ossobv / pysigset

Python blocking/suspending signals under Linux/OSX using ctypes sigprocmask access

pysigset, signal blocking under GNU/Linux & OS X

Provides access to sigprocmask(2) and friends and convenience wrappers to python application developers wanting to SIG_BLOCK and SIG_UNBLOCK signals in critical sections of their code.

Most common usage

from signal import SIGINT, SIGTERM
from pysigset import suspended_signals

with suspended_signals(SIGINT, SIGTERM):
    # Signals are blocked here..
    pass
# Any pending signal is fired now..

Also available

sigaddset(*args)
    int sigaddset(sigset_t *set, int signum)

sigdelset(*args)
    int sigdelset(sigset_t *set, int signum)

sigemptyset(*args)
    int sigemptyset(sigset_t *set)

sigfillset(*args)
    int sigfillset(sigset_t *set)

sigismember(*args)
    int sigismember(const sigset_t *set, int signum)

sigpending(*args)
    int sigpending(sigset_t *set)

sigprocmask(*args)
    int sigprocmask(int how, const sigset_t *set, sigset_t *oldset)

sigsuspend(*args)
    int sigsuspend(const sigset_t *mask)

Similar tools

python-signalfd provides access to sigprocmask and signalfd. Its advantage is access to signalfd. Its disadvantage is a compilation requirement.

pysigset has a pythonic interface and requires only ctypes access to libc.so.6 or libSystem.B.dylib.

Changes

2021-05-03: 0.4.0

• Change License to LGPL 3.

2015-09-22: 0.3.2

• Python 3 compatibility (thanks Kevin Pouget).
• Update version, update trove classifiers; adding Python 3, moving to Production/Stable.

2015-05-23: 0.2.2

• Fix so we can install using setup.py again.

2013-07-30: 0.2.1

• Fix so the RST is displayed on PyPI.

2013-07-30: 0.2

• Add support for OS X / Darwin (thanks Dan Sully (dsully))
• Add support for easy uploading to PyPI.

2013-04-15: 0.1

• Initial release.

Copyright

Copyright 2013-2021, Walter Doekes (OSSO B.V.)

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this program. If not, see http://www.gnu.org/licenses/.

pysigset's Issues

Check two py3 fixes from pjump

pjump@25e91e8
pjump@2e9b479

Refactor binrepr() function into callable instance

class Binrepr(object):
    def __call__(self, integer):
        ...
binrepr = Binrepr()

Methods:

• _list_to_str()
• _int_to_list()

Move main() code into test_ file

Moving the main() code to a test_pysigset.py file makes sense:

• better BCH points
• less code loaded into memory which we're not using

Don't forget to update pysigset version and pushing to pypi when fixing stuff.

Refactor SIGSET.__repr__() to call other methods

def __repr__(self):
    human_sigs = _get_human_signals()
    return '{%s}' % (', '.join(ret),)

def _get_human_signals(self):
        ret = []
        for i, bitmask in enumerate(self.val):
            if bitmask:
                ret.extend(self._get_XXX(mask2list, i, bitmask)
    return ret

def _get_XXX(...):
                if mask2list and i <= 1:  # 64 bits in the first two int32s
                    numbers = mask2list(bitmask)  # sorted from low to high
                    if i == 1:
                        numbers = [i << 1 for i in numbers]
                    for number in numbers:
                        ret.append(SIGNAMES.get(number, 'SIG%d' % (number,)))
                else:
                    strvalue = binrepr and binrepr(bitmask) or str(bitmask)
                    ret.append('%d: %s' % (i, strvalue))
    return ret

Or something..

Add __doc__ setting to _wrap() function

sigemptyset = _wrap(libc.sigemptyset, [0])
sigemptyset.__doc__ = 'int sigemptyset(sigset_t *set)'

This could be:

sigemptyset = _wrap(
    libc.sigemptyset, [0], 'int sigemptyset(sigset_t *set)')

Add BCH badge to README

Make BCH happy by removing two "code" lookalikes

else:  # platform.system() == 'Linux'

Replace with "is" or something, so it doesn't think the code is "removed".

Same with:

Copyright 2013-2015, Walter Doekes (OSSO B.V.) <wjdoekes osso nl>

It thinks that is code. Replace with e-mail address with + in it?

please improve examples in documentation

It is not clear to me how to instantiate a sigset in order to then pass it to pysigset.sigaddset(). Please could you improve the examples in the "Most common usage" section to cover instantiation of a sigset (mysigset = ???) and a call to sigsetadd() (??? = sigsetadd(mysigset???, signal.SIGCHLD???) Thanks.