Mercurial > hg
view mercurial/server.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 | bfcd0d227972 |
children | d4a2e0d5d042 |
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# server.py - utility and factory of server # # Copyright 2005-2007 Matt Mackall <mpm@selenic.com> # # 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 import tempfile from .i18n import _ from . import ( chgserver, cmdutil, commandserver, error, hgweb, pycompat, util, ) def runservice(opts, parentfn=None, initfn=None, runfn=None, logfile=None, runargs=None, appendpid=False): '''Run a command as a service.''' def writepid(pid): if opts['pid_file']: if appendpid: mode = 'ab' else: mode = 'wb' fp = open(opts['pid_file'], mode) fp.write('%d\n' % pid) fp.close() if opts['daemon'] and not opts['daemon_postexec']: # Signal child process startup with file removal lockfd, lockpath = tempfile.mkstemp(prefix='hg-service-') os.close(lockfd) try: if not runargs: runargs = util.hgcmd() + pycompat.sysargv[1:] runargs.append('--daemon-postexec=unlink:%s' % lockpath) # Don't pass --cwd to the child process, because we've already # changed directory. for i in xrange(1, len(runargs)): if runargs[i].startswith('--cwd='): del runargs[i] break elif runargs[i].startswith('--cwd'): del runargs[i:i + 2] break def condfn(): return not os.path.exists(lockpath) pid = util.rundetached(runargs, condfn) if pid < 0: raise error.Abort(_('child process failed to start')) writepid(pid) finally: util.tryunlink(lockpath) if parentfn: return parentfn(pid) else: return if initfn: initfn() if not opts['daemon']: writepid(util.getpid()) if opts['daemon_postexec']: try: os.setsid() except AttributeError: pass for inst in opts['daemon_postexec']: if inst.startswith('unlink:'): lockpath = inst[7:] os.unlink(lockpath) elif inst.startswith('chdir:'): os.chdir(inst[6:]) elif inst != 'none': raise error.Abort(_('invalid value for --daemon-postexec: %s') % inst) util.hidewindow() util.stdout.flush() util.stderr.flush() nullfd = os.open(os.devnull, os.O_RDWR) logfilefd = nullfd if logfile: logfilefd = os.open(logfile, os.O_RDWR | os.O_CREAT | os.O_APPEND, 0o666) os.dup2(nullfd, 0) os.dup2(logfilefd, 1) os.dup2(logfilefd, 2) if nullfd not in (0, 1, 2): os.close(nullfd) if logfile and logfilefd not in (0, 1, 2): os.close(logfilefd) if runfn: return runfn() _cmdservicemap = { 'chgunix': chgserver.chgunixservice, 'pipe': commandserver.pipeservice, 'unix': commandserver.unixforkingservice, } def _createcmdservice(ui, repo, opts): mode = opts['cmdserver'] try: return _cmdservicemap[mode](ui, repo, opts) except KeyError: raise error.Abort(_('unknown mode %s') % mode) def _createhgwebservice(ui, repo, opts): # this way we can check if something was given in the command-line if opts.get('port'): opts['port'] = util.getport(opts.get('port')) alluis = {ui} if repo: baseui = repo.baseui alluis.update([repo.baseui, repo.ui]) else: baseui = ui webconf = opts.get('web_conf') or opts.get('webdir_conf') if webconf: if opts.get('subrepos'): raise error.Abort(_('--web-conf cannot be used with --subrepos')) # load server settings (e.g. web.port) to "copied" ui, which allows # hgwebdir to reload webconf cleanly servui = ui.copy() servui.readconfig(webconf, sections=['web']) alluis.add(servui) elif opts.get('subrepos'): servui = ui # If repo is None, hgweb.createapp() already raises a proper abort # message as long as webconf is None. if repo: webconf = dict() cmdutil.addwebdirpath(repo, "", webconf) else: servui = ui optlist = ("name templates style address port prefix ipv6" " accesslog errorlog certificate encoding") for o in optlist.split(): val = opts.get(o, '') if val in (None, ''): # should check against default options instead continue for u in alluis: u.setconfig("web", o, val, 'serve') app = hgweb.createapp(baseui, repo, webconf) return hgweb.httpservice(servui, app, opts) def createservice(ui, repo, opts): if opts["cmdserver"]: return _createcmdservice(ui, repo, opts) else: return _createhgwebservice(ui, repo, opts)