Python os.close函数代码示例

	def _start_post_builddir_lock(self, lock_future=None, start_ipc_daemon=False):
		if lock_future is not None:
			if lock_future is not self._start_future:
				raise AssertionError('lock_future is not self._start_future')
			self._start_future = None
			if lock_future.cancelled():
				self._build_dir = None
				self.cancelled = True
				self._was_cancelled()
				self._async_wait()
				return

			lock_future.result()

		if start_ipc_daemon:
			self.settings['PORTAGE_IPC_DAEMON'] = "1"
			self._start_ipc_daemon()

		if self.fd_pipes is None:
			self.fd_pipes = {}
		null_fd = None
		if 0 not in self.fd_pipes and \
			self.phase not in self._phases_interactive_whitelist and \
			"interactive" not in self.settings.get("PROPERTIES", "").split():
			null_fd = os.open('/dev/null', os.O_RDONLY)
			self.fd_pipes[0] = null_fd

		try:
			SpawnProcess._start(self)
		finally:
			if null_fd is not None:
				os.close(null_fd)

	def _unregister(self):

		if self._reg_id is not None:
			self.scheduler.source_remove(self._reg_id)
			self._reg_id = None

		if self.input_fd is not None:
			if isinstance(self.input_fd, int):
				os.close(self.input_fd)
			else:
				self.input_fd.close()
			self.input_fd = None

		if self.stdout_fd is not None:
			os.close(self.stdout_fd)
			self.stdout_fd = None

		if self._log_file is not None:
			self._log_file.close()
			self._log_file = None

		if self._log_file_real is not None:
			# Avoid "ResourceWarning: unclosed file" since python 3.2.
			self._log_file_real.close()
			self._log_file_real = None

		self._registered = False

	def _start(self):
		in_pr, in_pw = os.pipe()
		out_pr, out_pw = os.pipe()
		self._files = {}
		self._files['pipe_in'] = in_pr
		self._files['pipe_out'] = out_pw

		fcntl.fcntl(in_pr, fcntl.F_SETFL,
			fcntl.fcntl(in_pr, fcntl.F_GETFL) | os.O_NONBLOCK)

		# FD_CLOEXEC is enabled by default in Python >=3.4.
		if sys.hexversion < 0x3040000:
			try:
				fcntl.FD_CLOEXEC
			except AttributeError:
				pass
			else:
				fcntl.fcntl(in_pr, fcntl.F_SETFD,
					fcntl.fcntl(in_pr, fcntl.F_GETFD) | fcntl.FD_CLOEXEC)

		self._reg_id = self.scheduler.io_add_watch(in_pr,
			self.scheduler.IO_IN, self._output_handler)
		self._registered = True
		self._proc = SpawnProcess(
			args=[portage._python_interpreter,
				os.path.join(portage._bin_path, 'lock-helper.py'), self.path],
				env=dict(os.environ, PORTAGE_PYM_PATH=portage._pym_path),
				fd_pipes={0:out_pr, 1:in_pw, 2:sys.__stderr__.fileno()},
				scheduler=self.scheduler)
		self._proc.addExitListener(self._proc_exit)
		self._proc.start()
		os.close(out_pr)
		os.close(in_pw)

	def _elog_output_handler(self, fd, event):
		output = None
		if event & self.scheduler.IO_IN:
			try:
				output = os.read(fd, self._bufsize)
			except OSError as e:
				if e.errno not in (errno.EAGAIN, errno.EINTR):
					raise
		if output:
			lines = _unicode_decode(output).split('\n')
			if len(lines) == 1:
				self._buf += lines[0]
			else:
				lines[0] = self._buf + lines[0]
				self._buf = lines.pop()
				out = io.StringIO()
				for line in lines:
					funcname, phase, key, msg = line.split(' ', 3)
					self._elog_keys.add(key)
					reporter = getattr(portage.elog.messages, funcname)
					reporter(msg, phase=phase, key=key, out=out)

		if event & self.scheduler.IO_HUP:
			self.scheduler.source_remove(self._elog_reg_id)
			self._elog_reg_id = None
			os.close(self._elog_reader_fd)
			self._elog_reader_fd = None
			return False

		return True

	def _testPipeReader(self, master_fd, slave_fd, test_string):
		"""
		Use a poll loop to read data from a pipe and assert that
		the data written to the pipe is identical to the data
		read from the pipe.
		"""

		# WARNING: It is very important to use unbuffered mode here,
		# in order to avoid issue 5380 with python3.
		master_file = os.fdopen(master_fd, 'rb', 0)
		scheduler = global_event_loop()

		consumer = PipeReader(
			input_files={"producer" : master_file},
			_use_array=self._use_array,
			scheduler=scheduler)

		producer = PopenProcess(
			pipe_reader=consumer,
			proc=subprocess.Popen(["bash", "-c", self._echo_cmd % test_string],
				stdout=slave_fd),
			scheduler=scheduler)

		producer.start()
		os.close(slave_fd)
		producer.wait()
		consumer.wait()

		self.assertEqual(producer.returncode, os.EX_OK)
		self.assertEqual(consumer.returncode, os.EX_OK)

		return consumer.getvalue().decode('ascii', 'replace')

def _setup_pipes(fd_pipes, close_fds=True):
	"""Setup pipes for a forked process.

