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

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

Doc/whatsnew/3.7.rst

@@ -344,6 +344,9 @@ Build and C API Changes
   download a copy of 32-bit Python for this purpose.  (Contributed by Zachary
   Ware in :issue:`30450`.)
 
+* Support for building ``--without-threads`` is removed.
+  (Contributed by Antoine Pitrou in :issue:`31370`.).
+
 
 Deprecated
 ==========

Include/Python.h

@@ -18,7 +18,7 @@
 #error "Python's source code assumes C's unsigned char is an 8-bit type."
 #endif
 
-#if defined(__sgi) && defined(WITH_THREAD) && !defined(_SGI_MP_SOURCE)
+#if defined(__sgi) && !defined(_SGI_MP_SOURCE)
 #define _SGI_MP_SOURCE
 #endif
 

Include/ceval.h

@@ -183,8 +183,6 @@ PyAPI_FUNC(PyObject *) _PyEval_EvalFrameDefault(struct _frame *f, int exc);
 PyAPI_FUNC(PyThreadState *) PyEval_SaveThread(void);
 PyAPI_FUNC(void) PyEval_RestoreThread(PyThreadState *);
 
-#ifdef WITH_THREAD
-
 PyAPI_FUNC(int)  PyEval_ThreadsInitialized(void);
 PyAPI_FUNC(void) PyEval_InitThreads(void);
 #ifndef Py_LIMITED_API
@@ -213,15 +211,6 @@ PyAPI_FUNC(Py_ssize_t) _PyEval_RequestCodeExtraIndex(freefunc);
 #define Py_END_ALLOW_THREADS    PyEval_RestoreThread(_save); \
                  }
 
-#else /* !WITH_THREAD */
-
-#define Py_BEGIN_ALLOW_THREADS {
-#define Py_BLOCK_THREADS
-#define Py_UNBLOCK_THREADS
-#define Py_END_ALLOW_THREADS }
-
-#endif /* !WITH_THREAD */
-
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _PyEval_SliceIndex(PyObject *, Py_ssize_t *);
 PyAPI_FUNC(int) _PyEval_SliceIndexNotNone(PyObject *, Py_ssize_t *);

Include/import.h

@@ -100,13 +100,8 @@ PyAPI_FUNC(int) PyImport_ImportFrozenModule(
     );
 
 #ifndef Py_LIMITED_API
-#ifdef WITH_THREAD
 PyAPI_FUNC(void) _PyImport_AcquireLock(void);
 PyAPI_FUNC(int) _PyImport_ReleaseLock(void);
-#else
-#define _PyImport_AcquireLock()
-#define _PyImport_ReleaseLock() 1
-#endif
 
 PyAPI_FUNC(void) _PyImport_ReInitLock(void);
 

Include/pyport.h

@@ -797,4 +797,12 @@ extern _invalid_parameter_handler _Py_silent_invalid_parameter_handler;
 #include <android/api-level.h>
 #endif
 
+/* This macro used to tell whether Python was built with multithreading
+ * enabled.  Now multithreading is always enabled, but keep the macro
+ * for compatibility.
+ */
+#ifndef WITH_THREAD
+#define WITH_THREAD
+#endif
+
 #endif /* Py_PYPORT_H */

Include/pystate.h

@@ -218,12 +218,10 @@ PyAPI_FUNC(void) PyThreadState_Delete(PyThreadState *);
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(void) _PyThreadState_DeleteExcept(PyThreadState *tstate);
 #endif /* !Py_LIMITED_API */
-#ifdef WITH_THREAD
 PyAPI_FUNC(void) PyThreadState_DeleteCurrent(void);
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(void) _PyGILState_Reinit(void);
 #endif /* !Py_LIMITED_API */
-#endif
 
 /* Return the current thread state. The global interpreter lock must be held.
  * When the current thread state is NULL, this issues a fatal error (so that
@@ -257,7 +255,6 @@ typedef
     enum {PyGILState_LOCKED, PyGILState_UNLOCKED}
         PyGILState_STATE;
 
-#ifdef WITH_THREAD
 
 /* Ensure that the current thread is ready to call the Python
    C API, regardless of the current state of Python, or of its
@@ -319,7 +316,6 @@ PyAPI_FUNC(int) PyGILState_Check(void);
 PyAPI_FUNC(PyInterpreterState *) _PyGILState_GetInterpreterStateUnsafe(void);
 #endif
 
-#endif   /* #ifdef WITH_THREAD */
 
 /* The implementation of sys._current_frames()  Returns a dict mapping
    thread id to that thread's current frame.

Lib/_dummy_thread.py

@@ -1,163 +0,0 @@
-"""Drop-in replacement for the thread module.
-
-Meant to be used as a brain-dead substitute so that threaded code does
-not need to be rewritten for when the thread module is not present.
-
-Suggested usage is::
-
-    try:
-        import _thread
-    except ImportError:
-        import _dummy_thread as _thread
-
-"""
-# Exports only things specified by thread documentation;
-# skipping obsolete synonyms allocate(), start_new(), exit_thread().
-__all__ = ['error', 'start_new_thread', 'exit', 'get_ident', 'allocate_lock',
-           'interrupt_main', 'LockType']
-
-# A dummy value
-TIMEOUT_MAX = 2**31
-
-# NOTE: this module can be imported early in the extension building process,
-# and so top level imports of other modules should be avoided.  Instead, all
-# imports are done when needed on a function-by-function basis.  Since threads
-# are disabled, the import lock should not be an issue anyway (??).
-
-error = RuntimeError
-
-def start_new_thread(function, args, kwargs={}):
-    """Dummy implementation of _thread.start_new_thread().
-
-    Compatibility is maintained by making sure that ``args`` is a
-    tuple and ``kwargs`` is a dictionary.  If an exception is raised
-    and it is SystemExit (which can be done by _thread.exit()) it is
-    caught and nothing is done; all other exceptions are printed out
-    by using traceback.print_exc().
-
-    If the executed function calls interrupt_main the KeyboardInterrupt will be
-    raised when the function returns.
-
-    """
-    if type(args) != type(tuple()):
-        raise TypeError("2nd arg must be a tuple")
-    if type(kwargs) != type(dict()):
-        raise TypeError("3rd arg must be a dict")
-    global _main
-    _main = False
-    try:
-        function(*args, **kwargs)
-    except SystemExit:
-        pass
-    except:
-        import traceback
-        traceback.print_exc()
-    _main = True
-    global _interrupt
-    if _interrupt:
-        _interrupt = False
-        raise KeyboardInterrupt
-
-def exit():
-    """Dummy implementation of _thread.exit()."""
-    raise SystemExit
-
-def get_ident():
-    """Dummy implementation of _thread.get_ident().
-
-    Since this module should only be used when _threadmodule is not
-    available, it is safe to assume that the current process is the
-    only thread.  Thus a constant can be safely returned.
-    """
-    return 1
-
-def allocate_lock():
-    """Dummy implementation of _thread.allocate_lock()."""
-    return LockType()
-
-def stack_size(size=None):
-    """Dummy implementation of _thread.stack_size()."""
-    if size is not None:
-        raise error("setting thread stack size not supported")
-    return 0
-
-def _set_sentinel():
-    """Dummy implementation of _thread._set_sentinel()."""
-    return LockType()
-
-class LockType(object):
-    """Class implementing dummy implementation of _thread.LockType.
-
-    Compatibility is maintained by maintaining self.locked_status
-    which is a boolean that stores the state of the lock.  Pickling of
-    the lock, though, should not be done since if the _thread module is
-    then used with an unpickled ``lock()`` from here problems could
-    occur from this class not having atomic methods.
-
-    """
-
-    def __init__(self):
-        self.locked_status = False
-
-    def acquire(self, waitflag=None, timeout=-1):
-        """Dummy implementation of acquire().
-
-        For blocking calls, self.locked_status is automatically set to
-        True and returned appropriately based on value of
-        ``waitflag``.  If it is non-blocking, then the value is
-        actually checked and not set if it is already acquired.  This
-        is all done so that threading.Condition's assert statements
-        aren't triggered and throw a little fit.
-
-        """
-        if waitflag is None or waitflag:
-            self.locked_status = True
-            return True
-        else:
-            if not self.locked_status:
-                self.locked_status = True
-                return True
-            else:
-                if timeout > 0:
-                    import time
-                    time.sleep(timeout)
-                return False
-
-    __enter__ = acquire
-
-    def __exit__(self, typ, val, tb):
-        self.release()
-
-    def release(self):
-        """Release the dummy lock."""
-        # XXX Perhaps shouldn't actually bother to test?  Could lead
-        #     to problems for complex, threaded code.
-        if not self.locked_status:
-            raise error
-        self.locked_status = False
-        return True
-
-    def locked(self):
-        return self.locked_status
-
-    def __repr__(self):
-        return "<%s %s.%s object at %s>" % (
-            "locked" if self.locked_status else "unlocked",
-            self.__class__.__module__,
-            self.__class__.__qualname__,
-            hex(id(self))
-        )
-
-# Used to signal that interrupt_main was called in a "thread"
-_interrupt = False
-# True when not executing in a "thread"
-_main = True
-
-def interrupt_main():
-    """Set _interrupt flag to True to have start_new_thread raise
-    KeyboardInterrupt upon exiting."""
-    if _main:
-        raise KeyboardInterrupt
-    else:
-        global _interrupt
-        _interrupt = True

Lib/_pydecimal.py

@@ -436,75 +436,34 @@ _rounding_modes = (ROUND_DOWN, ROUND_HALF_UP, ROUND_HALF_EVEN, ROUND_CEILING,
 # work for older Pythons.  If threads are not part of the build, create a
 # mock threading object with threading.local() returning the module namespace.
 
-try:
+import threading
-    import threading
-except ImportError:
-    # Python was compiled without threads; create a mock object instead
-    class MockThreading(object):
-        def local(self, sys=sys):
-            return sys.modules[__xname__]
-    threading = MockThreading()
-    del MockThreading
 
-try:
+local = threading.local()
-    threading.local
+if hasattr(local, '__decimal_context__'):
+    del local.__decimal_context__
 
-except AttributeError:
+def getcontext(_local=local):
+    """Returns this thread's context.
 
-    # To fix reloading, force it to create a new context
+    If this thread does not yet have a context, returns
-    # Old contexts have different exceptions in their dicts, making problems.
+    a new context and sets this thread's context.
-    if hasattr(threading.current_thread(), '__decimal_context__'):
+    New contexts are copies of DefaultContext.
-        del threading.current_thread().__decimal_context__
+    """
-
+    try:
-    def setcontext(context):
+        return _local.__decimal_context__
-        """Set this thread's context to context."""
+    except AttributeError:
-        if context in (DefaultContext, BasicContext, ExtendedContext):
+        context = Context()
-            context = context.copy()
-            context.clear_flags()
-        threading.current_thread().__decimal_context__ = context
-
-    def getcontext():
-        """Returns this thread's context.
-
-        If this thread does not yet have a context, returns
-        a new context and sets this thread's context.
-        New contexts are copies of DefaultContext.
-        """
-        try:
-            return threading.current_thread().__decimal_context__
-        except AttributeError:
-            context = Context()
-            threading.current_thread().__decimal_context__ = context
-            return context
-
-else:
-
-    local = threading.local()
-    if hasattr(local, '__decimal_context__'):
-        del local.__decimal_context__
-
-    def getcontext(_local=local):
-        """Returns this thread's context.
-
-        If this thread does not yet have a context, returns
-        a new context and sets this thread's context.
-        New contexts are copies of DefaultContext.
-        """
-        try:
-            return _local.__decimal_context__
-        except AttributeError:
-            context = Context()
-            _local.__decimal_context__ = context
-            return context
-
-    def setcontext(context, _local=local):
-        """Set this thread's context to context."""
-        if context in (DefaultContext, BasicContext, ExtendedContext):
-            context = context.copy()
-            context.clear_flags()
         _local.__decimal_context__ = context
+        return context
 
-    del threading, local        # Don't contaminate the namespace
+def setcontext(context, _local=local):
+    """Set this thread's context to context."""
+    if context in (DefaultContext, BasicContext, ExtendedContext):
+        context = context.copy()
+        context.clear_flags()
+    _local.__decimal_context__ = context
+
+del threading, local        # Don't contaminate the namespace
 
 def localcontext(ctx=None):
     """Return a context manager for a copy of the supplied context

Lib/_pyio.py

@@ -9,10 +9,7 @@ import errno
 import stat
 import sys
 # Import _thread instead of threading to reduce startup cost
-try:
+from _thread import allocate_lock as Lock
-    from _thread import allocate_lock as Lock
-except ImportError:
-    from _dummy_thread import allocate_lock as Lock
 if sys.platform in {'win32', 'cygwin'}:
     from msvcrt import setmode as _setmode
 else:

Lib/_strptime.py

@@ -19,10 +19,7 @@ from re import escape as re_escape
 from datetime import (date as datetime_date,
                       timedelta as datetime_timedelta,
                       timezone as datetime_timezone)
-try:
+from _thread import allocate_lock as _thread_allocate_lock
-    from _thread import allocate_lock as _thread_allocate_lock
-except ImportError:
-    from _dummy_thread import allocate_lock as _thread_allocate_lock
 
 __all__ = []
 

Lib/bz2.py

@@ -14,11 +14,7 @@ import io
 import os
 import warnings
 import _compression
-
+from threading import RLock
-try:
-    from threading import RLock
-except ImportError:
-    from dummy_threading import RLock
 
 from _bz2 import BZ2Compressor, BZ2Decompressor
 

Lib/ctypes/test/test_errno.py

@@ -1,10 +1,8 @@
 import unittest, os, errno
+import threading
+
 from ctypes import *
 from ctypes.util import find_library
-try:
-    import threading
-except ImportError:
-    threading = None
 
 class Test(unittest.TestCase):
     def test_open(self):
@@ -25,26 +23,25 @@ class Test(unittest.TestCase):
         self.assertEqual(set_errno(32), errno.ENOENT)
         self.assertEqual(get_errno(), 32)
 
-        if threading:
+        def _worker():
-            def _worker():
-                set_errno(0)
-
-                libc = CDLL(libc_name, use_errno=False)
-                if os.name == "nt":
-                    libc_open = libc._open
-                else:
-                    libc_open = libc.open
-                libc_open.argtypes = c_char_p, c_int
-                self.assertEqual(libc_open(b"", 0), -1)
-                self.assertEqual(get_errno(), 0)
-
-            t = threading.Thread(target=_worker)
-            t.start()
-            t.join()
-
-            self.assertEqual(get_errno(), 32)
             set_errno(0)
 
+            libc = CDLL(libc_name, use_errno=False)
+            if os.name == "nt":
+                libc_open = libc._open
+            else:
+                libc_open = libc.open
+            libc_open.argtypes = c_char_p, c_int
+            self.assertEqual(libc_open(b"", 0), -1)
+            self.assertEqual(get_errno(), 0)
+
+        t = threading.Thread(target=_worker)
+        t.start()
+        t.join()
+
+        self.assertEqual(get_errno(), 32)
+        set_errno(0)
+
     @unittest.skipUnless(os.name == "nt", 'Test specific to Windows')
     def test_GetLastError(self):
         dll = WinDLL("kernel32", use_last_error=True)

Lib/dummy_threading.py

@@ -1,78 +0,0 @@
-"""Faux ``threading`` version using ``dummy_thread`` instead of ``thread``.
-
-The module ``_dummy_threading`` is added to ``sys.modules`` in order
-to not have ``threading`` considered imported.  Had ``threading`` been
-directly imported it would have made all subsequent imports succeed
-regardless of whether ``_thread`` was available which is not desired.
-
-"""
-from sys import modules as sys_modules
-
-import _dummy_thread
-
-# Declaring now so as to not have to nest ``try``s to get proper clean-up.
-holding_thread = False
-holding_threading = False
-holding__threading_local = False
-
-try:
-    # Could have checked if ``_thread`` was not in sys.modules and gone
-    # a different route, but decided to mirror technique used with
-    # ``threading`` below.
-    if '_thread' in sys_modules:
-        held_thread = sys_modules['_thread']
-        holding_thread = True
-    # Must have some module named ``_thread`` that implements its API
-    # in order to initially import ``threading``.
-    sys_modules['_thread'] = sys_modules['_dummy_thread']
-
-    if 'threading' in sys_modules:
-        # If ``threading`` is already imported, might as well prevent
-        # trying to import it more than needed by saving it if it is
-        # already imported before deleting it.
-        held_threading = sys_modules['threading']
-        holding_threading = True
-        del sys_modules['threading']
-
-    if '_threading_local' in sys_modules:
-        # If ``_threading_local`` is already imported, might as well prevent
-        # trying to import it more than needed by saving it if it is
-        # already imported before deleting it.
-        held__threading_local = sys_modules['_threading_local']
-        holding__threading_local = True
-        del sys_modules['_threading_local']
-
-    import threading
-    # Need a copy of the code kept somewhere...
-    sys_modules['_dummy_threading'] = sys_modules['threading']
-    del sys_modules['threading']
-    sys_modules['_dummy__threading_local'] = sys_modules['_threading_local']
-    del sys_modules['_threading_local']
-    from _dummy_threading import *
-    from _dummy_threading import __all__
-
-finally:
-    # Put back ``threading`` if we overwrote earlier
-
-    if holding_threading:
-        sys_modules['threading'] = held_threading
-        del held_threading
-    del holding_threading
-
-    # Put back ``_threading_local`` if we overwrote earlier
-
-    if holding__threading_local:
-        sys_modules['_threading_local'] = held__threading_local
-        del held__threading_local
-    del holding__threading_local
-
-    # Put back ``thread`` if we overwrote, else del the entry we made
-    if holding_thread:
-        sys_modules['_thread'] = held_thread
-        del held_thread
-    else:
-        del sys_modules['_thread']
-    del holding_thread
-
-    del _dummy_thread
-    del sys_modules

Lib/functools.py

@@ -22,13 +22,7 @@ from collections import namedtuple
 from types import MappingProxyType
 from weakref import WeakKeyDictionary
 from reprlib import recursive_repr
-try:
+from _thread import RLock
-    from _thread import RLock
-except ImportError:
-    class RLock:
-        'Dummy reentrant lock for builds without threads'
-        def __enter__(self): pass
-        def __exit__(self, exctype, excinst, exctb): pass
 
 
 ################################################################################

Lib/http/cookiejar.py

@@ -33,10 +33,7 @@ import datetime
 import re
 import time
 import urllib.parse, urllib.request
-try:
+import threading as _threading
-    import threading as _threading
-except ImportError:
-    import dummy_threading as _threading
 import http.client  # only for the default HTTP port
 from calendar import timegm
 

Lib/logging/__init__.py

@@ -37,10 +37,7 @@ __all__ = ['BASIC_FORMAT', 'BufferingFormatter', 'CRITICAL', 'DEBUG', 'ERROR',
            'warn', 'warning', 'getLogRecordFactory', 'setLogRecordFactory',
            'lastResort', 'raiseExceptions']
 
-try:
+import threading
-    import threading
-except ImportError: #pragma: no cover
-    threading = None
 
 __author__  = "Vinay Sajip <vinay_sajip@red-dove.com>"
 __status__  = "production"
@@ -210,11 +207,7 @@ def _checkLevel(level):
 #the lock would already have been acquired - so we need an RLock.
 #The same argument applies to Loggers and Manager.loggerDict.
 #
-if threading:
+_lock = threading.RLock()
-    _lock = threading.RLock()
-else: #pragma: no cover
-    _lock = None
-
 
 def _acquireLock():
     """
@@ -295,7 +288,7 @@ class LogRecord(object):
         self.created = ct
         self.msecs = (ct - int(ct)) * 1000
         self.relativeCreated = (self.created - _startTime) * 1000
-        if logThreads and threading:
+        if logThreads:
             self.thread = threading.get_ident()
             self.threadName = threading.current_thread().name
         else: # pragma: no cover
@@ -799,10 +792,7 @@ class Handler(Filterer):
         """
         Acquire a thread lock for serializing access to the underlying I/O.
         """
-        if threading:
+        self.lock = threading.RLock()
-            self.lock = threading.RLock()
-        else: #pragma: no cover
-            self.lock = None
 
     def acquire(self):
         """

