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| author | orivej <[email protected]> | 2022-02-10 16:45:01 +0300 |
|---|---|---|
| committer | Daniil Cherednik <[email protected]> | 2022-02-10 16:45:01 +0300 |
| commit | 2d37894b1b037cf24231090eda8589bbb44fb6fc (patch) | |
| tree | be835aa92c6248212e705f25388ebafcf84bc7a1 /contrib/tools/python3/src/Lib/concurrent | |
| parent | 718c552901d703c502ccbefdfc3c9028d608b947 (diff) | |
Restoring authorship annotation for <[email protected]>. Commit 2 of 2.
Diffstat (limited to 'contrib/tools/python3/src/Lib/concurrent')
5 files changed, 1270 insertions, 1270 deletions
diff --git a/contrib/tools/python3/src/Lib/concurrent/__init__.py b/contrib/tools/python3/src/Lib/concurrent/__init__.py index 9d4f425fe3e..196d3788575 100644 --- a/contrib/tools/python3/src/Lib/concurrent/__init__.py +++ b/contrib/tools/python3/src/Lib/concurrent/__init__.py @@ -1 +1 @@ -# This directory is a Python package. +# This directory is a Python package. diff --git a/contrib/tools/python3/src/Lib/concurrent/futures/__init__.py b/contrib/tools/python3/src/Lib/concurrent/futures/__init__.py index d463ee68953..d746aeac50a 100644 --- a/contrib/tools/python3/src/Lib/concurrent/futures/__init__.py +++ b/contrib/tools/python3/src/Lib/concurrent/futures/__init__.py @@ -1,53 +1,53 @@ -# Copyright 2009 Brian Quinlan. All Rights Reserved. -# Licensed to PSF under a Contributor Agreement. - -"""Execute computations asynchronously using threads or processes.""" - -__author__ = 'Brian Quinlan ([email protected])' - -from concurrent.futures._base import (FIRST_COMPLETED, - FIRST_EXCEPTION, - ALL_COMPLETED, - CancelledError, - TimeoutError, +# Copyright 2009 Brian Quinlan. All Rights Reserved. +# Licensed to PSF under a Contributor Agreement. + +"""Execute computations asynchronously using threads or processes.""" + +__author__ = 'Brian Quinlan ([email protected])' + +from concurrent.futures._base import (FIRST_COMPLETED, + FIRST_EXCEPTION, + ALL_COMPLETED, + CancelledError, + TimeoutError, InvalidStateError, - BrokenExecutor, - Future, - Executor, - wait, - as_completed) - -__all__ = ( - 'FIRST_COMPLETED', - 'FIRST_EXCEPTION', - 'ALL_COMPLETED', - 'CancelledError', - 'TimeoutError', - 'BrokenExecutor', - 'Future', - 'Executor', - 'wait', - 'as_completed', - 'ProcessPoolExecutor', - 'ThreadPoolExecutor', -) - - -def __dir__(): - return __all__ + ('__author__', '__doc__') - - -def __getattr__(name): - global ProcessPoolExecutor, ThreadPoolExecutor - - if name == 'ProcessPoolExecutor': - from .process import ProcessPoolExecutor as pe - ProcessPoolExecutor = pe - return pe - - if name == 'ThreadPoolExecutor': - from .thread import ThreadPoolExecutor as te - ThreadPoolExecutor = te - return te - - raise AttributeError(f"module {__name__} has no attribute {name}") + BrokenExecutor, + Future, + Executor, + wait, + as_completed) + +__all__ = ( + 'FIRST_COMPLETED', + 'FIRST_EXCEPTION', + 'ALL_COMPLETED', + 'CancelledError', + 'TimeoutError', + 'BrokenExecutor', + 'Future', + 'Executor', + 'wait', + 'as_completed', + 'ProcessPoolExecutor', + 'ThreadPoolExecutor', +) + + +def __dir__(): + return __all__ + ('__author__', '__doc__') + + +def __getattr__(name): + global ProcessPoolExecutor, ThreadPoolExecutor + + if name == 'ProcessPoolExecutor': + from .process import ProcessPoolExecutor as pe + ProcessPoolExecutor = pe + return pe + + if name == 'ThreadPoolExecutor': + from .thread import ThreadPoolExecutor as te + ThreadPoolExecutor = te + return te + + raise AttributeError(f"module {__name__} has no attribute {name}") diff --git a/contrib/tools/python3/src/Lib/concurrent/futures/_base.py b/contrib/tools/python3/src/Lib/concurrent/futures/_base.py index 5417b2851cc..5c00f2edbe5 100644 --- a/contrib/tools/python3/src/Lib/concurrent/futures/_base.py +++ b/contrib/tools/python3/src/Lib/concurrent/futures/_base.py @@ -1,445 +1,445 @@ -# Copyright 2009 Brian Quinlan. All Rights Reserved. -# Licensed to PSF under a Contributor Agreement. - -__author__ = 'Brian Quinlan ([email protected])' - -import collections -import logging -import threading -import time +# Copyright 2009 Brian Quinlan. All Rights Reserved. +# Licensed to PSF under a Contributor Agreement. + +__author__ = 'Brian Quinlan ([email protected])' + +import collections +import logging +import threading +import time import types - -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 - + +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 InvalidStateError(Error): """The operation is not allowed in this state.""" 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().add_result(future) - self.event.set() - - def add_exception(self, future): - super().add_exception(future) - self.event.set() - - def add_cancelled(self, future): - super().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().__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().add_result(future) - self._decrement_pending_calls() - - def add_exception(self, future): - super().add_exception(future) - if self.stop_on_exception: - self.event.set() - else: - self._decrement_pending_calls() - - def add_cancelled(self, future): - super().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.monotonic() - - 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: - yield from _yield_finished_futures(finished, waiter, - ref_collect=(fs,)) - - while pending: - if timeout is None: - wait_timeout = None - else: - wait_timeout = end_time - time.monotonic() - 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() - yield from _yield_finished_futures(finished, waiter, - ref_collect=(fs, pending)) - - 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 +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().add_result(future) + self.event.set() + + def add_exception(self, future): + super().add_exception(future) + self.event.set() + + def add_cancelled(self, future): + super().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().