel(p)
+            PQfreeCancel(p)
 
     def cancel(self) -> None:
         """Requests that the server abandon processing of the current command.
diff --git a/psycopg/psycopg/server_cursor.py b/psycopg/psycopg/server_cursor.py
index 8ef1e9af9..a245d9573 100644
--- a/psycopg/psycopg/server_cursor.py
+++ b/psycopg/psycopg/server_cursor.py
@@ -4,9 +4,9 @@ psycopg server-side cursor objects.
 
 # Copyright (C) 2020-2021 The Psycopg Team
 
-import warnings
 from typing import Any, AsyncIterator, Generic, List, Iterable, Iterator
 from typing import Optional, TypeVar, TYPE_CHECKING
+from warnings import warn
 
 from . import pq
 from . import sql
@@ -200,7 +200,7 @@ class ServerCursor(Cursor[Row]):
 
     def __del__(self) -> None:
         if not self.closed:
-            warnings.warn(
+            warn(
                 f"the server-side cursor {self} was deleted while still open."
                 f" Please use 'with' or '.close()' to close the cursor properly",
                 ResourceWarning,
@@ -343,7 +343,7 @@ class AsyncServerCursor(AsyncCursor[Row]):
 
     def __del__(self) -> None:
         if not self.closed:
-            warnings.warn(
+            warn(
                 f"the server-side cursor {self} was deleted while still open."
                 f" Please use 'with' or '.close()' to close the cursor properly",
                 ResourceWarning,