Lib/logging/config.py

@@ -31,14 +31,9 @@ import logging.handlers
 import re
 import struct
 import sys
+import threading
 import traceback
 
-try:
-    import _thread as thread
-    import threading
-except ImportError: #pragma: no cover
-    thread = None
-
 from socketserver import ThreadingTCPServer, StreamRequestHandler
 
 
@@ -816,8 +811,6 @@ def listen(port=DEFAULT_LOGGING_CONFIG_PORT, verify=None):
     normal. Note that you can return transformed bytes, e.g. by decrypting
     the bytes passed in.
     """
-    if not thread: #pragma: no cover
-        raise NotImplementedError("listen() needs threading to work")
 
     class ConfigStreamHandler(StreamRequestHandler):
         """

Lib/logging/handlers.py

@@ -26,10 +26,7 @@ To use, simply 'import logging.handlers' and log away!
 import logging, socket, os, pickle, struct, time, re
 from stat import ST_DEV, ST_INO, ST_MTIME
 import queue
-try:
+import threading
-    import threading
-except ImportError: #pragma: no cover
-    threading = None
 
 #
 # Some constants...
@@ -1395,110 +1392,110 @@ class QueueHandler(logging.Handler):
         except Exception:
             self.handleError(record)
 
-if threading:
+
-    class QueueListener(object):
+class QueueListener(object):
+    """
+    This class implements an internal threaded listener which watches for
+    LogRecords being added to a queue, removes them and passes them to a
+    list of handlers for processing.
+    """
+    _sentinel = None
+
+    def __init__(self, queue, *handlers, respect_handler_level=False):
         """
-        This class implements an internal threaded listener which watches for
+        Initialise an instance with the specified queue and
-        LogRecords being added to a queue, removes them and passes them to a
+        handlers.
-        list of handlers for processing.
         """
-        _sentinel = None
+        self.queue = queue
+        self.handlers = handlers
+        self._thread = None
+        self.respect_handler_level = respect_handler_level
 
-        def __init__(self, queue, *handlers, respect_handler_level=False):
+    def dequeue(self, block):
-            """
+        """
-            Initialise an instance with the specified queue and
+        Dequeue a record and return it, optionally blocking.
-            handlers.
-            """
-            self.queue = queue
-            self.handlers = handlers
-            self._thread = None
-            self.respect_handler_level = respect_handler_level
 
-        def dequeue(self, block):
+        The base implementation uses get. You may want to override this method
-            """
+        if you want to use timeouts or work with custom queue implementations.
-            Dequeue a record and return it, optionally blocking.
+        """
+        return self.queue.get(block)
 
-            The base implementation uses get. You may want to override this method
+    def start(self):
-            if you want to use timeouts or work with custom queue implementations.
+        """
-            """
+        Start the listener.
-            return self.queue.get(block)
 
-        def start(self):
+        This starts up a background thread to monitor the queue for
-            """
+        LogRecords to process.
-            Start the listener.
+        """
+        self._thread = t = threading.Thread(target=self._monitor)
+        t.daemon = True
+        t.start()
 
-            This starts up a background thread to monitor the queue for
+    def prepare(self , record):
-            LogRecords to process.
+        """
-            """
+        Prepare a record for handling.
-            self._thread = t = threading.Thread(target=self._monitor)
-            t.daemon = True
-            t.start()
 
-        def prepare(self , record):
+        This method just returns the passed-in record. You may want to
-            """
+        override this method if you need to do any custom marshalling or
-            Prepare a record for handling.
+        manipulation of the record before passing it to the handlers.
+        """
+        return record
 
-            This method just returns the passed-in record. You may want to
+    def handle(self, record):
-            override this method if you need to do any custom marshalling or
+        """
-            manipulation of the record before passing it to the handlers.
+        Handle a record.
-            """
-            return record
 
-        def handle(self, record):
+        This just loops through the handlers offering them the record
-            """
+        to handle.
-            Handle a record.
+        """
+        record = self.prepare(record)
+        for handler in self.handlers:
+            if not self.respect_handler_level:
+                process = True
+            else:
+                process = record.levelno >= handler.level
+            if process:
+                handler.handle(record)
 
-            This just loops through the handlers offering them the record
+    def _monitor(self):
-            to handle.
+        """
-            """
+        Monitor the queue for records, and ask the handler
-            record = self.prepare(record)
+        to deal with them.
-            for handler in self.handlers:
-                if not self.respect_handler_level:
-                    process = True
-                else:
-                    process = record.levelno >= handler.level
-                if process:
-                    handler.handle(record)
 
-        def _monitor(self):
+        This method runs on a separate, internal thread.
-            """
+        The thread will terminate if it sees a sentinel object in the queue.
-            Monitor the queue for records, and ask the handler
+        """
-            to deal with them.
+        q = self.queue
-
+        has_task_done = hasattr(q, 'task_done')
-            This method runs on a separate, internal thread.
+        while True:
-            The thread will terminate if it sees a sentinel object in the queue.
+            try:
-            """
+                record = self.dequeue(True)
-            q = self.queue
+                if record is self._sentinel:
-            has_task_done = hasattr(q, 'task_done')
-            while True:
-                try:
-                    record = self.dequeue(True)
-                    if record is self._sentinel:
-                        break
-                    self.handle(record)
-                    if has_task_done:
-                        q.task_done()
-                except queue.Empty:
                     break
+                self.handle(record)
+                if has_task_done:
+                    q.task_done()
+            except queue.Empty:
+                break
 
-        def enqueue_sentinel(self):
+    def enqueue_sentinel(self):
-            """
+        """
-            This is used to enqueue the sentinel record.
+        This is used to enqueue the sentinel record.
 
-            The base implementation uses put_nowait. You may want to override this
+        The base implementation uses put_nowait. You may want to override this
-            method if you want to use timeouts or work with custom queue
+        method if you want to use timeouts or work with custom queue
-            implementations.
+        implementations.
-            """
+        """
-            self.queue.put_nowait(self._sentinel)
+        self.queue.put_nowait(self._sentinel)
 
-        def stop(self):
+    def stop(self):
-            """
+        """
-            Stop the listener.
+        Stop the listener.
 
-            This asks the thread to terminate, and then waits for it to do so.
+        This asks the thread to terminate, and then waits for it to do so.
-            Note that if you don't call this before your application exits, there
+        Note that if you don't call this before your application exits, there
-            may be some records still left on the queue, which won't be processed.
+        may be some records still left on the queue, which won't be processed.
-            """
+        """
-            self.enqueue_sentinel()
+        self.enqueue_sentinel()
-            self._thread.join()
+        self._thread.join()
-            self._thread = None
+        self._thread = None

Lib/queue.py

@@ -1,9 +1,6 @@
 '''A multi-producer, multi-consumer queue.'''
 
-try:
+import threading
-    import threading
-except ImportError:
-    import dummy_threading as threading
 from collections import deque
 from heapq import heappush, heappop
 from time import monotonic as time

Lib/reprlib.py

@@ -4,10 +4,7 @@ __all__ = ["Repr", "repr", "recursive_repr"]
 
 import builtins
 from itertools import islice
-try:
+from _thread import get_ident
-    from _thread import get_ident
-except ImportError:
-    from _dummy_thread import get_ident
 
 def recursive_repr(fillvalue='...'):
     'Decorator to make a repr function return fillvalue for a recursive call'

Lib/sched.py

@@ -26,10 +26,7 @@ has another way to reference private data (besides global variables).
 import time
 import heapq
 from collections import namedtuple
-try:
+import threading
-    import threading
-except ImportError:
-    import dummy_threading as threading
 from time import monotonic as _time
 
 __all__ = ["scheduler"]

Lib/socketserver.py

@@ -127,10 +127,7 @@ import socket
 import selectors
 import os
 import sys
-try:
+import threading
-    import threading
-except ImportError:
-    import dummy_threading as threading
 from io import BufferedIOBase
 from time import monotonic as time
 

Lib/sqlite3/test/dbapi.py

@@ -21,12 +21,9 @@
 #    misrepresented as being the original software.
 # 3. This notice may not be removed or altered from any source distribution.
 
+import threading
 import unittest
 import sqlite3 as sqlite
-try:
-    import threading
-except ImportError:
-    threading = None
 
 from test.support import TESTFN, unlink
 
@@ -503,7 +500,6 @@ class CursorTests(unittest.TestCase):
         self.assertEqual(results, expected)
 
 
-@unittest.skipUnless(threading, 'This test requires threading.')
 class ThreadTests(unittest.TestCase):
     def setUp(self):
         self.con = sqlite.connect(":memory:")

Lib/subprocess.py

@@ -138,10 +138,7 @@ else:
     import _posixsubprocess
     import select
     import selectors
-    try:
+    import threading
-        import threading
-    except ImportError:
-        import dummy_threading as threading
 
     # When select or poll has indicated that the file is writable,
     # we can write up to _PIPE_BUF bytes without risk of blocking.

Lib/tempfile.py

@@ -44,11 +44,7 @@ import shutil as _shutil
 import errno as _errno
 from random import Random as _Random
 import weakref as _weakref
-
+import _thread
-try:
-    import _thread
-except ImportError:
-    import _dummy_thread as _thread
 _allocate_lock = _thread.allocate_lock
 
 _text_openflags = _os.O_RDWR | _os.O_CREAT | _os.O_EXCL

Lib/test/fork_wait.py

@@ -10,9 +10,9 @@ active threads survive in the child after a fork(); this is an error.
 """
 
 import os, sys, time, unittest
+import threading
 import test.support as support
 
-threading = support.import_module('threading')
 
 LONGSLEEP = 2
 SHORTSLEEP = 0.5

Lib/test/libregrtest/runtest_mp.py

@@ -3,15 +3,11 @@ import json
 import os
 import queue
 import sys
+import threading
 import time
 import traceback
 import types
 from test import support
-try:
-    import threading
-except ImportError:
-    print("Multiprocess option requires thread support")
-    sys.exit(2)
 
 from test.libregrtest.runtest import (
     runtest, INTERRUPTED, CHILD_ERROR, PROGRESS_MIN_TIME,

Lib/test/libregrtest/save_env.py

@@ -5,12 +5,9 @@ import os
 import shutil
 import sys
 import sysconfig
+import threading
 import warnings
 from test import support
-try:
-    import threading
-except ImportError:
-    threading = None
 try:
     import _multiprocessing, multiprocessing.process
 except ImportError:
@@ -181,13 +178,9 @@ class saved_test_environment:
     # Controlling dangling references to Thread objects can make it easier
     # to track reference leaks.
     def get_threading__dangling(self):
-        if not threading:
-            return None
         # This copies the weakrefs without making any strong reference
         return threading._dangling.copy()
     def restore_threading__dangling(self, saved):
-        if not threading:
-            return
         threading._dangling.clear()
         threading._dangling.update(saved)
 

Lib/test/support/__init__.py

@@ -25,17 +25,14 @@ import subprocess
 import sys
 import sysconfig
 import tempfile
+import _thread
+import threading
 import time
 import types
 import unittest
 import urllib.error
 import warnings
 
-try:
-    import _thread, threading
-except ImportError:
-    _thread = None
-    threading = None
 try:
     import multiprocessing.process
 except ImportError:
@@ -2028,16 +2025,11 @@ environment_altered = False
 # at the end of a test run.
 
 def threading_setup():
-    if _thread:
+    return _thread._count(), threading._dangling.copy()
-        return _thread._count(), threading._dangling.copy()
-    else:
-        return 1, ()
 
 def threading_cleanup(*original_values):
     global environment_altered
 
-    if not _thread:
-        return
     _MAX_COUNT = 100
     t0 = time.monotonic()
     for count in range(_MAX_COUNT):
@@ -2061,9 +2053,6 @@ def reap_threads(func):
     ensure that the threads are cleaned up even when the test fails.
     If threading is unavailable this function does nothing.
     """
-    if not _thread:
-        return func
-
     @functools.wraps(func)
     def decorator(*args):
         key = threading_setup()

Lib/test/test_asynchat.py

@@ -2,110 +2,104 @@
 
 from test import support
 
-# If this fails, the test will be skipped.
-thread = support.import_module('_thread')
-
 import asynchat
 import asyncore
 import errno
 import socket
 import sys
+import _thread as thread
+import threading
 import time
 import unittest
 import unittest.mock
-try:
-    import threading
-except ImportError:
-    threading = None
 
 HOST = support.HOST
 SERVER_QUIT = b'QUIT\n'
 TIMEOUT = 3.0
 
-if threading:
-    class echo_server(threading.Thread):
-        # parameter to determine the number of bytes passed back to the
-        # client each send
-        chunk_size = 1
 
-        def __init__(self, event):
+class echo_server(threading.Thread):
-            threading.Thread.__init__(self)
+    # parameter to determine the number of bytes passed back to the
-            self.event = event
+    # client each send
-            self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    chunk_size = 1
-            self.port = support.bind_port(self.sock)
-            # This will be set if the client wants us to wait before echoing
-            # data back.
-            self.start_resend_event = None
 
-        def run(self):
+    def __init__(self, event):
-            self.sock.listen()
+        threading.Thread.__init__(self)
-            self.event.set()
+        self.event = event
-            conn, client = self.sock.accept()
+        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-            self.buffer = b""
+        self.port = support.bind_port(self.sock)
-            # collect data until quit message is seen
+        # This will be set if the client wants us to wait before echoing
-            while SERVER_QUIT not in self.buffer:
+        # data back.
-                data = conn.recv(1)
+        self.start_resend_event = None
-                if not data:
-                    break
-                self.buffer = self.buffer + data
 
-            # remove the SERVER_QUIT message
+    def run(self):
-            self.buffer = self.buffer.replace(SERVER_QUIT, b'')
+        self.sock.listen()
+        self.event.set()
+        conn, client = self.sock.accept()
+        self.buffer = b""
+        # collect data until quit message is seen
+        while SERVER_QUIT not in self.buffer:
+            data = conn.recv(1)
+            if not data:
+                break
+            self.buffer = self.buffer + data
 
-            if self.start_resend_event:
+        # remove the SERVER_QUIT message
-                self.start_resend_event.wait()
+        self.buffer = self.buffer.replace(SERVER_QUIT, b'')
 
-            # re-send entire set of collected data
+        if self.start_resend_event:
-            try:
+            self.start_resend_event.wait()
-                # this may fail on some tests, such as test_close_when_done,
+
-                # since the client closes the channel when it's done sending
+        # re-send entire set of collected data
-                while self.buffer:
+        try:
-                    n = conn.send(self.buffer[:self.chunk_size])
+            # this may fail on some tests, such as test_close_when_done,
-                    time.sleep(0.001)
+            # since the client closes the channel when it's done sending
-                    self.buffer = self.buffer[n:]
+            while self.buffer:
-            except:
+                n = conn.send(self.buffer[:self.chunk_size])
+                time.sleep(0.001)
+                self.buffer = self.buffer[n:]
+        except:
+            pass
+
+        conn.close()
+        self.sock.close()
+
+class echo_client(asynchat.async_chat):
+
+    def __init__(self, terminator, server_port):
+        asynchat.async_chat.__init__(self)
+        self.contents = []
+        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.connect((HOST, server_port))
+        self.set_terminator(terminator)
+        self.buffer = b""
+
+        def handle_connect(self):
+            pass
+
+        if sys.platform == 'darwin':
+            # select.poll returns a select.POLLHUP at the end of the tests
+            # on darwin, so just ignore it
+            def handle_expt(self):
                 pass
 
-            conn.close()
+    def collect_incoming_data(self, data):
-            self.sock.close()
+        self.buffer += data
 
-    class echo_client(asynchat.async_chat):
+    def found_terminator(self):
+        self.contents.append(self.buffer)
+        self.buffer = b""
 
-        def __init__(self, terminator, server_port):
+def start_echo_server():
-            asynchat.async_chat.__init__(self)
+    event = threading.Event()
-            self.contents = []
+    s = echo_server(event)
-            self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
+    s.start()
-            self.connect((HOST, server_port))
+    event.wait()
-            self.set_terminator(terminator)
+    event.clear()
-            self.buffer = b""
+    time.sleep(0.01)   # Give server time to start accepting.
-
+    return s, event
-            def handle_connect(self):
-                pass
-
-            if sys.platform == 'darwin':
-                # select.poll returns a select.POLLHUP at the end of the tests
-                # on darwin, so just ignore it
-                def handle_expt(self):
-                    pass
-
-        def collect_incoming_data(self, data):
-            self.buffer += data
-
-        def found_terminator(self):
-            self.contents.append(self.buffer)
-            self.buffer = b""
-
-    def start_echo_server():
-        event = threading.Event()
-        s = echo_server(event)
-        s.start()
-        event.wait()
-        event.clear()
-        time.sleep(0.01)   # Give server time to start accepting.
-        return s, event
 
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class TestAsynchat(unittest.TestCase):
     usepoll = False
 

Lib/test/test_asyncio/__init__.py

@@ -1,8 +1,6 @@
 import os
 from test.support import load_package_tests, import_module
 
-# Skip tests if we don't have threading.
-import_module('threading')
 # Skip tests if we don't have concurrent.futures.
 import_module('concurrent.futures')
 

Lib/test/test_asyncore.py

@@ -7,6 +7,7 @@ import sys
 import time
 import errno
 import struct
+import threading
 
 from test import support
 from io import BytesIO
@@ -14,10 +15,6 @@ from io import BytesIO
 if support.PGO:
     raise unittest.SkipTest("test is not helpful for PGO")
 
-try:
-    import threading
-except ImportError:
-    threading = None
 
 TIMEOUT = 3
 HAS_UNIX_SOCKETS = hasattr(socket, 'AF_UNIX')
@@ -326,7 +323,6 @@ class DispatcherWithSendTests(unittest.TestCase):
     def tearDown(self):
         asyncore.close_all()
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     @support.reap_threads
     def test_send(self):
         evt = threading.Event()
@@ -776,7 +772,6 @@ class BaseTestAPI:
                 self.assertTrue(s.socket.getsockopt(socket.SOL_SOCKET,
                                                      socket.SO_REUSEADDR))
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     @support.reap_threads
     def test_quick_connect(self):
         # see: http://bugs.python.org/issue10340

Lib/test/test_bz2.py

@@ -10,13 +10,10 @@ import pathlib
 import random
 import shutil
 import subprocess
+import threading
 from test.support import unlink
 import _compression
 
-try:
-    import threading
-except ImportError:
-    threading = None
 
 # Skip tests if the bz2 module doesn't exist.
 bz2 = support.import_module('bz2')
@@ -491,7 +488,6 @@ class BZ2FileTest(BaseTest):
         else:
             self.fail("1/0 didn't raise an exception")
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def testThreading(self):
         # Issue #7205: Using a BZ2File from several threads shouldn't deadlock.
         data = b"1" * 2**20
@@ -504,13 +500,6 @@ class BZ2FileTest(BaseTest):
             with support.start_threads(threads):
                 pass
 
-    def testWithoutThreading(self):
-        module = support.import_fresh_module("bz2", blocked=("threading",))
-        with module.BZ2File(self.filename, "wb") as f:
-            f.write(b"abc")
-        with module.BZ2File(self.filename, "rb") as f:
-            self.assertEqual(f.read(), b"abc")
-
     def testMixedIterationAndReads(self):
         self.createTempFile()
         linelen = len(self.TEXT_LINES[0])

Lib/test/test_capi.py

@@ -11,6 +11,7 @@ import subprocess
 import sys
 import sysconfig
 import textwrap
+import threading
 import time
 import unittest
 from test import support
@@ -20,10 +21,7 @@ try:
     import _posixsubprocess
 except ImportError:
     _posixsubprocess = None
-try:
+
-    import threading
-except ImportError:
-    threading = None
 # Skip this test if the _testcapi module isn't available.
 _testcapi = support.import_module('_testcapi')
 
@@ -52,7 +50,6 @@ class CAPITest(unittest.TestCase):
         self.assertEqual(testfunction.attribute, "test")
         self.assertRaises(AttributeError, setattr, inst.testfunction, "attribute", "test")
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_no_FatalError_infinite_loop(self):
         with support.SuppressCrashReport():
             p = subprocess.Popen([sys.executable, "-c",
@@ -276,7 +273,6 @@ class CAPITest(unittest.TestCase):
         self.assertIn(b'MemoryError 3 30', out)
 