__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().add_result(future) + self._decrement_pending_calls() + + def add_exception(self, future): + super().add_exception(future) + if self.stop_on_exception: + self.event.set() + else: + self._decrement_pending_calls() + + def add_cancelled(self, future): + super().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.monotonic() + + 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: + yield from _yield_finished_futures(finished, waiter, + ref_collect=(fs,)) + + while pending: + if timeout is None: + wait_timeout = None + else: + wait_timeout = end_time - time.monotonic() + 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() + yield from _yield_finished_futures(finished, waiter, + ref_collect=(fs, pending)) + + 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. Duplicate futures given to *fs* are removed and will be returned only once. - """ + """ fs = set(fs) - with _AcquireFutures(fs): + with _AcquireFutures(fs): done = {f for f in fs if f._state in [CANCELLED_AND_NOTIFIED, FINISHED]} not_done = 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) + 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, 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._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) - - 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: + +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._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) + + 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: try: raise self._exception finally: # Break a reference cycle with the exception in self._exception self = None - 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 + 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 try: fn(self) except Exception: LOGGER.exception('exception calling callback for %r', 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. - """ + + 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. + """ try: 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: @@ -449,196 +449,196 @@ class Future(object): finally: # Break a reference cycle with the exception in self._exception self = None - - 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. - """ - - with self._condition: - if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]: - raise CancelledError() - elif self._state == FINISHED: - return self._exception - - self._condition.wait(timeout) - - if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]: - raise CancelledError() - elif self._state == FINISHED: - return self._exception - else: - raise TimeoutError() - - # 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: + + 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. + """ + + with self._condition: + if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]: + raise CancelledError() + elif self._state == FINISHED: + return self._exception + + self._condition.wait(timeout) + + if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]: + raise CancelledError() + elif self._state == FINISHED: + return self._exception + else: + raise TimeoutError() + + # 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: if self._state in {CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED}: raise InvalidStateError('{}: {!r}'.format(self._state, self)) - 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(self, exception): - """Sets the result of the future as being the given exception. - - 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(self, exception): + """Sets the result of the future as being the given exception. + + Should only be used by Executor implementations and unit tests. + """ + with self._condition: if self._state in {CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED}: raise InvalidStateError('{}: {!r}'.format(self._state, self)) - self._exception = exception - self._state = FINISHED - for waiter in self._waiters: - waiter.add_exception(self) - self._condition.notify_all() - self._invoke_callbacks() - + self._exception = exception + self._state = FINISHED + for waiter in self._waiters: + waiter.add_exception(self) + self._condition.notify_all() + self._invoke_callbacks() + __class_getitem__ = classmethod(types.GenericAlias) -class Executor(object): - """This is an abstract base class for concrete asynchronous executors.""" - +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, timeout=None, chunksize=1): - """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. - chunksize: The size of the chunks the iterable will be broken into - before being passed to a child process. This argument is only - used by ProcessPoolExecutor; it is ignored by - ThreadPoolExecutor. - - 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. - """ - if timeout is not None: - end_time = timeout + time.monotonic() - - fs = [self.submit(fn, *args) for args in zip(*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.monotonic()) - finally: - for future in fs: - future.cancel() - return result_iterator() - + """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, timeout=None, chunksize=1): + """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. + chunksize: The size of the chunks the iterable will be broken into + before being passed to a child process. This argument is only + used by ProcessPoolExecutor; it is ignored by + ThreadPoolExecutor. + + 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. + """ + if timeout is not None: + end_time = timeout + time.monotonic() + + fs = [self.submit(fn, *args) for args in zip(*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.monotonic()) + finally: + for future in fs: + future.cancel() + return result_iterator() + def shutdown(self, wait=True, *, cancel_futures=False): - """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. + """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. cancel_futures: If True then shutdown will cancel all pending futures. Futures that are completed or running will not be cancelled. - """ - pass - - def __enter__(self): - return self - - def __exit__(self, exc_type, exc_val, exc_tb): - self.shutdown(wait=True) - return False - - -class BrokenExecutor(RuntimeError): - """ - Raised when a executor has become non-functional after a severe failure. - """ + """ + pass + + def __enter__(self): + return self + + def __exit__(self, exc_type, exc_val, exc_tb): + self.shutdown(wait=True) + return False + + +class BrokenExecutor(RuntimeError): + """ + Raised when a executor has become non-functional after a severe failure. + """ diff --git a/contrib/tools/python3/src/Lib/concurrent/futures/process.py b/contrib/tools/python3/src/Lib/concurrent/futures/process.py index e99881798c2..a29e5247ab8 100644 --- a/contrib/tools/python3/src/Lib/concurrent/futures/process.py +++ b/contrib/tools/python3/src/Lib/concurrent/futures/process.py @@ -1,278 +1,278 @@ -# Copyright 2009 Brian Quinlan. All Rights Reserved. -# Licensed to PSF under a Contributor Agreement. - -"""Implements ProcessPoolExecutor. - +# Copyright 2009 Brian Quinlan. All Rights Reserved. +# Licensed to PSF under a Contributor Agreement. + +"""Implements ProcessPoolExecutor. + The following diagram and text describe the data-flow through the system: - -|======================= In-process =====================|== Out-of-process ==| - -+----------+ +----------+ +--------+ +-----------+ +---------+ -| | => | Work Ids | | | | Call Q | | Process | -| | +----------+ | | +-----------+ | Pool | -| | | ... | | | | ... | +---------+ -| | | 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 "Result Q" -""" - -__author__ = 'Brian Quinlan ([email protected])' - -import os -from concurrent.futures import _base -import queue -import multiprocessing as mp + +|======================= In-process =====================|== Out-of-process ==| + ++----------+ +----------+ +--------+ +-----------+ +---------+ +| | => | Work Ids | | | | Call Q | | Process | +| | +----------+ | | +-----------+ | Pool | +| | | ... | | | | ... | +---------+ +| | | 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 "Result Q" +""" + +__author__ = 'Brian Quinlan ([email protected])' + +import os +from concurrent.futures import _base +import queue +import multiprocessing as mp import multiprocessing.connection -from multiprocessing.queues import Queue -import threading -import weakref -from functools import partial -import itertools +from multiprocessing.queues import Queue +import threading +import weakref +from functools import partial +import itertools import sys -import traceback - - -_threads_wakeups = weakref.WeakKeyDictionary() -_global_shutdown = False - - -class _ThreadWakeup: - def __init__(self): +import traceback + + +_threads_wakeups = weakref.WeakKeyDictionary() +_global_shutdown = False + + +class _ThreadWakeup: + def __init__(self): self._closed = False - self._reader, self._writer = mp.Pipe(duplex=False) - - def close(self): + self._reader, self._writer = mp.Pipe(duplex=False) + + def close(self): if not self._closed: self._closed = True self._writer.close() self._reader.close() - - def wakeup(self): + + def wakeup(self): if not self._closed: self._writer.send_bytes(b"") - - def clear(self): + + def clear(self): if not self._closed: while self._reader.poll(): self._reader.recv_bytes() - - -def _python_exit(): - global _global_shutdown - _global_shutdown = True - items = list(_threads_wakeups.items()) - for _, thread_wakeup in items: + + +def _python_exit(): + global _global_shutdown + _global_shutdown = True + items = list(_threads_wakeups.items()) + for _, thread_wakeup in items: # call not protected by ProcessPoolExecutor._shutdown_lock - thread_wakeup.wakeup() - for t, _ in items: - t.join() - + thread_wakeup.wakeup() + for t, _ in items: + t.join() + # Register for `_python_exit()` to be called just before joining all # non-daemon threads. This is used instead of `atexit.register()` for # compatibility with subinterpreters, which no longer support daemon threads. # See bpo-39812 for context. threading._register_atexit(_python_exit) -# 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 - - +# 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 + + # On Windows, WaitForMultipleObjects is used to wait for processes to finish. # It can wait on, at most, 63 objects. There is an overhead of two objects: # - the result queue reader # - the thread wakeup reader _MAX_WINDOWS_WORKERS = 63 - 2 -# Hack to embed stringification of remote traceback in local traceback - -class _RemoteTraceback(Exception): - def __init__(self, tb): - self.tb = tb - def __str__(self): - return self.tb - -class _ExceptionWithTraceback: - def __init__(self, exc, tb): - tb = traceback.format_exception(type(exc), exc, tb) - tb = ''.join(tb) - self.exc = exc - self.tb = '\n"""\n%s"""' % tb - def __reduce__(self): - return _rebuild_exc, (self.exc, self.tb) - -def _rebuild_exc(exc, tb): - exc.__cause__ = _RemoteTraceback(tb) - return exc - -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 - - -class _SafeQueue(Queue): - """Safe Queue set exception to the future object linked to a job""" +# Hack to embed stringification of remote traceback in local traceback + +class _RemoteTraceback(Exception): + def __init__(self, tb): + self.tb = tb + def __str__(self): + return self.tb + +class _ExceptionWithTraceback: + def __init__(self, exc, tb): + tb = traceback.format_exception(type(exc), exc, tb) + tb = ''.join(tb) + self.exc = exc + self.tb = '\n"""\n%s"""' % tb + def __reduce__(self): + return _rebuild_exc, (self.exc, self.tb) + +def _rebuild_exc(exc, tb): + exc.__cause__ = _RemoteTraceback(tb) + return exc + +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 + + +class _SafeQueue(Queue): + """Safe Queue set exception to the future object linked to a job""" def __init__(self, max_size=0, *, ctx, pending_work_items, shutdown_lock, thread_wakeup): - self.pending_work_items = pending_work_items + self.pending_work_items = pending_work_items self.shutdown_lock = shutdown_lock self.thread_wakeup = thread_wakeup - super().__init__(max_size, ctx=ctx) - - def _on_queue_feeder_error(self, e, obj): - if isinstance(obj, _CallItem): - tb = traceback.format_exception(type(e), e, e.__traceback__) - e.