obsolete: explicitly track folds inside the markers
We now record information to be able to recognize "fold" event from
obsolescence markers. To do so, we track the following pieces of information:
a) a fold ID. Unique to that fold (per successor),
b) the number of predecessors,
c) the index of the predecessor in that fold.
We will now be able to create an algorithm able to find "predecessorssets".
We now store this data in the generic "metadata" field of the markers.
Updating the format to have a more compact storage for this would be useful.
This way of tracking a fold through multiple markers could be applied to split
too. This would have two advantages:
1) We get a simpler format, since number of successors is limited to [0-1].
2) We can better deal with situations where only some of the split successors
are pushed to a remote repository.
We should look into the relevance of such a change before updating the on-disk
format.
note: unlike splits, folds do not have to deal with cases where only some of
the markers have been synchronized. As they all share the same successor
changesets, they are all relevant to the same nodes.
#!/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
_BOOL = ctypes.c_long
_DWORD = ctypes.c_ulong
_UINT = ctypes.c_uint
_HANDLE = ctypes.c_void_p
ctypes.windll.kernel32.CloseHandle.argtypes = [_HANDLE]
ctypes.windll.kernel32.CloseHandle.restype = _BOOL
ctypes.windll.kernel32.GetLastError.argtypes = []
ctypes.windll.kernel32.GetLastError.restype = _DWORD
ctypes.windll.kernel32.OpenProcess.argtypes = [_DWORD, _BOOL, _DWORD]
ctypes.windll.kernel32.OpenProcess.restype = _HANDLE
ctypes.windll.kernel32.TerminateProcess.argtypes = [_HANDLE, _UINT]
ctypes.windll.kernel32.TerminateProcess.restype = _BOOL
ctypes.windll.kernel32.WaitForSingleObject.argtypes = [_HANDLE, _DWORD]
ctypes.windll.kernel32.WaitForSingleObject.restype = _DWORD
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
WAIT_FAILED = _DWORD(0xFFFFFFFF).value
handle = ctypes.windll.kernel32.OpenProcess(
PROCESS_TERMINATE|SYNCHRONIZE|PROCESS_QUERY_INFORMATION,
False, pid)
if handle is None:
_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))
elif r == WAIT_FAILED:
_check(0) # err stored in GetLastError()
# 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')
elif r == WAIT_FAILED:
_check(0) # err stored in GetLastError()
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:
pids = []
with open(pidfile) as fp:
for line in fp:
try:
pid = int(line)
if pid <= 0:
raise ValueError
except ValueError:
logfn('# Not killing daemon process %s - invalid pid'
% line.rstrip())
continue
pids.append(pid)
for pid in pids:
kill(pid, logfn, tryhard)
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, remove=True)