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class TestPendingCalls(unittest.TestCase):
 
     def pendingcalls_submit(self, l, n):
@@ -685,7 +681,6 @@ class SkipitemTest(unittest.TestCase):
             parse((1,), {}, 'O|OO', ['', 'a', ''])
 
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class TestThreadState(unittest.TestCase):
 
     @support.reap_threads
@@ -762,7 +757,6 @@ class PyMemDebugTests(unittest.TestCase):
         regex = regex.format(ptr=self.PTR_REGEX)
         self.assertRegex(out, regex)
 
-    @unittest.skipUnless(threading, 'Test requires a GIL (multithreading)')
     def check_malloc_without_gil(self, code):
         out = self.check(code)
         expected = ('Fatal Python error: Python memory allocator called '

Lib/test/test_concurrent_futures.py

@@ -4,10 +4,6 @@ import test.support
 test.support.import_module('_multiprocessing')
 # Skip tests if sem_open implementation is broken.
 test.support.import_module('multiprocessing.synchronize')
-# import threading after _multiprocessing to raise a more relevant error
-# message: "No module named _multiprocessing". _multiprocessing is not compiled
-# without thread support.
-test.support.import_module('threading')
 
 from test.support.script_helper import assert_python_ok
 

Lib/test/test_contextlib.py

@@ -3,13 +3,10 @@
 import io
 import sys
 import tempfile
+import threading
 import unittest
 from contextlib import *  # Tests __all__
 from test import support
-try:
-    import threading
-except ImportError:
-    threading = None
 
 
 class TestAbstractContextManager(unittest.TestCase):
@@ -275,7 +272,6 @@ class FileContextTestCase(unittest.TestCase):
         finally:
             support.unlink(tfn)
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class LockContextTestCase(unittest.TestCase):
 
     def boilerPlate(self, lock, locked):

Lib/test/test_decimal.py

@@ -38,10 +38,7 @@ from test.support import (import_fresh_module, TestFailed,
                           run_with_locale, cpython_only)
 import random
 import inspect
-try:
+import threading
-    import threading
-except ImportError:
-    threading = None
 
 
 C = import_fresh_module('decimal', fresh=['_decimal'])
@@ -1625,10 +1622,10 @@ class ThreadingTest(unittest.TestCase):
         DefaultContext.Emax = save_emax
         DefaultContext.Emin = save_emin
 
-@unittest.skipUnless(threading, 'threading required')
+
 class CThreadingTest(ThreadingTest):
     decimal = C
-@unittest.skipUnless(threading, 'threading required')
+
 class PyThreadingTest(ThreadingTest):
     decimal = P
 

Lib/test/test_docxmlrpc.py

@@ -1,8 +1,8 @@
 from xmlrpc.server import DocXMLRPCServer
 import http.client
 import sys
+import threading
 from test import support
-threading = support.import_module('threading')
 import unittest
 
 def make_request_and_skipIf(condition, reason):

Lib/test/test_dummy_thread.py

@@ -1,255 +0,0 @@
-import _dummy_thread as _thread
-import time
-import queue
-import random
-import unittest
-from test import support
-from unittest import mock
-
-DELAY = 0
-
-
-class LockTests(unittest.TestCase):
-    """Test lock objects."""
-
-    def setUp(self):
-        # Create a lock
-        self.lock = _thread.allocate_lock()
-
-    def test_initlock(self):
-        #Make sure locks start locked
-        self.assertFalse(self.lock.locked(),
-                        "Lock object is not initialized unlocked.")
-
-    def test_release(self):
-        # Test self.lock.release()
-        self.lock.acquire()
-        self.lock.release()
-        self.assertFalse(self.lock.locked(),
-                        "Lock object did not release properly.")
-
-    def test_LockType_context_manager(self):
-        with _thread.LockType():
-            pass
-        self.assertFalse(self.lock.locked(),
-                         "Acquired Lock was not released")
-
-    def test_improper_release(self):
-        #Make sure release of an unlocked thread raises RuntimeError
-        self.assertRaises(RuntimeError, self.lock.release)
-
-    def test_cond_acquire_success(self):
-        #Make sure the conditional acquiring of the lock works.
-        self.assertTrue(self.lock.acquire(0),
-                        "Conditional acquiring of the lock failed.")
-
-    def test_cond_acquire_fail(self):
-        #Test acquiring locked lock returns False
-        self.lock.acquire(0)
-        self.assertFalse(self.lock.acquire(0),
-                        "Conditional acquiring of a locked lock incorrectly "
-                         "succeeded.")
-
-    def test_uncond_acquire_success(self):
-        #Make sure unconditional acquiring of a lock works.
-        self.lock.acquire()
-        self.assertTrue(self.lock.locked(),
-                        "Uncondional locking failed.")
-
-    def test_uncond_acquire_return_val(self):
-        #Make sure that an unconditional locking returns True.
-        self.assertIs(self.lock.acquire(1), True,
-                        "Unconditional locking did not return True.")
-        self.assertIs(self.lock.acquire(), True)
-
-    def test_uncond_acquire_blocking(self):
-        #Make sure that unconditional acquiring of a locked lock blocks.
-        def delay_unlock(to_unlock, delay):
-            """Hold on to lock for a set amount of time before unlocking."""
-            time.sleep(delay)
-            to_unlock.release()
-
-        self.lock.acquire()
-        start_time = int(time.time())
-        _thread.start_new_thread(delay_unlock,(self.lock, DELAY))
-        if support.verbose:
-            print()
-            print("*** Waiting for thread to release the lock "\
-            "(approx. %s sec.) ***" % DELAY)
-        self.lock.acquire()
-        end_time = int(time.time())
-        if support.verbose:
-            print("done")
-        self.assertGreaterEqual(end_time - start_time, DELAY,
-                        "Blocking by unconditional acquiring failed.")
-
-    @mock.patch('time.sleep')
-    def test_acquire_timeout(self, mock_sleep):
-        """Test invoking acquire() with a positive timeout when the lock is
-        already acquired. Ensure that time.sleep() is invoked with the given
-        timeout and that False is returned."""
-
-        self.lock.acquire()
-        retval = self.lock.acquire(waitflag=0, timeout=1)
-        self.assertTrue(mock_sleep.called)
-        mock_sleep.assert_called_once_with(1)
-        self.assertEqual(retval, False)
-
-    def test_lock_representation(self):
-        self.lock.acquire()
-        self.assertIn("locked", repr(self.lock))
-        self.lock.release()
-        self.assertIn("unlocked", repr(self.lock))
-
-
-class MiscTests(unittest.TestCase):
-    """Miscellaneous tests."""
-
-    def test_exit(self):
-        self.assertRaises(SystemExit, _thread.exit)
-
-    def test_ident(self):
-        self.assertIsInstance(_thread.get_ident(), int,
-                              "_thread.get_ident() returned a non-integer")
-        self.assertGreater(_thread.get_ident(), 0)
-
-    def test_LockType(self):
-        self.assertIsInstance(_thread.allocate_lock(), _thread.LockType,
-                              "_thread.LockType is not an instance of what "
-                              "is returned by _thread.allocate_lock()")
-
-    def test_set_sentinel(self):
-        self.assertIsInstance(_thread._set_sentinel(), _thread.LockType,
-                              "_thread._set_sentinel() did not return a "
-                              "LockType instance.")
-
-    def test_interrupt_main(self):
-        #Calling start_new_thread with a function that executes interrupt_main
-        # should raise KeyboardInterrupt upon completion.
-        def call_interrupt():
-            _thread.interrupt_main()
-
-        self.assertRaises(KeyboardInterrupt,
-                          _thread.start_new_thread,
-                          call_interrupt,
-                          tuple())
-
-    def test_interrupt_in_main(self):
-        self.assertRaises(KeyboardInterrupt, _thread.interrupt_main)
-
-    def test_stack_size_None(self):
-        retval = _thread.stack_size(None)
-        self.assertEqual(retval, 0)
-
-    def test_stack_size_not_None(self):
-        with self.assertRaises(_thread.error) as cm:
-            _thread.stack_size("")
-        self.assertEqual(cm.exception.args[0],
-                         "setting thread stack size not supported")
-
-
-class ThreadTests(unittest.TestCase):
-    """Test thread creation."""
-
-    def test_arg_passing(self):
-        #Make sure that parameter passing works.
-        def arg_tester(queue, arg1=False, arg2=False):
-            """Use to test _thread.start_new_thread() passes args properly."""
-            queue.put((arg1, arg2))
-
-        testing_queue = queue.Queue(1)
-        _thread.start_new_thread(arg_tester, (testing_queue, True, True))
-        result = testing_queue.get()
-        self.assertTrue(result[0] and result[1],
-                        "Argument passing for thread creation "
-                        "using tuple failed")
-
-        _thread.start_new_thread(
-                arg_tester,
-                tuple(),
-                {'queue':testing_queue, 'arg1':True, 'arg2':True})
-
-        result = testing_queue.get()
-        self.assertTrue(result[0] and result[1],
-                        "Argument passing for thread creation "
-                        "using kwargs failed")
-
-        _thread.start_new_thread(
-                arg_tester,
-                (testing_queue, True),
-                {'arg2':True})
-
-        result = testing_queue.get()
-        self.assertTrue(result[0] and result[1],
-                        "Argument passing for thread creation using both tuple"
-                        " and kwargs failed")
-
-    def test_multi_thread_creation(self):
-        def queue_mark(queue, delay):
-            time.sleep(delay)
-            queue.put(_thread.get_ident())
-
-        thread_count = 5
-        testing_queue = queue.Queue(thread_count)
-
-        if support.verbose:
-            print()
-            print("*** Testing multiple thread creation "
-                  "(will take approx. %s to %s sec.) ***" % (
-                    DELAY, thread_count))
-
-        for count in range(thread_count):
-            if DELAY:
-                local_delay = round(random.random(), 1)
-            else:
-                local_delay = 0
-            _thread.start_new_thread(queue_mark,
-                                     (testing_queue, local_delay))
-        time.sleep(DELAY)
-        if support.verbose:
-            print('done')
-        self.assertEqual(testing_queue.qsize(), thread_count,
-                         "Not all %s threads executed properly "
-                         "after %s sec." % (thread_count, DELAY))
-
-    def test_args_not_tuple(self):
-        """
-        Test invoking start_new_thread() with a non-tuple value for "args".
-        Expect TypeError with a meaningful error message to be raised.
-        """
-        with self.assertRaises(TypeError) as cm:
-            _thread.start_new_thread(mock.Mock(), [])
-        self.assertEqual(cm.exception.args[0], "2nd arg must be a tuple")
-
-    def test_kwargs_not_dict(self):
-        """
-        Test invoking start_new_thread() with a non-dict value for "kwargs".
-        Expect TypeError with a meaningful error message to be raised.
-        """
-        with self.assertRaises(TypeError) as cm:
-            _thread.start_new_thread(mock.Mock(), tuple(), kwargs=[])
-        self.assertEqual(cm.exception.args[0], "3rd arg must be a dict")
-
-    def test_SystemExit(self):
-        """
-        Test invoking start_new_thread() with a function that raises
-        SystemExit.
-        The exception should be discarded.
-        """
-        func = mock.Mock(side_effect=SystemExit())
-        try:
-            _thread.start_new_thread(func, tuple())
-        except SystemExit:
-            self.fail("start_new_thread raised SystemExit.")
-
-    @mock.patch('traceback.print_exc')
-    def test_RaiseException(self, mock_print_exc):
-        """
-        Test invoking start_new_thread() with a function that raises exception.
-
-        The exception should be discarded and the traceback should be printed
-        via traceback.print_exc()
-        """
-        func = mock.Mock(side_effect=Exception)
-        _thread.start_new_thread(func, tuple())
-        self.assertTrue(mock_print_exc.called)

Lib/test/test_dummy_threading.py

@@ -1,60 +0,0 @@
-from test import support
-import unittest
-import dummy_threading as _threading
-import time
-
-class DummyThreadingTestCase(unittest.TestCase):
-
-    class TestThread(_threading.Thread):
-
-        def run(self):
-            global running
-            global sema
-            global mutex
-            # Uncomment if testing another module, such as the real 'threading'
-            # module.
-            #delay = random.random() * 2
-            delay = 0
-            if support.verbose:
-                print('task', self.name, 'will run for', delay, 'sec')
-            sema.acquire()
-            mutex.acquire()
-            running += 1
-            if support.verbose:
-                print(running, 'tasks are running')
-            mutex.release()
-            time.sleep(delay)
-            if support.verbose:
-                print('task', self.name, 'done')
-            mutex.acquire()
-            running -= 1
-            if support.verbose:
-                print(self.name, 'is finished.', running, 'tasks are running')
-            mutex.release()
-            sema.release()
-
-    def setUp(self):
-        self.numtasks = 10
-        global sema
-        sema = _threading.BoundedSemaphore(value=3)
-        global mutex
-        mutex = _threading.RLock()
-        global running
-        running = 0
-        self.threads = []
-
-    def test_tasks(self):
-        for i in range(self.numtasks):
-            t = self.TestThread(name="<thread %d>"%i)
-            self.threads.append(t)
-            t.start()
-
-        if support.verbose:
-            print('waiting for all tasks to complete')
-        for t in self.threads:
-            t.join()
-        if support.verbose:
-            print('all tasks done')
-
-if __name__ == '__main__':
-    unittest.main()

Lib/test/test_email/test_email.py

@@ -12,10 +12,7 @@ from io import StringIO, BytesIO
 from itertools import chain
 from random import choice
 from socket import getfqdn
-try:
+from threading import Thread
-    from threading import Thread
-except ImportError:
-    from dummy_threading import Thread
 
 import email
 import email.policy

Lib/test/test_enum.py

@@ -2,15 +2,12 @@ import enum
 import inspect
 import pydoc
 import unittest
+import threading
 from collections import OrderedDict
 from enum import Enum, IntEnum, EnumMeta, Flag, IntFlag, unique, auto
 from io import StringIO
 from pickle import dumps, loads, PicklingError, HIGHEST_PROTOCOL
 from test import support
-try:
-    import threading
-except ImportError:
-    threading = None
 
 
 # for pickle tests
@@ -1988,7 +1985,6 @@ class TestFlag(unittest.TestCase):
             d = 6
         self.assertEqual(repr(Bizarre(7)), '<Bizarre.d|c|b: 7>')
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     @support.reap_threads
     def test_unique_composite(self):
         # override __eq__ to be identity only
@@ -2339,7 +2335,6 @@ class TestIntFlag(unittest.TestCase):
         for f in Open:
             self.assertEqual(bool(f.value), bool(f))
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     @support.reap_threads
     def test_unique_composite(self):
         # override __eq__ to be identity only

Lib/test/test_faulthandler.py

@@ -8,14 +8,10 @@ import sys
 from test import support
 from test.support import script_helper, is_android, requires_android_level
 import tempfile
+import threading
 import unittest
 from textwrap import dedent
 
-try:
-    import threading
-    HAVE_THREADS = True
-except ImportError:
-    HAVE_THREADS = False
 try:
     import _testcapi
 except ImportError:
@@ -154,7 +150,6 @@ class FaultHandlerTests(unittest.TestCase):
             3,
             'Segmentation fault')
 
-    @unittest.skipIf(not HAVE_THREADS, 'need threads')
     def test_fatal_error_c_thread(self):
         self.check_fatal_error("""
             import faulthandler
@@ -231,7 +226,7 @@ class FaultHandlerTests(unittest.TestCase):
             2,
             'xyz')
 
-    @unittest.skipIf(sys.platform.startswith('openbsd') and HAVE_THREADS,
+    @unittest.skipIf(sys.platform.startswith('openbsd'),
                      "Issue #12868: sigaltstack() doesn't work on "
                      "OpenBSD if Python is compiled with pthread")
     @unittest.skipIf(not hasattr(faulthandler, '_stack_overflow'),
@@ -456,7 +451,6 @@ class FaultHandlerTests(unittest.TestCase):
         self.assertEqual(trace, expected)
         self.assertEqual(exitcode, 0)
 
-    @unittest.skipIf(not HAVE_THREADS, 'need threads')
     def check_dump_traceback_threads(self, filename):
         """
         Call explicitly dump_traceback(all_threads=True) and check the output.

Lib/test/test_fork1.py

@@ -5,6 +5,7 @@ import _imp as imp
 import os
 import signal
 import sys
+import threading
 import time
 import unittest
 
@@ -12,7 +13,6 @@ from test.fork_wait import ForkWait
 from test.support import (reap_children, get_attribute,
                           import_module, verbose)
 
-threading = import_module('threading')
 
 # Skip test if fork does not exist.
 get_attribute(os, 'fork')

Lib/test/test_ftplib.py

@@ -10,6 +10,7 @@ import socket
 import io
 import errno
 import os
+import threading
 import time
 try:
     import ssl
@@ -19,7 +20,6 @@ except ImportError:
 from unittest import TestCase, skipUnless
 from test import support
 from test.support import HOST, HOSTv6
-threading = support.import_module('threading')
 
 TIMEOUT = 3
 # the dummy data returned by server over the data channel when

Lib/test/test_functools.py

@@ -8,15 +8,12 @@ import pickle
 from random import choice
 import sys
 from test import support
+import threading
 import time
 import unittest
 import unittest.mock
 from weakref import proxy
 import contextlib
-try:
-    import threading
-except ImportError:
-    threading = None
 
 import functools
 
@@ -1406,7 +1403,6 @@ class TestLRU:
         for attr in self.module.WRAPPER_ASSIGNMENTS:
             self.assertEqual(getattr(g, attr), getattr(f, attr))
 
-    @unittest.skipUnless(threading, 'This test requires threading.')
     def test_lru_cache_threaded(self):
         n, m = 5, 11
         def orig(x, y):
@@ -1455,7 +1451,6 @@ class TestLRU:
         finally:
             sys.setswitchinterval(orig_si)
 
-    @unittest.skipUnless(threading, 'This test requires threading.')
     def test_lru_cache_threaded2(self):
         # Simultaneous call with the same arguments
         n, m = 5, 7
@@ -1483,7 +1478,6 @@ class TestLRU:
                 pause.reset()
                 self.assertEqual(f.cache_info(), (0, (i+1)*n, m*n, i+1))
 
-    @unittest.skipUnless(threading, 'This test requires threading.')
     def test_lru_cache_threaded3(self):
         @self.module.lru_cache(maxsize=2)
         def f(x):

Lib/test/test_gc.py

@@ -8,11 +8,7 @@ import sys
 import time
 import gc
 import weakref
-
+import threading
-try:
-    import threading
-except ImportError:
-    threading = None
 
 try:
     from _testcapi import with_tp_del
@@ -352,7 +348,6 @@ class GCTests(unittest.TestCase):
                 v = {1: v, 2: Ouch()}
         gc.disable()
 
-    @unittest.skipUnless(threading, "test meaningless on builds without threads")
     def test_trashcan_threads(self):
         # Issue #13992: trashcan mechanism should be thread-safe
         NESTING = 60

Lib/test/test_gdb.py

@@ -12,12 +12,6 @@ import sysconfig
 import textwrap
 import unittest
 
-# Is this Python configured to support threads?
-try:
-    import _thread
-except ImportError:
-    _thread = None
-
 from test import support
 from test.support import run_unittest, findfile, python_is_optimized
 
@@ -755,8 +749,6 @@ Traceback \(most recent call first\):
     foo\(1, 2, 3\)
 ''')
 
-    @unittest.skipUnless(_thread,
-                         "Python was compiled without thread support")
     def test_threads(self):
         'Verify that "py-bt" indicates threads that are waiting for the GIL'
         cmd = '''
@@ -794,8 +786,6 @@ id(42)
     # Some older versions of gdb will fail with
     #  "Cannot find new threads: generic error"
     # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround
-    @unittest.skipUnless(_thread,
-                         "Python was compiled without thread support")
     def test_gc(self):
         'Verify that "py-bt" indicates if a thread is garbage-collecting'
         cmd = ('from gc import collect\n'
@@ -822,8 +812,6 @@ id(42)
     # Some older versions of gdb will fail with
     #  "Cannot find new threads: generic error"
     # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround
-    @unittest.skipUnless(_thread,
-                         "Python was compiled without thread support")
     def test_pycfunction(self):
         'Verify that "py-bt" displays invocations of PyCFunction instances'
         # Tested function must not be defined with METH_NOARGS or METH_O,

Lib/test/test_hashlib.py

@@ -12,10 +12,7 @@ import hashlib
 import itertools
 import os
 import sys
-try:
+import threading
-    import threading
-except ImportError:
-    threading = None
 import unittest
 import warnings
 from test import support
@@ -738,7 +735,6 @@ class HashLibTestCase(unittest.TestCase):
         m = hashlib.md5(b'x' * gil_minsize)
         self.assertEqual(m.hexdigest(), 'cfb767f225d58469c5de3632a8803958')
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     @support.reap_threads
     def test_threaded_hashing(self):
         # Updating the same hash object from several threads at once

Lib/test/test_httpservers.py

@@ -22,12 +22,13 @@ import urllib.parse
 import tempfile
 import time
 import datetime
+import threading
 from unittest import mock
 from io import BytesIO
 
 import unittest
 from test import support
-threading = support.import_module('threading')
+
 
 class NoLogRequestHandler:
     def log_message(self, *args):

Lib/test/test_idle.py

@@ -3,7 +3,6 @@ from test.support import import_module
 
 # Skip test if _thread or _tkinter wasn't built, if idlelib is missing,
 # or if tcl/tk is not the 8.5+ needed for ttk widgets.
-import_module('threading')  # imported by PyShell, imports _thread
 tk = import_module('tkinter')  # imports _tkinter
 if tk.TkVersion < 8.5:
     raise unittest.SkipTest("IDLE requires tk 8.5 or later.")

