On Unix, subprocess.Popen.send_signal() now polls the process status.
Polling reduces the risk of sending a signal to the wrong process if
the process completed, the Popen.returncode attribute is still None,
and the pid has been reassigned (recycled) to a new different
process.
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.
* bpo-38456: Use /bin/true in test_subprocess.
Instead of sys.executable, "-c", "pass" or "import sys; sys.exit(0)"
use /bin/true when it is available. On a reasonable machine this
shaves up to two seconds wall time off the otherwise ~40sec execution
on a --with-pydebug build. It should be more notable on many
buildbots or overloaded slower I/O systems (CI, etc).
* subprocess.Popen now longer uses posix_spawn() if uid, gid or gids are set.
* test_subprocess: add "nobody" and "nfsnobody" group names for test_group().
* test_subprocess: test_user() and test_group() are now also tested with close_fds=False.
* subprocess: Add user, group and extra_groups paremeters to subprocess.Popen
This adds a `user` parameter to the Popen constructor that will call
setreuid() in the child before calling exec(). This allows processes
running as root to safely drop privileges before running the subprocess
without having to use a preexec_fn.
This also adds a `group` parameter that will call setregid() in
the child process before calling exec().
Finally an `extra_groups` parameter was added that will call
setgroups() to set the supplimental groups.
Fixes a possible hang when using a timeout on subprocess.run() while
capturing output. If the child process spawned its own children or otherwise
connected its stdout or stderr handles with another process, we could hang
after the timeout was reached and our child was killed when attempting to read
final output from the pipes.
As noted by @eryksun in [1] and [2], using _cleanup and _active(in
__del__) is not necessary on Windows, since:
> Unlike Unix, a process in Windows doesn't have to be waited on by
> its parent to avoid a zombie. Keeping the handle open will actually
> create a zombie until the next _cleanup() call, which may be never
> if Popen() isn't called again.
This patch simply defines `subprocess._active` as `None`, for which we already
have the proper logic in place in `subprocess.Popen.__del__`, that prevents it
from trying to append the process to the `_active`. This patch also defines
`subprocess._cleanup` as a noop for Windows.
[1] https://bugs.python.org/issue37380#msg346333
[2] https://bugs.python.org/issue36067#msg336262
Signed-off-by: Ruslan Kuprieiev <ruslan@iterative.ai>
If buffering=1 is specified for open() in binary mode, it is silently
treated as buffering=-1 (i.e., the default buffer size).
Coupled with the fact that line buffering is always supported in Python 2,
such behavior caused several issues (e.g., bpo-10344, bpo-21332).
Warn that line buffering is not supported if open() is called with
binary mode and buffering=1.
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.
subprocess.Popen now copies the startupinfo argument to leave it
unchanged: it will modify the copy, so that the same STARTUPINFO
object can be used multiple times.
Add subprocess.STARTUPINFO.copy() method.
* Add support.MS_WINDOWS: True if Python is running on Microsoft Windows.
* Add support.MACOS: True if Python is running on Apple macOS.
* Replace support.is_android with support.ANDROID
* Replace support.is_jython with support.JYTHON
* Cleanup code to initialize unix_shell
bpo-32844: subprocess: Fix a potential misredirection of a low fd to stderr.
When redirecting, subprocess attempts to achieve the following state:
each fd to be redirected to is less than or equal to the fd
it is redirected from, which is necessary because redirection
occurs in the ascending order of destination descriptors.
It fails to do so in a couple of corner cases,
for example, if 1 is redirected to 2 and 0 is closed in the parent.
Do not allow receiving a SIGINT to cause the subprocess module to trigger an
immediate SIGKILL of the child process. SIGINT is normally sent to all child
processes by the OS at the same time already as was the established normal
behavior in 2.7 and 3.2. This behavior change was introduced during the fix to https://bugs.python.org/issue12494 and is generally surprising to command line
tool users who expect other tools launched in child processes to get their own
SIGINT and do their own cleanup.
In Python 3.3-3.6 subprocess.call and subprocess.run would immediately
SIGKILL the child process upon receiving a SIGINT (which raises a
KeyboardInterrupt). We now give the child a small amount of time to
exit gracefully before resorting to a SIGKILL.
