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.
Tests now call busy_retry() and sleeping_retry() with SHORT_TIMEOUT
or LONG_TIMEOUT (of test.support), rather than hardcoded constants.
Add also WAIT_ACTIVE_CHILDREN_TIMEOUT constant to
_test_multiprocessing.
Add an optional keyword 'shutdown_timeout' parameter to the
multiprocessing.BaseManager constructor. Kill the process if
terminate() takes longer than the timeout.
Multiprocessing tests pass test.support.SHORT_TIMEOUT
to BaseManager.shutdown_timeout.
Skip tests on ASAN and/or MSAN builds:
* multiprocessing tests
* test___all__
* test_concurrent_futures
* test_decimal
* test_peg_generator
* test_tools
The ASAN job of GitHub Actions no longer excludes these tests.
For threads, and for multiprocessing, it's always been the case that ``args=list`` works fine when passed to ``Process()`` or ``Thread()``, and such code is common in the wild. But, according to the docs, only a tuple can be used. This brings the docs into synch with reality.
Doc changes by Charlie Zhao.
Co-authored-by: Tim Peters <tim.peters@gmail.com>
Add a PID to names of POSIX shared memory objects to allow
running multiprocessing tests (test_multiprocessing_fork,
test_multiprocessing_spawn, etc) in parallel.
On Linux, skip tests using multiprocessing if the current user cannot
create a file in /dev/shm/ directory. Add the
skip_if_broken_multiprocessing_synchronize() function to the
test.support module.
* Move socket related functions from test.support to socket_helper.
* Import socket, nntplib and urllib.error lazily in transient_internet().
* Remove importing multiprocess.
Log "Warning -- ..." test warnings into sys.__stderr__ rather than
sys.stderr, to ensure to display them even if sys.stderr is captured.
test.libregrtest.utils.print_warning() now calls
test.support.print_warning().
Moreover, the following tests now check the child process exit code:
* test_os.PtyTests
* test_mailbox.test_lock_conflict()
* test_tempfile.test_process_awareness()
* test_uuid.testIssue8621()
* multiprocessing resource tracker tests
When the pull is not used via the context manager or terminate() is called, there is a system in multiprocessing.util that handles finalization of all pools via an atexit handler (the Finalize) class. This class registers the _terminate_pool handler in the registry of finalizers of the module, and that registry is called on interpreter exit via _exit_function. The problem is that the "happy" path with the context manager or manual call to finalize() does some extra steps that _terminate_pool does not. The step that is not executed when the atexit() handler calls _terminate_pool is pinging the _change_notifier queue to unblock the maintenance threads.
This commit moves the notification to the _terminate_pool function so is called from both code paths.
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
Multiprocessing and concurrent.futures tests now stop the resource
tracker process when tests complete.
Add ResourceTracker._stop() method to
multiprocessing.resource_tracker.
Add _cleanup_tests() helper function to multiprocessing.util: share
code between multiprocessing and concurrent.futures tests.
Replace hardcoded timeout constants in tests with SHORT_TIMEOUT of
test.support, so it's easier to ajdust this timeout for all tests at
once.
SHORT_TIMEOUT is 30 seconds by default, but it can be longer
depending on --timeout command line option.
The change makes almost all timeouts longer, except
test_reap_children() of test_support which is made 2x shorter:
SHORT_TIMEOUT should be enough. If this test starts to fail,
LONG_TIMEOUT should be used instead.
Uniformize also "from test import support" import in some test files.
Replace hardcoded timeout constants in tests with LONG_TIMEOUT of
test.support, so it's easier to ajdust this timeout for all tests at
once.
LONG_TIMEOUT is 5 minutes by default, but it can be longer depending
on --timeout command line option.
This PR implements a fix for `multiprocessing.Process` objects; the error occurs when Processes are created using either `fork` or `forkserver` as the `start_method`.
In these instances, the `MainThread` of the newly created `Process` object retains all attributes from its parent's `MainThread` object, including the `native_id` attribute. The resulting behavior is such that the new process' `MainThread` captures an incorrect/outdated `native_id` (the parent's instead of its own).
This change forces the Process object to update its `native_id` attribute during the bootstrap process.
cc @vstinner
https://bugs.python.org/issue38707
Automerge-Triggered-By: @pitrou
Gregory P. Smith
Serhiy Storchaka
Jack Hindmarch
Koki Saito
Christian Heimes
Kumar Aditya
Irit Katriel
Victor Stinner
Leo Trol
Géry Ogam
Charlie Zhao
Kumar Aditya
Nikita Sobolev
finefoot
Inada Naoki
Vinay Sharma
Hai Shi
idomic
Antoine Pitrou
Batuhan Taşkaya
Pablo Galindo
Christopher Hunt
Jake Tesler