Lib/test/test_imaplib.py

@@ -1,8 +1,4 @@
 from test import support
-# If we end up with a significant number of tests that don't require
-# threading, this test module should be split.  Right now we skip
-# them all if we don't have threading.
-threading = support.import_module('threading')
 
 from contextlib import contextmanager
 import imaplib
@@ -10,6 +6,7 @@ import os.path
 import socketserver
 import time
 import calendar
+import threading
 
 from test.support import (reap_threads, verbose, transient_internet,
                           run_with_tz, run_with_locale, cpython_only)

Lib/test/test_imp.py

@@ -1,7 +1,3 @@
-try:
-    import _thread
-except ImportError:
-    _thread = None
 import importlib
 import importlib.util
 import os
@@ -23,7 +19,6 @@ def requires_load_dynamic(meth):
                            'imp.load_dynamic() required')(meth)
 
 
-@unittest.skipIf(_thread is None, '_thread module is required')
 class LockTests(unittest.TestCase):
 
     """Very basic test of import lock functions."""

Lib/test/test_importlib/test_locks.py

@@ -3,134 +3,112 @@ from . import util as test_util
 init = test_util.import_importlib('importlib')
 
 import sys
+import threading
 import unittest
 import weakref
 
 from test import support
-
+from test import lock_tests
-try:
-    import threading
-except ImportError:
-    threading = None
-else:
-    from test import lock_tests
-
-if threading is not None:
-    class ModuleLockAsRLockTests:
-        locktype = classmethod(lambda cls: cls.LockType("some_lock"))
-
-        # _is_owned() unsupported
-        test__is_owned = None
-        # acquire(blocking=False) unsupported
-        test_try_acquire = None
-        test_try_acquire_contended = None
-        # `with` unsupported
-        test_with = None
-        # acquire(timeout=...) unsupported
-        test_timeout = None
-        # _release_save() unsupported
-        test_release_save_unacquired = None
-        # lock status in repr unsupported
-        test_repr = None
-        test_locked_repr = None
-
-    LOCK_TYPES = {kind: splitinit._bootstrap._ModuleLock
-                  for kind, splitinit in init.items()}
-
-    (Frozen_ModuleLockAsRLockTests,
-     Source_ModuleLockAsRLockTests
-     ) = test_util.test_both(ModuleLockAsRLockTests, lock_tests.RLockTests,
-                             LockType=LOCK_TYPES)
-else:
-    LOCK_TYPES = {}
-
-    class Frozen_ModuleLockAsRLockTests(unittest.TestCase):
-        pass
-
-    class Source_ModuleLockAsRLockTests(unittest.TestCase):
-        pass
 
 
-if threading is not None:
+class ModuleLockAsRLockTests:
-    class DeadlockAvoidanceTests:
+    locktype = classmethod(lambda cls: cls.LockType("some_lock"))
 
-        def setUp(self):
+    # _is_owned() unsupported
+    test__is_owned = None
+    # acquire(blocking=False) unsupported
+    test_try_acquire = None
+    test_try_acquire_contended = None
+    # `with` unsupported
+    test_with = None
+    # acquire(timeout=...) unsupported
+    test_timeout = None
+    # _release_save() unsupported
+    test_release_save_unacquired = None
+    # lock status in repr unsupported
+    test_repr = None
+    test_locked_repr = None
+
+LOCK_TYPES = {kind: splitinit._bootstrap._ModuleLock
+              for kind, splitinit in init.items()}
+
+(Frozen_ModuleLockAsRLockTests,
+ Source_ModuleLockAsRLockTests
+ ) = test_util.test_both(ModuleLockAsRLockTests, lock_tests.RLockTests,
+                         LockType=LOCK_TYPES)
+
+
+class DeadlockAvoidanceTests:
+
+    def setUp(self):
+        try:
+            self.old_switchinterval = sys.getswitchinterval()
+            support.setswitchinterval(0.000001)
+        except AttributeError:
+            self.old_switchinterval = None
+
+    def tearDown(self):
+        if self.old_switchinterval is not None:
+            sys.setswitchinterval(self.old_switchinterval)
+
+    def run_deadlock_avoidance_test(self, create_deadlock):
+        NLOCKS = 10
+        locks = [self.LockType(str(i)) for i in range(NLOCKS)]
+        pairs = [(locks[i], locks[(i+1)%NLOCKS]) for i in range(NLOCKS)]
+        if create_deadlock:
+            NTHREADS = NLOCKS
+        else:
+            NTHREADS = NLOCKS - 1
+        barrier = threading.Barrier(NTHREADS)
+        results = []
+
+        def _acquire(lock):
+            """Try to acquire the lock. Return True on success,
+            False on deadlock."""
             try:
-                self.old_switchinterval = sys.getswitchinterval()
+                lock.acquire()
-                support.setswitchinterval(0.000001)
+            except self.DeadlockError:
-            except AttributeError:
+                return False
-                self.old_switchinterval = None
-
-        def tearDown(self):
-            if self.old_switchinterval is not None:
-                sys.setswitchinterval(self.old_switchinterval)
-
-        def run_deadlock_avoidance_test(self, create_deadlock):
-            NLOCKS = 10
-            locks = [self.LockType(str(i)) for i in range(NLOCKS)]
-            pairs = [(locks[i], locks[(i+1)%NLOCKS]) for i in range(NLOCKS)]
-            if create_deadlock:
-                NTHREADS = NLOCKS
             else:
-                NTHREADS = NLOCKS - 1
+                return True
-            barrier = threading.Barrier(NTHREADS)
-            results = []
 
-            def _acquire(lock):
+        def f():
-                """Try to acquire the lock. Return True on success,
+            a, b = pairs.pop()
-                False on deadlock."""
+            ra = _acquire(a)
-                try:
+            barrier.wait()
-                    lock.acquire()
+            rb = _acquire(b)
-                except self.DeadlockError:
+            results.append((ra, rb))
-                    return False
+            if rb:
-                else:
+                b.release()
-                    return True
+            if ra:
+                a.release()
+        lock_tests.Bunch(f, NTHREADS).wait_for_finished()
+        self.assertEqual(len(results), NTHREADS)
+        return results
 
-            def f():
+    def test_deadlock(self):
-                a, b = pairs.pop()
+        results = self.run_deadlock_avoidance_test(True)
-                ra = _acquire(a)
+        # At least one of the threads detected a potential deadlock on its
-                barrier.wait()
+        # second acquire() call.  It may be several of them, because the
-                rb = _acquire(b)
+        # deadlock avoidance mechanism is conservative.
-                results.append((ra, rb))
+        nb_deadlocks = results.count((True, False))
-                if rb:
+        self.assertGreaterEqual(nb_deadlocks, 1)
-                    b.release()
+        self.assertEqual(results.count((True, True)), len(results) - nb_deadlocks)
-                if ra:
-                    a.release()
-            lock_tests.Bunch(f, NTHREADS).wait_for_finished()
-            self.assertEqual(len(results), NTHREADS)
-            return results
 
-        def test_deadlock(self):
+    def test_no_deadlock(self):
-            results = self.run_deadlock_avoidance_test(True)
+        results = self.run_deadlock_avoidance_test(False)
-            # At least one of the threads detected a potential deadlock on its
+        self.assertEqual(results.count((True, False)), 0)
-            # second acquire() call.  It may be several of them, because the
+        self.assertEqual(results.count((True, True)), len(results))
-            # deadlock avoidance mechanism is conservative.
-            nb_deadlocks = results.count((True, False))
-            self.assertGreaterEqual(nb_deadlocks, 1)
-            self.assertEqual(results.count((True, True)), len(results) - nb_deadlocks)
-
-        def test_no_deadlock(self):
-            results = self.run_deadlock_avoidance_test(False)
-            self.assertEqual(results.count((True, False)), 0)
-            self.assertEqual(results.count((True, True)), len(results))
 
 
-    DEADLOCK_ERRORS = {kind: splitinit._bootstrap._DeadlockError
+DEADLOCK_ERRORS = {kind: splitinit._bootstrap._DeadlockError
-                       for kind, splitinit in init.items()}
+                   for kind, splitinit in init.items()}
 
-    (Frozen_DeadlockAvoidanceTests,
+(Frozen_DeadlockAvoidanceTests,
-     Source_DeadlockAvoidanceTests
+ Source_DeadlockAvoidanceTests
-     ) = test_util.test_both(DeadlockAvoidanceTests,
+ ) = test_util.test_both(DeadlockAvoidanceTests,
-                             LockType=LOCK_TYPES,
+                         LockType=LOCK_TYPES,
-                             DeadlockError=DEADLOCK_ERRORS)
+                         DeadlockError=DEADLOCK_ERRORS)
-else:
-    DEADLOCK_ERRORS = {}
-
-    class Frozen_DeadlockAvoidanceTests(unittest.TestCase):
-        pass
-
-    class Source_DeadlockAvoidanceTests(unittest.TestCase):
-        pass
 
 
 class LifetimeTests:

Lib/test/test_io.py

@@ -28,6 +28,7 @@ import pickle
 import random
 import signal
 import sys
+import threading
 import time
 import unittest
 import warnings
@@ -40,10 +41,6 @@ from test.support.script_helper import assert_python_ok, run_python_until_end
 import codecs
 import io  # C implementation of io
 import _pyio as pyio # Python implementation of io
-try:
-    import threading
-except ImportError:
-    threading = None
 
 try:
     import ctypes
@@ -443,8 +440,6 @@ class IOTest(unittest.TestCase):
             (self.BytesIO, "rws"), (self.StringIO, "rws"),
         )
         for [test, abilities] in tests:
-            if test is pipe_writer and not threading:
-                continue  # Skip subtest that uses a background thread
             with self.subTest(test), test() as obj:
                 readable = "r" in abilities
                 self.assertEqual(obj.readable(), readable)
@@ -1337,7 +1332,6 @@ class BufferedReaderTest(unittest.TestCase, CommonBufferedTests):
 
         self.assertEqual(b"abcdefg", bufio.read())
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     @support.requires_resource('cpu')
     def test_threads(self):
         try:
@@ -1664,7 +1658,6 @@ class BufferedWriterTest(unittest.TestCase, CommonBufferedTests):
         with self.open(support.TESTFN, "rb", buffering=0) as f:
             self.assertEqual(f.read(), b"abc")
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     @support.requires_resource('cpu')
     def test_threads(self):
         try:
@@ -3053,7 +3046,6 @@ class TextIOWrapperTest(unittest.TestCase):
             self.assertEqual(f.errors, "replace")
 
     @support.no_tracing
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_threads_write(self):
         # Issue6750: concurrent writes could duplicate data
         event = threading.Event()
@@ -3804,7 +3796,6 @@ class CMiscIOTest(MiscIOTest):
         b = bytearray(2)
         self.assertRaises(ValueError, bufio.readinto, b)
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def check_daemon_threads_shutdown_deadlock(self, stream_name):
         # Issue #23309: deadlocks at shutdown should be avoided when a
         # daemon thread and the main thread both write to a file.
@@ -3868,7 +3859,6 @@ class SignalsTest(unittest.TestCase):
     def alarm_interrupt(self, sig, frame):
         1/0
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def check_interrupted_write(self, item, bytes, **fdopen_kwargs):
         """Check that a partial write, when it gets interrupted, properly
         invokes the signal handler, and bubbles up the exception raised
@@ -3990,7 +3980,6 @@ class SignalsTest(unittest.TestCase):
         self.check_interrupted_read_retry(lambda x: x,
                                           mode="r")
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def check_interrupted_write_retry(self, item, **fdopen_kwargs):
         """Check that a buffered write, when it gets interrupted (either
         returning a partial result or EINTR), properly invokes the signal

Lib/test/test_logging.py

@@ -42,22 +42,19 @@ import tempfile
 from test.support.script_helper import assert_python_ok
 from test import support
 import textwrap
+import threading
 import time
 import unittest
 import warnings
 import weakref
-try:
+
-    import threading
+import asyncore
-    # The following imports are needed only for tests which
+from http.server import HTTPServer, BaseHTTPRequestHandler
-    # require threading
+import smtpd
-    import asyncore
+from urllib.parse import urlparse, parse_qs
-    from http.server import HTTPServer, BaseHTTPRequestHandler
+from socketserver import (ThreadingUDPServer, DatagramRequestHandler,
-    import smtpd
+                          ThreadingTCPServer, StreamRequestHandler)
-    from urllib.parse import urlparse, parse_qs
+
-    from socketserver import (ThreadingUDPServer, DatagramRequestHandler,
-                              ThreadingTCPServer, StreamRequestHandler)
-except ImportError:
-    threading = None
 try:
     import win32evtlog, win32evtlogutil, pywintypes
 except ImportError:
@@ -625,7 +622,6 @@ class HandlerTest(BaseTest):
             os.unlink(fn)
 
     @unittest.skipIf(os.name == 'nt', 'WatchedFileHandler not appropriate for Windows.')
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_race(self):
         # Issue #14632 refers.
         def remove_loop(fname, tries):
@@ -719,276 +715,274 @@ class StreamHandlerTest(BaseTest):
 # -- The following section could be moved into a server_helper.py module
 # -- if it proves to be of wider utility than just test_logging
 
-if threading:
+class TestSMTPServer(smtpd.SMTPServer):
-    class TestSMTPServer(smtpd.SMTPServer):
+    """
-        """
+    This class implements a test SMTP server.
-        This class implements a test SMTP server.
 
-        :param addr: A (host, port) tuple which the server listens on.
+    :param addr: A (host, port) tuple which the server listens on.
-                     You can specify a port value of zero: the server's
+                 You can specify a port value of zero: the server's
-                     *port* attribute will hold the actual port number
+                 *port* attribute will hold the actual port number
-                     used, which can be used in client connections.
+                 used, which can be used in client connections.
-        :param handler: A callable which will be called to process
+    :param handler: A callable which will be called to process
-                        incoming messages. The handler will be passed
+                    incoming messages. The handler will be passed
-                        the client address tuple, who the message is from,
+                    the client address tuple, who the message is from,
-                        a list of recipients and the message data.
+                    a list of recipients and the message data.
+    :param poll_interval: The interval, in seconds, used in the underlying
+                          :func:`select` or :func:`poll` call by
+                          :func:`asyncore.loop`.
+    :param sockmap: A dictionary which will be used to hold
+                    :class:`asyncore.dispatcher` instances used by
+                    :func:`asyncore.loop`. This avoids changing the
+                    :mod:`asyncore` module's global state.
+    """
+
+    def __init__(self, addr, handler, poll_interval, sockmap):
+        smtpd.SMTPServer.__init__(self, addr, None, map=sockmap,
+                                  decode_data=True)
+        self.port = self.socket.getsockname()[1]
+        self._handler = handler
+        self._thread = None
+        self.poll_interval = poll_interval
+
+    def process_message(self, peer, mailfrom, rcpttos, data):
+        """
+        Delegates to the handler passed in to the server's constructor.
+
+        Typically, this will be a test case method.
+        :param peer: The client (host, port) tuple.
+        :param mailfrom: The address of the sender.
+        :param rcpttos: The addresses of the recipients.
+        :param data: The message.
+        """
+        self._handler(peer, mailfrom, rcpttos, data)
+
+    def start(self):
+        """
+        Start the server running on a separate daemon thread.
+        """
+        self._thread = t = threading.Thread(target=self.serve_forever,
+                                            args=(self.poll_interval,))
+        t.setDaemon(True)
+        t.start()
+
+    def serve_forever(self, poll_interval):
+        """
+        Run the :mod:`asyncore` loop until normal termination
+        conditions arise.
         :param poll_interval: The interval, in seconds, used in the underlying
                               :func:`select` or :func:`poll` call by
                               :func:`asyncore.loop`.
-        :param sockmap: A dictionary which will be used to hold
-                        :class:`asyncore.dispatcher` instances used by
-                        :func:`asyncore.loop`. This avoids changing the
-                        :mod:`asyncore` module's global state.
         """
+        try:
+            asyncore.loop(poll_interval, map=self._map)
+        except OSError:
+            # On FreeBSD 8, closing the server repeatably
+            # raises this error. We swallow it if the
+            # server has been closed.
+            if self.connected or self.accepting:
+                raise
 
-        def __init__(self, addr, handler, poll_interval, sockmap):
+    def stop(self, timeout=None):
-            smtpd.SMTPServer.__init__(self, addr, None, map=sockmap,
+        """
-                                      decode_data=True)
+        Stop the thread by closing the server instance.
-            self.port = self.socket.getsockname()[1]
+        Wait for the server thread to terminate.
-            self._handler = handler
-            self._thread = None
-            self.poll_interval = poll_interval
 
-        def process_message(self, peer, mailfrom, rcpttos, data):
+        :param timeout: How long to wait for the server thread
-            """
+                        to terminate.
-            Delegates to the handler passed in to the server's constructor.
+        """
+        self.close()
+        self._thread.join(timeout)
+        asyncore.close_all(map=self._map, ignore_all=True)
 
-            Typically, this will be a test case method.
+        alive = self._thread.is_alive()
-            :param peer: The client (host, port) tuple.
+        self._thread = None
-            :param mailfrom: The address of the sender.
+        if alive:
-            :param rcpttos: The addresses of the recipients.
+            self.fail("join() timed out")
-            :param data: The message.
-            """
-            self._handler(peer, mailfrom, rcpttos, data)
 
-        def start(self):
+class ControlMixin(object):
-            """
+    """
-            Start the server running on a separate daemon thread.
+    This mixin is used to start a server on a separate thread, and
-            """
+    shut it down programmatically. Request handling is simplified - instead
-            self._thread = t = threading.Thread(target=self.serve_forever,
+    of needing to derive a suitable RequestHandler subclass, you just
-                                                args=(self.poll_interval,))
+    provide a callable which will be passed each received request to be
-            t.setDaemon(True)
+    processed.
-            t.start()
 
-        def serve_forever(self, poll_interval):
+    :param handler: A handler callable which will be called with a
-            """
+                    single parameter - the request - in order to
-            Run the :mod:`asyncore` loop until normal termination
+                    process the request. This handler is called on the
-            conditions arise.
+                    server thread, effectively meaning that requests are
-            :param poll_interval: The interval, in seconds, used in the underlying
+                    processed serially. While not quite Web scale ;-),
-                                  :func:`select` or :func:`poll` call by
+                    this should be fine for testing applications.
-                                  :func:`asyncore.loop`.
+    :param poll_interval: The polling interval in seconds.
-            """
+    """
-            try:
+    def __init__(self, handler, poll_interval):
-                asyncore.loop(poll_interval, map=self._map)
+        self._thread = None
-            except OSError:
+        self.poll_interval = poll_interval
-                # On FreeBSD 8, closing the server repeatably
+        self._handler = handler
-                # raises this error. We swallow it if the
+        self.ready = threading.Event()
-                # server has been closed.
-                if self.connected or self.accepting:
-                    raise
 
-        def stop(self, timeout=None):
+    def start(self):
-            """
+        """
-            Stop the thread by closing the server instance.
+        Create a daemon thread to run the server, and start it.
-            Wait for the server thread to terminate.
+        """
+        self._thread = t = threading.Thread(target=self.serve_forever,
+                                            args=(self.poll_interval,))
+        t.setDaemon(True)
+        t.start()
 
-            :param timeout: How long to wait for the server thread
+    def serve_forever(self, poll_interval):
-                            to terminate.
+        """
-            """
+        Run the server. Set the ready flag before entering the
-            self.close()
+        service loop.
+        """
+        self.ready.set()
+        super(ControlMixin, self).serve_forever(poll_interval)
+
+    def stop(self, timeout=None):
+        """
+        Tell the server thread to stop, and wait for it to do so.
+
+        :param timeout: How long to wait for the server thread
+                        to terminate.
+        """
+        self.shutdown()
+        if self._thread is not None:
             self._thread.join(timeout)
-            asyncore.close_all(map=self._map, ignore_all=True)
-
             alive = self._thread.is_alive()
             self._thread = None
             if alive:
                 self.fail("join() timed out")
+        self.server_close()
+        self.ready.clear()
 
-    class ControlMixin(object):
+class TestHTTPServer(ControlMixin, HTTPServer):
-        """
+    """
-        This mixin is used to start a server on a separate thread, and
+    An HTTP server which is controllable using :class:`ControlMixin`.
-        shut it down programmatically. Request handling is simplified - instead
-        of needing to derive a suitable RequestHandler subclass, you just
-        provide a callable which will be passed each received request to be
-        processed.
 
