Patchwork D12248: thirdparty: delete concurrent.futures

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Submitter phabricator
Date March 2, 2022, 12:44 a.m.
Message ID <differential-rev-PHID-DREV-lz2gf7uddfzpr4ucxsxf-req@mercurial-scm.org>
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Permalink /patch/50590/
State New
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phabricator - March 2, 2022, 12:44 a.m.
indygreg created this revision.
Herald added a reviewer: hg-reviewers.
Herald added a subscriber: mercurial-patches.

REVISION SUMMARY
  Now that we require Python 3 we no longer need this library as the
  functionality provided by the standard library is sufficient.

REPOSITORY
  rHG Mercurial

BRANCH
  default

REVISION DETAIL
  https://phab.mercurial-scm.org/D12248

AFFECTED FILES
  mercurial/thirdparty/concurrent/LICENSE
  mercurial/thirdparty/concurrent/__init__.py
  mercurial/thirdparty/concurrent/futures/__init__.py
  mercurial/thirdparty/concurrent/futures/_base.py
  mercurial/thirdparty/concurrent/futures/process.py
  mercurial/thirdparty/concurrent/futures/thread.py
  setup.py

CHANGE DETAILS




To: indygreg, #hg-reviewers
Cc: mercurial-patches, mercurial-devel

Patch

diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -1336,13 +1336,6 @@ 
     ):
         packages.append('mercurial.templates.%s' % name)
 
-if sys.version_info[0] == 2:
-    packages.extend(
-        [
-            'mercurial.thirdparty.concurrent',
-            'mercurial.thirdparty.concurrent.futures',
-        ]
-    )
 
 if 'HG_PY2EXE_EXTRA_INSTALL_PACKAGES' in os.environ:
     # py2exe can't cope with namespace packages very well, so we have to
diff --git a/mercurial/thirdparty/concurrent/futures/thread.py b/mercurial/thirdparty/concurrent/futures/thread.py
deleted file mode 100644
--- a/mercurial/thirdparty/concurrent/futures/thread.py
+++ /dev/null
@@ -1,162 +0,0 @@ 
-# Copyright 2009 Brian Quinlan. All Rights Reserved.
-# Licensed to PSF under a Contributor Agreement.
-
-"""Implements ThreadPoolExecutor."""
-
-from __future__ import absolute_import
-
-import atexit
-from . import _base
-import itertools
-import Queue as queue
-import threading
-import weakref
-import sys
-
-try:
-    from multiprocessing import cpu_count
-except ImportError:
-    # some platforms don't have multiprocessing
-    def cpu_count():
-        return None
-
-__author__ = 'Brian Quinlan (brian@sweetapp.com)'
-
-# Workers are created as daemon threads. This is done to allow the interpreter
-# to exit when there are still idle threads in a ThreadPoolExecutor's thread
-# pool (i.e. shutdown() was not called). However, allowing workers to die with
-# the interpreter has two undesirable properties:
-#   - The workers would still be running during interpretor shutdown,
-#     meaning that they would fail in unpredictable ways.
-#   - The workers could be killed while evaluating a work item, which could
-#     be bad if the callable being evaluated has external side-effects e.g.
-#     writing to a file.
-#
-# To work around this problem, an exit handler is installed which tells the
-# workers to exit when their work queues are empty and then waits until the
-# threads finish.
-
-_threads_queues = weakref.WeakKeyDictionary()
-_shutdown = False
-
-def _python_exit():
-    global _shutdown
-    _shutdown = True
-    items = list(_threads_queues.items()) if _threads_queues else ()
-    for t, q in items:
-        q.put(None)
-    for t, q in items:
-        t.join(sys.maxint)
-
-atexit.register(_python_exit)
-
-class _WorkItem(object):
-    def __init__(self, future, fn, args, kwargs):
-        self.future = future
-        self.fn = fn
-        self.args = args
-        self.kwargs = kwargs
-
-    def run(self):
-        if not self.future.set_running_or_notify_cancel():
-            return
-
-        try:
-            result = self.fn(*self.args, **self.kwargs)
-        except:
-            e, tb = sys.exc_info()[1:]
-            self.future.set_exception_info(e, tb)
-        else:
-            self.future.set_result(result)
-
-def _worker(executor_reference, work_queue):
-    try:
-        while True:
-            work_item = work_queue.get(block=True)
-            if work_item is not None:
-                work_item.run()
-                # Delete references to object. See issue16284
-                del work_item
-                continue
-            executor = executor_reference()
-            # Exit if:
-            #   - The interpreter is shutting down OR
-            #   - The executor that owns the worker has been collected OR
-            #   - The executor that owns the worker has been shutdown.
-            if _shutdown or executor is None or executor._shutdown:
-                # Notice other workers
-                work_queue.put(None)
-                return
-            del executor
-    except:
-        _base.LOGGER.critical('Exception in worker', exc_info=True)
-
-
-class ThreadPoolExecutor(_base.Executor):
-
-    # Used to assign unique thread names when thread_name_prefix is not supplied.
-    _counter = itertools.count().next
-
-    def __init__(self, max_workers=None, thread_name_prefix=''):
-        """Initializes a new ThreadPoolExecutor instance.
-
-        Args:
-            max_workers: The maximum number of threads that can be used to
-                execute the given calls.
-            thread_name_prefix: An optional name prefix to give our threads.
-        """
-        if max_workers is None:
-            # Use this number because ThreadPoolExecutor is often
-            # used to overlap I/O instead of CPU work.
