Issue #23865: close() methods in multiple modules now are idempotent and more

robust at shutdown. If needs to release multiple resources, they are released
even if errors are occured.

Lib/aifc.py

@@ -357,9 +357,12 @@ class Aifc_read:
         self._soundpos = 0
 
     def close(self):
-        if self._decomp:
-            self._decomp.CloseDecompressor()
+        decomp = self._decomp
+        try:
+            if decomp:
                 self._decomp = None
+                decomp.CloseDecompressor()
+        finally:
             self._file.close()
 
     def tell(self):

Lib/binhex.py

@@ -32,7 +32,8 @@ class Error(Exception):
     pass
 
 # States (what have we written)
-[_DID_HEADER, _DID_DATA, _DID_RSRC] = range(3)
+_DID_HEADER = 0
+_DID_DATA = 1
 
 # Various constants
 REASONABLY_LARGE=32768  # Minimal amount we pass the rle-coder
@@ -235,6 +236,9 @@ class BinHex:
         self._write(data)
 
     def close(self):
+        if self.state is None:
+            return
+        try:
             if self.state < _DID_DATA:
                 self.close_data()
             if self.state != _DID_DATA:
@@ -243,9 +247,11 @@ class BinHex:
                 raise Error, \
                     "Incorrect resource-datasize, diff=%r" % (self.rlen,)
             self._writecrc()
-        self.ofp.close()
+        finally:
             self.state = None
+            ofp = self.ofp
             del self.ofp
+            ofp.close()
 
 def binhex(inp, out):
     """(infilename, outfilename) - Create binhex-encoded copy of a file"""
@@ -463,10 +469,14 @@ class HexBin:
         return self._read(n)
 
     def close(self):
+        if self.state is None:
+            return
+        try:
             if self.rlen:
                 dummy = self.read_rsrc(self.rlen)
             self._checkcrc()
-        self.state = _DID_RSRC
+        finally:
+            self.state = None
             self.ifp.close()
 
 def hexbin(inp, out):

Lib/chunk.py

@@ -85,7 +85,9 @@ class Chunk:
 
     def close(self):
         if not self.closed:
+            try:
                 self.skip()
+            finally:
                 self.closed = True
 
     def isatty(self):

Lib/distutils/text_file.py

@@ -124,11 +124,11 @@ class TextFile:
     def close (self):
         """Close the current file and forget everything we know about it
            (filename, current line number)."""
-
-        self.file.close ()
+        file = self.file
         self.file = None
         self.filename = None
         self.current_line = None
+        file.close()
 
 
     def gen_error (self, msg, line=None):

Lib/dumbdbm.py

@@ -209,7 +209,9 @@ class _Database(UserDict.DictMixin):
         return len(self._index)
 
     def close(self):
+        try:
             self._commit()
+        finally:
             self._index = self._datfile = self._dirfile = self._bakfile = None
 
     __del__ = close

Lib/fileinput.py

@@ -233,7 +233,9 @@ class FileInput:
         self.close()
 
     def close(self):
+        try:
             self.nextfile()
+        finally:
             self._files = ()
 
     def __iter__(self):
@@ -270,14 +272,16 @@ class FileInput:
 
         output = self._output
         self._output = 0
+        try:
             if output:
                 output.close()
-
+        finally:
             file = self._file
             self._file = 0
+            try:
                 if file and not self._isstdin:
                     file.close()
-
+            finally:
                 backupfilename = self._backupfilename
                 self._backupfilename = 0
                 if backupfilename and not self._backup:

Lib/ftplib.py

@@ -594,11 +594,16 @@ class FTP:
 
     def close(self):
         '''Close the connection without assuming anything about it.'''
-        if self.file is not None:
-            self.file.close()
-        if self.sock is not None:
-            self.sock.close()
-        self.file = self.sock = None
+        try:
+            file = self.file
+            self.file = None
+            if file is not None:
+                file.close()
+        finally:
+            sock = self.sock
+            self.sock = None
+            if sock is not None:
+                sock.close()
 
 try:
     import ssl

Lib/gzip.py

@@ -369,19 +369,21 @@ class GzipFile(io.BufferedIOBase):
         return self.fileobj is None
 
     def close(self):
-        if self.fileobj is None:
+        fileobj = self.fileobj
+        if fileobj is None:
             return
+        self.fileobj = None
+        try:
             if self.mode == WRITE:
-            self.fileobj.write(self.compress.flush())
-            write32u(self.fileobj, self.crc)
+                fileobj.write(self.compress.flush())
+                write32u(fileobj, self.crc)
                 # self.size may exceed 2GB, or even 4GB
-            write32u(self.fileobj, self.size & 0xffffffffL)
-            self.fileobj = None
-        elif self.mode == READ:
-            self.fileobj = None
-        if self.myfileobj:
-            self.myfileobj.close()
+                write32u(fileobj, self.size & 0xffffffffL)
+        finally:
+            myfileobj = self.myfileobj
+            if myfileobj:
                 self.myfileobj = None
+                myfileobj.close()
 
     def flush(self,zlib_mode=zlib.Z_SYNC_FLUSH):
         self._check_closed()

