bpo-47015: Update test_os from asyncore to asyncio (GH-31876)

2 files changed, 81 insertions, 157 deletions

diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 426d2ae..9a60bf5 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -2,6 +2,7 @@
 # does add tests for a few functions which have been determined to be more
 # portable than they had been thought to be.
 
+import asyncio
 import codecs
 import contextlib
 import decimal
@@ -23,7 +24,6 @@ import subprocess
 import sys
 import sysconfig
 import tempfile
-import threading
 import time
 import types
 import unittest
@@ -33,15 +33,9 @@ from test import support
 from test.support import import_helper
 from test.support import os_helper
 from test.support import socket_helper
-from test.support import threading_helper
 from test.support import warnings_helper
 from platform import win32_is_iot
 
-with warnings.catch_warnings():
-    warnings.simplefilter('ignore', DeprecationWarning)
-    import asynchat
-    import asyncore
-
 try:
     import resource
 except ImportError:
@@ -101,6 +95,10 @@ requires_splice_pipe = unittest.skipIf(sys.platform.startswith("aix"),
                                        'on AIX, splice() only accepts sockets')
 
 
+def tearDownModule():
+    asyncio.set_event_loop_policy(None)
+
+
 class MiscTests(unittest.TestCase):
     def test_getcwd(self):
         cwd = os.getcwd()
@@ -3228,94 +3226,8 @@ class ProgramPriorityTests(unittest.TestCase):
                     raise
 
 
-class SendfileTestServer(asyncore.dispatcher, threading.Thread):
-
-    class Handler(asynchat.async_chat):
-
-        def __init__(self, conn):
-            asynchat.async_chat.__init__(self, conn)
-            self.in_buffer = []
-            self.accumulate = True
-            self.closed = False
-            self.push(b"220 ready\r\n")
-
-        def handle_read(self):
-            data = self.recv(4096)
-            if self.accumulate:
-                self.in_buffer.append(data)
-
-        def get_data(self):
-            return b''.join(self.in_buffer)
-
-        def handle_close(self):
-            self.close()
-            self.closed = True
-
-        def handle_error(self):
-            raise
-
-    def __init__(self, address):
-        threading.Thread.__init__(self)
-        asyncore.dispatcher.__init__(self)
-        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
-        self.bind(address)
-        self.listen(5)
-        self.host, self.port = self.socket.getsockname()[:2]
-        self.handler_instance = None
-        self._active = False
-        self._active_lock = threading.Lock()
-
-    # --- public API
-
-    @property
-    def running(self):
-        return self._active
-
-    def start(self):
-        assert not self.running
-        self.__flag = threading.Event()
-        threading.Thread.start(self)
-        self.__flag.wait()
-
-    def stop(self):
-        assert self.running
-        self._active = False
-        self.join()
-
-    def wait(self):
-        # wait for handler connection to be closed, then stop the server
-        while not getattr(self.handler_instance, "closed", False):
-            time.sleep(0.001)
-        self.stop()
-
-    # --- internals
-
-    def run(self):
-        self._active = True
-        self.__flag.set()
-        while self._active and asyncore.socket_map:
-            self._active_lock.acquire()
-            asyncore.loop(timeout=0.001, count=1)
-            self._active_lock.release()
-        asyncore.close_all()
-
-    def handle_accept(self):
-        conn, addr = self.accept()
-        self.handler_instance = self.Handler(conn)
-
-    def handle_connect(self):
-        self.close()
-    handle_read = handle_connect
-
-    def writable(self):
-        return 0
-
-    def handle_error(self):
-        raise
-
-
 @unittest.skipUnless(hasattr(os, 'sendfile'), "test needs os.sendfile()")
-class TestSendfile(unittest.TestCase):
+class TestSendfile(unittest.IsolatedAsyncioTestCase):
 