-            max_workers = (cpu_count() or 1) * 5
-        if max_workers <= 0:
-            raise ValueError("max_workers must be greater than 0")
-
-        self._max_workers = max_workers
-        self._work_queue = queue.Queue()
-        self._threads = set()
-        self._shutdown = False
-        self._shutdown_lock = threading.Lock()
-        self._thread_name_prefix = (thread_name_prefix or
-                                    ("ThreadPoolExecutor-%d" % self._counter()))
-
-    def submit(self, fn, *args, **kwargs):
-        with self._shutdown_lock:
-            if self._shutdown:
-                raise RuntimeError('cannot schedule new futures after shutdown')
-
-            f = _base.Future()
-            w = _WorkItem(f, fn, args, kwargs)
-
-            self._work_queue.put(w)
-            self._adjust_thread_count()
-            return f
-    submit.__doc__ = _base.Executor.submit.__doc__
-
-    def _adjust_thread_count(self):
-        # When the executor gets lost, the weakref callback will wake up
-        # the worker threads.
-        def weakref_cb(_, q=self._work_queue):
-            q.put(None)
-        # TODO(bquinlan): Should avoid creating new threads if there are more
-        # idle threads than items in the work queue.
-        num_threads = len(self._threads)
-        if num_threads < self._max_workers:
-            thread_name = '%s_%d' % (self._thread_name_prefix or self,
-                                     num_threads)
-            t = threading.Thread(name=thread_name, target=_worker,
-                                 args=(weakref.ref(self, weakref_cb),
-                                       self._work_queue))
-            t.daemon = True
-            t.start()
-            self._threads.add(t)
-            _threads_queues[t] = self._work_queue
-
-    def shutdown(self, wait=True):
-        with self._shutdown_lock:
-            self._shutdown = True
-            self._work_queue.put(None)
-        if wait:
-            for t in self._threads:
-                t.join(sys.maxint)
-    shutdown.__doc__ = _base.Executor.shutdown.__doc__
diff --git a/mercurial/thirdparty/concurrent/futures/process.py b/mercurial/thirdparty/concurrent/futures/process.py
deleted file mode 100644
--- a/mercurial/thirdparty/concurrent/futures/process.py
+++ /dev/null
@@ -1,365 +0,0 @@ 
-# Copyright 2009 Brian Quinlan. All Rights Reserved.
-# Licensed to PSF under a Contributor Agreement.
-
-"""Implements ProcessPoolExecutor.
-
-The follow diagram and text describe the data-flow through the system:
-
-|======================= In-process =====================|== Out-of-process ==|
-
-+----------+     +----------+       +--------+     +-----------+    +---------+
-|          |  => | Work Ids |    => |        |  => | Call Q    | => |         |
-|          |     +----------+       |        |     +-----------+    |         |
-|          |     | ...      |       |        |     | ...       |    |         |
-|          |     | 6        |       |        |     | 5, call() |    |         |
-|          |     | 7        |       |        |     | ...       |    |         |
-| Process  |     | ...      |       | Local  |     +-----------+    | Process |
-|  Pool    |     +----------+       | Worker |                      |  #1..n  |
-| Executor |                        | Thread |                      |         |
-|          |     +----------- +     |        |     +-----------+    |         |
-|          | <=> | Work Items | <=> |        | <=  | Result Q  | <= |         |
-|          |     +------------+     |        |     +-----------+    |         |
-|          |     | 6: call()  |     |        |     | ...       |    |         |
-|          |     |    future  |     |        |     | 4, result |    |         |
-|          |     | ...        |     |        |     | 3, except |    |         |
-+----------+     +------------+     +--------+     +-----------+    +---------+
-
-Executor.submit() called:
-- creates a uniquely numbered _WorkItem and adds it to the "Work Items" dict
-- adds the id of the _WorkItem to the "Work Ids" queue
-
-Local worker thread:
-- reads work ids from the "Work Ids" queue and looks up the corresponding
-  WorkItem from the "Work Items" dict: if the work item has been cancelled then
-  it is simply removed from the dict, otherwise it is repackaged as a
-  _CallItem and put in the "Call Q". New _CallItems are put in the "Call Q"
-  until "Call Q" is full. NOTE: the size of the "Call Q" is kept small because
-  calls placed in the "Call Q" can no longer be cancelled with Future.cancel().
-- reads _ResultItems from "Result Q", updates the future stored in the
-  "Work Items" dict and deletes the dict entry
-
-Process #1..n:
-- reads _CallItems from "Call Q", executes the calls, and puts the resulting
-  _ResultItems in "Request Q"
-"""
-
-from __future__ import absolute_import
-
-import atexit
-from . import _base
-import Queue as queue
-import multiprocessing
-import threading
-import weakref
-import sys
-
-__author__ = 'Brian Quinlan (brian@sweetapp.com)'
-
-# Workers are created as daemon threads and processes. This is done to allow the
-# interpreter to exit when there are still idle processes in a
-# ProcessPoolExecutor's process pool (i.e. shutdown() was not called). However,
-# allowing workers to die with the interpreter has two undesirable properties:
-#   - The workers would still be running during interpretor shutdown,
-#     meaning that they would fail in unpredictable ways.
-#   - The workers could be killed while evaluating a work item, which could
-#     be bad if the callable being evaluated has external side-effects e.g.
-#     writing to a file.
-#
-# To work around this problem, an exit handler is installed which tells the
-# workers to exit when their work queues are empty and then waits until the
-# threads/processes finish.
-
-_threads_queues = weakref.WeakKeyDictionary()
-_shutdown = False
-
-def _python_exit():
-    global _shutdown
-    _shutdown = True
-    items = list(_threads_queues.items()) if _threads_queues else ()
-    for t, q in items:
-        q.put(None)
-    for t, q in items:
-        t.join(sys.maxint)
-
-# Controls how many more calls than processes will be queued in the call queue.
