57 lines
1.8 KiB
Python
57 lines
1.8 KiB
Python
# -*- coding: utf-8 -*-
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# *****************************************************************************
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#
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# This program is free software; you can redistribute it and/or modify it under
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# the terms of the GNU General Public License as published by the Free Software
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# Foundation; either version 2 of the License, or (at your option) any later
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# version.
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#
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# This program is distributed in the hope that it will be useful, but WITHOUT
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# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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# details.
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#
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# You should have received a copy of the GNU General Public License along with
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# this program; if not, write to the Free Software Foundation, Inc.,
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# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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#
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# Module authors:
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# Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
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#
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# *****************************************************************************
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"""Define pidfile helpers"""
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import atexit
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import os
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import psutil
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def read_pidfile(pidfile):
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"""read the given pidfile, return the pid as an int
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or None upon errors (file not existing)"""
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try:
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with open(pidfile, 'r', encoding='utf-8') as f:
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return int(f.read())
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except (OSError, IOError):
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return None
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def remove_pidfile(pidfile):
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"""remove the given pidfile, typically at end of the process"""
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os.remove(pidfile)
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def write_pidfile(pidfile, pid):
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"""write the given pid to the given pidfile"""
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with open(pidfile, 'w', encoding='utf-8') as f:
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f.write('%d\n' % pid)
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atexit.register(remove_pidfile, pidfile)
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def check_pidfile(pidfile):
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"""check if the process from a given pidfile is still running"""
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pid = read_pidfile(pidfile)
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return False if pid is None else psutil.pid_exists(pid)
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