def open_checkpoint(cls, filename, force=False, state=None):
"""
Acquire a locked checkpoint stream.
"""
safe_mkdir(os.path.dirname(filename))
fp = lock_file(filename, "a+")
if fp in (None, False):
if force:
log.info('Found existing runner, forcing leadership forfeit.')
state = state or CheckpointDispatcher.from_file(filename)
if cls.kill_runner(state):
log.info('Successfully killed leader.')
# TODO(wickman) Blocking may not be the best idea here. Perhaps block up to
# a maximum timeout. But blocking is necessary because os.kill does not immediately
# release the lock if we're in force mode.
fp = lock_file(filename, "a+", blocking=True)
else:
log.error('Found existing runner, cannot take control.')
if fp in (None, False):
raise cls.PermissionError(
'Could not open locked checkpoint: %s, lock_file = %s' %
(filename, fp))
ckpt = ThriftRecordWriter(fp)
ckpt.set_sync(True)
return ckpt
def daemonize(pidfile=None, stdout='/dev/null', stderr='/dev/null'):
global _PIDFILE
def daemon_fork():
try:
if os.fork() > 0:
os._exit(0)
except OSError as e:
sys.stderr.write('Failed to fork: %s\n' % e)
sys.exit(1)
daemon_fork()
os.setsid()
daemon_fork()
if pidfile:
_PIDFILE = lock_file(pidfile, 'w+')
if _PIDFILE:
pid = os.getpid()
sys.stderr.write('Writing pid %s into %s\n' % (pid, pidfile))
_PIDFILE.write(str(pid))
_PIDFILE.flush()
else:
sys.stderr.write('Could not acquire pidfile %s, another process running!\n' % pidfile)
sys.exit(1)
def shutdown():
os.unlink(pidfile)
_PIDFILE.close()
atexit.register(shutdown)
sys.stdin = open('/dev/null', 'r')
sys.stdout = open(stdout, 'a+')
sys.stderr = open(stderr, 'a+', 1)
def _setup_ckpt(self):
"""Set up the checkpoint: must be run on the parent."""
self._log('initializing checkpoint file: %s' % self.ckpt_file())
ckpt_fp = lock_file(self.ckpt_file(), "a+")
if ckpt_fp in (None, False):
raise self.CheckpointError('Could not acquire checkpoint permission or lock for %s!' %
self.ckpt_file())
self._ckpt_head = os.path.getsize(self.ckpt_file())
ckpt_fp.seek(self._ckpt_head)
self._ckpt = ThriftRecordWriter(ckpt_fp)
self._ckpt.set_sync(True)
def _setup_ckpt(self):
"""Set up the checkpoint: must be run on the parent."""
self._log('initializing checkpoint file: %s' % self.ckpt_file())
ckpt_fp = lock_file(self.ckpt_file(), "a+")
if ckpt_fp in (None, False):
raise self.CheckpointError('Could not acquire checkpoint permission or lock for %s!' %
self.ckpt_file())
self._ckpt_head = os.path.getsize(self.ckpt_file())
ckpt_fp.seek(self._ckpt_head)
self._ckpt = ThriftRecordWriter(ckpt_fp)
self._ckpt.set_sync(True)
def open_checkpoint(cls, filename, force=False, state=None):
"""
Acquire a locked checkpoint stream.
"""
safe_mkdir(os.path.dirname(filename))
fp = lock_file(filename, "a+")
if fp in (None, False):
if force:
log.info("Found existing runner, forcing leadership forfeit.")
state = state or CheckpointDispatcher.from_file(filename)
if cls.kill_runner(state):
log.info("Successfully killed leader.")
# TODO(wickman) Blocking may not be the best idea here. Perhaps block up to
# a maximum timeout. But blocking is necessary because os.kill does not immediately
# release the lock if we're in force mode.
fp = lock_file(filename, "a+", blocking=True)
else:
log.error("Found existing runner, cannot take control.")
if fp in (None, False):
raise cls.PermissionError("Could not open locked checkpoint: %s, lock_file = %s" % (filename, fp))
ckpt = ThriftRecordWriter(fp)
ckpt.set_sync(True)
return ckpt
def _daemonize(pidfile, stdout, stderr, quiet, exit_parent):
global _PIDFILE
def daemon_fork(exit_parent=True):
try:
if os.fork() > 0:
if exit_parent:
os._exit(0)
return True
return False
except OSError as e:
sys.stderr.write('Failed to fork: %s\n' % e)
sys.exit(1)
parent = daemon_fork(exit_parent)
if parent:
return True
os.setsid()
daemon_fork()
if pidfile:
_PIDFILE = lock_file(pidfile, 'w+')
if _PIDFILE:
pid = os.getpid()
if not quiet:
sys.stderr.write('Writing pid %s into %s\n' % (pid, pidfile))
_PIDFILE.write(str(pid))
_PIDFILE.flush()
else:
if not quiet:
sys.stderr.write(
'Could not acquire pidfile %s, another process running!\n'
% pidfile)
sys.exit(1)
def shutdown():
os.unlink(pidfile)
_PIDFILE.close()
atexit.register(shutdown)
sys.stdin = open('/dev/null', 'r')
sys.stdout = open(stdout, 'a+')
sys.stderr = open(stderr, 'a+', 1)