-# A smaller number will mean that processes spend more time idle waiting for
-# work while a larger number will make Future.cancel() succeed less frequently
-# (Futures in the call queue cannot be cancelled).
-EXTRA_QUEUED_CALLS = 1
-
-class _WorkItem(object):
-    def __init__(self, future, fn, args, kwargs):
-        self.future = future
-        self.fn = fn
-        self.args = args
-        self.kwargs = kwargs
-
-class _ResultItem(object):
-    def __init__(self, work_id, exception=None, result=None):
-        self.work_id = work_id
-        self.exception = exception
-        self.result = result
-
-class _CallItem(object):
-    def __init__(self, work_id, fn, args, kwargs):
-        self.work_id = work_id
-        self.fn = fn
-        self.args = args
-        self.kwargs = kwargs
-
-def _process_worker(call_queue, result_queue):
-    """Evaluates calls from call_queue and places the results in result_queue.
-
-    This worker is run in a separate process.
-
-    Args:
-        call_queue: A multiprocessing.Queue of _CallItems that will be read and
-            evaluated by the worker.
-        result_queue: A multiprocessing.Queue of _ResultItems that will written
-            to by the worker.
-        shutdown: A multiprocessing.Event that will be set as a signal to the
-            worker that it should exit when call_queue is empty.
-    """
-    while True:
-        call_item = call_queue.get(block=True)
-        if call_item is None:
-            # Wake up queue management thread
-            result_queue.put(None)
-            return
-        try:
-            r = call_item.fn(*call_item.args, **call_item.kwargs)
-        except:
-            e = sys.exc_info()[1]
-            result_queue.put(_ResultItem(call_item.work_id,
-                                         exception=e))
-        else:
-            result_queue.put(_ResultItem(call_item.work_id,
-                                         result=r))
-
-def _add_call_item_to_queue(pending_work_items,
-                            work_ids,
-                            call_queue):
-    """Fills call_queue with _WorkItems from pending_work_items.
-
-    This function never blocks.
-
-    Args:
-        pending_work_items: A dict mapping work ids to _WorkItems e.g.
-            {5: <_WorkItem...>, 6: <_WorkItem...>, ...}
-        work_ids: A queue.Queue of work ids e.g. Queue([5, 6, ...]). Work ids
-            are consumed and the corresponding _WorkItems from
-            pending_work_items are transformed into _CallItems and put in
-            call_queue.
-        call_queue: A multiprocessing.Queue that will be filled with _CallItems
-            derived from _WorkItems.
-    """
-    while True:
-        if call_queue.full():
-            return
-        try:
-            work_id = work_ids.get(block=False)
-        except queue.Empty:
-            return
-        else:
-            work_item = pending_work_items[work_id]
-
-            if work_item.future.set_running_or_notify_cancel():
-                call_queue.put(_CallItem(work_id,
-                                         work_item.fn,
-                                         work_item.args,
-                                         work_item.kwargs),
-                               block=True)
-            else:
-                del pending_work_items[work_id]
-                continue
-
-def _queue_management_worker(executor_reference,
-                             processes,
-                             pending_work_items,
-                             work_ids_queue,
-                             call_queue,
-                             result_queue):
-    """Manages the communication between this process and the worker processes.
-
-    This function is run in a local thread.
-
-    Args:
-        executor_reference: A weakref.ref to the ProcessPoolExecutor that owns
-            this thread. Used to determine if the ProcessPoolExecutor has been
-            garbage collected and that this function can exit.
-        process: A list of the multiprocessing.Process instances used as
-            workers.
-        pending_work_items: A dict mapping work ids to _WorkItems e.g.
-            {5: <_WorkItem...>, 6: <_WorkItem...>, ...}
-        work_ids_queue: A queue.Queue of work ids e.g. Queue([5, 6, ...]).
-        call_queue: A multiprocessing.Queue that will be filled with _CallItems
-            derived from _WorkItems for processing by the process workers.
-        result_queue: A multiprocessing.Queue of _ResultItems generated by the
-            process workers.
-    """
-    nb_shutdown_processes = [0]
-    def shutdown_one_process():
-        """Tell a worker to terminate, which will in turn wake us again"""
-        call_queue.put(None)
-        nb_shutdown_processes[0] += 1
-    while True:
-        _add_call_item_to_queue(pending_work_items,
-                                work_ids_queue,
-                                call_queue)
-
-        result_item = result_queue.get(block=True)
-        if result_item is not None:
-            work_item = pending_work_items[result_item.work_id]
-            del pending_work_items[result_item.work_id]
-
-            if result_item.exception:
-                work_item.future.set_exception(result_item.exception)
-            else:
-                work_item.future.set_result(result_item.result)
-            # Delete references to object. See issue16284
-            del work_item
-        # Check whether we should start shutting down.
-        executor = executor_reference()
-        # No more work items can be added if:
-        #   - The interpreter is shutting down OR
-        #   - The executor that owns this worker has been collected OR
-        #   - The executor that owns this worker has been shutdown.
-        if _shutdown or executor is None or executor._shutdown_thread:
-            # Since no new work items can be added, it is safe to shutdown
-            # this thread if there are no pending work items.
-            if not pending_work_items:
-                while nb_shutdown_processes[0] < len(processes):
-                    shutdown_one_process()
-                # If .join() is not called on the created processes then
-                # some multiprocessing.Queue methods may deadlock on Mac OS
-                # X.