	WARNING: When not followed by exec, the close_fds behavior
	can trigger interference from destructors that close file
	descriptors. This interference happens when the garbage
	collector intermittently executes such destructors after their
	corresponding file descriptors have been re-used, leading
	to intermittent "[Errno 9] Bad file descriptor" exceptions in
	forked processes. This problem has been observed with PyPy 1.8,
	and also with CPython under some circumstances (as triggered
	by xmpppy in bug #374335). In order to close a safe subset of
	file descriptors, see portage.locks._close_fds().
	"""
	my_fds = {}
	# To protect from cases where direct assignment could
	# clobber needed fds ({1:2, 2:1}) we first dupe the fds
	# into unused fds.
	for fd in fd_pipes:
		my_fds[fd] = os.dup(fd_pipes[fd])
	# Then assign them to what they should be.
	for fd in my_fds:
		os.dup2(my_fds[fd], fd)

	if close_fds:
		# Then close _all_ fds that haven't been explicitly
		# requested to be kept open.
		for fd in get_open_fds():
			if fd not in my_fds:
				try:
					os.close(fd)
				except OSError:
					pass

	def _unregister(self):
		"""
		Unregister from the scheduler and close open files.
		"""

		if not self.unmerge:
			# Populate the vardbapi cache for the new package
			# while its inodes are still hot.
			try:
				self.vartree.dbapi.aux_get(self.settings.mycpv, ["EAPI"])
			except KeyError:
				pass

		self._unlock_vdb()
		if self._elog_reg_id is not None:
			self.scheduler.source_remove(self._elog_reg_id)
			self._elog_reg_id = None
		if self._elog_reader_fd is not None:
			os.close(self._elog_reader_fd)
			self._elog_reader_fd = None
		if self._elog_keys is not None:
			for key in self._elog_keys:
				portage.elog.elog_process(key, self.settings,
					phasefilter=("prerm", "postrm"))
			self._elog_keys = None

		super(MergeProcess, self)._unregister()

def perform_checksum(filename, hashname="MD5", calc_prelink=0):
	"""
	Run a specific checksum against a file. The filename can
	be either unicode or an encoded byte string. If filename
	is unicode then a UnicodeDecodeError will be raised if
	necessary.

	@param filename: File to run the checksum against
	@type filename: String
	@param hashname: The type of hash function to run
	@type hashname: String
	@param calc_prelink: Whether or not to reverse prelink before running the checksum
	@type calc_prelink: Integer
	@rtype: Tuple
	@return: The hash and size of the data
	"""
	global prelink_capable
	# Make sure filename is encoded with the correct encoding before
	# it is passed to spawn (for prelink) and/or the hash function.
	filename = _unicode_encode(filename,
		encoding=_encodings['fs'], errors='strict')
	myfilename = filename
	prelink_tmpfile = None
	try:
		if (calc_prelink and prelink_capable and
		    is_prelinkable_elf(filename)):
			# Create non-prelinked temporary file to checksum.
			# Files rejected by prelink are summed in place.
			try:
				tmpfile_fd, prelink_tmpfile = tempfile.mkstemp()
				try:
					retval = portage.process.spawn([PRELINK_BINARY,
						"--verify", filename], fd_pipes={1:tmpfile_fd})
				finally:
					os.close(tmpfile_fd)
				if retval == os.EX_OK:
					myfilename = prelink_tmpfile
			except portage.exception.CommandNotFound:
				# This happens during uninstallation of prelink.
				prelink_capable = False
		try:
			if hashname not in hashfunc_map:
				raise portage.exception.DigestException(hashname + \
					" hash function not available (needs dev-python/pycrypto)")
			myhash, mysize = hashfunc_map[hashname](myfilename)
		except (OSError, IOError) as e:
			if e.errno in (errno.ENOENT, errno.ESTALE):
				raise portage.exception.FileNotFound(myfilename)
			elif e.errno == portage.exception.PermissionDenied.errno:
				raise portage.exception.PermissionDenied(myfilename)
			raise
		return myhash, mysize
	finally:
		if prelink_tmpfile:
			try:
				os.unlink(prelink_tmpfile)
			except OSError as e:
				if e.errno != errno.ENOENT:
					raise
				del e

	def _testPipeLogger(self, test_string):

		producer = PopenProcess(proc=subprocess.Popen(
			["bash", "-c", self._echo_cmd % test_string],
			stdout=subprocess.PIPE, stderr=subprocess.STDOUT),
			scheduler=global_event_loop())

		fd, log_file_path = tempfile.mkstemp()
		try:

			consumer = PipeLogger(background=True,
				input_fd=os.dup(producer.proc.stdout.fileno()),
				log_file_path=log_file_path)