-        :param handler: A handler callable which will be called with a
+    :param addr: A tuple with the IP address and port to listen on.
-                        single parameter - the request - in order to
+    :param handler: A handler callable which will be called with a
-                        process the request. This handler is called on the
+                    single parameter - the request - in order to
-                        server thread, effectively meaning that requests are
+                    process the request.
-                        processed serially. While not quite Web scale ;-),
+    :param poll_interval: The polling interval in seconds.
-                        this should be fine for testing applications.
+    :param log: Pass ``True`` to enable log messages.
-        :param poll_interval: The polling interval in seconds.
+    """
-        """
+    def __init__(self, addr, handler, poll_interval=0.5,
-        def __init__(self, handler, poll_interval):
+                 log=False, sslctx=None):
-            self._thread = None
+        class DelegatingHTTPRequestHandler(BaseHTTPRequestHandler):
-            self.poll_interval = poll_interval
+            def __getattr__(self, name, default=None):
-            self._handler = handler
+                if name.startswith('do_'):
-            self.ready = threading.Event()
+                    return self.process_request
+                raise AttributeError(name)
 
-        def start(self):
+            def process_request(self):
-            """
+                self.server._handler(self)
-            Create a daemon thread to run the server, and start it.
-            """
-            self._thread = t = threading.Thread(target=self.serve_forever,
-                                                args=(self.poll_interval,))
-            t.setDaemon(True)
-            t.start()
 
-        def serve_forever(self, poll_interval):
+            def log_message(self, format, *args):
-            """
+                if log:
-            Run the server. Set the ready flag before entering the
+                    super(DelegatingHTTPRequestHandler,
-            service loop.
+                          self).log_message(format, *args)
-            """
+        HTTPServer.__init__(self, addr, DelegatingHTTPRequestHandler)
-            self.ready.set()
+        ControlMixin.__init__(self, handler, poll_interval)
-            super(ControlMixin, self).serve_forever(poll_interval)
+        self.sslctx = sslctx
 
-        def stop(self, timeout=None):
+    def get_request(self):
-            """
+        try:
-            Tell the server thread to stop, and wait for it to do so.
+            sock, addr = self.socket.accept()
+            if self.sslctx:
+                sock = self.sslctx.wrap_socket(sock, server_side=True)
+        except OSError as e:
+            # socket errors are silenced by the caller, print them here
+            sys.stderr.write("Got an error:\n%s\n" % e)
+            raise
+        return sock, addr
 
-            :param timeout: How long to wait for the server thread
+class TestTCPServer(ControlMixin, ThreadingTCPServer):
-                            to terminate.
+    """
-            """
+    A TCP server which is controllable using :class:`ControlMixin`.
-            self.shutdown()
-            if self._thread is not None:
-                self._thread.join(timeout)
-                alive = self._thread.is_alive()
-                self._thread = None
-                if alive:
-                    self.fail("join() timed out")
-            self.server_close()
-            self.ready.clear()
 
-    class TestHTTPServer(ControlMixin, HTTPServer):
+    :param addr: A tuple with the IP address and port to listen on.
-        """
+    :param handler: A handler callable which will be called with a single
-        An HTTP server which is controllable using :class:`ControlMixin`.
+                    parameter - the request - in order to process the request.
+    :param poll_interval: The polling interval in seconds.
+    :bind_and_activate: If True (the default), binds the server and starts it
+                        listening. If False, you need to call
+                        :meth:`server_bind` and :meth:`server_activate` at
+                        some later time before calling :meth:`start`, so that
+                        the server will set up the socket and listen on it.
+    """
 
-        :param addr: A tuple with the IP address and port to listen on.
+    allow_reuse_address = True
-        :param handler: A handler callable which will be called with a
-                        single parameter - the request - in order to
-                        process the request.
-        :param poll_interval: The polling interval in seconds.
-        :param log: Pass ``True`` to enable log messages.
-        """
-        def __init__(self, addr, handler, poll_interval=0.5,
-                     log=False, sslctx=None):
-            class DelegatingHTTPRequestHandler(BaseHTTPRequestHandler):
-                def __getattr__(self, name, default=None):
-                    if name.startswith('do_'):
-                        return self.process_request
-                    raise AttributeError(name)
 
-                def process_request(self):
+    def __init__(self, addr, handler, poll_interval=0.5,
-                    self.server._handler(self)
+                 bind_and_activate=True):
+        class DelegatingTCPRequestHandler(StreamRequestHandler):
 
-                def log_message(self, format, *args):
+            def handle(self):
-                    if log:
+                self.server._handler(self)
-                        super(DelegatingHTTPRequestHandler,
+        ThreadingTCPServer.__init__(self, addr, DelegatingTCPRequestHandler,
-                              self).log_message(format, *args)
+                                    bind_and_activate)
-            HTTPServer.__init__(self, addr, DelegatingHTTPRequestHandler)
+        ControlMixin.__init__(self, handler, poll_interval)
-            ControlMixin.__init__(self, handler, poll_interval)
-            self.sslctx = sslctx
 
-        def get_request(self):
+    def server_bind(self):
-            try:
+        super(TestTCPServer, self).server_bind()
-                sock, addr = self.socket.accept()
+        self.port = self.socket.getsockname()[1]
-                if self.sslctx:
-                    sock = self.sslctx.wrap_socket(sock, server_side=True)
-            except OSError as e:
-                # socket errors are silenced by the caller, print them here
-                sys.stderr.write("Got an error:\n%s\n" % e)
-                raise
-            return sock, addr
 
-    class TestTCPServer(ControlMixin, ThreadingTCPServer):
+class TestUDPServer(ControlMixin, ThreadingUDPServer):
-        """
+    """
-        A TCP server which is controllable using :class:`ControlMixin`.
+    A UDP server which is controllable using :class:`ControlMixin`.
 
-        :param addr: A tuple with the IP address and port to listen on.
+    :param addr: A tuple with the IP address and port to listen on.
-        :param handler: A handler callable which will be called with a single
+    :param handler: A handler callable which will be called with a
-                        parameter - the request - in order to process the request.
+                    single parameter - the request - in order to
-        :param poll_interval: The polling interval in seconds.
+                    process the request.
-        :bind_and_activate: If True (the default), binds the server and starts it
+    :param poll_interval: The polling interval for shutdown requests,
-                            listening. If False, you need to call
+                          in seconds.
-                            :meth:`server_bind` and :meth:`server_activate` at
+    :bind_and_activate: If True (the default), binds the server and
-                            some later time before calling :meth:`start`, so that
+                        starts it listening. If False, you need to
-                            the server will set up the socket and listen on it.
+                        call :meth:`server_bind` and
-        """
+                        :meth:`server_activate` at some later time
+                        before calling :meth:`start`, so that the server will
+                        set up the socket and listen on it.
+    """
+    def __init__(self, addr, handler, poll_interval=0.5,
+                 bind_and_activate=True):
+        class DelegatingUDPRequestHandler(DatagramRequestHandler):
 
-        allow_reuse_address = True
+            def handle(self):
+                self.server._handler(self)
 
-        def __init__(self, addr, handler, poll_interval=0.5,
+            def finish(self):
-                     bind_and_activate=True):
+                data = self.wfile.getvalue()
-            class DelegatingTCPRequestHandler(StreamRequestHandler):
+                if data:
+                    try:
+                        super(DelegatingUDPRequestHandler, self).finish()
+                    except OSError:
+                        if not self.server._closed:
+                            raise
 
-                def handle(self):
+        ThreadingUDPServer.__init__(self, addr,
-                    self.server._handler(self)
+                                    DelegatingUDPRequestHandler,
-            ThreadingTCPServer.__init__(self, addr, DelegatingTCPRequestHandler,
+                                    bind_and_activate)
-                                        bind_and_activate)
+        ControlMixin.__init__(self, handler, poll_interval)
-            ControlMixin.__init__(self, handler, poll_interval)
+        self._closed = False
 
-        def server_bind(self):
+    def server_bind(self):
-            super(TestTCPServer, self).server_bind()
+        super(TestUDPServer, self).server_bind()
-            self.port = self.socket.getsockname()[1]
+        self.port = self.socket.getsockname()[1]
 
-    class TestUDPServer(ControlMixin, ThreadingUDPServer):
+    def server_close(self):
-        """
+        super(TestUDPServer, self).server_close()
-        A UDP server which is controllable using :class:`ControlMixin`.
+        self._closed = True
 
-        :param addr: A tuple with the IP address and port to listen on.
+if hasattr(socket, "AF_UNIX"):
-        :param handler: A handler callable which will be called with a
+    class TestUnixStreamServer(TestTCPServer):
-                        single parameter - the request - in order to
+        address_family = socket.AF_UNIX
-                        process the request.
-        :param poll_interval: The polling interval for shutdown requests,
-                              in seconds.
-        :bind_and_activate: If True (the default), binds the server and
-                            starts it listening. If False, you need to
-                            call :meth:`server_bind` and
-                            :meth:`server_activate` at some later time
-                            before calling :meth:`start`, so that the server will
-                            set up the socket and listen on it.
-        """
-        def __init__(self, addr, handler, poll_interval=0.5,
-                     bind_and_activate=True):
-            class DelegatingUDPRequestHandler(DatagramRequestHandler):
 
-                def handle(self):
+    class TestUnixDatagramServer(TestUDPServer):
-                    self.server._handler(self)
+        address_family = socket.AF_UNIX
-
-                def finish(self):
-                    data = self.wfile.getvalue()
-                    if data:
-                        try:
-                            super(DelegatingUDPRequestHandler, self).finish()
-                        except OSError:
-                            if not self.server._closed:
-                                raise
-
-            ThreadingUDPServer.__init__(self, addr,
-                                        DelegatingUDPRequestHandler,
-                                        bind_and_activate)
-            ControlMixin.__init__(self, handler, poll_interval)
-            self._closed = False
-
-        def server_bind(self):
-            super(TestUDPServer, self).server_bind()
-            self.port = self.socket.getsockname()[1]
-
-        def server_close(self):
-            super(TestUDPServer, self).server_close()
-            self._closed = True
-
-    if hasattr(socket, "AF_UNIX"):
-        class TestUnixStreamServer(TestTCPServer):
-            address_family = socket.AF_UNIX
-
-        class TestUnixDatagramServer(TestUDPServer):
-            address_family = socket.AF_UNIX
 
 # - end of server_helper section
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class SMTPHandlerTest(BaseTest):
     TIMEOUT = 8.0
 
@@ -1472,14 +1466,12 @@ class ConfigFileTest(BaseTest):
 
 
 @unittest.skipIf(True, "FIXME: bpo-30830")
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class SocketHandlerTest(BaseTest):
 
     """Test for SocketHandler objects."""
 
-    if threading:
+    server_class = TestTCPServer
-        server_class = TestTCPServer
+    address = ('localhost', 0)
-        address = ('localhost', 0)
 
     def setUp(self):
         """Set up a TCP server to receive log messages, and a SocketHandler
@@ -1573,12 +1565,11 @@ def _get_temp_domain_socket():
 
 @unittest.skipIf(True, "FIXME: bpo-30830")
 @unittest.skipUnless(hasattr(socket, "AF_UNIX"), "Unix sockets required")
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class UnixSocketHandlerTest(SocketHandlerTest):
 
     """Test for SocketHandler with unix sockets."""
 
-    if threading and hasattr(socket, "AF_UNIX"):
+    if hasattr(socket, "AF_UNIX"):
         server_class = TestUnixStreamServer
 
     def setUp(self):
@@ -1591,14 +1582,12 @@ class UnixSocketHandlerTest(SocketHandlerTest):
         support.unlink(self.address)
 
 @unittest.skipIf(True, "FIXME: bpo-30830")
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class DatagramHandlerTest(BaseTest):
 
     """Test for DatagramHandler."""
 
-    if threading:
+    server_class = TestUDPServer
-        server_class = TestUDPServer
+    address = ('localhost', 0)
-        address = ('localhost', 0)
 
     def setUp(self):
         """Set up a UDP server to receive log messages, and a DatagramHandler
@@ -1659,12 +1648,11 @@ class DatagramHandlerTest(BaseTest):
 
 @unittest.skipIf(True, "FIXME: bpo-30830")
 @unittest.skipUnless(hasattr(socket, "AF_UNIX"), "Unix sockets required")
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class UnixDatagramHandlerTest(DatagramHandlerTest):
 
     """Test for DatagramHandler using Unix sockets."""
 
-    if threading and hasattr(socket, "AF_UNIX"):
+    if hasattr(socket, "AF_UNIX"):
         server_class = TestUnixDatagramServer
 
     def setUp(self):
@@ -1676,14 +1664,12 @@ class UnixDatagramHandlerTest(DatagramHandlerTest):
         DatagramHandlerTest.tearDown(self)
         support.unlink(self.address)
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class SysLogHandlerTest(BaseTest):
 
     """Test for SysLogHandler using UDP."""
 
-    if threading:
+    server_class = TestUDPServer
-        server_class = TestUDPServer
+    address = ('localhost', 0)
-        address = ('localhost', 0)
 
     def setUp(self):
         """Set up a UDP server to receive log messages, and a SysLogHandler
@@ -1747,12 +1733,11 @@ class SysLogHandlerTest(BaseTest):
 
 @unittest.skipIf(True, "FIXME: bpo-30830")
 @unittest.skipUnless(hasattr(socket, "AF_UNIX"), "Unix sockets required")
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class UnixSysLogHandlerTest(SysLogHandlerTest):
 
     """Test for SysLogHandler with Unix sockets."""
 
-    if threading and hasattr(socket, "AF_UNIX"):
+    if hasattr(socket, "AF_UNIX"):
         server_class = TestUnixDatagramServer
 
     def setUp(self):
@@ -1767,7 +1752,6 @@ class UnixSysLogHandlerTest(SysLogHandlerTest):
 @unittest.skipIf(True, "FIXME: bpo-30830")
 @unittest.skipUnless(support.IPV6_ENABLED,
                      'IPv6 support required for this test.')
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class IPv6SysLogHandlerTest(SysLogHandlerTest):
 
     """Test for SysLogHandler with IPv6 host."""
@@ -1783,7 +1767,6 @@ class IPv6SysLogHandlerTest(SysLogHandlerTest):
         self.server_class.address_family = socket.AF_INET
         super(IPv6SysLogHandlerTest, self).tearDown()
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class HTTPHandlerTest(BaseTest):
     """Test for HTTPHandler."""
 
@@ -2892,7 +2875,6 @@ class ConfigDictTest(BaseTest):
     # listen() uses ConfigSocketReceiver which is based
     # on socketserver.ThreadingTCPServer
     @unittest.skipIf(True, "FIXME: bpo-30830")
-    @unittest.skipUnless(threading, 'listen() needs threading to work')
     def setup_via_listener(self, text, verify=None):
         text = text.encode("utf-8")
         # Ask for a randomly assigned port (by using port 0)
@@ -2923,7 +2905,6 @@ class ConfigDictTest(BaseTest):
             if t.is_alive():
                 self.fail("join() timed out")
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_listen_config_10_ok(self):
         with support.captured_stdout() as output:
             self.setup_via_listener(json.dumps(self.config10))
@@ -2943,7 +2924,6 @@ class ConfigDictTest(BaseTest):
                 ('ERROR', '4'),
             ], stream=output)
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_listen_config_1_ok(self):
         with support.captured_stdout() as output:
             self.setup_via_listener(textwrap.dedent(ConfigFileTest.config1))
@@ -2958,7 +2938,6 @@ class ConfigDictTest(BaseTest):
             # Original logger output is empty.
             self.assert_log_lines([])
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_listen_verify(self):
 
         def verify_fail(stuff):
@@ -3713,9 +3692,8 @@ class LogRecordTest(BaseTest):
     def test_optional(self):
         r = logging.makeLogRecord({})
         NOT_NONE = self.assertIsNotNone
-        if threading:
+        NOT_NONE(r.thread)
-            NOT_NONE(r.thread)
+        NOT_NONE(r.threadName)
-            NOT_NONE(r.threadName)
         NOT_NONE(r.process)
         NOT_NONE(r.processName)
         log_threads = logging.logThreads

Lib/test/test_nntplib.py

@@ -6,6 +6,8 @@ import unittest
 import functools
 import contextlib
 import os.path
+import threading
+
 from test import support
 from nntplib import NNTP, GroupInfo
 import nntplib
@@ -14,10 +16,7 @@ try:
     import ssl
 except ImportError:
     ssl = None
-try:
+
-    import threading
-except ImportError:
-    threading = None
 
 TIMEOUT = 30
 certfile = os.path.join(os.path.dirname(__file__), 'keycert3.pem')
@@ -1520,7 +1519,7 @@ class MockSslTests(MockSocketTests):
     def nntp_class(*pos, **kw):
         return nntplib.NNTP_SSL(*pos, ssl_context=bypass_context, **kw)
 
-@unittest.skipUnless(threading, 'requires multithreading')
+
 class LocalServerTests(unittest.TestCase):
     def setUp(self):
         sock = socket.socket()

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):
+        def __init__(self, conn):
-                asynchat.async_chat.__init__(self, conn)
+            asynchat.async_chat.__init__(self, conn)
-                self.in_buffer = []
+            self.in_buffer = []
-                self.closed = False
+            self.closed = False
-                self.push(b"220 ready\r\n")
+            self.push(b"220 ready\r\n")
 
-            def handle_read(self):
+        def handle_read(self):
-                data = self.recv(4096)
+            data = self.recv(4096)
-                self.in_buffer.append(data)
+            self.in_buffer.append(data)
 
-            def get_data(self):
+        def get_data(self):
-                return b''.join(self.in_buffer)
+            return b''.join(self.in_buffer)
 
-            def handle_close(self):
+        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
+            self.closed = True
-
-        def writable(self):
-            return 0
 
         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):
 

Lib/test/test_pdb.py

@@ -1040,9 +1040,6 @@ class PdbTestCase(unittest.TestCase):
         # invoking "continue" on a non-main thread triggered an exception
         # inside signal.signal
 