-                for p in processes:
-                    p.join()
-                call_queue.close()
-                return
-        del executor
-
-_system_limits_checked = False
-_system_limited = None
-def _check_system_limits():
-    global _system_limits_checked, _system_limited
-    if _system_limits_checked:
-        if _system_limited:
-            raise NotImplementedError(_system_limited)
-    _system_limits_checked = True
-    try:
-        import os
-        nsems_max = os.sysconf("SC_SEM_NSEMS_MAX")
-    except (AttributeError, ValueError):
-        # sysconf not available or setting not available
-        return
-    if nsems_max == -1:
-        # indetermine limit, assume that limit is determined
-        # by available memory only
-        return
-    if nsems_max >= 256:
-        # minimum number of semaphores available
-        # according to POSIX
-        return
-    _system_limited = "system provides too few semaphores (%d available, 256 necessary)" % nsems_max
-    raise NotImplementedError(_system_limited)
-
-
-class ProcessPoolExecutor(_base.Executor):
-    def __init__(self, max_workers=None):
-        """Initializes a new ProcessPoolExecutor instance.
-
-        Args:
-            max_workers: The maximum number of processes that can be used to
-                execute the given calls. If None or not given then as many
-                worker processes will be created as the machine has processors.
-        """
-        _check_system_limits()
-
-        if max_workers is None:
-            self._max_workers = multiprocessing.cpu_count()
-        else:
-            if max_workers <= 0:
-                raise ValueError("max_workers must be greater than 0")
-
-            self._max_workers = max_workers
-
-        # Make the call queue slightly larger than the number of processes to
-        # prevent the worker processes from idling. But don't make it too big
-        # because futures in the call queue cannot be cancelled.
-        self._call_queue = multiprocessing.Queue(self._max_workers +
-                                                 EXTRA_QUEUED_CALLS)
-        self._result_queue = multiprocessing.Queue()
-        self._work_ids = queue.Queue()
-        self._queue_management_thread = None
-        self._processes = set()
-
-        # Shutdown is a two-step process.
-        self._shutdown_thread = False
-        self._shutdown_lock = threading.Lock()
-        self._queue_count = 0
-        self._pending_work_items = {}
-
-    def _start_queue_management_thread(self):
-        # When the executor gets lost, the weakref callback will wake up
-        # the queue management thread.
-        def weakref_cb(_, q=self._result_queue):
-            q.put(None)
-        if self._queue_management_thread is None:
-            self._queue_management_thread = threading.Thread(
-                    target=_queue_management_worker,
-                    args=(weakref.ref(self, weakref_cb),
-                          self._processes,
-                          self._pending_work_items,
-                          self._work_ids,
-                          self._call_queue,
-                          self._result_queue))
-            self._queue_management_thread.daemon = True
-            self._queue_management_thread.start()
-            _threads_queues[self._queue_management_thread] = self._result_queue
-
-    def _adjust_process_count(self):
-        for _ in range(len(self._processes), self._max_workers):
-            p = multiprocessing.Process(
-                    target=_process_worker,
-                    args=(self._call_queue,
-                          self._result_queue))
-            p.start()
-            self._processes.add(p)
-
-    def submit(self, fn, *args, **kwargs):
-        with self._shutdown_lock:
-            if self._shutdown_thread:
-                raise RuntimeError('cannot schedule new futures after shutdown')
-
-            f = _base.Future()
-            w = _WorkItem(f, fn, args, kwargs)
-
-            self._pending_work_items[self._queue_count] = w
-            self._work_ids.put(self._queue_count)
-            self._queue_count += 1
-            # Wake up queue management thread
-            self._result_queue.put(None)
-
-            self._start_queue_management_thread()
-            self._adjust_process_count()
-            return f
-    submit.__doc__ = _base.Executor.submit.__doc__
-
-    def shutdown(self, wait=True):
-        with self._shutdown_lock:
-            self._shutdown_thread = True
-        if self._queue_management_thread:
-            # Wake up queue management thread
-            self._result_queue.put(None)
-            if wait:
-                self._queue_management_thread.join(sys.maxint)
-        # To reduce the risk of openning too many files, remove references to
-        # objects that use file descriptors.
-        self._queue_management_thread = None
-        self._call_queue = None
-        self._result_queue = None
-        self._processes = None
-    shutdown.__doc__ = _base.Executor.shutdown.__doc__
-
-atexit.register(_python_exit)
diff --git a/mercurial/thirdparty/concurrent/futures/_base.py b/mercurial/thirdparty/concurrent/futures/_base.py
deleted file mode 100644
--- a/mercurial/thirdparty/concurrent/futures/_base.py
+++ /dev/null
@@ -1,669 +0,0 @@ 
-# Copyright 2009 Brian Quinlan. All Rights Reserved.
-# Licensed to PSF under a Contributor Agreement.
-
-from __future__ import absolute_import
-
-import collections
-import logging
-import threading
-import itertools
-import time
-import types
-
-__author__ = 'Brian Quinlan (brian@sweetapp.com)'
-
-FIRST_COMPLETED = 'FIRST_COMPLETED'
-FIRST_EXCEPTION = 'FIRST_EXCEPTION'
-ALL_COMPLETED = 'ALL_COMPLETED'
-_AS_COMPLETED = '_AS_COMPLETED'
-
-# Possible future states (for internal use by the futures package).
-PENDING = 'PENDING'
-RUNNING = 'RUNNING'
-# The future was cancelled by the user...
-CANCELLED = 'CANCELLED'
-# ...and _Waiter.add_cancelled() was called by a worker.
-CANCELLED_AND_NOTIFIED = 'CANCELLED_AND_NOTIFIED'
-FINISHED = 'FINISHED'
-
-_FUTURE_STATES = [
-    PENDING,
-    RUNNING,
-    CANCELLED,
-    CANCELLED_AND_NOTIFIED,
-    FINISHED
-]
-
-_STATE_TO_DESCRIPTION_MAP = {
-    PENDING: "pending",
-    RUNNING: "running",
-    CANCELLED: "cancelled",
-    CANCELLED_AND_NOTIFIED: "cancelled",
-    FINISHED: "finished"
-}
-
-# Logger for internal use by the futures package.
