Commit Graph

118 Commits

Author SHA1 Message Date
Victor Stinner a46e960768
gh-109649: Use os.process_cpu_count() (#110165)
Replace os.cpu_count() with os.process_cpu_count() in modules:

* compileall
* concurrent.futures
* multiprocessing

Replace os.cpu_count() with os.process_cpu_count() in programs:

* _decimal deccheck.py test
* freeze.py
* multissltests.py
* python -m test (regrtest)
* wasm_build.py

Other changes:

* test.pythoninfo logs os.process_cpu_count().
* regrtest gets os.process_cpu_count() / os.cpu_count() in headers.
2023-10-01 03:14:57 +02:00
Victor Stinner 6351842121
gh-109047: concurrent.futures catches PythonFinalizationError (#109810)
concurrent.futures: The *executor manager thread* now catches
exceptions when adding an item to the *call queue*. During Python
finalization, creating a new thread can now raise RuntimeError. Catch
the exception and call terminate_broken() in this case.

Add test_python_finalization_error() to test_concurrent_futures.

concurrent.futures._ExecutorManagerThread changes:

* terminate_broken() no longer calls shutdown_workers() since the
  call queue is no longer working anymore (read and write ends of
  the queue pipe are closed).
* terminate_broken() now terminates child processes, not only
  wait until they complete.
* _ExecutorManagerThread.terminate_broken() now holds shutdown_lock
  to prevent race conditons with ProcessPoolExecutor.submit().

multiprocessing.Queue changes:

* Add _terminate_broken() method.
* _start_thread() sets _thread to None on exception to prevent
  leaking "dangling threads" even if the thread was not started
  yet.
2023-09-29 19:31:19 +00:00
Victor Stinner ae1d99c2ed
Remove concurrent.futures deadcode: process_result_item() (#109906)
process_result_item() cannot be called with an int anymore, the
protocol changed.
2023-09-26 21:33:59 +02:00
Serhiy Storchaka 0b4e090422
gh-109370: Fix unexpected traceback output in test_concurrent_futures (GH-109780)
Follow-up of gh-107219.

* Only close the connection writer on Windows.
* Also use existing constant _winapi.ERROR_OPERATION_ABORTED instead of
  WSA_OPERATION_ABORTED.
2023-09-26 10:06:07 +03:00
elfstrom 405b06375a
gh-105829: Fix concurrent.futures.ProcessPoolExecutor deadlock (#108513)
This fixes issue #105829, https://github.com/python/cpython/issues/105829

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Antoine Pitrou <antoine@python.org>
Co-authored-by: Chris Withers <chris@withers.org>
Co-authored-by: Thomas Moreau <thomas.moreau.2010@gmail.com>
2023-09-22 13:55:56 +01:00
Heinz-Alexander Fuetterer ef6d475db3
Fix typos in docs and comments (#109619) 2023-09-20 16:58:23 +00:00
Victor Stinner a9b1f84790
gh-107219: Fix concurrent.futures terminate_broken() (#109244)
Fix a race condition in concurrent.futures. When a process in the
process pool was terminated abruptly (while the future was running or
pending), close the connection write end. If the call queue is
blocked on sending bytes to a worker process, closing the connection
write end interrupts the send, so the queue can be closed.

Changes:

* _ExecutorManagerThread.terminate_broken() now closes
  call_queue._writer.
* multiprocessing PipeConnection.close() now interrupts
  WaitForMultipleObjects() in _send_bytes() by cancelling the
  overlapped operation.
2023-09-11 08:11:31 +00:00
Victor Stinner a8cae4071c
gh-107219: Fix concurrent.futures terminate_broken() (#108974)
Fix a race condition in _ExecutorManagerThread.terminate_broken():
ignore the InvalidStateError on future.set_exception(). It can happen
if the future is cancelled before the caller.

Moreover, test_crash_big_data() now waits explicitly until the
executor completes.
2023-09-06 15:57:01 +02:00
Louis Paulot 6782fc0502
gh-94777: Fix deadlock in ProcessPoolExecutor (#94784)
Fixes a hang in multiprocessing process pool executor when a child process crashes and code could otherwise block on writing to the pipe.  See GH-94777 for more details.
2023-07-10 21:45:27 +00:00
Andrii Kuzmin 0242e9a57a
gh-102024: Reduced _idle_semaphore.release calls (#102025)
Reduced _idle_semaphore.release calls in concurrent.futures.thread._worker
_idle_semaphore.release() is now only called if only work_queue is empty.