__cause__ = _RemoteTraceback('\n"""\n{}"""'.format(''.join(tb))) - work_item = self.pending_work_items.pop(obj.work_id, None) + super().__init__(max_size, ctx=ctx) + + def _on_queue_feeder_error(self, e, obj): + if isinstance(obj, _CallItem): + tb = traceback.format_exception(type(e), e, e.__traceback__) + e.__cause__ = _RemoteTraceback('\n"""\n{}"""'.format(''.join(tb))) + work_item = self.pending_work_items.pop(obj.work_id, None) with self.shutdown_lock: self.thread_wakeup.wakeup() # work_item can be None if another process terminated. In this # case, the executor_manager_thread fails all work_items # with BrokenProcessPool - if work_item is not None: - work_item.future.set_exception(e) - else: - super()._on_queue_feeder_error(e, obj) - - -def _get_chunks(*iterables, chunksize): - """ Iterates over zip()ed iterables in chunks. """ - it = zip(*iterables) - while True: - chunk = tuple(itertools.islice(it, chunksize)) - if not chunk: - return - yield chunk - + if work_item is not None: + work_item.future.set_exception(e) + else: + super()._on_queue_feeder_error(e, obj) + + +def _get_chunks(*iterables, chunksize): + """ Iterates over zip()ed iterables in chunks. """ + it = zip(*iterables) + while True: + chunk = tuple(itertools.islice(it, chunksize)) + if not chunk: + return + yield chunk + + +def _process_chunk(fn, chunk): + """ Processes a chunk of an iterable passed to map. + + Runs the function passed to map() on a chunk of the + iterable passed to map. + + This function is run in a separate process. + + """ + return [fn(*args) for args in chunk] -def _process_chunk(fn, chunk): - """ Processes a chunk of an iterable passed to map. - - Runs the function passed to map() on a chunk of the - iterable passed to map. - - This function is run in a separate process. - - """ - return [fn(*args) for args in chunk] - - -def _sendback_result(result_queue, work_id, result=None, exception=None): - """Safely send back the given result or exception""" - try: - result_queue.put(_ResultItem(work_id, result=result, - exception=exception)) - except BaseException as e: - exc = _ExceptionWithTraceback(e, e.__traceback__) - result_queue.put(_ResultItem(work_id, exception=exc)) - - -def _process_worker(call_queue, result_queue, initializer, initargs): - """Evaluates calls from call_queue and places the results in result_queue. - - This worker is run in a separate process. - - Args: - call_queue: A ctx.Queue of _CallItems that will be read and - evaluated by the worker. - result_queue: A ctx.Queue of _ResultItems that will written - to by the worker. - initializer: A callable initializer, or None - initargs: A tuple of args for the initializer - """ - if initializer is not None: - try: - initializer(*initargs) - except BaseException: - _base.LOGGER.critical('Exception in initializer:', exc_info=True) - # The parent will notice that the process stopped and - # mark the pool broken - return - while True: - call_item = call_queue.get(block=True) - if call_item is None: - # Wake up queue management thread - result_queue.put(os.getpid()) - return - try: - r = call_item.fn(*call_item.args, **call_item.kwargs) - except BaseException as e: - exc = _ExceptionWithTraceback(e, e.__traceback__) - _sendback_result(result_queue, call_item.work_id, exception=exc) - else: - _sendback_result(result_queue, call_item.work_id, result=r) + +def _sendback_result(result_queue, work_id, result=None, exception=None): + """Safely send back the given result or exception""" + try: + result_queue.put(_ResultItem(work_id, result=result, + exception=exception)) + except BaseException as e: + exc = _ExceptionWithTraceback(e, e.__traceback__) + result_queue.put(_ResultItem(work_id, exception=exc)) + + +def _process_worker(call_queue, result_queue, initializer, initargs): + """Evaluates calls from call_queue and places the results in result_queue. + + This worker is run in a separate process. + + Args: + call_queue: A ctx.Queue of _CallItems that will be read and + evaluated by the worker. + result_queue: A ctx.Queue of _ResultItems that will written + to by the worker. + initializer: A callable initializer, or None + initargs: A tuple of args for the initializer + """ + if initializer is not None: + try: + initializer(*initargs) + except BaseException: + _base.LOGGER.critical('Exception in initializer:', exc_info=True) + # The parent will notice that the process stopped and + # mark the pool broken + return + while True: + call_item = call_queue.get(block=True) + if call_item is None: + # Wake up queue management thread + result_queue.put(os.getpid()) + return + try: + r = call_item.fn(*call_item.args, **call_item.kwargs) + except BaseException as e: + exc = _ExceptionWithTraceback(e, e.__traceback__) + _sendback_result(result_queue, call_item.work_id, exception=exc) + else: + _sendback_result(result_queue, call_item.work_id, result=r) del r - - # Liberate the resource as soon as possible, to avoid holding onto - # open files or shared memory that is not needed anymore - del call_item - - + + # Liberate the resource as soon as possible, to avoid holding onto + # open files or shared memory that is not needed anymore + del call_item + + class _ExecutorManagerThread(threading.Thread): """Manages the communication between this process and the worker processes. - + The manager is run in a local thread. - - Args: + + Args: executor: A reference to the ProcessPoolExecutor that owns this thread. A weakref will be own by the manager as well as references to internal objects used to introspect the state of the executor. - """ - + """ + def __init__(self, executor): # Store references to necessary internals of the executor. - + # A _ThreadWakeup to allow waking up the queue_manager_thread from the # main Thread and avoid deadlocks caused by permanently locked queues. self.thread_wakeup = executor._executor_manager_thread_wakeup self.shutdown_lock = executor._shutdown_lock - + # A weakref.ref to the ProcessPoolExecutor that owns this thread. Used # to determine if the ProcessPoolExecutor has been garbage collected # and that the manager can exit. @@ -286,28 +286,28 @@ class _ExecutorManagerThread(threading.Thread): ' QueueManager wakeup') with shutdown_lock: thread_wakeup.wakeup() - + self.executor_reference = weakref.ref(executor, weakref_cb) - + # A list of the ctx.Process instances used as workers. self.processes = executor._processes - + # A ctx.Queue that will be filled with _CallItems derived from # _WorkItems for processing by the process workers. self.call_queue = executor._call_queue - + # A ctx.SimpleQueue of _ResultItems generated by the process workers. self.result_queue = executor._result_queue - + # A queue.Queue of work ids e.g. Queue([5, 6, ...]). self.work_ids_queue = executor._work_ids - + # A dict mapping work ids to _WorkItems e.g. # {5: <_WorkItem...