-LOGGER = logging.getLogger("concurrent.futures")
-
-class Error(Exception):
-    """Base class for all future-related exceptions."""
-    pass
-
-class CancelledError(Error):
-    """The Future was cancelled."""
-    pass
-
-class TimeoutError(Error):
-    """The operation exceeded the given deadline."""
-    pass
-
-class _Waiter(object):
-    """Provides the event that wait() and as_completed() block on."""
-    def __init__(self):
-        self.event = threading.Event()
-        self.finished_futures = []
-
-    def add_result(self, future):
-        self.finished_futures.append(future)
-
-    def add_exception(self, future):
-        self.finished_futures.append(future)
-
-    def add_cancelled(self, future):
-        self.finished_futures.append(future)
-
-class _AsCompletedWaiter(_Waiter):
-    """Used by as_completed()."""
-
-    def __init__(self):
-        super(_AsCompletedWaiter, self).__init__()
-        self.lock = threading.Lock()
-
-    def add_result(self, future):
-        with self.lock:
-            super(_AsCompletedWaiter, self).add_result(future)
-            self.event.set()
-
-    def add_exception(self, future):
-        with self.lock:
-            super(_AsCompletedWaiter, self).add_exception(future)
-            self.event.set()
-
-    def add_cancelled(self, future):
-        with self.lock:
-            super(_AsCompletedWaiter, self).add_cancelled(future)
-            self.event.set()
-
-class _FirstCompletedWaiter(_Waiter):
-    """Used by wait(return_when=FIRST_COMPLETED)."""
-
-    def add_result(self, future):
-        super(_FirstCompletedWaiter, self).add_result(future)
-        self.event.set()
-
-    def add_exception(self, future):
-        super(_FirstCompletedWaiter, self).add_exception(future)
-        self.event.set()
-
-    def add_cancelled(self, future):
-        super(_FirstCompletedWaiter, self).add_cancelled(future)
-        self.event.set()
-
-class _AllCompletedWaiter(_Waiter):
-    """Used by wait(return_when=FIRST_EXCEPTION and ALL_COMPLETED)."""
-
-    def __init__(self, num_pending_calls, stop_on_exception):
-        self.num_pending_calls = num_pending_calls
-        self.stop_on_exception = stop_on_exception
-        self.lock = threading.Lock()
-        super(_AllCompletedWaiter, self).__init__()
-
-    def _decrement_pending_calls(self):
-        with self.lock:
-            self.num_pending_calls -= 1
-            if not self.num_pending_calls:
-                self.event.set()
-
-    def add_result(self, future):
-        super(_AllCompletedWaiter, self).add_result(future)
-        self._decrement_pending_calls()
-
-    def add_exception(self, future):
-        super(_AllCompletedWaiter, self).add_exception(future)
-        if self.stop_on_exception:
-            self.event.set()
-        else:
-            self._decrement_pending_calls()
-
-    def add_cancelled(self, future):
-        super(_AllCompletedWaiter, self).add_cancelled(future)
-        self._decrement_pending_calls()
-
-class _AcquireFutures(object):
-    """A context manager that does an ordered acquire of Future conditions."""
-
-    def __init__(self, futures):
-        self.futures = sorted(futures, key=id)
-
-    def __enter__(self):
-        for future in self.futures:
-            future._condition.acquire()
-
-    def __exit__(self, *args):
-        for future in self.futures:
-            future._condition.release()
-
-def _create_and_install_waiters(fs, return_when):
-    if return_when == _AS_COMPLETED:
-        waiter = _AsCompletedWaiter()
-    elif return_when == FIRST_COMPLETED:
-        waiter = _FirstCompletedWaiter()
-    else:
-        pending_count = sum(
-                f._state not in [CANCELLED_AND_NOTIFIED, FINISHED] for f in fs)
-
-        if return_when == FIRST_EXCEPTION:
-            waiter = _AllCompletedWaiter(pending_count, stop_on_exception=True)
-        elif return_when == ALL_COMPLETED:
-            waiter = _AllCompletedWaiter(pending_count, stop_on_exception=False)
-        else:
-            raise ValueError("Invalid return condition: %r" % return_when)
-
-    for f in fs:
-        f._waiters.append(waiter)
-
-    return waiter
-
-
-def _yield_finished_futures(fs, waiter, ref_collect):
-    """
-    Iterate on the list *fs*, yielding finished futures one by one in
-    reverse order.
-    Before yielding a future, *waiter* is removed from its waiters
-    and the future is removed from each set in the collection of sets
-    *ref_collect*.
-
-    The aim of this function is to avoid keeping stale references after
-    the future is yielded and before the iterator resumes.
-    """
-    while fs:
-        f = fs[-1]
-        for futures_set in ref_collect:
-            futures_set.remove(f)
-        with f._condition:
-            f._waiters.remove(waiter)
-        del f
-        # Careful not to keep a reference to the popped value
-        yield fs.pop()
-
-
-def as_completed(fs, timeout=None):
-    """An iterator over the given futures that yields each as it completes.
-
-    Args:
-        fs: The sequence of Futures (possibly created by different Executors) to
-            iterate over.
-        timeout: The maximum number of seconds to wait. If None, then there
-            is no limit on the wait time.
-
-    Returns:
-        An iterator that yields the given Futures as they complete (finished or
-        cancelled). If any given Futures are duplicated, they will be returned
-        once.
-
-    Raises:
-        TimeoutError: If the entire result iterator could not be generated
-            before the given timeout.