---------

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com>
2023-05-25 22:48:40 -07:00
yonatanp 2dc94634b5
gh-94440: Fix issue of ProcessPoolExecutor shutdown hanging (#94468)
Fix an issue of concurrent.futures ProcessPoolExecutor shutdown hanging.

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2023-03-15 21:44:52 -07:00
Alex Waygood 401d7a7f00
gh-102515: Remove unused imports in the `Lib/` directory (#102516) 2023-03-08 11:45:38 +00:00
Gregory P. Smith d4c410f0f9
gh-84559: Remove the new multiprocessing warning, too disruptive. (#101551)
This reverts the core of #100618 while leaving relevant documentation
improvements and minor refactorings in place.
2023-02-03 15:20:46 -08:00
Gregory P. Smith 0ca67e6313
GH-84559: Deprecate fork being the multiprocessing default. (#100618)
This starts the process. Users who don't specify their own start method
and use the default on platforms where it is 'fork' will see a
DeprecationWarning upon multiprocessing.Pool() construction or upon
multiprocessing.Process.start() or concurrent.futures.ProcessPool use.

See the related issue and documentation within this change for details.
2023-02-02 15:50:35 -08:00
Thomas Grainger e16d4ed590
gh-95166: cancel map waited on future on timeout (GH-95169)
Co-authored-by: Kumar Aditya <59607654+kumaraditya303@users.noreply.github.com>
2022-07-28 11:20:10 +02:00
Gregory P. Smith ebb37fc3fd
gh-90622: Do not spawn ProcessPool workers on demand via fork method. (#91598)
Do not spawn ProcessPool workers on demand when they spawn via fork.

This avoids potential deadlocks in the child processes due to forking from
a multithreaded process.
2022-05-08 09:20:34 -07:00
Gregory P. Smith fa4f0a134e
gh-90622: Prevent max_tasks_per_child use with a fork mp_context. (#91587)
Prevent `max_tasks_per_child` use with a "fork" mp_context to avoid deadlocks.

Also defaults to "spawn" when no mp_context is supplied for safe convenience.
2022-05-06 00:04:53 -07:00
themylogin 9c204b148f
bpo-46787: Fix `ProcessPoolExecutor exception` memory leak (GH-31408) (#31408)
Do not store `ProcessPoolExecutor` work item exception traceback that prevents
exception frame locals from being garbage collected.
2022-05-02 14:24:39 -06:00
Yiannis Hadjicharalambous b11243e85e
concurrent.futures: Fix typo in docstring (#92121) 2022-05-02 09:05:26 -06:00
Serhiy Storchaka 6927632492
Remove trailing spaces (GH-31695) 2022-03-05 17:47:00 +02:00
Thomas Grainger 9b12b1b803
bpo-46522: fix concurrent.futures and io AttributeError messages (GH-30887)
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Andrew Svetlov <andrew.svetlov@gmail.com>
2022-02-23 02:25:00 +02:00
Kumar Aditya 7d7817cf0f
bpo-20369: concurrent.futures.wait() now deduplicates futures given a… (GH-30168)
* bpo-20369: concurrent.futures.wait() now deduplicates futures given as arg.

* 📜🤖 Added by blurb_it.

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
2022-01-04 13:36:13 +00:00
Kumar Aditya da4b214304
bpo-42413: Replace `concurrent.futures.TimeoutError` and `asyncio.TimeoutError` with builtin `TimeoutError` (GH-30197)
Co-authored-by: Andrew Svetlov <andrew.svetlov@gmail.com>
2021-12-19 13:22:40 +02:00
Jakub Kulík 7431448b81
bpo-43498: Fix dictionary iteration error in _ExecutorManagerThread (GH-24868) 2021-11-29 14:02:56 +02:00
Logan Jones fdc0e09c33
bpo-44733: Add max_tasks_per_child to ProcessPoolExecutor (GH-27373)
Co-authored-by: Antoine Pitrou <antoine@python.org>
2021-11-20 21:19:41 +01:00
nullptr 0bfa1106ac
bpo-45021: Fix a hang in forked children (GH-28007)
_global_shutdown_lock should be reinitialized in forked children
2021-09-20 11:30:19 -07:00
Machinexa2 d56e700d6c
Use `from` imports (GH-26594)
from imports
2021-06-08 06:47:15 -03:00
Jesús Cea 32430aadad
bpo-35930: Raising an exception raised in a "future" instance will create reference cycles (#24995)
Before: https://lists.es.python.org/pipermail/general/attachments/20201229/0c14bc58/attachment-0002.png

After: https://lists.es.python.org/pipermail/general/attachments/20201229/0c14bc58/attachment-0003.png
2021-03-29 19:22:13 +02:00
Asheesh Laroia bf2e7e55d7
bpo-40692: Run more test_concurrent_futures tests (GH-20239)
In the case of multiprocessing.synchronize() being missing, the
test_concurrent_futures test suite now skips only the tests that
require multiprocessing.synchronize().

