bpo-31370: Remove support for threads-less builds (#3385)

* Remove Setup.config
* Always define WITH_THREAD for compatibility.

Lib/test/test_os.py

@@ -22,15 +22,13 @@ import stat
 import subprocess
 import sys
 import sysconfig
+import threading
 import time
 import unittest
 import uuid
 import warnings
 from test import support
-try:
-    import threading
-except ImportError:
-    threading = None
+
 try:
     import resource
 except ImportError:
@@ -2516,92 +2514,90 @@ class ProgramPriorityTests(unittest.TestCase):
                     raise
 
 
-if threading is not None:
-    class SendfileTestServer(asyncore.dispatcher, threading.Thread):
+class SendfileTestServer(asyncore.dispatcher, threading.Thread):
 
-        class Handler(asynchat.async_chat):
+    class Handler(asynchat.async_chat):
 
-            def __init__(self, conn):
-                asynchat.async_chat.__init__(self, conn)
-                self.in_buffer = []
-                self.closed = False
-                self.push(b"220 ready\r\n")
+        def __init__(self, conn):
+            asynchat.async_chat.__init__(self, conn)
+            self.in_buffer = []
+            self.closed = False
+            self.push(b"220 ready\r\n")
 
-            def handle_read(self):
-                data = self.recv(4096)
-                self.in_buffer.append(data)
+        def handle_read(self):
+            data = self.recv(4096)
+            self.in_buffer.append(data)
 
-            def get_data(self):
-                return b''.join(self.in_buffer)
+        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):
+        def handle_close(self):
             self.close()
-        handle_read = handle_connect
-
-        def writable(self):
-            return 0
+            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(threading is not None, "test needs threading module")
 @unittest.skipUnless(hasattr(os, 'sendfile'), "test needs os.sendfile()")
 class TestSendfile(unittest.TestCase):