Lib/httplib.py

@@ -560,9 +560,10 @@ class HTTPResponse:
         return True
 
     def close(self):
-        if self.fp:
-            self.fp.close()
+        fp = self.fp
+        if fp:
             self.fp = None
+            fp.close()
 
     def isclosed(self):
         # NOTE: it is possible that we will not ever call self.close(). This
@@ -835,13 +836,17 @@ class HTTPConnection:
 
     def close(self):
         """Close the connection to the HTTP server."""
-        if self.sock:
-            self.sock.close()   # close it manually... there may be other refs
-            self.sock = None
-        if self.__response:
-            self.__response.close()
-            self.__response = None
         self.__state = _CS_IDLE
+        try:
+            sock = self.sock
+            if sock:
+                self.sock = None
+                sock.close()   # close it manually... there may be other refs
+        finally:
+            response = self.__response
+            if response:
+                self.__response = None
+                response.close()
 
     def send(self, data):
         """Send `data' to the server."""

Lib/logging/__init__.py

@@ -915,12 +915,17 @@ class FileHandler(StreamHandler):
         Closes the stream.
         """
         self.acquire()
+        try:
             try:
                 if self.stream:
+                    try:
                         self.flush()
-                if hasattr(self.stream, "close"):
-                    self.stream.close()
+                    finally:
+                        stream = self.stream
                         self.stream = None
+                        if hasattr(stream, "close"):
+                            stream.close()
+            finally:
                 # Issue #19523: call unconditionally to
                 # prevent a handler leak when delay is set
                 StreamHandler.close(self)

Lib/logging/handlers.py

@@ -588,9 +588,10 @@ class SocketHandler(logging.Handler):
         """
         self.acquire()
         try:
-            if self.sock:
-                self.sock.close()
+            sock = self.sock
+            if sock:
                 self.sock = None
+                sock.close()
         finally:
             self.release()
         logging.Handler.close(self)
@@ -1160,7 +1161,9 @@ class BufferingHandler(logging.Handler):
 
         This version just flushes and chains to the parent class' close().
         """
+        try:
             self.flush()
+        finally:
             logging.Handler.close(self)
 
 class MemoryHandler(BufferingHandler):
@@ -1213,7 +1216,9 @@ class MemoryHandler(BufferingHandler):
         """
         Flush, set the target to None and lose the buffer.
         """
+        try:
             self.flush()
+        finally:
             self.acquire()
             try:
                 self.target = None

Lib/mailbox.py

@@ -719,9 +719,13 @@ class _singlefileMailbox(Mailbox):
 
     def close(self):
         """Flush and close the mailbox."""
+        try:
             self.flush()
+        finally:
+            try:
                 if self._locked:
                     self.unlock()
+            finally:
                 self._file.close()  # Sync has been done by self.flush() above.
 
     def _lookup(self, key=None):

Lib/multiprocessing/connection.py

@@ -285,9 +285,13 @@ class SocketListener(object):
         return conn
 
     def close(self):
+        try:
             self._socket.close()
-        if self._unlink is not None:
-            self._unlink()
+        finally:
+            unlink = self._unlink
+            if unlink is not None:
+                self._unlink = None
+                unlink()
 
 
 def SocketClient(address):

Lib/multiprocessing/queues.py

@@ -156,9 +156,13 @@ class Queue(object):
 
     def close(self):
         self._closed = True
+        try:
             self._reader.close()
-        if self._close:
-            self._close()
+        finally:
+            close = self._close
+            if close:
+                self._close = None
+                close()
 
     def join_thread(self):
         debug('Queue.join_thread()')

Lib/shelve.py

@@ -140,16 +140,20 @@ class Shelf(UserDict.DictMixin):
             pass
 
     def close(self):
+        if self.dict is None:
+            return
+        try:
             self.sync()
             try:
                 self.dict.close()
             except AttributeError:
                 pass
+        finally:
             # Catch errors that may happen when close is called from __del__
             # because CPython is in interpreter shutdown.
             try:
                 self.dict = _ClosedDict()
-        except (NameError, TypeError):
+            except:
                 self.dict = None
 
     def __del__(self):

Lib/smtplib.py

@@ -750,12 +750,16 @@ class SMTP:
 
     def close(self):
         """Close the connection to the SMTP server."""
-        if self.file:
-            self.file.close()
+        try:
+            file = self.file
             self.file = None
-        if self.sock:
-            self.sock.close()
+            if file:
+                file.close()
+        finally:
+            sock = self.sock
             self.sock = None
+            if sock:
+                sock.close()
 
 
     def quit(self):

Lib/tarfile.py

@@ -492,6 +492,8 @@ class _Stream:
         if self.closed:
             return
 
+        self.closed = True
+        try:
             if self.mode == "w" and self.comptype != "tar":
                 self.buf += self.cmp.flush()
 
@@ -507,12 +509,10 @@ class _Stream:
                     # it to look positive on all boxes.
                     self.fileobj.write(struct.pack("<L", self.crc & 0xffffffffL))
                     self.fileobj.write(struct.pack("<L", self.pos & 0xffffFFFFL))
-
+        finally:
             if not self._extfileobj:
                 self.fileobj.close()
 
