bpo-6721: When os.fork() was called while another thread holds a logging lock, the child process may deadlock when it tries to log. This fixes that by acquiring all logging locks before fork and releasing them afterwards.
A regression test that fails before this change is included.
Within the new unittest itself: There is a small _potential_ due to mixing of fork and a thread in the child process if the parent's thread happened to hold a non-reentrant library call lock (malloc?) when the os.fork() happens. buildbots and time will tell if this actually manifests itself in this test or not. :/ A functionality test that avoids that would be a challenge.
An alternate test that isn't trying to produce the deadlock itself but just checking that the release and acquire calls are made would be the next best alternative if so.
[bpo-34658](https://www.bugs.python.org/issue34658): Fix a rare interpreter unhandled exception state SystemError only
seen when using subprocess with a preexec_fn while an after_parent handler has
been registered with os.register_at_fork and the fork system call fails.
https://bugs.python.org/issue34658
This causes the tearDown code to only unimport the test modules specifically created as part of each test via the self.mkhier method rather than abusing test.support.modules_setup() and the scary test.support.modules_cleanup() code.
https://bugs.python.org/issue34200
Store a weak reference to stream readerfor breaking strong references
It breaks the strong reference loop between reader and protocol and allows to detect and close the socket if the stream is deleted (garbage collected)
Address a C undefined behavior signed integer overflow issue in set object table resizing. Our -fwrapv compiler flag and practical reasons why sets are unlikely to get this large should mean this was never an issue but it was incorrect code that generates code analysis warnings.
<!-- issue-number: [bpo-1621](https://www.bugs.python.org/issue1621) -->
https://bugs.python.org/issue1621
<!-- /issue-number -->
When subprocess.Popen() stdin= stdout= or stderr= handles are specified
and appear in pass_fds=, don't close the original fds after dup'ing them.
This implementation and unittest primarily came from @izbyshev (see the PR)
See also b89b52f284
This also removes the old manual p2cread, c2pwrite, and errwrite closing logic
as inheritable flags and _close_open_fds takes care of that properly today without special treatment.
This code is within child_exec() where it is the only thread so there is no
race condition between the dup and _Py_set_inheritable_async_safe call.
The recursive frame pruning code always undercounted the number of elided frames
by one. That is, in the "[Previous line repeated N more times]" message, N would
always be one too few. Near the recursive pruning cutoff, one frame could be
silently dropped. That situation is demonstrated in the OP of the bug report.
The fix is to start the identical frame counter at 1.
Some methods of the SMTP class use mutable default arguments. Specially
`send_message` is affected as it mutates one of the args by appending items
to it, which has side effects on further calls.
* Add %T format to PyUnicode_FromFormatV(), and so to
PyUnicode_FromFormat() and PyErr_Format(), to format an object type
name: equivalent to "%s" with Py_TYPE(obj)->tp_name.
* Replace Py_TYPE(obj)->tp_name with %T format in unicodeobject.c.
* Add unit test on %T format.
* Rename unicode_fromformat_write_cstr() to
unicode_fromformat_write_utf8(), to make the intent more explicit.
Release GIL on grp.getgrnam(), grp.getgrgid(), pwd.getpwnam() and
pwd.getpwuid() if reentrant variants of these functions are available.
Patch by William Grzybowski.
Lisa Roach
Gregory P. Smith
Windson yang
Andrew Svetlov
Michael Felt
Benjamin Peterson
Eric V. Smith
Tony Flury
Oren Milman
Ethan Furman
Raymond Hettinger
orlnub123
Cheryl Sabella
Sergey Fedoseev
Max Bélanger
Victor Stinner
guoci
wim glenn
Zackery Spytz
Ned Deily
Matthias Bussonnier
Lew Kurtz
Zachary Ware
Rahul Jha
Berker Peksag
Julien Malard
Pablo Aguiar
William Grzybowski
Pablo Galindo
jdemeyer
Tal Einat
Erik Janssens
Alexander Buchkovsky