This is also the case for subprocess.Popen.__exit__ which would
previously block indefinitely waiting for the child to die. This was
hidden from many users by virtue of subprocess.call and subprocess.run
sending the signal immediately.
Behavior change: subprocess.Popen.__exit__ will not block indefinitely
when the exiting exception is a KeyboardInterrupt. This is done for
user friendliness as people expect their ^C to actually happen. This
could cause occasional orphaned Popen objects when not using `call` or
`run` with a child process that hasn't exited.
Refactoring involved: The Popen.wait method deals with the
KeyboardInterrupt second chance, existing platform specific internals
have been renamed to _wait().
Also fixes comment typos.
Some tests failed when the PATH environment variable contained a path
to an existing file. Fix tests to ignore also NotADirectoryError, not
only FileNotFoundError and PermissionError.
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.
Improve human friendliness of the Popen API: Add text=False as a
keyword-only argument to subprocess.Popen along with a Popen
attribute .text_mode and set this based on the
encoding/errors/universal_newlines/text arguments.
The universal_newlines parameter and attribute are maintained for
backwards compatibility.
Fix test_exception_errpipe_bad_data() and
test_exception_errpipe_normal() of test_subprocess: mock os.waitpid()
to avoid calling the real os.waitpid(0, 0) which is an unexpected
side effect of the test.
* bpo-30121: Fix debug assert in subprocess on Windows
This is caused by closing HANDLEs using os.close which is for CRT file
descriptors and not for HANDLEs.
* bpo-30121: Suppress debug assertion in test_subprocess when ran directly
The current test_child_terminated_in_stopped_state() function test
creates a child process which calls ptrace(PTRACE_TRACEME, 0, 0) and
then crash (SIGSEGV). The problem is that calling os.waitpid() in the
parent process is not enough to close the process: the child process
remains alive and so the unit test leaks a child process in a
strange state. Closing the child process requires non-trivial code,
maybe platform specific.
Remove the functional test and replaces it with an unit test which
mocks os.waitpid() using a new _testcapi.W_STOPCODE() function to
test the WIFSTOPPED() path.
bpo-30764, bpo-29335: test_child_terminated_in_stopped_state() of
test_subprocess now uses support.SuppressCrashReport() to prevent the
creation of a core dump on FreeBSD.
- new PYTHONCOERCECLOCALE config setting
- coerces legacy C locale to C.UTF-8, C.utf8 or UTF-8 by default
- always uses C.UTF-8 on Android
- uses `surrogateescape` on stdin and stdout in the coercion
target locales
- configure option to disable locale coercion at build time
- configure option to disable C locale warning at build time
Bugfix: This test wasn't being run because it was skipping based on the
presence of Py_ENABLE_SHARED rather than its value. It is always present
on POSIX systems but defaults to 0.
Refactoring: Move the environment variables that can be ignored into a
function. Parse the list from the child process and filter out the ones
to exclude in the parent before checking that the rest is empty.
Feature: Adds always present environment variables to ignore when
running in a Gentoo sandbox so that the test can pass there.
The Windows-specific subprocess.STARTUPINFO class now accepts
keyword-only arguments to its constructor to set the various
data attributes.
Patch by Subhendu Ghosh.
The OS X buildbots were failing at the second setrlimit() call with EPERM, as
if they were trying to raise the hard limit. The call should be keeping the
hard limit the same and raising the soft limit back to its original value, so
I don't understand the failure.
The helper was added in 76641824cf05 11 years ago and it can be
removed now since all supported Python versions have tempfile.mkstemp().
Patch by Nir Soffer.
Victor Stinner
Batuhan Taşkaya
Andrey Doroschenko
Pablo Galindo
Gregory P. Smith
Victor Stinner
Patrick McLean
Min ho Kim
Ruslan Kuprieiev
Serhiy Storchaka
Alexey Izbyshev
Zackery Spytz
Michael Felt
Alexey Izbyshev
Zachary Ware
Anders Lorentsen
Bo Bayles
Victor Stinner
Segev Finer
andyclegg
Oren Milman
Antoine Pitrou
Ammar Askar
Ned Deily
Ville Skyttä
Nick Coghlan
Sayan Chowdhury
Subhendu Ghosh
Xavier de Gaye
Martin Panter
Steve Dower
Raymond Hettinger
Berker Peksag