>, 6: <_WorkItem...>, ...} self.pending_work_items = executor._pending_work_items - + super().__init__() - + def run(self): # Main loop for the executor manager thread. @@ -364,30 +364,30 @@ class _ExecutorManagerThread(threading.Thread): continue def wait_result_broken_or_wakeup(self): - # Wait for a result to be ready in the result_queue while checking - # that all worker processes are still running, or for a wake up - # signal send. The wake up signals come either from new tasks being - # submitted, from the executor being shutdown/gc-ed, or from the - # shutdown of the python interpreter. + # Wait for a result to be ready in the result_queue while checking + # that all worker processes are still running, or for a wake up + # signal send. The wake up signals come either from new tasks being + # submitted, from the executor being shutdown/gc-ed, or from the + # shutdown of the python interpreter. result_reader = self.result_queue._reader assert not self.thread_wakeup._closed wakeup_reader = self.thread_wakeup._reader readers = [result_reader, wakeup_reader] worker_sentinels = [p.sentinel for p in list(self.processes.values())] ready = mp.connection.wait(readers + worker_sentinels) - - cause = None - is_broken = True + + cause = None + is_broken = True result_item = None - if result_reader in ready: - try: - result_item = result_reader.recv() - is_broken = False - except BaseException as e: - cause = traceback.format_exception(type(e), e, e.__traceback__) - - elif wakeup_reader in ready: - is_broken = False + if result_reader in ready: + try: + result_item = result_reader.recv() + is_broken = False + except BaseException as e: + cause = traceback.format_exception(type(e), e, e.__traceback__) + + elif wakeup_reader in ready: + is_broken = False with self.shutdown_lock: self.thread_wakeup.clear() @@ -398,40 +398,40 @@ class _ExecutorManagerThread(threading.Thread): # Process the received a result_item. This can be either the PID of a # worker that exited gracefully or a _ResultItem - if isinstance(result_item, int): - # Clean shutdown of a worker using its PID - # (avoids marking the executor broken) + if isinstance(result_item, int): + # Clean shutdown of a worker using its PID + # (avoids marking the executor broken) assert self.is_shutting_down() p = self.processes.pop(result_item) - p.join() + p.join() if not self.processes: self.join_executor_internals() - return + return else: # Received a _ResultItem so mark the future as completed. work_item = self.pending_work_items.pop(result_item.work_id, None) - # work_item can be None if another process terminated (see above) - if work_item is not None: - if result_item.exception: - work_item.future.set_exception(result_item.exception) - else: - work_item.future.set_result(result_item.result) - + # work_item can be None if another process terminated (see above) + if work_item is not None: + if result_item.exception: + work_item.future.set_exception(result_item.exception) + else: + work_item.future.set_result(result_item.result) + def is_shutting_down(self): # Check whether we should start shutting down the executor. executor = self.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. + # 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. return (_global_shutdown or executor is None or executor._shutdown_thread) - + def terminate_broken(self, cause): # Terminate the executor because it is in a broken state. The cause # argument can be used to display more information on the error that # lead the executor into becoming broken. - + # Mark the process pool broken so that submits fail right now. executor = self.executor_reference() if executor is not None: @@ -522,108 +522,108 @@ class _ExecutorManagerThread(threading.Thread): return sum(p.is_alive() for p in self.processes.values()) -_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: - nsems_max = os.sysconf("SC_SEM_NSEMS_MAX") - except (AttributeError, ValueError): - # sysconf not available or setting not available - return - if nsems_max == -1: - # indetermined 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) - - -def _chain_from_iterable_of_lists(iterable): - """ - Specialized implementation of itertools.chain.from_iterable. - Each item in *iterable* should be a list. This function is - careful not to keep references to yielded objects. - """ - for element in iterable: - element.reverse() - while element: - yield element.pop() - - -class BrokenProcessPool(_base.BrokenExecutor): - """ - Raised when a process in a ProcessPoolExecutor terminated abruptly - while a future was in the running state. - """ - - -class ProcessPoolExecutor(_base.Executor): - def __init__(self, max_workers=None, mp_context=None, - initializer=None, initargs=()): - """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. - mp_context: A multiprocessing context to launch the workers. This - object should provide SimpleQueue, Queue and Process. +_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: + nsems_max = os.sysconf("SC_SEM_NSEMS_MAX") + except (AttributeError, ValueError): + # sysconf not available or setting not available + return + if nsems_max == -1: + # indetermined 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) + + +def _chain_from_iterable_of_lists(iterable): + """ + Specialized implementation of itertools.chain.from_iterable. + Each