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v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision f4d644f36ffb6cb11b34bfcf533c14cfaebf709a authored by Gregory P. Smith on 30 January 2018, 05:27:39 UTC, committed by GitHub on 30 January 2018, 05:27:39 UTC 
bpo-25942: make subprocess more graceful on ^C (GH-5026)
 
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.
1 parent 83e64c8
Raw File
Tip revision: f4d644f36ffb6cb11b34bfcf533c14cfaebf709a authored by Gregory P. Smith on 30 January 2018, 05:27:39 UTC
bpo-25942: make subprocess more graceful on ^C (GH-5026)
Tip revision: f4d644f
_bootlocale.py 
"""A minimal subset of the locale module used at interpreter startup
(imported by the _io module), in order to reduce startup time.

Don't import directly from third-party code; use the `locale` module instead!
"""

import sys
import _locale

if sys.platform.startswith("win"):
    def getpreferredencoding(do_setlocale=True):
        if sys.flags.utf8_mode:
            return 'UTF-8'
        return _locale._getdefaultlocale()[1]
else:
    try:
        _locale.CODESET
    except AttributeError:
        if hasattr(sys, 'getandroidapilevel'):
            # On Android langinfo.h and CODESET are missing, and UTF-8 is
            # always used in mbstowcs() and wcstombs().
            def getpreferredencoding(do_setlocale=True):
                return 'UTF-8'
        else:
            def getpreferredencoding(do_setlocale=True):
                if sys.flags.utf8_mode:
                    return 'UTF-8'
                # This path for legacy systems needs the more complex
                # getdefaultlocale() function, import the full locale module.
                import locale
                return locale.getpreferredencoding(do_setlocale)
    else:
        def getpreferredencoding(do_setlocale=True):
            assert not do_setlocale
            if sys.flags.utf8_mode:
                return 'UTF-8'
            result = _locale.nl_langinfo(_locale.CODESET)
            if not result and sys.platform == 'darwin':
                # nl_langinfo can return an empty string
                # when the setting has an invalid value.
                # Default to UTF-8 in that case because
                # UTF-8 is the default charset on OSX and
                # returning nothing will crash the
                # interpreter.
                result = 'UTF-8'
            return result
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