-        self.closed = True
-
     def _init_read_gz(self):
         """Initialize for reading a gzip compressed fileobj.
         """
@@ -1796,6 +1796,8 @@ class TarFile(object):
         if self.closed:
             return
 
+        self.closed = True
+        try:
             if self.mode in "aw":
                 self.fileobj.write(NUL * (BLOCKSIZE * 2))
                 self.offset += (BLOCKSIZE * 2)
@@ -1804,10 +1806,9 @@ class TarFile(object):
                 blocks, remainder = divmod(self.offset, RECORDSIZE)
                 if remainder > 0:
                     self.fileobj.write(NUL * (RECORDSIZE - remainder))
-
+        finally:
             if not self._extfileobj:
                 self.fileobj.close()
-        self.closed = True
 
     def getmember(self, name):
         """Return a TarInfo object for member `name'. If `name' can not be

Lib/telnetlib.py

@@ -254,12 +254,13 @@ class Telnet:
 
     def close(self):
         """Close the connection."""
-        if self.sock:
-            self.sock.close()
+        sock = self.sock
         self.sock = 0
         self.eof = 1
         self.iacseq = ''
         self.sb = 0
+        if sock:
+            sock.close()
 
     def get_socket(self):
         """Return the socket object used internally."""

Lib/tempfile.py

@@ -413,7 +413,9 @@ class _TemporaryFileWrapper:
         def close(self):
             if not self.close_called:
                 self.close_called = True
+                try:
                     self.file.close()
+                finally:
                     if self.delete:
                         self.unlink(self.name)
 

Lib/urllib.py

@@ -994,12 +994,17 @@ class addclosehook(addbase):
         self.hookargs = hookargs
 
     def close(self):
-        if self.closehook:
-            self.closehook(*self.hookargs)
+        try:
+            closehook = self.closehook
+            hookargs = self.hookargs
+            if closehook:
                 self.closehook = None
                 self.hookargs = None
+                closehook(*hookargs)
+        finally:
             addbase.close(self)
 
+
 class addinfo(addbase):
     """class to add an info() method to an open file."""
 

Lib/wave.py

@@ -180,10 +180,11 @@ class Wave_read:
         self._soundpos = 0
 
     def close(self):
-        if self._i_opened_the_file:
-            self._i_opened_the_file.close()
-            self._i_opened_the_file = None
         self._file = None
+        file = self._i_opened_the_file
+        if file:
+            self._i_opened_the_file = None
+            file.close()
 
     def tell(self):
         return self._soundpos
@@ -444,17 +445,18 @@ class Wave_write:
             self._patchheader()
 
     def close(self):
-        if self._file:
         try:
+            if self._file:
                 self._ensure_header_written(0)
                 if self._datalength != self._datawritten:
                     self._patchheader()
                 self._file.flush()
         finally:
             self._file = None
-        if self._i_opened_the_file:
-            self._i_opened_the_file.close()
+            file = self._i_opened_the_file
+            if file:
                 self._i_opened_the_file = None
+                file.close()
 
     #
     # Internal methods.

Lib/xml/sax/expatreader.py

@@ -214,11 +214,13 @@ class ExpatParser(xmlreader.IncrementalParser, xmlreader.Locator):
             self._err_handler.fatalError(exc)
 
     def close(self):
-        if self._entity_stack:
+        if self._entity_stack or self._parser is None:
             # If we are completing an external entity, do nothing here
             return
+        try:
             self.feed("", isFinal = 1)
             self._cont_handler.endDocument()
+        finally:
             self._parsing = 0
             # break cycle created by expat handlers pointing to our methods
             self._parser = None

Lib/xmlrpclib.py

@@ -558,8 +558,13 @@ else:
             self._parser.Parse(data, 0)
 
         def close(self):
-            self._parser.Parse("", 1) # end of data
+            try:
+                parser = self._parser
+            except AttributeError:
+                pass
+            else:
                 del self._target, self._parser # get rid of circular references
+                parser.Parse("", 1) # end of data
 
 class SlowParser:
     """Default XML parser (based on xmllib.XMLParser)."""
@@ -1214,7 +1219,9 @@ class GzipDecodedResponse(gzip.GzipFile if gzip else object):
         gzip.GzipFile.__init__(self, mode="rb", fileobj=self.stringio)
 
     def close(self):
+        try:
             gzip.GzipFile.close(self)
+        finally:
             self.stringio.close()
 
 
@@ -1384,9 +1391,10 @@ class Transport:
     # Used in the event of socket errors.
     #
     def close(self):
-        if self._connection[1]:
-            self._connection[1].close()
+        host, connection = self._connection
+        if connection:
             self._connection = (None, None)
+            connection.close()
 
     ##
     # Send request header.

Misc/NEWS

@@ -21,6 +21,10 @@ Core and Builtins
 Library
 -------
 
+- Issue #23865: close() methods in multiple modules now are idempotent and more
+  robust at shutdown. If needs to release multiple resources, they are released
+  even if errors are occured.
+
 - Issue #23881: urllib.ftpwrapper constructor now closes the socket if the FTP
   connection failed.