Mercurial > hg
view mercurial/rcutil.py @ 35460:8652ab4046e4
osutil: add a function to unblock signals
Signals could be blocked by something like:
#include <unistd.h>
#include <signal.h>
int main(int argc, char * const argv[]) {
sigset_t set;
sigfillset(&set);
sigprocmask(SIG_BLOCK, &set, NULL);
execv("/bin/hg", argv);
return 0;
}
One of the problems is if SIGCHLD is blocked, chgserver would not reap
zombie workers since it depends on SIGCHLD handler entirely.
While it's the parent process to blame but it seems a good idea to just
unblock the signal from hg. FWIW git does that for SIGPIPE already [1].
Unfortunately Python 2 does not reset or provide APIs to change signal
masks. Therefore let's add one in osutil. Note: Python 3.3 introduced
`signal.pthread_sigmask` which solves the problem.
`sigprocmask` is part of POSIX [2] so there is no feature testing in
`setup.py`.
[1]: https://github.com/git/git/commit/7559a1be8a0afb10df41d25e4cf4c5285a5faef1
[2]: http://pubs.opengroup.org/onlinepubs/7908799/xsh/sigprocmask.html
Differential Revision: https://phab.mercurial-scm.org/D1736
author | Jun Wu <quark@fb.com> |
---|---|
date | Wed, 20 Dec 2017 02:13:35 -0800 |
parents | 75979c8d4572 |
children | edbcf5b239f9 |
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# rcutil.py - utilities about config paths, special config sections etc. # # Copyright Mercurial Contributors # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import os from . import ( encoding, pycompat, util, ) if pycompat.iswindows: from . import scmwindows as scmplatform else: from . import scmposix as scmplatform fallbackpager = scmplatform.fallbackpager systemrcpath = scmplatform.systemrcpath userrcpath = scmplatform.userrcpath def _expandrcpath(path): '''path could be a file or a directory. return a list of file paths''' p = util.expandpath(path) if os.path.isdir(p): join = os.path.join return [join(p, f) for f, k in util.listdir(p) if f.endswith('.rc')] return [p] def envrcitems(env=None): '''Return [(section, name, value, source)] config items. The config items are extracted from environment variables specified by env, used to override systemrc, but not userrc. If env is not provided, encoding.environ will be used. ''' if env is None: env = encoding.environ checklist = [ ('EDITOR', 'ui', 'editor'), ('VISUAL', 'ui', 'editor'), ('PAGER', 'pager', 'pager'), ] result = [] for envname, section, configname in checklist: if envname not in env: continue result.append((section, configname, env[envname], '$%s' % envname)) return result def defaultrcpath(): '''return rc paths in default.d''' path = [] defaultpath = os.path.join(util.datapath, 'default.d') if os.path.isdir(defaultpath): path = _expandrcpath(defaultpath) return path def rccomponents(): '''return an ordered [(type, obj)] about where to load configs. respect $HGRCPATH. if $HGRCPATH is empty, only .hg/hgrc of current repo is used. if $HGRCPATH is not set, the platform default will be used. if a directory is provided, *.rc files under it will be used. type could be either 'path' or 'items', if type is 'path', obj is a string, and is the config file path. if type is 'items', obj is a list of (section, name, value, source) that should fill the config directly. ''' envrc = ('items', envrcitems()) if 'HGRCPATH' in encoding.environ: # assume HGRCPATH is all about user configs so environments can be # overridden. _rccomponents = [envrc] for p in encoding.environ['HGRCPATH'].split(pycompat.ospathsep): if not p: continue _rccomponents.extend(('path', p) for p in _expandrcpath(p)) else: normpaths = lambda paths: [('path', os.path.normpath(p)) for p in paths] _rccomponents = normpaths(defaultrcpath() + systemrcpath()) _rccomponents.append(envrc) _rccomponents.extend(normpaths(userrcpath())) return _rccomponents def defaultpagerenv(): '''return a dict of default environment variables and their values, intended to be set before starting a pager. ''' return {'LESS': 'FRX', 'LV': '-c'}