item in *iterable* should be a list. This function is + careful not to keep references to yielded objects. + """ + for element in iterable: + element.reverse() + while element: + yield element.pop() + + +class BrokenProcessPool(_base.BrokenExecutor): + """ + Raised when a process in a ProcessPoolExecutor terminated abruptly + while a future was in the running state. + """ + + +class ProcessPoolExecutor(_base.Executor): + def __init__(self, max_workers=None, mp_context=None, + initializer=None, initargs=()): + """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. + mp_context: A multiprocessing context to launch the workers. This + object should provide SimpleQueue, Queue and Process. initializer: A callable used to initialize worker processes. - initargs: A tuple of arguments to pass to the initializer. - """ - _check_system_limits() - - if max_workers is None: - self._max_workers = os.cpu_count() or 1 + initargs: A tuple of arguments to pass to the initializer. + """ + _check_system_limits() + + if max_workers is None: + self._max_workers = os.cpu_count() or 1 if sys.platform == 'win32': self._max_workers = min(_MAX_WINDOWS_WORKERS, self._max_workers) - else: - if max_workers <= 0: - raise ValueError("max_workers must be greater than 0") + else: + if max_workers <= 0: + raise ValueError("max_workers must be greater than 0") elif (sys.platform == 'win32' and max_workers > _MAX_WINDOWS_WORKERS): raise ValueError( f"max_workers must be <= {_MAX_WINDOWS_WORKERS}") - - self._max_workers = max_workers - - if mp_context is None: - mp_context = mp.get_context() - self._mp_context = mp_context - - if initializer is not None and not callable(initializer): - raise TypeError("initializer must be a callable") - self._initializer = initializer - self._initargs = initargs - - # Management thread + + self._max_workers = max_workers + + if mp_context is None: + mp_context = mp.get_context() + self._mp_context = mp_context + + if initializer is not None and not callable(initializer): + raise TypeError("initializer must be a callable") + self._initializer = initializer + self._initargs = initargs + + # Management thread self._executor_manager_thread = None - - # Map of pids to processes - self._processes = {} - - # Shutdown is a two-step process. - self._shutdown_thread = False - self._shutdown_lock = threading.Lock() + + # Map of pids to processes + self._processes = {} + + # Shutdown is a two-step process. + self._shutdown_thread = False + self._shutdown_lock = threading.Lock() self._idle_worker_semaphore = threading.Semaphore(0) - self._broken = False - self._queue_count = 0 - self._pending_work_items = {} + self._broken = False + self._queue_count = 0 + self._pending_work_items = {} self._cancel_pending_futures = False - + # _ThreadWakeup is a communication channel used to interrupt the wait # of the main loop of executor_manager_thread from another thread (e.g. # when calling executor.submit or executor.shutdown). We do not use the @@ -634,118 +634,118 @@ class ProcessPoolExecutor(_base.Executor): # _shutdown_lock must be locked to access _ThreadWakeup. self._executor_manager_thread_wakeup = _ThreadWakeup() - # Create communication channels for the executor - # 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. - queue_size = self._max_workers + EXTRA_QUEUED_CALLS - self._call_queue = _SafeQueue( - max_size=queue_size, ctx=self._mp_context, + # Create communication channels for the executor + # 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. + queue_size = self._max_workers + EXTRA_QUEUED_CALLS + self._call_queue = _SafeQueue( + max_size=queue_size, ctx=self._mp_context, pending_work_items=self._pending_work_items, shutdown_lock=self._shutdown_lock, thread_wakeup=self._executor_manager_thread_wakeup) - # Killed worker processes can produce spurious "broken pipe" - # tracebacks in the queue's own worker thread. But we detect killed - # processes anyway, so silence the tracebacks. - self._call_queue._ignore_epipe = True - self._result_queue = mp_context.SimpleQueue() - self._work_ids = queue.Queue() - + # Killed worker processes can produce spurious "broken pipe" + # tracebacks in the queue's own worker thread. But we detect killed + # processes anyway, so silence the tracebacks. + self._call_queue._ignore_epipe = True + self._result_queue = mp_context.SimpleQueue() + self._work_ids = queue.Queue() + def _start_executor_manager_thread(self): if self._executor_manager_thread is None: - # Start the processes so that their sentinels are known. + # Start the processes so that their sentinels are known. self._executor_manager_thread = _ExecutorManagerThread(self) self._executor_manager_thread.start() _threads_wakeups[self._executor_manager_thread] = \ self._executor_manager_thread_wakeup - - def _adjust_process_count(self): + + def _adjust_process_count(self): # if there's an idle process, we don't need to spawn a new one. if self._idle_worker_semaphore.acquire(blocking=False): return process_count = len(self._processes) if process_count < self._max_workers: - p = self._mp_context.Process( - target=_process_worker, - args=(self._call_queue, - self._result_queue, - self._initializer, - self._initargs)) - p.start() - self._processes[p.pid] = p - + p = self._mp_context.Process( + target=_process_worker, + args=(self._call_queue, + self._result_queue, + self._initializer, + self._initargs)) + p.start() + self._processes[p.pid] = p + def submit(self, fn, /, *args, **kwargs): - with self._shutdown_lock: - if self._broken: - raise BrokenProcessPool(self._broken) - if self._shutdown_thread: - raise RuntimeError('cannot schedule new futures after shutdown') - if _global_shutdown: - raise RuntimeError('cannot schedule new futures after ' - 'interpreter 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 + with self._shutdown_lock: + if self._broken: + raise BrokenProcessPool(self._broken) + if self._shutdown_thread: + raise RuntimeError('cannot schedule new futures after shutdown') + if _global_shutdown: + raise RuntimeError('cannot schedule new futures after ' + 'interpreter 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._executor_manager_thread_wakeup.wakeup() - + self._adjust_process_count() self._start_executor_manager_thread() - return f - submit.