The picklers do no longer allocate temporary memory when dumping large
bytes and str objects into a file object. Instead the data is
directly streamed into the underlying file object.
Previously the C implementation would buffer all content and issue a
single call to file.write() at the end of the dump. With protocol 4
this behavior has changed to issue one call to file.write() per frame.
The Python pickler with protocol 4 now dumps each frame content as a
memoryview to an IOBytes instance that is never reused and the
memoryview is no longer released after the call to write. This makes it
possible for the file object to delay access to the memoryview of
previous frames without forcing any additional memory copy as was
already possible with the C pickler.
Add a new argument "-m" to the pdb module to allow
users to run `python -m pdb -m my_module_name`.
This relies on private APIs in the runpy module to work,
but we can get away with that since they're both part of
the standard library and can be updated together if
the runpy internals get refactored.
Fix deadlocks in :class:`concurrent.futures.ProcessPoolExecutor` when task arguments or results cause pickling or unpickling errors.
This should make sure that calls to the :class:`ProcessPoolExecutor` API always eventually return.
Skip the test which fails on FreeBSD with POSIX locale.
Skip the test to fix FreeBSD buildbots, until a fix can be found, so
the buildbots can catch other regressions.
Skip the test failing randomly because of known race condition.
Skip the test to fix macOS buildbots until a decision is made on the
proper fix for the race condition.
* Make ssh_handshake_timeout None by default.
* Raise ValueError if ssl_handshake_timeout is used without ssl.
* Raise ValueError if ssl_handshake_timeout is not positive.
The last part of test_close_fds() doesn't match its own comment.
The following assertion always holds because fds_to_keep and open_fds
are disjoint by construction.
self.assertFalse(remaining_fds & fds_to_keep & open_fds,
"Some fds not in pass_fds were left open")
Fix the code to match the message in the assertion.
Even though Python marks any handles it opens as non-inheritable there
is still a race when using `subprocess.Popen` since creating a process
with redirected stdio requires temporarily creating inheritable handles.
By implementing support for `subprocess.Popen(close_fds=True)` we fix
this race.
In order to implement this we use PROC_THREAD_ATTRIBUTE_HANDLE_LIST
which is available since Windows Vista. Which allows to pass an explicit
list of handles to inherit when creating a process.
This commit also adds `STARTUPINFO.lpAttributeList["handle_list"]`
which can be used to control PROC_THREAD_ATTRIBUTE_HANDLE_LIST
directly.