-        # raises SkipTest if python was built without threads
-        support.import_module('threading')
-
         with open(support.TESTFN, 'wb') as f:
             f.write(textwrap.dedent("""
                 import threading

Lib/test/test_poll.py

@@ -4,10 +4,7 @@ import os
 import subprocess
 import random
 import select
-try:
+import threading
-    import threading
-except ImportError:
-    threading = None
 import time
 import unittest
 from test.support import TESTFN, run_unittest, reap_threads, cpython_only
@@ -179,7 +176,6 @@ class PollTests(unittest.TestCase):
         self.assertRaises(OverflowError, pollster.poll, INT_MAX + 1)
         self.assertRaises(OverflowError, pollster.poll, UINT_MAX + 1)
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     @reap_threads
     def test_threaded_poll(self):
         r, w = os.pipe()

Lib/test/test_poplib.py

@@ -9,10 +9,10 @@ import asynchat
 import socket
 import os
 import errno
+import threading
 
 from unittest import TestCase, skipUnless
 from test import support as test_support
-threading = test_support.import_module('threading')
 
 HOST = test_support.HOST
 PORT = 0

Lib/test/test_pydoc.py

@@ -20,6 +20,7 @@ import urllib.parse
 import xml.etree
 import xml.etree.ElementTree
 import textwrap
+import threading
 from io import StringIO
 from collections import namedtuple
 from test.support.script_helper import assert_python_ok
@@ -30,10 +31,6 @@ from test.support import (
 )
 from test import pydoc_mod
 
-try:
-    import threading
-except ImportError:
-    threading = None
 
 class nonascii:
     'Це не латиниця'
@@ -902,7 +899,6 @@ class TestDescriptions(unittest.TestCase):
             "stat(path, *, dir_fd=None, follow_symlinks=True)")
 
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class PydocServerTest(unittest.TestCase):
     """Tests for pydoc._start_server"""
 

Lib/test/test_queue.py

@@ -1,10 +1,11 @@
 # Some simple queue module tests, plus some failure conditions
 # to ensure the Queue locks remain stable.
 import queue
+import threading
 import time
 import unittest
 from test import support
-threading = support.import_module('threading')
+
 
 QUEUE_SIZE = 5
 

Lib/test/test_regrtest.py

@@ -15,6 +15,7 @@ import sys
 import sysconfig
 import tempfile
 import textwrap
+import threading
 import unittest
 from test import libregrtest
 from test import support
@@ -741,12 +742,7 @@ class ArgsTestCase(BaseTestCase):
         code = TEST_INTERRUPTED
         test = self.create_test("sigint", code=code)
 
-        try:
+        for multiprocessing in (False, True):
-            import threading
-            tests = (False, True)
-        except ImportError:
-            tests = (False,)
-        for multiprocessing in tests:
             if multiprocessing:
                 args = ("--slowest", "-j2", test)
             else:

Lib/test/test_robotparser.py

@@ -1,14 +1,11 @@
 import io
 import os
+import threading
 import unittest
 import urllib.robotparser
 from collections import namedtuple
 from test import support
 from http.server import BaseHTTPRequestHandler, HTTPServer
-try:
-    import threading
-except ImportError:
-    threading = None
 
 
 class BaseRobotTest:
@@ -255,7 +252,6 @@ class RobotHandler(BaseHTTPRequestHandler):
         pass
 
 
-@unittest.skipUnless(threading, 'threading required for this test')
 class PasswordProtectedSiteTestCase(unittest.TestCase):
 
     def setUp(self):

Lib/test/test_sched.py

@@ -1,11 +1,9 @@
 import queue
 import sched
+import threading
 import time
 import unittest
-try:
+
-    import threading
-except ImportError:
-    threading = None
 
 TIMEOUT = 10
 
@@ -58,7 +56,6 @@ class TestCase(unittest.TestCase):
         scheduler.run()
         self.assertEqual(l, [0.01, 0.02, 0.03, 0.04, 0.05])
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_enter_concurrent(self):
         q = queue.Queue()
         fun = q.put
@@ -113,7 +110,6 @@ class TestCase(unittest.TestCase):
         scheduler.run()
         self.assertEqual(l, [0.02, 0.03, 0.04])
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_cancel_concurrent(self):
         q = queue.Queue()
         fun = q.put

Lib/test/test_signal.py

@@ -5,14 +5,11 @@ import socket
 import statistics
 import subprocess
 import sys
+import threading
 import time
 import unittest
 from test import support
 from test.support.script_helper import assert_python_ok, spawn_python
-try:
-    import threading
-except ImportError:
-    threading = None
 try:
     import _testcapi
 except ImportError:
@@ -21,7 +18,6 @@ except ImportError:
 
 class GenericTests(unittest.TestCase):
 
-    @unittest.skipIf(threading is None, "test needs threading module")
     def test_enums(self):
         for name in dir(signal):
             sig = getattr(signal, name)
@@ -807,7 +803,6 @@ class PendingSignalsTests(unittest.TestCase):
                          'need signal.sigwait()')
     @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'),
                          'need signal.pthread_sigmask()')
-    @unittest.skipIf(threading is None, "test needs threading module")
     def test_sigwait_thread(self):
         # Check that calling sigwait() from a thread doesn't suspend the whole
         # process. A new interpreter is spawned to avoid problems when mixing

Lib/test/test_smtplib.py

@@ -15,14 +15,11 @@ import time
 import select
 import errno
 import textwrap
+import threading
 
 import unittest
 from test import support, mock_socket
 
-try:
-    import threading
-except ImportError:
-    threading = None
 
 HOST = support.HOST
 
@@ -191,7 +188,6 @@ MSG_END = '------------ END MESSAGE ------------\n'
 # test server times out, causing the test to fail.
 
 # Test behavior of smtpd.DebuggingServer
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class DebuggingServerTests(unittest.TestCase):
 
     maxDiff = None
@@ -570,7 +566,6 @@ class NonConnectingTests(unittest.TestCase):
 
 
 # test response of client to a non-successful HELO message
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class BadHELOServerTests(unittest.TestCase):
 
     def setUp(self):
@@ -590,7 +585,6 @@ class BadHELOServerTests(unittest.TestCase):
                             HOST, self.port, 'localhost', 3)
 
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class TooLongLineTests(unittest.TestCase):
     respdata = b'250 OK' + (b'.' * smtplib._MAXLINE * 2) + b'\n'
 
@@ -835,7 +829,6 @@ class SimSMTPServer(smtpd.SMTPServer):
 
 # Test various SMTP & ESMTP commands/behaviors that require a simulated server
 # (i.e., something with more features than DebuggingServer)
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class SMTPSimTests(unittest.TestCase):
 
     def setUp(self):
@@ -1091,7 +1084,6 @@ class SimSMTPUTF8Server(SimSMTPServer):
         self.last_rcpt_options = rcpt_options
 
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class SMTPUTF8SimTests(unittest.TestCase):
 
     maxDiff = None
@@ -1227,7 +1219,6 @@ class SimSMTPAUTHInitialResponseServer(SimSMTPServer):
     channel_class = SimSMTPAUTHInitialResponseChannel
 
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class SMTPAUTHInitialResponseSimTests(unittest.TestCase):
     def setUp(self):
         self.real_getfqdn = socket.getfqdn

Lib/test/test_socket.py

@@ -21,6 +21,8 @@ import pickle
 import struct
 import random
 import string
+import _thread as thread
+import threading
 try:
     import multiprocessing
 except ImportError:
@@ -35,12 +37,6 @@ MSG = 'Michael Gilfix was here\u1234\r\n'.encode('utf-8') ## test unicode string
 
 VSOCKPORT = 1234
 
-try:
-    import _thread as thread
-    import threading
-except ImportError:
-    thread = None
-    threading = None
 try:
     import _socket
 except ImportError:
@@ -143,18 +139,17 @@ class ThreadSafeCleanupTestCase(unittest.TestCase):
     with a recursive lock.
     """
 
-    if threading:
+    def __init__(self, *args, **kwargs):
-        def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
-            super().__init__(*args, **kwargs)
+        self._cleanup_lock = threading.RLock()
-            self._cleanup_lock = threading.RLock()
 
-        def addCleanup(self, *args, **kwargs):
+    def addCleanup(self, *args, **kwargs):
-            with self._cleanup_lock:
+        with self._cleanup_lock:
-                return super().addCleanup(*args, **kwargs)
+            return super().addCleanup(*args, **kwargs)
 
-        def doCleanups(self, *args, **kwargs):
+    def doCleanups(self, *args, **kwargs):
-            with self._cleanup_lock:
+        with self._cleanup_lock:
-                return super().doCleanups(*args, **kwargs)
+            return super().doCleanups(*args, **kwargs)
 
 class SocketCANTest(unittest.TestCase):
 
@@ -407,7 +402,6 @@ class ThreadedRDSSocketTest(SocketRDSTest, ThreadableTest):
         ThreadableTest.clientTearDown(self)
 
 @unittest.skipIf(fcntl is None, "need fcntl")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 @unittest.skipUnless(HAVE_SOCKET_VSOCK,
           'VSOCK sockets required for this test.')
 @unittest.skipUnless(get_cid() != 2,
@@ -1684,7 +1678,6 @@ class BasicCANTest(unittest.TestCase):
 
 
 @unittest.skipUnless(HAVE_SOCKET_CAN, 'SocketCan required for this test.')
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class CANTest(ThreadedCANSocketTest):
 
     def __init__(self, methodName='runTest'):
@@ -1838,7 +1831,6 @@ class BasicRDSTest(unittest.TestCase):
 
 
 @unittest.skipUnless(HAVE_SOCKET_RDS, 'RDS sockets required for this test.')
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RDSTest(ThreadedRDSSocketTest):
 
     def __init__(self, methodName='runTest'):
@@ -1977,7 +1969,7 @@ class BasicVSOCKTest(unittest.TestCase):
                              s.getsockopt(socket.AF_VSOCK,
                              socket.SO_VM_SOCKETS_BUFFER_MIN_SIZE))
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
+
 class BasicTCPTest(SocketConnectedTest):
 
     def __init__(self, methodName='runTest'):
@@ -2100,7 +2092,7 @@ class BasicTCPTest(SocketConnectedTest):
     def _testDetach(self):
         self.serv_conn.send(MSG)
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
+
 class BasicUDPTest(ThreadedUDPSocketTest):
 
     def __init__(self, methodName='runTest'):
@@ -3697,17 +3689,14 @@ class SendrecvmsgUDPTestBase(SendrecvmsgDgramFlagsBase,
     pass
 
 @requireAttrs(socket.socket, "sendmsg")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class SendmsgUDPTest(SendmsgConnectionlessTests, SendrecvmsgUDPTestBase):
     pass
 
 @requireAttrs(socket.socket, "recvmsg")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgUDPTest(RecvmsgTests, SendrecvmsgUDPTestBase):
     pass
 
 @requireAttrs(socket.socket, "recvmsg_into")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgIntoUDPTest(RecvmsgIntoTests, SendrecvmsgUDPTestBase):
     pass
 
@@ -3724,21 +3713,18 @@ class SendrecvmsgUDP6TestBase(SendrecvmsgDgramFlagsBase,
 @requireAttrs(socket.socket, "sendmsg")
 @unittest.skipUnless(support.IPV6_ENABLED, 'IPv6 required for this test.')
 @requireSocket("AF_INET6", "SOCK_DGRAM")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class SendmsgUDP6Test(SendmsgConnectionlessTests, SendrecvmsgUDP6TestBase):
     pass
 
 @requireAttrs(socket.socket, "recvmsg")
 @unittest.skipUnless(support.IPV6_ENABLED, 'IPv6 required for this test.')
 @requireSocket("AF_INET6", "SOCK_DGRAM")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgUDP6Test(RecvmsgTests, SendrecvmsgUDP6TestBase):
     pass
 
 @requireAttrs(socket.socket, "recvmsg_into")
 @unittest.skipUnless(support.IPV6_ENABLED, 'IPv6 required for this test.')
 @requireSocket("AF_INET6", "SOCK_DGRAM")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgIntoUDP6Test(RecvmsgIntoTests, SendrecvmsgUDP6TestBase):
     pass
 
@@ -3746,7 +3732,6 @@ class RecvmsgIntoUDP6Test(RecvmsgIntoTests, SendrecvmsgUDP6TestBase):
 @unittest.skipUnless(support.IPV6_ENABLED, 'IPv6 required for this test.')
 @requireAttrs(socket, "IPPROTO_IPV6")
 @requireSocket("AF_INET6", "SOCK_DGRAM")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgRFC3542AncillaryUDP6Test(RFC3542AncillaryTest,
                                       SendrecvmsgUDP6TestBase):
     pass
@@ -3755,7 +3740,6 @@ class RecvmsgRFC3542AncillaryUDP6Test(RFC3542AncillaryTest,
 @unittest.skipUnless(support.IPV6_ENABLED, 'IPv6 required for this test.')
 @requireAttrs(socket, "IPPROTO_IPV6")
 @requireSocket("AF_INET6", "SOCK_DGRAM")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgIntoRFC3542AncillaryUDP6Test(RecvmsgIntoMixin,
                                           RFC3542AncillaryTest,
                                           SendrecvmsgUDP6TestBase):
@@ -3767,18 +3751,15 @@ class SendrecvmsgTCPTestBase(SendrecvmsgConnectedBase,
     pass
 
 @requireAttrs(socket.socket, "sendmsg")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class SendmsgTCPTest(SendmsgStreamTests, SendrecvmsgTCPTestBase):
     pass
 
 @requireAttrs(socket.socket, "recvmsg")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgTCPTest(RecvmsgTests, RecvmsgGenericStreamTests,
                      SendrecvmsgTCPTestBase):
     pass
 
 @requireAttrs(socket.socket, "recvmsg_into")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgIntoTCPTest(RecvmsgIntoTests, RecvmsgGenericStreamTests,
                          SendrecvmsgTCPTestBase):
     pass
@@ -3791,13 +3772,11 @@ class SendrecvmsgSCTPStreamTestBase(SendrecvmsgSCTPFlagsBase,
 
 @requireAttrs(socket.socket, "sendmsg")
 @requireSocket("AF_INET", "SOCK_STREAM", "IPPROTO_SCTP")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class SendmsgSCTPStreamTest(SendmsgStreamTests, SendrecvmsgSCTPStreamTestBase):
     pass
 
 @requireAttrs(socket.socket, "recvmsg")
 @requireSocket("AF_INET", "SOCK_STREAM", "IPPROTO_SCTP")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgSCTPStreamTest(RecvmsgTests, RecvmsgGenericStreamTests,
                             SendrecvmsgSCTPStreamTestBase):
 
@@ -3811,7 +3790,6 @@ class RecvmsgSCTPStreamTest(RecvmsgTests, RecvmsgGenericStreamTests,
 
 @requireAttrs(socket.socket, "recvmsg_into")
 @requireSocket("AF_INET", "SOCK_STREAM", "IPPROTO_SCTP")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgIntoSCTPStreamTest(RecvmsgIntoTests, RecvmsgGenericStreamTests,
                                 SendrecvmsgSCTPStreamTestBase):
 
@@ -3830,33 +3808,28 @@ class SendrecvmsgUnixStreamTestBase(SendrecvmsgConnectedBase,
 
 @requireAttrs(socket.socket, "sendmsg")
 @requireAttrs(socket, "AF_UNIX")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class SendmsgUnixStreamTest(SendmsgStreamTests, SendrecvmsgUnixStreamTestBase):
     pass
 
 @requireAttrs(socket.socket, "recvmsg")
 @requireAttrs(socket, "AF_UNIX")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgUnixStreamTest(RecvmsgTests, RecvmsgGenericStreamTests,
                             SendrecvmsgUnixStreamTestBase):
     pass
 
 @requireAttrs(socket.socket, "recvmsg_into")
 @requireAttrs(socket, "AF_UNIX")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgIntoUnixStreamTest(RecvmsgIntoTests, RecvmsgGenericStreamTests,
                                 SendrecvmsgUnixStreamTestBase):
     pass
 
 @requireAttrs(socket.socket, "sendmsg", "recvmsg")
 @requireAttrs(socket, "AF_UNIX", "SOL_SOCKET", "SCM_RIGHTS")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgSCMRightsStreamTest(SCMRightsTest, SendrecvmsgUnixStreamTestBase):
     pass
 
 @requireAttrs(socket.socket, "sendmsg", "recvmsg_into")
 @requireAttrs(socket, "AF_UNIX", "SOL_SOCKET", "SCM_RIGHTS")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class RecvmsgIntoSCMRightsStreamTest(RecvmsgIntoMixin, SCMRightsTest,
                                      SendrecvmsgUnixStreamTestBase):
     pass
@@ -3944,7 +3917,6 @@ class InterruptedRecvTimeoutTest(InterruptedTimeoutBase, UDPTestBase):
 @requireAttrs(signal, "siginterrupt")
 @unittest.skipUnless(hasattr(signal, "alarm") or hasattr(signal, "setitimer"),
                      "Don't have signal.alarm or signal.setitimer")
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class InterruptedSendTimeoutTest(InterruptedTimeoutBase,
                                  ThreadSafeCleanupTestCase,
                                  SocketListeningTestMixin, TCPTestBase):
@@ -3997,7 +3969,6 @@ class InterruptedSendTimeoutTest(InterruptedTimeoutBase,
         self.checkInterruptedSend(self.serv_conn.sendmsg, [b"a"*512])
 
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class TCPCloserTest(ThreadedTCPSocketTest):
 
     def testClose(self):
@@ -4017,7 +3988,7 @@ class TCPCloserTest(ThreadedTCPSocketTest):
         self.cli.connect((HOST, self.port))
         time.sleep(1.0)
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
+
 class BasicSocketPairTest(SocketPairTest):
 
     def __init__(self, methodName='runTest'):
@@ -4052,7 +4023,7 @@ class BasicSocketPairTest(SocketPairTest):
         msg = self.cli.recv(1024)
         self.assertEqual(msg, MSG)
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
+
 class NonBlockingTCPTests(ThreadedTCPSocketTest):
 
     def __init__(self, methodName='runTest'):
@@ -4180,7 +4151,7 @@ class NonBlockingTCPTests(ThreadedTCPSocketTest):
         time.sleep(0.1)
         self.cli.send(MSG)
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
+
 class FileObjectClassTestCase(SocketConnectedTest):
     """Unit tests for the object returned by socket.makefile()
 
@@ -4564,7 +4535,6 @@ class NetworkConnectionNoServer(unittest.TestCase):
                 socket.create_connection((HOST, 1234))
 
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class NetworkConnectionAttributesTest(SocketTCPTest, ThreadableTest):
 
     def __init__(self, methodName='runTest'):
@@ -4633,7 +4603,7 @@ class NetworkConnectionAttributesTest(SocketTCPTest, ThreadableTest):
         self.addCleanup(self.cli.close)
         self.assertEqual(self.cli.gettimeout(), 30)
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
+
 class NetworkConnectionBehaviourTest(SocketTCPTest, ThreadableTest):
 
     def __init__(self, methodName='runTest'):
@@ -4877,7 +4847,7 @@ class TestUnixDomain(unittest.TestCase):
         self.addCleanup(support.unlink, path)
         self.assertEqual(self.sock.getsockname(), path)
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
+
 class BufferIOTest(SocketConnectedTest):
     """
     Test the buffer versions of socket.recv() and socket.send().
@@ -5050,7 +5020,6 @@ class TIPCThreadableTest(unittest.TestCase, ThreadableTest):
         self.cli.close()
 
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class ContextManagersTest(ThreadedTCPSocketTest):
 
     def _testSocketClass(self):
@@ -5312,7 +5281,6 @@ class TestSocketSharing(SocketTCPTest):
                     source.close()
 
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
 class SendfileUsingSendTest(ThreadedTCPSocketTest):
     """
     Test the send() implementation of socket.sendfile().
@@ -5570,7 +5538,6 @@ class SendfileUsingSendTest(ThreadedTCPSocketTest):
                                        meth, file, count=-1)
 
 
-@unittest.skipUnless(thread, 'Threading required for this test.')
 @unittest.skipUnless(hasattr(os, "sendfile"),
                      'os.sendfile() required for this test.')
 class SendfileUsingSendfileTest(SendfileUsingSendTest):

Lib/test/test_socketserver.py

@@ -9,15 +9,13 @@ import select
 import signal
 import socket
 import tempfile
+import threading
 import unittest
 import socketserver
 
 import test.support
 from test.support import reap_children, reap_threads, verbose
-try:
+
-    import threading
-except ImportError:
-    threading = None
 
 test.support.requires("network")
 
@@ -68,7 +66,6 @@ def simple_subprocess(testcase):
     testcase.assertEqual(72 << 8, status)
 
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class SocketServerTest(unittest.TestCase):
     """Test all socket servers."""
 