__doc__ = _base.Executor.submit.__doc__ - - def map(self, fn, *iterables, timeout=None, chunksize=1): - """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. - chunksize: If greater than one, the iterables will be chopped into - chunks of size chunksize and submitted to the process pool. - If set to one, the items in the list will be sent one at a 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. - """ - if chunksize < 1: - raise ValueError("chunksize must be >= 1.") - - results = super().map(partial(_process_chunk, fn), - _get_chunks(*iterables, chunksize=chunksize), - timeout=timeout) - return _chain_from_iterable_of_lists(results) - + return f + submit.__doc__ = _base.Executor.submit.__doc__ + + def map(self, fn, *iterables, timeout=None, chunksize=1): + """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. + chunksize: If greater than one, the iterables will be chopped into + chunks of size chunksize and submitted to the process pool. + If set to one, the items in the list will be sent one at a 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. + """ + if chunksize < 1: + raise ValueError("chunksize must be >= 1.") + + results = super().map(partial(_process_chunk, fn), + _get_chunks(*iterables, chunksize=chunksize), + timeout=timeout) + return _chain_from_iterable_of_lists(results) + def shutdown(self, wait=True, *, cancel_futures=False): - with self._shutdown_lock: + with self._shutdown_lock: self._cancel_pending_futures = cancel_futures - self._shutdown_thread = True + self._shutdown_thread = True if self._executor_manager_thread_wakeup is not None: # Wake up queue management thread self._executor_manager_thread_wakeup.wakeup() if self._executor_manager_thread is not None and wait: self._executor_manager_thread.join() - # To reduce the risk of opening too many files, remove references to - # objects that use file descriptors. + # To reduce the risk of opening too many files, remove references to + # objects that use file descriptors. self._executor_manager_thread = None self._call_queue = None if self._result_queue is not None and wait: self._result_queue.close() - self._result_queue = None - self._processes = None + self._result_queue = None + self._processes = None self._executor_manager_thread_wakeup = None - - shutdown.__doc__ = _base.Executor.shutdown.__doc__ + + shutdown.__doc__ = _base.Executor.shutdown.__doc__ diff --git a/contrib/tools/python3/src/Lib/concurrent/futures/thread.py b/contrib/tools/python3/src/Lib/concurrent/futures/thread.py index 2fd1dde9aee..51c942f51ab 100644 --- a/contrib/tools/python3/src/Lib/concurrent/futures/thread.py +++ b/contrib/tools/python3/src/Lib/concurrent/futures/thread.py @@ -1,137 +1,137 @@ -# Copyright 2009 Brian Quinlan. All Rights Reserved. -# Licensed to PSF under a Contributor Agreement. - -"""Implements ThreadPoolExecutor.""" - -__author__ = 'Brian Quinlan ([email protected])' - -from concurrent.futures import _base -import itertools -import queue -import threading +# Copyright 2009 Brian Quinlan. All Rights Reserved. +# Licensed to PSF under a Contributor Agreement. + +"""Implements ThreadPoolExecutor.""" + +__author__ = 'Brian Quinlan ([email protected])' + +from concurrent.futures import _base +import itertools +import queue +import threading import types -import weakref -import os - - -_threads_queues = weakref.WeakKeyDictionary() -_shutdown = False +import weakref +import os + + +_threads_queues = weakref.WeakKeyDictionary() +_shutdown = False # Lock that ensures that new workers are not created while the interpreter is # shutting down. Must be held while mutating _threads_queues and _shutdown. _global_shutdown_lock = threading.Lock() - -def _python_exit(): - global _shutdown + +def _python_exit(): + global _shutdown with _global_shutdown_lock: _shutdown = True - items = list(_threads_queues.items()) - for t, q in items: - q.put(None) - for t, q in items: - t.join() - + items = list(_threads_queues.items()) + for t, q in items: + q.put(None) + for t, q in items: + t.join() + # Register for `_python_exit()` to be called just before joining all # non-daemon threads. This is used instead of `atexit.register()` for # compatibility with subinterpreters, which no longer support daemon threads. # See bpo-39812 for context. threading._register_atexit(_python_exit) - + # At fork, reinitialize the `_global_shutdown_lock` lock in the child process if hasattr(os, 'register_at_fork'): os.register_at_fork(before=_global_shutdown_lock.acquire, after_in_child=_global_shutdown_lock._at_fork_reinit, after_in_parent=_global_shutdown_lock.release) - -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 BaseException as exc: - self.future.set_exception(exc) - # Break a reference cycle with the exception 'exc' - self = None - else: - self.future.set_result(result) - + +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 BaseException as exc: + self.future.set_exception(exc) + # Break a reference cycle with the exception 'exc' + self = None + else: + self.future.set_result(result) + __class_getitem__ = classmethod(types.GenericAlias) - -def _worker(executor_reference, work_queue, initializer, initargs): - if initializer is not None: - try: - initializer(*initargs) - except BaseException: - _base.LOGGER.critical('Exception in initializer:', exc_info=True) - executor = executor_reference() - if executor is not None: - executor._initializer_failed() - return - 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 + +def _worker(executor_reference, work_queue, initializer, initargs): + if initializer is not None: + try: + initializer(*initargs) + except BaseException: + _base.LOGGER.critical('Exception in initializer:', exc_info=True) + executor = executor_reference() + if executor is not None: + executor._initializer_failed() + return + 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 # attempt to