     DATA = b"12345abcde" * 16 * 1024  # 160 KiB
     SUPPORT_HEADERS_TRAILERS = not sys.platform.startswith("linux") and \
@@ -3328,40 +3240,52 @@ class TestSendfile(unittest.TestCase):
 
     @classmethod
     def setUpClass(cls):
-        cls.key = threading_helper.threading_setup()
         create_file(os_helper.TESTFN, cls.DATA)
 
     @classmethod
     def tearDownClass(cls):
-        threading_helper.threading_cleanup(*cls.key)
         os_helper.unlink(os_helper.TESTFN)
 
-    def setUp(self):
-        self.server = SendfileTestServer((socket_helper.HOST, 0))
-        self.server.start()
+    @staticmethod
+    async def chunks(reader):
+        while not reader.at_eof():
+            yield await reader.read()
+
+    async def handle_new_client(self, reader, writer):
+        self.server_buffer = b''.join([x async for x in self.chunks(reader)])
+        writer.close()
+        self.server.close()  # The test server processes a single client only
+
+    async def asyncSetUp(self):
+        self.server_buffer = b''
+        self.server = await asyncio.start_server(self.handle_new_client,
+                                                 socket_helper.HOSTv4)
+        server_name = self.server.sockets[0].getsockname()
         self.client = socket.socket()
-        self.client.connect((self.server.host, self.server.port))
-        self.client.settimeout(1)
-        # synchronize by waiting for "220 ready" response
-        self.client.recv(1024)
+        self.client.setblocking(False)
+        await asyncio.get_running_loop().sock_connect(self.client, server_name)
         self.sockno = self.client.fileno()
         self.file = open(os_helper.TESTFN, 'rb')
         self.fileno = self.file.fileno()
 
-    def tearDown(self):
+    async def asyncTearDown(self):
         self.file.close()
         self.client.close()
-        if self.server.running:
-            self.server.stop()
-        self.server = None
+        await self.server.wait_closed()
+
+    # Use the test subject instead of asyncio.loop.sendfile
+    @staticmethod
+    async def async_sendfile(*args, **kwargs):
+        return await asyncio.to_thread(os.sendfile, *args, **kwargs)
 
-    def sendfile_wrapper(self, *args, **kwargs):
+    @staticmethod
+    async def sendfile_wrapper(*args, **kwargs):
         """A higher level wrapper representing how an application is
         supposed to use sendfile().
         """
         while True:
             try:
-                return os.sendfile(*args, **kwargs)
+                return await TestSendfile.async_sendfile(*args, **kwargs)
             except OSError as err:
                 if err.errno == errno.ECONNRESET:
                     # disconnected
@@ -3372,13 +3296,14 @@ class TestSendfile(unittest.TestCase):
                 else:
                     raise
 
-    def test_send_whole_file(self):
+    async def test_send_whole_file(self):
         # normal send
         total_sent = 0
         offset = 0
         nbytes = 4096
         while total_sent < len(self.DATA):
-            sent = self.sendfile_wrapper(self.sockno, self.fileno, offset, nbytes)
+            sent = await self.sendfile_wrapper(self.sockno, self.fileno,
+                                               offset, nbytes)
             if sent == 0:
                 break
             offset += sent
@@ -3389,19 +3314,19 @@ class TestSendfile(unittest.TestCase):
         self.assertEqual(total_sent, len(self.DATA))
         self.client.shutdown(socket.SHUT_RDWR)
         self.client.close()
-        self.server.wait()
-        data = self.server.handler_instance.get_data()
-        self.assertEqual(len(data), len(self.DATA))
-        self.assertEqual(data, self.DATA)
+        await self.server.wait_closed()
+        self.assertEqual(len(self.server_buffer), len(self.DATA))
+        self.assertEqual(self.server_buffer, self.DATA)
 