@@ -306,12 +303,10 @@ class ErrorHandlerTest(unittest.TestCase):
             BaseErrorTestServer(SystemExit)
         self.check_result(handled=False)
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_threading_handled(self):
         ThreadingErrorTestServer(ValueError)
         self.check_result(handled=True)
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_threading_not_handled(self):
         ThreadingErrorTestServer(SystemExit)
         self.check_result(handled=False)
@@ -396,7 +391,6 @@ class SocketWriterTest(unittest.TestCase):
         self.assertIsInstance(server.wfile, io.BufferedIOBase)
         self.assertEqual(server.wfile_fileno, server.request_fileno)
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_write(self):
         # Test that wfile.write() sends data immediately, and that it does
         # not truncate sends when interrupted by a Unix signal

Lib/test/test_subprocess.py

@@ -14,6 +14,7 @@ import selectors
 import sysconfig
 import select
 import shutil
+import threading
 import gc
 import textwrap
 
@@ -24,11 +25,6 @@ except ImportError:
 else:
     import ctypes.util
 
-try:
-    import threading
-except ImportError:
-    threading = None
-
 try:
     import _testcapi
 except ImportError:
@@ -1196,7 +1192,6 @@ class ProcessTestCase(BaseTestCase):
         self.assertEqual(stderr, "")
         self.assertEqual(proc.returncode, 0)
 
-    @unittest.skipIf(threading is None, "threading required")
     def test_double_close_on_error(self):
         # Issue #18851
         fds = []
@@ -1226,7 +1221,6 @@ class ProcessTestCase(BaseTestCase):
             if exc is not None:
                 raise exc
 
-    @unittest.skipIf(threading is None, "threading required")
     def test_threadsafe_wait(self):
         """Issue21291: Popen.wait() needs to be threadsafe for returncode."""
         proc = subprocess.Popen([sys.executable, '-c',

Lib/test/test_sys.py

@@ -10,15 +10,12 @@ import codecs
 import gc
 import sysconfig
 import locale
+import threading
 
 # count the number of test runs, used to create unique
 # strings to intern in test_intern()
 numruns = 0
 
-try:
-    import threading
-except ImportError:
-    threading = None
 
 class SysModuleTest(unittest.TestCase):
 
@@ -172,7 +169,6 @@ class SysModuleTest(unittest.TestCase):
                 sys.setcheckinterval(n)
                 self.assertEqual(sys.getcheckinterval(), n)
 
-    @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_switchinterval(self):
         self.assertRaises(TypeError, sys.setswitchinterval)
         self.assertRaises(TypeError, sys.setswitchinterval, "a")
@@ -348,21 +344,8 @@ class SysModuleTest(unittest.TestCase):
         )
 
     # sys._current_frames() is a CPython-only gimmick.
-    def test_current_frames(self):
-        have_threads = True
-        try:
-            import _thread
-        except ImportError:
-            have_threads = False
-
-        if have_threads:
-            self.current_frames_with_threads()
-        else:
-            self.current_frames_without_threads()
-
-    # Test sys._current_frames() in a WITH_THREADS build.
     @test.support.reap_threads
-    def current_frames_with_threads(self):
+    def test_current_frames(self):
         import threading
         import traceback
 
@@ -426,15 +409,6 @@ class SysModuleTest(unittest.TestCase):
         leave_g.set()
         t.join()
 
-    # Test sys._current_frames() when thread support doesn't exist.
-    def current_frames_without_threads(self):
-        # Not much happens here:  there is only one thread, with artificial
-        # "thread id" 0.
-        d = sys._current_frames()
-        self.assertEqual(len(d), 1)
-        self.assertIn(0, d)
-        self.assertTrue(d[0] is sys._getframe())
-
     def test_attributes(self):
         self.assertIsInstance(sys.api_version, int)
         self.assertIsInstance(sys.argv, list)
@@ -516,8 +490,6 @@ class SysModuleTest(unittest.TestCase):
         if not sys.platform.startswith('win'):
             self.assertIsInstance(sys.abiflags, str)
 
-    @unittest.skipUnless(hasattr(sys, 'thread_info'),
-                         'Threading required for this test.')
     def test_thread_info(self):
         info = sys.thread_info
         self.assertEqual(len(info), 3)

Lib/test/test_telnetlib.py

@@ -1,11 +1,11 @@
 import socket
 import selectors
 import telnetlib
+import threading
 import contextlib
 
 from test import support
 import unittest
-threading = support.import_module('threading')
 
 HOST = support.HOST
 

Lib/test/test_threaded_import.py

@@ -11,12 +11,12 @@ import importlib
 import sys
 import time
 import shutil
+import threading
 import unittest
 from unittest import mock
 from test.support import (
     verbose, import_module, run_unittest, TESTFN, reap_threads,
     forget, unlink, rmtree, start_threads)
-threading = import_module('threading')
 
 def task(N, done, done_tasks, errors):
     try:

Lib/test/test_threadedtempfile.py

@@ -19,9 +19,9 @@ FILES_PER_THREAD = 50
 import tempfile
 
 from test.support import start_threads, import_module
-threading = import_module('threading')
 import unittest
 import io
+import threading
 from traceback import print_exc
 
 startEvent = threading.Event()

Lib/test/test_threading.py

@@ -9,8 +9,8 @@ from test.support.script_helper import assert_python_ok, assert_python_failure
 
 import random
 import sys
-_thread = import_module('_thread')
+import _thread
-threading = import_module('threading')
+import threading
 import time
 import unittest
 import weakref

Lib/test/test_threading_local.py

@@ -5,8 +5,8 @@ import weakref
 import gc
 
 # Modules under test
-_thread = support.import_module('_thread')
+import _thread
-threading = support.import_module('threading')
+import threading
 import _threading_local
 
 

Lib/test/test_time.py

@@ -8,10 +8,6 @@ import sys
 import sysconfig
 import time
 import unittest
-try:
-    import threading
-except ImportError:
-    threading = None
 try:
     import _testcapi
 except ImportError:

Lib/test/test_tracemalloc.py

@@ -7,10 +7,7 @@ from unittest.mock import patch
 from test.support.script_helper import (assert_python_ok, assert_python_failure,
                                         interpreter_requires_environment)
 from test import support
-try:
+
-    import threading
-except ImportError:
-    threading = None
 try:
     import _testcapi
 except ImportError:

Lib/test/test_urllib2_localnet.py

@@ -4,13 +4,12 @@ import email
 import urllib.parse
 import urllib.request
 import http.server
+import threading
 import unittest
 import hashlib
 
 from test import support
 
-threading = support.import_module('threading')
-
 try:
     import ssl
 except ImportError:
@@ -276,7 +275,6 @@ class FakeProxyHandler(http.server.BaseHTTPRequestHandler):
 
 # Test cases
 
-@unittest.skipUnless(threading, "Threading required for this test.")
 class BasicAuthTests(unittest.TestCase):
     USER = "testUser"
     PASSWD = "testPass"
@@ -317,7 +315,6 @@ class BasicAuthTests(unittest.TestCase):
         self.assertRaises(urllib.error.HTTPError, urllib.request.urlopen, self.server_url)
 
 
-@unittest.skipUnless(threading, "Threading required for this test.")
 class ProxyAuthTests(unittest.TestCase):
     URL = "http://localhost"
 
@@ -439,7 +436,6 @@ def GetRequestHandler(responses):
     return FakeHTTPRequestHandler
 
 
-@unittest.skipUnless(threading, "Threading required for this test.")
 class TestUrlopen(unittest.TestCase):
     """Tests urllib.request.urlopen using the network.
 

Lib/test/test_venv.py

@@ -15,15 +15,10 @@ import sys
 import tempfile
 from test.support import (captured_stdout, captured_stderr,
                           can_symlink, EnvironmentVarGuard, rmtree)
+import threading
 import unittest
 import venv
 
-
-try:
-    import threading
-except ImportError:
-    threading = None
-
 try:
     import ctypes
 except ImportError:
@@ -420,8 +415,6 @@ class EnsurePipTest(BaseTest):
         if not system_site_packages:
             self.assert_pip_not_installed()
 
-    @unittest.skipUnless(threading, 'some dependencies of pip import threading'
-                                    ' module unconditionally')
     # Issue #26610: pip/pep425tags.py requires ctypes
     @unittest.skipUnless(ctypes, 'pip requires ctypes')
     def test_with_pip(self):

Lib/test/test_weakref.py

@@ -6,6 +6,7 @@ import weakref
 import operator
 import contextlib
 import copy
+import threading
 import time
 
 from test import support
@@ -78,7 +79,6 @@ def collect_in_thread(period=0.0001):
     """
     Ensure GC collections happen in a different thread, at a high frequency.
     """
-    threading = support.import_module('threading')
     please_stop = False
 
     def collect():

Lib/test/test_xmlrpc.py

@@ -10,6 +10,7 @@ import xmlrpc.server
 import http.client
 import http, http.server
 import socket
+import threading
 import re
 import io
 import contextlib
@@ -19,10 +20,6 @@ try:
     import gzip
 except ImportError:
     gzip = None
-try:
-    import threading
-except ImportError:
-    threading = None
 
 alist = [{'astring': 'foo@bar.baz.spam',
           'afloat': 7283.43,
@@ -307,7 +304,6 @@ class XMLRPCTestCase(unittest.TestCase):
         except OSError:
             self.assertTrue(has_ssl)
 
-    @unittest.skipUnless(threading, "Threading required for this test.")
     def test_keepalive_disconnect(self):
         class RequestHandler(http.server.BaseHTTPRequestHandler):
             protocol_version = "HTTP/1.1"
@@ -747,7 +743,6 @@ def make_request_and_skipIf(condition, reason):
         return make_request_and_skip
     return decorator
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class BaseServerTestCase(unittest.TestCase):
     requestHandler = None
     request_count = 1
@@ -1206,7 +1201,6 @@ class FailingMessageClass(http.client.HTTPMessage):
         return super().get(key, failobj)
 
 
-@unittest.skipUnless(threading, 'Threading required for this test.')
 class FailingServerTestCase(unittest.TestCase):
     def setUp(self):
         self.evt = threading.Event()

Lib/threading.py

@@ -990,38 +990,12 @@ class Thread:
 
     def _delete(self):
         "Remove current thread from the dict of currently running threads."
-
+        with _active_limbo_lock:
-        # Notes about running with _dummy_thread:
+            del _active[get_ident()]
-        #
+            # There must not be any python code between the previous line
-        # Must take care to not raise an exception if _dummy_thread is being
+            # and after the lock is released.  Otherwise a tracing function
-        # used (and thus this module is being used as an instance of
+            # could try to acquire the lock again in the same thread, (in
-        # dummy_threading).  _dummy_thread.get_ident() always returns 1 since
+            # current_thread()), and would block.
-        # there is only one thread if _dummy_thread is being used.  Thus
-        # len(_active) is always <= 1 here, and any Thread instance created
-        # overwrites the (if any) thread currently registered in _active.
-        #
-        # An instance of _MainThread is always created by 'threading'.  This
-        # gets overwritten the instant an instance of Thread is created; both
-        # threads return 1 from _dummy_thread.get_ident() and thus have the
-        # same key in the dict.  So when the _MainThread instance created by
-        # 'threading' tries to clean itself up when atexit calls this method
-        # it gets a KeyError if another Thread instance was created.
-        #
-        # This all means that KeyError from trying to delete something from
-        # _active if dummy_threading is being used is a red herring.  But
-        # since it isn't if dummy_threading is *not* being used then don't
-        # hide the exception.
-
-        try:
-            with _active_limbo_lock:
-                del _active[get_ident()]
-                # There must not be any python code between the previous line
-                # and after the lock is released.  Otherwise a tracing function
-                # could try to acquire the lock again in the same thread, (in
-                # current_thread()), and would block.
-        except KeyError:
-            if 'dummy_threading' not in _sys.modules:
-                raise
 
     def join(self, timeout=None):
         """Wait until the thread terminates.

Lib/trace.py

@@ -61,21 +61,15 @@ import dis
 import pickle
 from time import monotonic as _time
 
-try:
+import threading
-    import threading
-except ImportError:
-    _settrace = sys.settrace
 
-    def _unsettrace():
+def _settrace(func):
-        sys.settrace(None)
+    threading.settrace(func)
-else:
+    sys.settrace(func)
-    def _settrace(func):
-        threading.settrace(func)
-        sys.settrace(func)
 
-    def _unsettrace():
+def _unsettrace():
-        sys.settrace(None)
+    sys.settrace(None)
-        threading.settrace(None)
+    threading.settrace(None)
 
 PRAGMA_NOCOVER = "#pragma NO COVER"
 

Lib/zipfile.py

@@ -12,11 +12,7 @@ import stat
 import shutil
 import struct
 import binascii
-
+import threading
-try:
-    import threading
-except ImportError:
-    import dummy_threading as threading
 
 try:
     import zlib # We may need its compression method

Makefile.pre.in

@@ -220,7 +220,6 @@ LIBC=		@LIBC@
 SYSLIBS=	$(LIBM) $(LIBC)
 SHLIBS=		@SHLIBS@
 
-THREADOBJ=	@THREADOBJ@
 DLINCLDIR=	@DLINCLDIR@
 DYNLOADFILE=	@DYNLOADFILE@
 MACHDEP_OBJS=	@MACHDEP_OBJS@
@@ -354,6 +353,7 @@ PYTHON_OBJS=	\
 		Python/structmember.o \
 		Python/symtable.o \
 		Python/sysmodule.o \
+		Python/thread.o \
 		Python/traceback.o \
 		Python/getopt.o \
 		Python/pystrcmp.o \
@@ -365,7 +365,6 @@ PYTHON_OBJS=	\
 		Python/$(DYNLOADFILE) \
 		$(LIBOBJS) \
 		$(MACHDEP_OBJS) \
-		$(THREADOBJ) \
 		$(DTRACE_OBJS)
 
 
@@ -655,12 +654,10 @@ oldsharedmods: $(SHAREDMODS)
 Makefile Modules/config.c: Makefile.pre \
 				$(srcdir)/Modules/config.c.in \
 				$(MAKESETUP) \
-				Modules/Setup.config \
 				Modules/Setup \
 				Modules/Setup.local
 	$(SHELL) $(MAKESETUP) -c $(srcdir)/Modules/config.c.in \
 				-s Modules \
-				Modules/Setup.config \
 				Modules/Setup.local \
 				Modules/Setup
 	@mv config.c Modules
@@ -1421,7 +1418,6 @@ libainstall:	@DEF_MAKE_RULE@ python-config
 	$(INSTALL_DATA) Makefile $(DESTDIR)$(LIBPL)/Makefile
 	$(INSTALL_DATA) Modules/Setup $(DESTDIR)$(LIBPL)/Setup
 	$(INSTALL_DATA) Modules/Setup.local $(DESTDIR)$(LIBPL)/Setup.local
-	$(INSTALL_DATA) Modules/Setup.config $(DESTDIR)$(LIBPL)/Setup.config
 	$(INSTALL_DATA) Misc/python.pc $(DESTDIR)$(LIBPC)/python-$(VERSION).pc
 	$(INSTALL_SCRIPT) $(srcdir)/Modules/makesetup $(DESTDIR)$(LIBPL)/makesetup
 	$(INSTALL_SCRIPT) $(srcdir)/install-sh $(DESTDIR)$(LIBPL)/install-sh
@@ -1642,7 +1638,7 @@ distclean: clobber
 	    if test "$$file" != "$(srcdir)/Lib/test/data/README"; then rm "$$file"; fi; \
 	done
 	-rm -f core Makefile Makefile.pre config.status \
-		Modules/Setup Modules/Setup.local Modules/Setup.config \
+		Modules/Setup Modules/Setup.local \
 		Modules/ld_so_aix Modules/python.exp Misc/python.pc \
 		Misc/python-config.sh
 	-rm -f python*-gdb.py

Misc/NEWS.d/next/Build/2017-09-06-23-14-08.bpo-31370.-j4kN4.rst

@@ -0,0 +1,5 @@
+Remove support for building --without-threads.
+
+This option is not really useful anymore in the 21st century. Removing lots
+of conditional paths allows us to simplify the code base, including in
+difficult to maintain low-level internal code.

Modules/Setup.config.in

@@ -1,10 +0,0 @@
-# This file is transmogrified into Setup.config by config.status.
-
-# The purpose of this file is to conditionally enable certain modules
-# based on configure-time options.
-
-# Threading
-@USE_THREAD_MODULE@_thread _threadmodule.c
-
-# The rest of the modules previously listed in this file are built
-# by the setup.py script in Python 2.1 and later.

Modules/Setup.dist

@@ -123,6 +123,7 @@ atexit atexitmodule.c      # Register functions to be run at interpreter-shutdow
 _signal signalmodule.c
 _stat _stat.c			# stat.h interface
 time timemodule.c	# -lm # time operations and variables
+_thread _threadmodule.c         # low-level threading interface
 
 # access to ISO C locale support
 _locale _localemodule.c  # -lintl
@@ -216,8 +217,6 @@ _symtable symtablemodule.c
 
 # The crypt module is now disabled by default because it breaks builds
 # on many systems (where -lcrypt is needed), e.g. Linux (I believe).
-#
-# First, look at Setup.config; configure may have set this for you.
 
 #_crypt _cryptmodule.c # -lcrypt	# crypt(3); needs -lcrypt on some systems
 
@@ -308,8 +307,6 @@ _symtable symtablemodule.c
 # Curses support, requiring the System V version of curses, often
 # provided by the ncurses library.  e.g. on Linux, link with -lncurses
 # instead of -lcurses).
-#
-# First, look at Setup.config; configure may have set this for you.
 
 #_curses _cursesmodule.c -lcurses -ltermcap
 # Wrapper for the panel library that's part of ncurses and SYSV curses.
@@ -323,18 +320,9 @@ _symtable symtablemodule.c
 # implementation independent wrapper for these; dbm/dumb.py provides
 # similar functionality (but slower of course) implemented in Python.
 
-# The standard Unix dbm module has been moved to Setup.config so that
-# it will be compiled as a shared library by default.  Compiling it as
-# a built-in module causes conflicts with the pybsddb3 module since it
-# creates a static dependency on an out-of-date version of db.so.
-#
-# First, look at Setup.config; configure may have set this for you.
-
 #_dbm _dbmmodule.c 	# dbm(3) may require -lndbm or similar
 
 # Anthony Baxter's gdbm module.  GNU dbm(3) will require -lgdbm:
-#
-# First, look at Setup.config; configure may have set this for you.
 