Validate that multiprocessing.synchronize exists as part of
_check_system_limits(), allowing ProcessPoolExecutor to raise
NotImplementedError during __init__, rather than crashing with
ImportError during __init__ when creating a lock imported from
multiprocessing.synchronize.

Use _check_system_limits() to disable tests of
ProcessPoolExecutor on systems without multiprocessing.synchronize.

Running the test suite without multiprocessing.synchronize reveals
that Lib/compileall.py crashes when it uses a ProcessPoolExecutor.
Therefore, change Lib/compileall.py to call _check_system_limits()
before creating the ProcessPoolExecutor.

Note that both Lib/compileall.py and Lib/test/test_compileall.py
were attempting to sanity-check ProcessPoolExecutor by expecting
ImportError. In multiprocessing.resource_tracker, sem_unlink() is also absent
on platforms where POSIX semaphores aren't available. Avoid using
sem_unlink() if it, too, does not exist.

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
2021-02-08 03:15:51 +00:00
Shantanu 17dc1b789e
bpo-39349: Add cancel_futures to Executor.shutdown base class (GH-22023)
* Add cancel_futures parameter to the Executor base class, since it was missed in the original PR (https://github.com/python/cpython/pull/18057) that added cancel_futures.
2020-09-01 17:18:07 -04:00
Victor Stinner 90549676e0
bpo-40443: Remove unused imports in the stdlib (GH-19803) 2020-04-30 11:26:33 +02:00
Victor Stinner a4dfe8ede5
bpo-39995: Fix concurrent.futures _ThreadWakeup (GH-19760)
Fix a race condition in concurrent.futures._ThreadWakeup: access to
_ThreadWakeup is now protected with the shutdown lock.
2020-04-29 03:32:06 +02:00
Victor Stinner 1a275013d1
bpo-30966: concurrent.futures.Process.shutdown() closes queue (GH-19738)
Process.shutdown(wait=True) of concurrent.futures now closes
explicitly the result queue.
2020-04-27 20:53:37 +02:00
Kyle Stanley 1ac6e37929
bpo-39207: Spawn workers on demand in ProcessPoolExecutor (GH-19453)
Roughly based on 904e34d4e6, but with a few substantial differences.

/cc @pitrou @brianquinlan
2020-04-19 07:00:59 -07:00
Batuhan Taşkaya 0361556537
bpo-39481: PEP 585 for a variety of modules (GH-19423)
- concurrent.futures
- ctypes
- http.cookies
- multiprocessing
- queue
- tempfile
- unittest.case
- urllib.parse
2020-04-10 07:46:36 -07:00
Kyle Stanley b61b818d91
bpo-39812: Remove daemon threads in concurrent.futures (GH-19149)
Remove daemon threads from :mod:`concurrent.futures` by adding
an internal `threading._register_atexit()`, which calls registered functions
prior to joining all non-daemon threads. This allows for compatibility
with subinterpreters, which don't support daemon threads.
2020-03-27 20:31:22 +01:00
Thomas Moreau 0e89076247
bpo-39678: refactor queue manager thread (GH-18551) 2020-03-01 21:49:14 +01:00
Thomas Moreau a5cbab552d
bpo-39104: Fix hanging ProcessPoolExecutor on shutdown nowait with pickling failure (GH-17670)
As reported initially by @rad-pat in #6084, the following script causes a deadlock.

```
from concurrent.futures import ProcessPoolExecutor


class ObjectWithPickleError():
    """Triggers a RuntimeError when sending job to the workers"""

    def __reduce__(self):
        raise RuntimeError()


if __name__ == "__main__":
    e = ProcessPoolExecutor()
    f = e.submit(id, ObjectWithPickleError())
    e.shutdown(wait=False)
    f.result()  # Deadlock on get
```