-    """
-    if timeout is not None:
-        end_time = timeout + time.time()
-
-    fs = set(fs)
-    total_futures = len(fs)
-    with _AcquireFutures(fs):
-        finished = set(
-                f for f in fs
-                if f._state in [CANCELLED_AND_NOTIFIED, FINISHED])
-        pending = fs - finished
-        waiter = _create_and_install_waiters(fs, _AS_COMPLETED)
-    finished = list(finished)
-    try:
-        for f in _yield_finished_futures(finished, waiter,
-                                         ref_collect=(fs,)):
-            f = [f]
-            yield f.pop()
-
-        while pending:
-            if timeout is None:
-                wait_timeout = None
-            else:
-                wait_timeout = end_time - time.time()
-                if wait_timeout < 0:
-                    raise TimeoutError(
-                            '%d (of %d) futures unfinished' % (
-                            len(pending), total_futures))
-
-            waiter.event.wait(wait_timeout)
-
-            with waiter.lock:
-                finished = waiter.finished_futures
-                waiter.finished_futures = []
-                waiter.event.clear()
-
-            # reverse to keep finishing order
-            finished.reverse()
-            for f in _yield_finished_futures(finished, waiter,
-                                             ref_collect=(fs, pending)):
-                f = [f]
-                yield f.pop()
-
-    finally:
-        # Remove waiter from unfinished futures
-        for f in fs:
-            with f._condition:
-                f._waiters.remove(waiter)
-
-DoneAndNotDoneFutures = collections.namedtuple(
-        'DoneAndNotDoneFutures', 'done not_done')
-def wait(fs, timeout=None, return_when=ALL_COMPLETED):
-    """Wait for the futures in the given sequence to complete.
-
-    Args:
-        fs: The sequence of Futures (possibly created by different Executors) to
-            wait upon.
-        timeout: The maximum number of seconds to wait. If None, then there
-            is no limit on the wait time.
-        return_when: Indicates when this function should return. The options
-            are:
-
-            FIRST_COMPLETED - Return when any future finishes or is
-                              cancelled.
-            FIRST_EXCEPTION - Return when any future finishes by raising an
-                              exception. If no future raises an exception
-                              then it is equivalent to ALL_COMPLETED.
-            ALL_COMPLETED -   Return when all futures finish or are cancelled.
-
-    Returns:
-        A named 2-tuple of sets. The first set, named 'done', contains the
-        futures that completed (is finished or cancelled) before the wait
-        completed. The second set, named 'not_done', contains uncompleted
-        futures.
-    """
-    with _AcquireFutures(fs):
-        done = set(f for f in fs
-                   if f._state in [CANCELLED_AND_NOTIFIED, FINISHED])
-        not_done = set(fs) - done
-
-        if (return_when == FIRST_COMPLETED) and done:
-            return DoneAndNotDoneFutures(done, not_done)
-        elif (return_when == FIRST_EXCEPTION) and done:
-            if any(f for f in done
-                   if not f.cancelled() and f.exception() is not None):
-                return DoneAndNotDoneFutures(done, not_done)
-
-        if len(done) == len(fs):
-            return DoneAndNotDoneFutures(done, not_done)
-
-        waiter = _create_and_install_waiters(fs, return_when)
-
-    waiter.event.wait(timeout)
-    for f in fs:
-        with f._condition:
-            f._waiters.remove(waiter)
-
-    done.update(waiter.finished_futures)
-    return DoneAndNotDoneFutures(done, set(fs) - done)
-
-class Future(object):
-    """Represents the result of an asynchronous computation."""
-
-    def __init__(self):
-        """Initializes the future. Should not be called by clients."""
-        self._condition = threading.Condition()
-        self._state = PENDING
-        self._result = None
-        self._exception = None
-        self._traceback = None
-        self._waiters = []
-        self._done_callbacks = []
-
-    def _invoke_callbacks(self):
-        for callback in self._done_callbacks:
-            try:
-                callback(self)
-            except Exception:
-                LOGGER.exception('exception calling callback for %r', self)
-            except BaseException:
-                # Explicitly let all other new-style exceptions through so
-                # that we can catch all old-style exceptions with a simple
-                # "except:" clause below.
-                #
-                # All old-style exception objects are instances of
-                # types.InstanceType, but "except types.InstanceType:" does
-                # not catch old-style exceptions for some reason.  Thus, the
-                # only way to catch all old-style exceptions without catching
-                # any new-style exceptions is to filter out the new-style
-                # exceptions, which all derive from BaseException.
-                raise
-            except:
-                # Because of the BaseException clause above, this handler only
-                # executes for old-style exception objects.
-                LOGGER.exception('exception calling callback for %r', self)
-
-    def __repr__(self):
-        with self._condition:
-            if self._state == FINISHED:
-                if self._exception:
-                    return '<%s at %#x state=%s raised %s>' % (
-                        self.__class__.__name__,
-                        id(self),
-                        _STATE_TO_DESCRIPTION_MAP[self._state],
-                        self._exception.__class__.__name__)
-                else:
-                    return '<%s at %#x state=%s returned %s>' % (
-                        self.__class__.__name__,
-                        id(self),
-                        _STATE_TO_DESCRIPTION_MAP[self._state],
-                        self._result.__class__.__name__)
-            return '<%s at %#x state=%s>' % (
-                    self.__class__.__name__,
-                    id(self),
-                   _STATE_TO_DESCRIPTION_MAP[self._state])
-
-    def cancel(self):
-        """Cancel the future if possible.
-
-        Returns True if the future was cancelled, False otherwise. A future
-        cannot be cancelled if it is running or has already completed.
-        """
-        with self._condition:
-            if self._state in [RUNNING, FINISHED]:
-                return False
-
-            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
-                return True
-
-            self._state = CANCELLED
-            self._condition.notify_all()
-
-        self._invoke_callbacks()
-        return True
-
-    def cancelled(self):
-        """Return True if the future was cancelled."""