 #_gdbm _gdbmmodule.c -I/usr/local/include -L/usr/local/lib -lgdbm
 

Modules/_blake2/blake2b_impl.c

@@ -15,9 +15,7 @@
 
 #include "Python.h"
 #include "pystrhex.h"
-#ifdef WITH_THREAD
 #include "pythread.h"
-#endif
 
 #include "../hashlib.h"
 #include "blake2ns.h"
@@ -41,9 +39,7 @@ typedef struct {
     PyObject_HEAD
     blake2b_param    param;
     blake2b_state    state;
-#ifdef WITH_THREAD
     PyThread_type_lock lock;
-#endif
 } BLAKE2bObject;
 
 #include "clinic/blake2b_impl.c.h"
@@ -60,11 +56,9 @@ new_BLAKE2bObject(PyTypeObject *type)
 {
     BLAKE2bObject *self;
     self = (BLAKE2bObject *)type->tp_alloc(type, 0);
-#ifdef WITH_THREAD
     if (self != NULL) {
         self->lock = NULL;
     }
-#endif
     return self;
 }
 
@@ -292,7 +286,6 @@ _blake2b_blake2b_update(BLAKE2bObject *self, PyObject *obj)
 
     GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);
 
-#ifdef WITH_THREAD
     if (self->lock == NULL && buf.len >= HASHLIB_GIL_MINSIZE)
         self->lock = PyThread_allocate_lock();
 
@@ -305,9 +298,6 @@ _blake2b_blake2b_update(BLAKE2bObject *self, PyObject *obj)
     } else {
         blake2b_update(&self->state, buf.buf, buf.len);
     }
-#else
-    blake2b_update(&self->state, buf.buf, buf.len);
-#endif /* !WITH_THREAD */
     PyBuffer_Release(&buf);
 
     Py_RETURN_NONE;
@@ -407,12 +397,10 @@ py_blake2b_dealloc(PyObject *self)
     /* Try not to leave state in memory. */
     secure_zero_memory(&obj->param, sizeof(obj->param));
     secure_zero_memory(&obj->state, sizeof(obj->state));
-#ifdef WITH_THREAD
     if (obj->lock) {
         PyThread_free_lock(obj->lock);
         obj->lock = NULL;
     }
-#endif
     PyObject_Del(self);
 }
 

Modules/_blake2/blake2s_impl.c

@@ -15,9 +15,7 @@
 
 #include "Python.h"
 #include "pystrhex.h"
-#ifdef WITH_THREAD
 #include "pythread.h"
-#endif
 
 #include "../hashlib.h"
 #include "blake2ns.h"
@@ -41,9 +39,7 @@ typedef struct {
     PyObject_HEAD
     blake2s_param    param;
     blake2s_state    state;
-#ifdef WITH_THREAD
     PyThread_type_lock lock;
-#endif
 } BLAKE2sObject;
 
 #include "clinic/blake2s_impl.c.h"
@@ -60,11 +56,9 @@ new_BLAKE2sObject(PyTypeObject *type)
 {
     BLAKE2sObject *self;
     self = (BLAKE2sObject *)type->tp_alloc(type, 0);
-#ifdef WITH_THREAD
     if (self != NULL) {
         self->lock = NULL;
     }
-#endif
     return self;
 }
 
@@ -292,7 +286,6 @@ _blake2s_blake2s_update(BLAKE2sObject *self, PyObject *obj)
 
     GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);
 
-#ifdef WITH_THREAD
     if (self->lock == NULL && buf.len >= HASHLIB_GIL_MINSIZE)
         self->lock = PyThread_allocate_lock();
 
@@ -305,9 +298,6 @@ _blake2s_blake2s_update(BLAKE2sObject *self, PyObject *obj)
     } else {
         blake2s_update(&self->state, buf.buf, buf.len);
     }
-#else
-    blake2s_update(&self->state, buf.buf, buf.len);
-#endif /* !WITH_THREAD */
     PyBuffer_Release(&buf);
 
     Py_RETURN_NONE;
@@ -407,12 +397,10 @@ py_blake2s_dealloc(PyObject *self)
     /* Try not to leave state in memory. */
     secure_zero_memory(&obj->param, sizeof(obj->param));
     secure_zero_memory(&obj->state, sizeof(obj->state));
-#ifdef WITH_THREAD
     if (obj->lock) {
         PyThread_free_lock(obj->lock);
         obj->lock = NULL;
     }
-#endif
     PyObject_Del(self);
 }
 

Modules/_bz2module.c

@@ -5,9 +5,7 @@
 #include "Python.h"
 #include "structmember.h"
 
-#ifdef WITH_THREAD
 #include "pythread.h"
-#endif
 
 #include <bzlib.h>
 #include <stdio.h>
@@ -23,7 +21,6 @@
 #endif  /* ! BZ_CONFIG_ERROR */
 
 
-#ifdef WITH_THREAD
 #define ACQUIRE_LOCK(obj) do { \
     if (!PyThread_acquire_lock((obj)->lock, 0)) { \
         Py_BEGIN_ALLOW_THREADS \
@@ -31,19 +28,13 @@
         Py_END_ALLOW_THREADS \
     } } while (0)
 #define RELEASE_LOCK(obj) PyThread_release_lock((obj)->lock)
-#else
-#define ACQUIRE_LOCK(obj)
-#define RELEASE_LOCK(obj)
-#endif
 
 
 typedef struct {
     PyObject_HEAD
     bz_stream bzs;
     int flushed;
-#ifdef WITH_THREAD
     PyThread_type_lock lock;
-#endif
 } BZ2Compressor;
 
 typedef struct {
@@ -59,9 +50,7 @@ typedef struct {
        separately. Conversion and looping is encapsulated in
        decompress_buf() */
     size_t bzs_avail_in_real;
-#ifdef WITH_THREAD
     PyThread_type_lock lock;
-#endif
 } BZ2Decompressor;
 
 static PyTypeObject BZ2Compressor_Type;
@@ -325,13 +314,11 @@ _bz2_BZ2Compressor___init___impl(BZ2Compressor *self, int compresslevel)
         return -1;
     }
 
-#ifdef WITH_THREAD
     self->lock = PyThread_allocate_lock();
     if (self->lock == NULL) {
         PyErr_SetString(PyExc_MemoryError, "Unable to allocate lock");
         return -1;
     }
-#endif
 
     self->bzs.opaque = NULL;
     self->bzs.bzalloc = BZ2_Malloc;
@@ -343,10 +330,8 @@ _bz2_BZ2Compressor___init___impl(BZ2Compressor *self, int compresslevel)
     return 0;
 
 error:
-#ifdef WITH_THREAD
     PyThread_free_lock(self->lock);
     self->lock = NULL;
-#endif
     return -1;
 }
 
@@ -354,10 +339,8 @@ static void
 BZ2Compressor_dealloc(BZ2Compressor *self)
 {
     BZ2_bzCompressEnd(&self->bzs);
-#ifdef WITH_THREAD
     if (self->lock != NULL)
         PyThread_free_lock(self->lock);
-#endif
     Py_TYPE(self)->tp_free((PyObject *)self);
 }
 
@@ -651,13 +634,11 @@ _bz2_BZ2Decompressor___init___impl(BZ2Decompressor *self)
 {
     int bzerror;
 
-#ifdef WITH_THREAD
     self->lock = PyThread_allocate_lock();
     if (self->lock == NULL) {
         PyErr_SetString(PyExc_MemoryError, "Unable to allocate lock");
         return -1;
     }
-#endif
 
     self->needs_input = 1;
     self->bzs_avail_in_real = 0;
@@ -675,10 +656,8 @@ _bz2_BZ2Decompressor___init___impl(BZ2Decompressor *self)
 
 error:
     Py_CLEAR(self->unused_data);
-#ifdef WITH_THREAD
     PyThread_free_lock(self->lock);
     self->lock = NULL;
-#endif
     return -1;
 }
 
@@ -689,10 +668,8 @@ BZ2Decompressor_dealloc(BZ2Decompressor *self)
         PyMem_Free(self->input_buffer);
     BZ2_bzDecompressEnd(&self->bzs);
     Py_CLEAR(self->unused_data);
-#ifdef WITH_THREAD
     if (self->lock != NULL)
         PyThread_free_lock(self->lock);
-#endif
     Py_TYPE(self)->tp_free((PyObject *)self);
 }
 

Modules/_ctypes/_ctypes.c

@@ -5410,9 +5410,7 @@ PyInit__ctypes(void)
    ob_type is the metatype (the 'type'), defaults to PyType_Type,
    tp_base is the base type, defaults to 'object' aka PyBaseObject_Type.
 */
-#ifdef WITH_THREAD
     PyEval_InitThreads();
-#endif
     m = PyModule_Create(&_ctypesmodule);
     if (!m)
         return NULL;

Modules/_ctypes/callbacks.c

@@ -137,9 +137,7 @@ static void _CallPythonObject(void *mem,
     Py_ssize_t nArgs;
     PyObject *error_object = NULL;
     int *space;
-#ifdef WITH_THREAD
     PyGILState_STATE state = PyGILState_Ensure();
-#endif
 
     nArgs = PySequence_Length(converters);
     /* Hm. What to return in case of error?
@@ -281,9 +279,7 @@ if (x == NULL) _PyTraceback_Add(what, "_ctypes/callbacks.c", __LINE__ - 1), PyEr
     Py_XDECREF(result);
   Done:
     Py_XDECREF(arglist);
-#ifdef WITH_THREAD
     PyGILState_Release(state);
-#endif
 }
 
 static void closure_fcn(ffi_cif *cif,
@@ -347,7 +343,7 @@ CThunkObject *_ctypes_alloc_callback(PyObject *callable,
     assert(CThunk_CheckExact((PyObject *)p));
 
     p->pcl_write = ffi_closure_alloc(sizeof(ffi_closure),
-									 &p->pcl_exec);
+                                                                         &p->pcl_exec);
     if (p->pcl_write == NULL) {
         PyErr_NoMemory();
         goto error;
@@ -397,8 +393,8 @@ CThunkObject *_ctypes_alloc_callback(PyObject *callable,
     result = ffi_prep_closure(p->pcl_write, &p->cif, closure_fcn, p);
 #else
     result = ffi_prep_closure_loc(p->pcl_write, &p->cif, closure_fcn,
-				  p,
+                                  p,
-				  p->pcl_exec);
+                                  p->pcl_exec);
 #endif
     if (result != FFI_OK) {
         PyErr_Format(PyExc_RuntimeError,
@@ -422,9 +418,7 @@ CThunkObject *_ctypes_alloc_callback(PyObject *callable,
 static void LoadPython(void)
 {
     if (!Py_IsInitialized()) {
-#ifdef WITH_THREAD
         PyEval_InitThreads();
-#endif
         Py_Initialize();
     }
 }
@@ -495,18 +489,12 @@ STDAPI DllGetClassObject(REFCLSID rclsid,
                          LPVOID *ppv)
 {
     long result;
-#ifdef WITH_THREAD
     PyGILState_STATE state;
-#endif
 
     LoadPython();
-#ifdef WITH_THREAD
     state = PyGILState_Ensure();
-#endif
     result = Call_GetClassObject(rclsid, riid, ppv);
-#ifdef WITH_THREAD
     PyGILState_Release(state);
-#endif
     return result;
 }
 
@@ -558,13 +546,9 @@ long Call_CanUnloadNow(void)
 STDAPI DllCanUnloadNow(void)
 {
     long result;
-#ifdef WITH_THREAD
     PyGILState_STATE state = PyGILState_Ensure();
-#endif
     result = Call_CanUnloadNow();
-#ifdef WITH_THREAD
     PyGILState_Release(state);
-#endif
     return result;
 }
 

Modules/_ctypes/callproc.c

@@ -745,9 +745,7 @@ static int _call_function_pointer(int flags,
                                   void *resmem,
                                   int argcount)
 {
-#ifdef WITH_THREAD
     PyThreadState *_save = NULL; /* For Py_BLOCK_THREADS and Py_UNBLOCK_THREADS */
-#endif
     PyObject *error_object = NULL;
     int *space;
     ffi_cif cif;
@@ -786,10 +784,8 @@ static int _call_function_pointer(int flags,
         if (error_object == NULL)
             return -1;
     }
-#ifdef WITH_THREAD
     if ((flags & FUNCFLAG_PYTHONAPI) == 0)
         Py_UNBLOCK_THREADS
-#endif
     if (flags & FUNCFLAG_USE_ERRNO) {
         int temp = space[0];
         space[0] = errno;
@@ -826,10 +822,8 @@ static int _call_function_pointer(int flags,
         space[0] = errno;
         errno = temp;
     }
-#ifdef WITH_THREAD
     if ((flags & FUNCFLAG_PYTHONAPI) == 0)
         Py_BLOCK_THREADS
-#endif
     Py_XDECREF(error_object);
 #ifdef MS_WIN32
 #ifndef DONT_USE_SEH
@@ -982,9 +976,7 @@ GetComError(HRESULT errcode, GUID *riid, IUnknown *pIunk)
     /* We absolutely have to release the GIL during COM method calls,
        otherwise we may get a deadlock!
     */
-#ifdef WITH_THREAD
     Py_BEGIN_ALLOW_THREADS
-#endif
 
     hr = pIunk->lpVtbl->QueryInterface(pIunk, &IID_ISupportErrorInfo, (void **)&psei);
     if (FAILED(hr))
@@ -1008,9 +1000,7 @@ GetComError(HRESULT errcode, GUID *riid, IUnknown *pIunk)
     pei->lpVtbl->Release(pei);
 
   failed:
-#ifdef WITH_THREAD
     Py_END_ALLOW_THREADS
-#endif
 
     progid = NULL;
     ProgIDFromCLSID(&guid, &progid);

Modules/_hashopenssl.c

@@ -53,9 +53,7 @@ typedef struct {
     PyObject_HEAD
     PyObject            *name;  /* name of this hash algorithm */
     EVP_MD_CTX          *ctx;   /* OpenSSL message digest context */
-#ifdef WITH_THREAD
     PyThread_type_lock   lock;  /* OpenSSL context lock */
-#endif
 } EVPobject;
 
 
@@ -122,9 +120,7 @@ newEVPobject(PyObject *name)
     /* save the name for .name to return */
     Py_INCREF(name);
     retval->name = name;
-#ifdef WITH_THREAD
     retval->lock = NULL;
-#endif
 
     return retval;
 }
@@ -153,10 +149,8 @@ EVP_hash(EVPobject *self, const void *vp, Py_ssize_t len)
 static void
 EVP_dealloc(EVPobject *self)
 {
-#ifdef WITH_THREAD
     if (self->lock != NULL)
         PyThread_free_lock(self->lock);
-#endif
     EVP_MD_CTX_free(self->ctx);
     Py_XDECREF(self->name);
     PyObject_Del(self);
@@ -267,7 +261,6 @@ EVP_update(EVPobject *self, PyObject *args)
 
     GET_BUFFER_VIEW_OR_ERROUT(obj, &view);
 
-#ifdef WITH_THREAD
     if (self->lock == NULL && view.len >= HASHLIB_GIL_MINSIZE) {
         self->lock = PyThread_allocate_lock();
         /* fail? lock = NULL and we fail over to non-threaded code. */
@@ -282,9 +275,6 @@ EVP_update(EVPobject *self, PyObject *args)
     } else {
         EVP_hash(self, view.buf, view.len);
     }
-#else
-    EVP_hash(self, view.buf, view.len);
-#endif
 
     PyBuffer_Release(&view);
     Py_RETURN_NONE;

Modules/_io/bufferedio.c

@@ -230,10 +230,8 @@ typedef struct {
        isn't ready for writing. */
     Py_off_t write_end;
 
-#ifdef WITH_THREAD
     PyThread_type_lock lock;
     volatile unsigned long owner;
-#endif
 
     Py_ssize_t buffer_size;
     Py_ssize_t buffer_mask;
@@ -267,8 +265,6 @@ typedef struct {
 
 /* These macros protect the buffered object against concurrent operations. */
 
-#ifdef WITH_THREAD
-
 static int
 _enter_buffered_busy(buffered *self)
 {
@@ -315,11 +311,6 @@ _enter_buffered_busy(buffered *self)
         PyThread_release_lock(self->lock); \
     } while(0);
 
-#else
-#define ENTER_BUFFERED(self) 1
-#define LEAVE_BUFFERED(self)
-#endif
-
 #define CHECK_INITIALIZED(self) \
     if (self->ok <= 0) { \
         if (self->detached) { \
@@ -401,12 +392,10 @@ buffered_dealloc(buffered *self)
         PyMem_Free(self->buffer);
         self->buffer = NULL;
     }
-#ifdef WITH_THREAD
     if (self->lock) {
         PyThread_free_lock(self->lock);
         self->lock = NULL;
     }
-#endif
     Py_CLEAR(self->dict);
     Py_TYPE(self)->tp_free((PyObject *)self);
 }
@@ -753,7 +742,6 @@ _buffered_init(buffered *self)
         PyErr_NoMemory();
         return -1;
     }
-#ifdef WITH_THREAD
     if (self->lock)
         PyThread_free_lock(self->lock);
     self->lock = PyThread_allocate_lock();
@@ -762,7 +750,6 @@ _buffered_init(buffered *self)
         return -1;
     }
     self->owner = 0;
-#endif
     /* Find out whether buffer_size is a power of 2 */
     /* XXX is this optimization useful? */
     for (n = self->buffer_size - 1; n & 1; n >>= 1)

Modules/_lzmamodule.c

@@ -9,16 +9,13 @@
 
 #include "Python.h"
 #include "structmember.h"
-#ifdef WITH_THREAD
 #include "pythread.h"
-#endif
 
 #include <stdarg.h>
 #include <string.h>
 
 #include <lzma.h>
 
-#ifdef WITH_THREAD
 #define ACQUIRE_LOCK(obj) do { \
     if (!PyThread_acquire_lock((obj)->lock, 0)) { \
         Py_BEGIN_ALLOW_THREADS \
@@ -26,10 +23,6 @@
         Py_END_ALLOW_THREADS \
     } } while (0)
 #define RELEASE_LOCK(obj) PyThread_release_lock((obj)->lock)
-#else
-#define ACQUIRE_LOCK(obj)
-#define RELEASE_LOCK(obj)
-#endif
 
 
 /* Container formats: */
@@ -48,9 +41,7 @@ typedef struct {
     lzma_allocator alloc;
     lzma_stream lzs;
     int flushed;
-#ifdef WITH_THREAD
     PyThread_type_lock lock;
-#endif
 } Compressor;
 
 typedef struct {
@@ -63,9 +54,7 @@ typedef struct {
     char needs_input;
     uint8_t *input_buffer;
     size_t input_buffer_size;
-#ifdef WITH_THREAD
     PyThread_type_lock lock;
-#endif
 } Decompressor;
 
 /* LZMAError class object. */
@@ -757,13 +746,11 @@ Compressor_init(Compressor *self, PyObject *args, PyObject *kwargs)
     self->alloc.free = PyLzma_Free;
     self->lzs.allocator = &self->alloc;
 
-#ifdef WITH_THREAD
     self->lock = PyThread_allocate_lock();
     if (self->lock == NULL) {
         PyErr_SetString(PyExc_MemoryError, "Unable to allocate lock");
         return -1;
     }
-#endif
 
     self->flushed = 0;
     switch (format) {
@@ -790,10 +777,8 @@ Compressor_init(Compressor *self, PyObject *args, PyObject *kwargs)
             break;
     }
 
-#ifdef WITH_THREAD
     PyThread_free_lock(self->lock);
     self->lock = NULL;
-#endif
     return -1;
 }
 
@@ -801,10 +786,8 @@ static void
 Compressor_dealloc(Compressor *self)
 {
     lzma_end(&self->lzs);
-#ifdef WITH_THREAD
     if (self->lock != NULL)
         PyThread_free_lock(self->lock);
-#endif
     Py_TYPE(self)->tp_free((PyObject *)self);
 }
 
@@ -1180,13 +1163,11 @@ _lzma_LZMADecompressor___init___impl(Decompressor *self, int format,
     self->lzs.allocator = &self->alloc;
     self->lzs.next_in = NULL;
 
-#ifdef WITH_THREAD
     self->lock = PyThread_allocate_lock();
     if (self->lock == NULL) {
         PyErr_SetString(PyExc_MemoryError, "Unable to allocate lock");
         return -1;
     }
-#endif
 
     self->check = LZMA_CHECK_UNKNOWN;
     self->needs_input = 1;
@@ -1230,10 +1211,8 @@ _lzma_LZMADecompressor___init___impl(Decompressor *self, int format,
 
 error:
     Py_CLEAR(self->unused_data);
-#ifdef WITH_THREAD
     PyThread_free_lock(self->lock);
     self->lock = NULL;
-#endif
     return -1;
 }
 
@@ -1245,10 +1224,8 @@ Decompressor_dealloc(Decompressor *self)
 
     lzma_end(&self->lzs);
     Py_CLEAR(self->unused_data);
-#ifdef WITH_THREAD
     if (self->lock != NULL)
         PyThread_free_lock(self->lock);
-#endif
     Py_TYPE(self)->tp_free((PyObject *)self);
 }