pycompat: make pycompat demandimport friendly
pycompat.py includes hack to import modules whose names are changed in Python 3.
We use try-except to load module according to the version of python. But this
method forces us to import the modules to raise an ImportError and hence making
it demandimport unfriendly.
This patch changes the try-except blocks to a single if-else block. To avoid
test-check-pyflakes.t complain about unused imports, pycompat.py is excluded
from the test.
#!/usr/bin/env python
from __future__ import absolute_import
import errno
import os
import signal
import sys
import time
if os.name =='nt':
import ctypes
def _check(ret, expectederr=None):
if ret == 0:
winerrno = ctypes.GetLastError()
if winerrno == expectederr:
return True
raise ctypes.WinError(winerrno)
def kill(pid, logfn, tryhard=True):
logfn('# Killing daemon process %d' % pid)
PROCESS_TERMINATE = 1
PROCESS_QUERY_INFORMATION = 0x400
SYNCHRONIZE = 0x00100000
WAIT_OBJECT_0 = 0
WAIT_TIMEOUT = 258
handle = ctypes.windll.kernel32.OpenProcess(
PROCESS_TERMINATE|SYNCHRONIZE|PROCESS_QUERY_INFORMATION,
False, pid)
if handle == 0:
_check(0, 87) # err 87 when process not found
return # process not found, already finished
try:
r = ctypes.windll.kernel32.WaitForSingleObject(handle, 100)
if r == WAIT_OBJECT_0:
pass # terminated, but process handle still available
elif r == WAIT_TIMEOUT:
_check(ctypes.windll.kernel32.TerminateProcess(handle, -1))
else:
_check(r)
# TODO?: forcefully kill when timeout
# and ?shorter waiting time? when tryhard==True
r = ctypes.windll.kernel32.WaitForSingleObject(handle, 100)
# timeout = 100 ms
if r == WAIT_OBJECT_0:
pass # process is terminated
elif r == WAIT_TIMEOUT:
logfn('# Daemon process %d is stuck')
else:
_check(r) # any error
except: #re-raises
ctypes.windll.kernel32.CloseHandle(handle) # no _check, keep error
raise
_check(ctypes.windll.kernel32.CloseHandle(handle))
else:
def kill(pid, logfn, tryhard=True):
try:
os.kill(pid, 0)
logfn('# Killing daemon process %d' % pid)
os.kill(pid, signal.SIGTERM)
if tryhard:
for i in range(10):
time.sleep(0.05)
os.kill(pid, 0)
else:
time.sleep(0.1)
os.kill(pid, 0)
logfn('# Daemon process %d is stuck - really killing it' % pid)
os.kill(pid, signal.SIGKILL)
except OSError as err:
if err.errno != errno.ESRCH:
raise
def killdaemons(pidfile, tryhard=True, remove=False, logfn=None):
if not logfn:
logfn = lambda s: s
# Kill off any leftover daemon processes
try:
fp = open(pidfile)
for line in fp:
try:
pid = int(line)
except ValueError:
continue
kill(pid, logfn, tryhard)
fp.close()
if remove:
os.unlink(pidfile)
except IOError:
pass
if __name__ == '__main__':
if len(sys.argv) > 1:
path, = sys.argv[1:]
else:
path = os.environ["DAEMON_PIDS"]
killdaemons(path)