-        with self._condition:
-            return self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]
-
-    def running(self):
-        """Return True if the future is currently executing."""
-        with self._condition:
-            return self._state == RUNNING
-
-    def done(self):
-        """Return True of the future was cancelled or finished executing."""
-        with self._condition:
-            return self._state in [CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED]
-
-    def __get_result(self):
-        if self._exception:
-            if isinstance(self._exception, types.InstanceType):
-                # The exception is an instance of an old-style class, which
-                # means type(self._exception) returns types.ClassType instead
-                # of the exception's actual class type.
-                exception_type = self._exception.__class__
-            else:
-                exception_type = type(self._exception)
-            raise exception_type, self._exception, self._traceback
-        else:
-            return self._result
-
-    def add_done_callback(self, fn):
-        """Attaches a callable that will be called when the future finishes.
-
-        Args:
-            fn: A callable that will be called with this future as its only
-                argument when the future completes or is cancelled. The callable
-                will always be called by a thread in the same process in which
-                it was added. If the future has already completed or been
-                cancelled then the callable will be called immediately. These
-                callables are called in the order that they were added.
-        """
-        with self._condition:
-            if self._state not in [CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED]:
-                self._done_callbacks.append(fn)
-                return
-        fn(self)
-
-    def result(self, timeout=None):
-        """Return the result of the call that the future represents.
-
-        Args:
-            timeout: The number of seconds to wait for the result if the future
-                isn't done. If None, then there is no limit on the wait time.
-
-        Returns:
-            The result of the call that the future represents.
-
-        Raises:
-            CancelledError: If the future was cancelled.
-            TimeoutError: If the future didn't finish executing before the given
-                timeout.
-            Exception: If the call raised then that exception will be raised.
-        """
-        with self._condition:
-            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
-                raise CancelledError()
-            elif self._state == FINISHED:
-                return self.__get_result()
-
-            self._condition.wait(timeout)
-
-            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
-                raise CancelledError()
-            elif self._state == FINISHED:
-                return self.__get_result()
-            else:
-                raise TimeoutError()
-
-    def exception_info(self, timeout=None):
-        """Return a tuple of (exception, traceback) raised by the call that the
-        future represents.
-
-        Args:
-            timeout: The number of seconds to wait for the exception if the
-                future isn't done. If None, then there is no limit on the wait
-                time.
-
-        Returns:
-            The exception raised by the call that the future represents or None
-            if the call completed without raising.
-
-        Raises:
-            CancelledError: If the future was cancelled.
-            TimeoutError: If the future didn't finish executing before the given
-                timeout.
-        """
-        with self._condition:
-            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
-                raise CancelledError()
-            elif self._state == FINISHED:
-                return self._exception, self._traceback
-
-            self._condition.wait(timeout)
-
-            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
-                raise CancelledError()
-            elif self._state == FINISHED:
-                return self._exception, self._traceback
-            else:
-                raise TimeoutError()
-
-    def exception(self, timeout=None):
-        """Return the exception raised by the call that the future represents.
-
-        Args:
-            timeout: The number of seconds to wait for the exception if the
-                future isn't done. If None, then there is no limit on the wait
-                time.
-
-        Returns:
-            The exception raised by the call that the future represents or None
-            if the call completed without raising.
-
-        Raises:
-            CancelledError: If the future was cancelled.
-            TimeoutError: If the future didn't finish executing before the given
-                timeout.
-        """
-        return self.exception_info(timeout)[0]
-
-    # The following methods should only be used by Executors and in tests.
-    def set_running_or_notify_cancel(self):
-        """Mark the future as running or process any cancel notifications.
-
-        Should only be used by Executor implementations and unit tests.
-
-        If the future has been cancelled (cancel() was called and returned
-        True) then any threads waiting on the future completing (though calls
-        to as_completed() or wait()) are notified and False is returned.
-
-        If the future was not cancelled then it is put in the running state
-        (future calls to running() will return True) and True is returned.
-
-        This method should be called by Executor implementations before
-        executing the work associated with this future. If this method returns
-        False then the work should not be executed.
-
-        Returns:
-            False if the Future was cancelled, True otherwise.
-
-        Raises:
-            RuntimeError: if this method was already called or if set_result()
-                or set_exception() was called.
-        """
-        with self._condition:
-            if self._state == CANCELLED:
-                self._state = CANCELLED_AND_NOTIFIED
-                for waiter in self._waiters:
-                    waiter.add_cancelled(self)
-                # self._condition.notify_all() is not necessary because
-                # self.cancel() triggers a notification.
-                return False
-            elif self._state == PENDING:
-                self._state = RUNNING
-                return True
-            else:
-                LOGGER.critical('Future %s in unexpected state: %s',
-                                id(self),
-                                self._state)
-                raise RuntimeError('Future in unexpected state')
-
-    def set_result(self, result):
-        """Sets the return value of work associated with the future.
-
-        Should only be used by Executor implementations and unit tests.
-        """
-        with self._condition:
-            self._result = result
-            self._state = FINISHED
-            for waiter in self._waiters:
-                waiter.add_result(self)
-            self._condition.notify_all()
-        self._invoke_callbacks()
-
-    def set_exception_info(self, exception, traceback):
-        """Sets the result of the future as being the given exception
-        and traceback.
-
-        Should only be used by Executor implementations and unit tests.
-        """
-        with self._condition:
-            self._exception = exception
-            self._traceback = traceback
-            self._state = FINISHED
-            for waiter in self._waiters:
-                waiter.add_exception(self)
-            self._condition.notify_all()
-        self._invoke_callbacks()
-
-    def set_exception(self, exception):
-        """Sets the result of the future as being the given exception.