This is caused by the fact that the main process is closing communication channels that might be necessary to the `queue_management_thread` later. To avoid this, this PR let the `queue_management_thread` manage all the closing.



https://bugs.python.org/issue39104



Automerge-Triggered-By: @pitrou
2020-02-16 10:09:26 -08:00
Kyle Stanley 339fd46cb7
bpo-39349: Add *cancel_futures* to Executor.shutdown() (GH-18057) 2020-02-02 13:49:00 +01:00
Brian Quinlan 242c26f53e
bpo-31783: Fix a race condition creating workers during shutdown (#13171)
* bpo-31783: Fix a race condition while creating workers during interpreter shutdown

* 📜🤖 Added by blurb_it.
2019-06-28 11:54:52 -07:00
ubordignon 552ace7498 Fix typo in Lib/concurrent/futures/thread.py (GH-13953) 2019-06-15 07:43:10 -04:00
Serhiy Storchaka 142566c028
[3.9] bpo-37116: Use PEP 570 syntax for positional-only parameters. (GH-12620)
Turn deprecation warnings added in 3.8 into TypeError.
2019-06-05 18:22:31 +03:00
Inada Naoki 9a7e5b1b42
bpo-35279: reduce default max_workers of ThreadPoolExecutor (GH-13618) 2019-05-28 21:02:52 +09:00
Sean 904e34d4e6 bpo-24882: Let ThreadPoolExecutor reuse idle threads before creating new thread (#6375)
* Fixes issue 24882

* Add news file entry for change.

* Change test_concurrent_futures.ThreadPoolShutdownTest

Adjust the shutdown test so that, after submitting three jobs
to the executor, the test checks for less than three threads,
instead of looking for exactly three threads.

If idle threads are being recycled properly, then we should have
less than three threads.

* Switched idle count to semaphor, Updated tests

As suggested by reviewer tomMoral, swapped lock-protected counter
with a semaphore to track the number of unused threads.

Adjusted test_threads_terminate to wait for completiton of the
previous future before submitting a new one (and checking the
number of threads used).

Also added a new test to confirm the thread pool can be saturated.

* Updates tests as requested by pitrou.

* Correct minor whitespace error.

* Make test_saturation faster
2019-05-22 23:29:58 +02:00
Sam Martin 2a3a2ece50 bpo-33110: Catch errors raised when running add_done_callback on already completed futures (GH-13141)
Wrap the callback call within the `add_done_callback` function within concurrent.futures, in order to behave in an identical manner to callbacks added to a running future are triggered once it has completed.
2019-05-22 23:29:02 +02:00
Brian Quinlan 39889864c0 bpo-26903: Limit ProcessPoolExecutor to 61 workers on Windows (GH-13132)
Co-Authored-By: brianquinlan <brian@sweetapp.com>
2019-05-08 14:04:53 -04:00
Brian Quinlan f7bda5c572 Don't import wait from connection, it shadows a name (GH-13112)
(lint cleanup) This import causes an argument parameter to shadow the global import name.
2019-05-07 13:31:11 -04:00
Serhiy Storchaka d53cf99dca
bpo-36542: Allow to overwrite the signature for Python functions. (GH-12705) 2019-05-06 22:40:27 +03:00
Thomas Grainger f938d8be4c Correct grammar in concurrent/futures/process.py docstring (GH-12761) 2019-04-12 09:17:17 -07:00
Serhiy Storchaka 42a139ed88
bpo-36492: Deprecate passing some arguments as keyword arguments. (GH-12637)
Deprecated passing the following arguments as keyword arguments:

- "func" in functools.partialmethod(), weakref.finalize(),
  profile.Profile.runcall(), cProfile.Profile.runcall(),
  bdb.Bdb.runcall(), trace.Trace.runfunc() and
  curses.wrapper().
- "function" in unittest.addModuleCleanup() and
  unittest.TestCase.addCleanup().
- "fn" in the submit() method of concurrent.futures.ThreadPoolExecutor
  and concurrent.futures.ProcessPoolExecutor.
- "callback" in contextlib.ExitStack.callback(),
  contextlib.AsyncExitStack.callback() and
  contextlib.AsyncExitStack.push_async_callback().
- "c" and "typeid" in the create() method of multiprocessing.managers.Server
  and multiprocessing.managers.SharedMemoryServer.
- "obj" in weakref.finalize().

Also allowed to pass arbitrary keyword arguments (even "self" and "func")
if the above arguments are passed as positional argument.
2019-04-01 09:16:35 +03:00