increment idle count executor = executor_reference() if executor is not None: executor._idle_semaphore.release() del executor - continue + 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: + # Flag the executor as shutting down as early as possible if it + # is not gc-ed yet. + if executor is not None: + executor._shutdown = True + # Notice other workers + work_queue.put(None) + return + del executor + except BaseException: + _base.LOGGER.critical('Exception in worker', exc_info=True) + + +class BrokenThreadPool(_base.BrokenExecutor): + """ + Raised when a worker thread in a ThreadPoolExecutor failed initializing. + """ + - 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: - # Flag the executor as shutting down as early as possible if it - # is not gc-ed yet. - if executor is not None: - executor._shutdown = True - # Notice other workers - work_queue.put(None) - return - del executor - except BaseException: - _base.LOGGER.critical('Exception in worker', exc_info=True) - - -class BrokenThreadPool(_base.BrokenExecutor): - """ - Raised when a worker thread in a ThreadPoolExecutor failed initializing. - """ - - -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='', - initializer=None, initargs=()): - """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. +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='', + initializer=None, initargs=()): + """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. initializer: A callable used to initialize worker threads. - initargs: A tuple of arguments to pass to the initializer. - """ - if max_workers is None: + initargs: A tuple of arguments to pass to the initializer. + """ + if max_workers is None: # ThreadPoolExecutor is often used to: # * CPU bound task which releases GIL # * I/O bound task (which releases GIL, of course) @@ -140,82 +140,82 @@ class ThreadPoolExecutor(_base.Executor): # But we limit it to 32 to avoid consuming surprisingly large resource # on many core machine. max_workers = min(32, (os.cpu_count() or 1) + 4) - if max_workers <= 0: - raise ValueError("max_workers must be greater than 0") - - if initializer is not None and not callable(initializer): - raise TypeError("initializer must be a callable") - - self._max_workers = max_workers - self._work_queue = queue.SimpleQueue() + if max_workers <= 0: + raise ValueError("max_workers must be greater than 0") + + if initializer is not None and not callable(initializer): + raise TypeError("initializer must be a callable") + + self._max_workers = max_workers + self._work_queue = queue.SimpleQueue() self._idle_semaphore = threading.Semaphore(0) - self._threads = set() - self._broken = False - self._shutdown = False - self._shutdown_lock = threading.Lock() - self._thread_name_prefix = (thread_name_prefix or - ("ThreadPoolExecutor-%d" % self._counter())) - self._initializer = initializer - self._initargs = initargs - + self._threads = set() + self._broken = False + self._shutdown = False + self._shutdown_lock = threading.Lock() + self._thread_name_prefix = (thread_name_prefix or + ("ThreadPoolExecutor-%d" % self._counter())) + self._initializer = initializer + self._initargs = initargs + def submit(self, fn, /, *args, **kwargs): with self._shutdown_lock, _global_shutdown_lock: - if self._broken: - raise BrokenThreadPool(self._broken) - - if self._shutdown: - raise RuntimeError('cannot schedule new futures after shutdown') - if _shutdown: - raise RuntimeError('cannot schedule new futures after ' - 'interpreter 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): + if self._broken: + raise BrokenThreadPool(self._broken) + + if self._shutdown: + raise RuntimeError('cannot schedule new futures after shutdown') + if _shutdown: + raise RuntimeError('cannot schedule new futures after ' + 'interpreter 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): # if idle threads are available, don't spin new threads if self._idle_semaphore.acquire(timeout=0): return - # When the executor gets lost, the weakref callback will wake up - # the worker threads. - def weakref_cb(_, q=self._work_queue): - q.put(None) + # When the executor gets lost, the weakref callback will wake up + # the worker threads. + def weakref_cb(_, q=self._work_queue): + q.put(None) + + 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, + self._initializer, + self._initargs)) + t.start() + self._threads.add(t) + _threads_queues[t] = self._work_queue + + def _initializer_failed(self): + with self._shutdown_lock: + self._broken = ('A thread initializer failed, the thread pool ' + 'is not usable anymore') + # Drain work queue and mark pending futures failed + while True: + try: + work_item = self._work_queue.get_nowait() + except queue.Empty: + break + if work_item is not None: + work_item.future.set_exception(BrokenThreadPool(self._broken)) - 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, - self._initializer, - self._initargs)) - t.start() - self._threads.add(t) - _threads_queues[t] = self._work_queue - - def _initializer_failed(self): - with self._shutdown_lock: - self._broken = ('A thread initializer failed, the thread pool ' - 'is not usable anymore') - # Drain work queue and mark pending futures failed - while True: - try: - work_item = self._work_queue.get_nowait() - except queue.Empty: - break - if work_item is not None: - work_item.future.set_exception(BrokenThreadPool(self._broken)) - def shutdown(self, wait=True, *, cancel_futures=False): - with self._shutdown_lock: - self._shutdown = True + with self._shutdown_lock: + self._shutdown = True if cancel_futures: # Drain all work items from the queue, and then cancel their # associated futures. @@ -229,8 +229,8 @@ class ThreadPoolExecutor(_base.Executor): # Send a wake-up to prevent threads calling # _work_queue.get(block=True) from permanently blocking. - self._work_queue.put(None) - if wait: - for t in self._threads: - t.join() - shutdown.__doc__ = _base.Executor.shutdown.__doc__ + self._work_queue.put(None) + if wait: + for t in self._threads: + t.join() + shutdown.__doc__ = _base.Executor.shutdown.__doc__ |