-
-        Should only be used by Executor implementations and unit tests.
-        """
-        self.set_exception_info(exception, None)
-
-class Executor(object):
-    """This is an abstract base class for concrete asynchronous executors."""
-
-    def submit(self, fn, *args, **kwargs):
-        """Submits a callable to be executed with the given arguments.
-
-        Schedules the callable to be executed as fn(*args, **kwargs) and returns
-        a Future instance representing the execution of the callable.
-
-        Returns:
-            A Future representing the given call.
-        """
-        raise NotImplementedError()
-
-    def map(self, fn, *iterables, **kwargs):
-        """Returns an iterator equivalent to map(fn, iter).
-
-        Args:
-            fn: A callable that will take as many arguments as there are
-                passed iterables.
-            timeout: The maximum number of seconds to wait. If None, then there
-                is no limit on the wait time.
-
-        Returns:
-            An iterator equivalent to: map(func, *iterables) but the calls may
-            be evaluated out-of-order.
-
-        Raises:
-            TimeoutError: If the entire result iterator could not be generated
-                before the given timeout.
-            Exception: If fn(*args) raises for any values.
-        """
-        timeout = kwargs.get('timeout')
-        if timeout is not None:
-            end_time = timeout + time.time()
-
-        fs = [self.submit(fn, *args) for args in itertools.izip(*iterables)]
-
-        # Yield must be hidden in closure so that the futures are submitted
-        # before the first iterator value is required.
-        def result_iterator():
-            try:
-                # reverse to keep finishing order
-                fs.reverse()
-                while fs:
-                    # Careful not to keep a reference to the popped future
-                    if timeout is None:
-                        yield fs.pop().result()
-                    else:
-                        yield fs.pop().result(end_time - time.time())
-            finally:
-                for future in fs:
-                    future.cancel()
-        return result_iterator()
-
-    def shutdown(self, wait=True):
-        """Clean-up the resources associated with the Executor.
-
-        It is safe to call this method several times. Otherwise, no other
-        methods can be called after this one.
-
-        Args:
-            wait: If True then shutdown will not return until all running
-                futures have finished executing and the resources used by the
-                executor have been reclaimed.
-        """
-        pass
-
-    def __enter__(self):
-        return self
-
-    def __exit__(self, exc_type, exc_val, exc_tb):
-        self.shutdown(wait=True)
-        return False
diff --git a/mercurial/thirdparty/concurrent/futures/__init__.py b/mercurial/thirdparty/concurrent/futures/__init__.py
deleted file mode 100644
--- a/mercurial/thirdparty/concurrent/futures/__init__.py
+++ /dev/null
@@ -1,27 +0,0 @@ 
-# Copyright 2009 Brian Quinlan. All Rights Reserved.
-# Licensed to PSF under a Contributor Agreement.
-
-"""Execute computations asynchronously using threads or processes."""
-
-from __future__ import absolute_import
-
-__author__ = 'Brian Quinlan (brian@sweetapp.com)'
-
-from ._base import (
-    FIRST_COMPLETED,
-    FIRST_EXCEPTION,
-    ALL_COMPLETED,
-    CancelledError,
-    TimeoutError,
-    Future,
-    Executor,
-    wait,
-    as_completed,
-)
-from .thread import ThreadPoolExecutor
-
-try:
-    from .process import ProcessPoolExecutor
-except ImportError:
-    # some platforms don't have multiprocessing
-    pass
diff --git a/mercurial/thirdparty/concurrent/__init__.py b/mercurial/thirdparty/concurrent/__init__.py
deleted file mode 100644
diff --git a/mercurial/thirdparty/concurrent/LICENSE b/mercurial/thirdparty/concurrent/LICENSE
deleted file mode 100644
--- a/mercurial/thirdparty/concurrent/LICENSE
+++ /dev/null
@@ -1,48 +0,0 @@ 
-PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
---------------------------------------------
-
-1. This LICENSE AGREEMENT is between the Python Software Foundation
-("PSF"), and the Individual or Organization ("Licensee") accessing and
-otherwise using this software ("Python") in source or binary form and
-its associated documentation.
-
-2. Subject to the terms and conditions of this License Agreement, PSF
-hereby grants Licensee a nonexclusive, royalty-free, world-wide
-license to reproduce, analyze, test, perform and/or display publicly,
-prepare derivative works, distribute, and otherwise use Python
-alone or in any derivative version, provided, however, that PSF's
-License Agreement and PSF's notice of copyright, i.e., "Copyright (c)
-2001, 2002, 2003, 2004, 2005, 2006 Python Software Foundation; All Rights
-Reserved" are retained in Python alone or in any derivative version 
-prepared by Licensee.
-
-3. In the event Licensee prepares a derivative work that is based on
-or incorporates Python or any part thereof, and wants to make
-the derivative work available to others as provided herein, then
-Licensee hereby agrees to include in any such work a brief summary of
-the changes made to Python.
-
-4. PSF is making Python available to Licensee on an "AS IS"
-basis.  PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
-IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND
-DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
-FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOT
-INFRINGE ANY THIRD PARTY RIGHTS.
-
-5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
-FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS
-A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON,
-OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
-
-6. This License Agreement will automatically terminate upon a material
-breach of its terms and conditions.
-
-7. Nothing in this License Agreement shall be deemed to create any
-relationship of agency, partnership, or joint venture between PSF and
-Licensee.  This License Agreement does not grant permission to use PSF
-trademarks or trade name in a trademark sense to endorse or promote
-products or services of Licensee, or any third party.
-
-8. By copying, installing or otherwise using Python, Licensee
-agrees to be bound by the terms and conditions of this License
-Agreement.