-    def test_send_at_certain_offset(self):
+    async def test_send_at_certain_offset(self):
         # start sending a file at a certain offset
         total_sent = 0
         offset = len(self.DATA) // 2
         must_send = len(self.DATA) - offset
         nbytes = 4096
         while total_sent < must_send:
-            sent = self.sendfile_wrapper(self.sockno, self.fileno, offset, nbytes)
+            sent = await self.sendfile_wrapper(self.sockno, self.fileno,
+                                               offset, nbytes)
             if sent == 0:
                 break
             offset += sent
@@ -3410,18 +3335,18 @@ class TestSendfile(unittest.TestCase):
 
         self.client.shutdown(socket.SHUT_RDWR)
         self.client.close()
-        self.server.wait()
-        data = self.server.handler_instance.get_data()
+        await self.server.wait_closed()
         expected = self.DATA[len(self.DATA) // 2:]
         self.assertEqual(total_sent, len(expected))
-        self.assertEqual(len(data), len(expected))
-        self.assertEqual(data, expected)
+        self.assertEqual(len(self.server_buffer), len(expected))
+        self.assertEqual(self.server_buffer, expected)
 
-    def test_offset_overflow(self):
+    async def test_offset_overflow(self):
         # specify an offset > file size
         offset = len(self.DATA) + 4096
         try:
-            sent = os.sendfile(self.sockno, self.fileno, offset, 4096)
+            sent = await self.async_sendfile(self.sockno, self.fileno,
+                                             offset, 4096)
         except OSError as e:
             # Solaris can raise EINVAL if offset >= file length, ignore.
             if e.errno != errno.EINVAL:
@@ -3430,39 +3355,38 @@ class TestSendfile(unittest.TestCase):
             self.assertEqual(sent, 0)
         self.client.shutdown(socket.SHUT_RDWR)
         self.client.close()
-        self.server.wait()
-        data = self.server.handler_instance.get_data()
-        self.assertEqual(data, b'')
+        await self.server.wait_closed()
+        self.assertEqual(self.server_buffer, b'')
 
-    def test_invalid_offset(self):
+    async def test_invalid_offset(self):
         with self.assertRaises(OSError) as cm:
-            os.sendfile(self.sockno, self.fileno, -1, 4096)
+            await self.async_sendfile(self.sockno, self.fileno, -1, 4096)
         self.assertEqual(cm.exception.errno, errno.EINVAL)
 
-    def test_keywords(self):
+    async def test_keywords(self):
         # Keyword arguments should be supported
-        os.sendfile(out_fd=self.sockno, in_fd=self.fileno,
-                    offset=0, count=4096)
+        await self.async_sendfile(out_fd=self.sockno, in_fd=self.fileno,
+                                  offset=0, count=4096)
         if self.SUPPORT_HEADERS_TRAILERS:
-            os.sendfile(out_fd=self.sockno, in_fd=self.fileno,
-                        offset=0, count=4096,
-                        headers=(), trailers=(), flags=0)
+            await self.async_sendfile(out_fd=self.sockno, in_fd=self.fileno,
+                                      offset=0, count=4096,
+                                      headers=(), trailers=(), flags=0)
 
     # --- headers / trailers tests
 
     @requires_headers_trailers
-    def test_headers(self):
+    async def test_headers(self):
         total_sent = 0
         expected_data = b"x" * 512 + b"y" * 256 + self.DATA[:-1]
-        sent = os.sendfile(self.sockno, self.fileno, 0, 4096,
-                            headers=[b"x" * 512, b"y" * 256])
+        sent = await self.async_sendfile(self.sockno, self.fileno, 0, 4096,
+                                         headers=[b"x" * 512, b"y" * 256])
         self.assertLessEqual(sent, 512 + 256 + 4096)
         total_sent += sent
         offset = 4096
         while total_sent < len(expected_data):
             nbytes = min(len(expected_data) - total_sent, 4096)
-            sent = self.sendfile_wrapper(self.sockno, self.fileno,
-                                                    offset, nbytes)
+            sent = await self.sendfile_wrapper(self.sockno, self.fileno,
+                                               offset, nbytes)
             if sent == 0:
                 break
             self.assertLessEqual(sent, nbytes)
@@ -3471,12 +3395,11 @@ class TestSendfile(unittest.TestCase):
 