			# Close the stdout pipe, since we duplicated it, and it
			# must be closed in order to avoid a ResourceWarning.
			producer.proc.stdout.close()
			producer.pipe_reader = consumer

			producer.start()
			producer.wait()

			self.assertEqual(producer.returncode, os.EX_OK)
			self.assertEqual(consumer.returncode, os.EX_OK)

			with open(log_file_path, 'rb') as f:
				content = f.read()

		finally:
			os.close(fd)
			os.unlink(log_file_path)

		return content.decode('ascii', 'replace')

	def _testPipeLogger(self, test_string):

		producer = PopenProcess(proc=subprocess.Popen(
			["bash", "-c", self._echo_cmd % test_string],
			stdout=subprocess.PIPE, stderr=subprocess.STDOUT),
			scheduler=global_event_loop())

		fd, log_file_path = tempfile.mkstemp()
		try:

			consumer = PipeLogger(background=True,
				input_fd=producer.proc.stdout,
				log_file_path=log_file_path)

			producer.pipe_reader = consumer

			producer.start()
			producer.wait()

			self.assertEqual(producer.returncode, os.EX_OK)
			self.assertEqual(consumer.returncode, os.EX_OK)

			with open(log_file_path, 'rb') as f:
				content = f.read()

		finally:
			os.close(fd)
			os.unlink(log_file_path)

		return content.decode('ascii', 'replace')

	def testLogfile(self):
		logfile = None
		try:
			fd, logfile = tempfile.mkstemp()
			os.close(fd)
			null_fd = os.open('/dev/null', os.O_RDWR)
			test_string = 2 * "blah blah blah\n"
			task_scheduler = TaskScheduler()
			proc = SpawnProcess(
				args=[BASH_BINARY, "-c",
				"echo -n '%s'" % test_string],
				env={}, fd_pipes={0:sys.stdin.fileno(), 1:null_fd, 2:null_fd},
				scheduler=task_scheduler.sched_iface,
				logfile=logfile)
			task_scheduler.add(proc)
			task_scheduler.run()
			os.close(null_fd)
			f = codecs.open(_unicode_encode(logfile,
				encoding=_encodings['fs'], errors='strict'),
				mode='r', encoding=_encodings['content'], errors='strict')
			log_content = f.read()
			f.close()
			# When logging passes through a pty, this comparison will fail
			# unless the oflag terminal attributes have the termios.OPOST
			# bit disabled. Otherwise, tranformations such as \n -> \r\n
			# may occur.
			self.assertEqual(test_string, log_content)
		finally:
			if logfile:
				try:
					os.unlink(logfile)
				except EnvironmentError as e:
					if e.errno != errno.ENOENT:
						raise
					del e

	def _spawn(self, args, fd_pipes=None, **kwargs):
		"""
		Fork a subprocess, apply local settings, and call fetch().
		"""

		parent_pid = os.getpid()
		pid = None
		try:
			pid = os.fork()

			if pid != 0:
				if not isinstance(pid, int):
					raise AssertionError(
						"fork returned non-integer: %s" % (repr(pid),))
				return [pid]

			rval = 1
			try:

				# Use default signal handlers in order to avoid problems
				# killing subprocesses as reported in bug #353239.
				signal.signal(signal.SIGINT, signal.SIG_DFL)
				signal.signal(signal.SIGTERM, signal.SIG_DFL)

				# Unregister SIGCHLD handler and wakeup_fd for the parent
				# process's event loop (bug 655656).
				signal.signal(signal.SIGCHLD, signal.SIG_DFL)
				try:
					wakeup_fd = signal.set_wakeup_fd(-1)
					if wakeup_fd > 0:
						os.close(wakeup_fd)
				except (ValueError, OSError):
					pass

				portage.locks._close_fds()
				# We don't exec, so use close_fds=False
				# (see _setup_pipes docstring).
				portage.process._setup_pipes(fd_pipes, close_fds=False)

				rval = self._run()
			except SystemExit:
				raise
			except:
				traceback.print_exc()
				# os._exit() skips stderr flush!
				sys.stderr.flush()
			finally:
				os._exit(rval)

		finally:
			if pid == 0 or (pid is None and os.getpid() != parent_pid):
				# Call os._exit() from a finally block in order
				# to suppress any finally blocks from earlier
				# in the call stack (see bug #345289). This
				# finally block has to be setup before the fork
				# in order to avoid a race condition.
				os._exit(1)

def _close_fds():
	"""
	This is intended to be called after a fork, in order to close file
	descriptors for locks held by the parent process. This can be called
	safely after a fork without exec, unlike the _setup_pipes close_fds
	behavior.
	"""
	while _open_fds:
		os.close(_open_fds.pop())

	def _check_sig_key(self):
		null_fd = os.open('/dev/null', os.O_RDONLY)
		popen_proc = PopenProcess(proc=subprocess.Popen(
			["gpg", "--verify", self._manifest_path],
			stdin=null_fd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT),
			pipe_reader=PipeReader())
		os.close(null_fd)
		popen_proc.pipe_reader.input_files = {
			"producer" : popen_proc.proc.stdout}
		self._start_task(popen_proc, self._check_sig_key_exit)

	def _unregister(self):
		self._registered = False

		if self._files is not None:
			try:
				pipe_in = self._files.pop('pipe_in')
			except KeyError:
				pass
			else:
				self.scheduler.remove_reader(pipe_in)
				os.close(pipe_in)