         self.assertEqual(total_sent, len(expected_data))
         self.client.close()
-        self.server.wait()
-        data = self.server.handler_instance.get_data()
-        self.assertEqual(hash(data), hash(expected_data))
+        await self.server.wait_closed()
+        self.assertEqual(hash(self.server_buffer), hash(expected_data))
 
     @requires_headers_trailers
-    def test_trailers(self):
+    async def test_trailers(self):
         TESTFN2 = os_helper.TESTFN + "2"
         file_data = b"abcdef"
 
@@ -3484,38 +3407,37 @@ class TestSendfile(unittest.TestCase):
         create_file(TESTFN2, file_data)
 
         with open(TESTFN2, 'rb') as f:
-            os.sendfile(self.sockno, f.fileno(), 0, 5,
-                        trailers=[b"123456", b"789"])
+            await self.async_sendfile(self.sockno, f.fileno(), 0, 5,
+                                      trailers=[b"123456", b"789"])
             self.client.close()
-            self.server.wait()
-            data = self.server.handler_instance.get_data()
-            self.assertEqual(data, b"abcde123456789")
+            await self.server.wait_closed()
+            self.assertEqual(self.server_buffer, b"abcde123456789")
 
     @requires_headers_trailers
     @requires_32b
-    def test_headers_overflow_32bits(self):
+    async def test_headers_overflow_32bits(self):
         self.server.handler_instance.accumulate = False
         with self.assertRaises(OSError) as cm:
-            os.sendfile(self.sockno, self.fileno, 0, 0,
-                        headers=[b"x" * 2**16] * 2**15)
+            await self.async_sendfile(self.sockno, self.fileno, 0, 0,
+                                      headers=[b"x" * 2**16] * 2**15)
         self.assertEqual(cm.exception.errno, errno.EINVAL)
 
     @requires_headers_trailers
     @requires_32b
-    def test_trailers_overflow_32bits(self):
+    async def test_trailers_overflow_32bits(self):
         self.server.handler_instance.accumulate = False
         with self.assertRaises(OSError) as cm:
-            os.sendfile(self.sockno, self.fileno, 0, 0,
-                        trailers=[b"x" * 2**16] * 2**15)
+            await self.async_sendfile(self.sockno, self.fileno, 0, 0,
+                                      trailers=[b"x" * 2**16] * 2**15)
         self.assertEqual(cm.exception.errno, errno.EINVAL)
 
     @requires_headers_trailers
     @unittest.skipUnless(hasattr(os, 'SF_NODISKIO'),
                          'test needs os.SF_NODISKIO')
-    def test_flags(self):
+    async def test_flags(self):
         try:
-            os.sendfile(self.sockno, self.fileno, 0, 4096,
-                        flags=os.SF_NODISKIO)
+            await self.async_sendfile(self.sockno, self.fileno, 0, 4096,
+                                      flags=os.SF_NODISKIO)
         except OSError as err:
             if err.errno not in (errno.EBUSY, errno.EAGAIN):
                 raise
diff --git a/Misc/NEWS.d/next/Tests/2022-03-13-23-43-40.bpo-47015.FjmCsz.rst b/Misc/NEWS.d/next/Tests/2022-03-13-23-43-40.bpo-47015.FjmCsz.rst
new file mode 100644
index 0000000..12c527a
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2022-03-13-23-43-40.bpo-47015.FjmCsz.rst
@@ -0,0 +1,2 @@
+A test case for :func:`os.sendfile` is converted from deprecated
+:mod:`asyncore` (see :pep:`594`) to :mod:`asyncio`. Patch by Oleg Iarygin.