import errno
import signal
import subprocess
+import logging ; log = logging.getLogger('pymin.procman')
-__ALL__ = ('ProcessManager', 'manager', 'register', 'unregister', 'call',
- 'start', 'stop', 'kill', 'get', 'has', 'sigchild_handler')
+__all__ = ('ProcessManager', 'manager', 'register', 'unregister', 'once',
+ 'start', 'stop', 'restart', 'kill', 'get', 'has', 'sigchild_handler')
class ProcessInfo:
def __init__(self, name, command, callback=None, persist=False,
- args=None, kw=None, max_errors=3):
- self.name = name
+ max_errors=3, args=None, kwargs=None):
+ self._name = name
self.command = command
self.callback = callback
if args is None: args = list()
self.args = args
- if kw is None: kw = dict()
- self.kw = kw
+ if kwargs is None: kwargs = dict()
+ self.kwargs = kwargs
self.persist = persist
self.max_errors = max_errors
self.clear()
def clear(self):
- self.dont_run = False
- self.signal = None
- self.process = None
- self.error_count = 0
- self.running = False
+ self._dont_run = False
+ self._signal = None
+ self._process = None
+ self._error_count = 0
def start(self):
assert self.process is None
self.restart()
def restart(self):
self.clear()
- self.process = subprocess.Popen(self.command, *self.args, **self.kw)
- self.running = True
+ log.debug(u'ProcessInfo.restart(): executing %s', self.command)
+ self._process = subprocess.Popen(self.command,
+ *self.args, **self.kwargs)
def stop(self):
assert self.process is not None
- self.dont_run = True
- if self.signal == signal.SIGTERM or self.signal == signal.SIGKILL:
+ self._dont_run = True
+ if self._signal == signal.SIGTERM or self._signal == signal.SIGKILL:
# Allready stopped, kill it
self.kill(signal.SIGKILL)
else:
# Stop it
self.kill(signal.SIGTERM)
def kill(self, signum):
+ log.debug(u'ProcessInfo.kill(): killing pid %s with signal %s',
+ self.process.pid, signum)
assert self.process is not None
os.kill(self.process.pid, signum)
- self.signal = signum
+ self._signal = signum
+ @property
+ def running(self):
+ return self.process is not None and self.process.poll() is None
+ @property
+ def name(self):
+ return self._name
+ @property
+ def process(self):
+ return self._process
+ @property
+ def error_count(self):
+ return self._error_count
def __repr__(self):
pid = None
if self.process is not None:
self.services = dict()
self.namemap = dict()
self.pidmap = dict()
+ log.debug(u'ProcessManager()')
def register(self, name, command, callback=None, persist=False,
- *args, **kw):
- self.services[name] = ProcessInfo(name, command, callback, persist,
- args, kw)
+ max_errors=3, *args, **kwargs):
+ log.debug(u'ProcessManager.register(%s, %s, %s, %s, %s, %s, %s)',
+ name, command, callback, persist, max_errors, args, kwargs)
+ assert not self.has(name)
+ pi = ProcessInfo(name, command, callback, persist, max_errors,
+ args, kwargs)
+ self.services[name] = pi
+ return pi
def unregister(self, name):
+ log.debug(u'ProcessManager.unregister(%s)', name)
+ pi = self.services[name]
del self.services[name]
+ return pi
def _call(self, pi):
pi.start()
self.namemap[pi.name] = self.pidmap[pi.process.pid] = pi
- def call(self, name, command, callback=None, persist=False, *args, **kw):
- pi = ProcessInfo(name, command, callback, persist, args, kw)
+ def once(self, name, command, callback=None, persist=False,
+ max_errors=3, *args, **kwargs):
+ log.debug(u'ProcessManager.once(%s, %s, %s, %s, %s, %s, %s)',
+ name, command, callback, persist, max_errors, args, kwargs)
+ assert not self.has(name)
+ pi = ProcessInfo(name, command, callback, persist, max_errors,
+ args, kwargs)
self._call(pi)
+ return pi
def start(self, name):
+ log.debug(u'ProcessManager.start(%s)', name)
assert name not in self.namemap
self._call(self.services[name])
def stop(self, name):
+ log.debug(u'ProcessManager.stop(%s)', name)
assert name in self.namemap
self.namemap[name].stop()
+ def restart(self, name):
+ log.debug(u'ProcessManager.restart(%s)', name)
+ # we have to check first in namemap in case is an unregistered
+ # process (added with once())
+ if name in self.namemap:
+ pi = self.namemap[name]
+ # the process will change its PID, so we delete it while we know it
+ del self.pidmap[pi.process.pid]
+ pi.stop()
+ pi.process.wait()
+ pi.restart()
+ # add the new PID
+ self.pidmap[pi.process.pid] = pi
+ else:
+ self.start(name)
+
def kill(self, name, signum):
+ log.debug(u'ProcessManager.kill(%s, %s)', name, signum)
assert name in self.namemap
self.namemap[name].kill(name, stop)
def sigchild_handler(self, signum, stack_frame=None):
+ log.debug(u'ProcessManager.sigchild_handler(%s)', signum)
try:
(pid, status) = os.waitpid(-1, os.WNOHANG)
except OSError, e:
+ log.debug(u'ProcessManager.sigchild_handler(): OSError')
if e.errno is errno.ECHILD:
+ log.debug(u'ProcessManager.sigchild_handler(): OSError ECHILD')
return
raise
+ log.debug(u'ProcessManager.sigchild_handler: pid=%s, status=%s',
+ pid, status)
while pid:
if pid in self.pidmap:
p = self.pidmap[pid]
p.process.returncode = status
if p.callback is not None:
+ log.debug(u'ProcessManager.sigchild_handler: '
+ u'calling %s(%s)', p.callback.__name__, p)
p.callback(self, p)
- if p.dont_run or not p.persist or p.error_count >= p.max_errors:
+ if (p._dont_run or not p.persist
+ or p._error_count >= p.max_errors):
+ log.debug(u"ProcessManager.sigchild_handler: can't "
+ u'persist, dont_run=%s, persist=%s, error_cout=%s, '
+ u'max_errors=%s', p._dont_run, p.persist,
+ p._error_count, p.max_errors)
del self.namemap[p.name]
del self.pidmap[pid]
p.clear()
else:
+ log.debug(u'ProcessManager.sigchild_handler: persist')
if p.process.returncode == 0:
- p.error_count = 0
+ p._error_count = 0
+ log.debug(u'ProcessManager.sigchild_handler: '
+ u'return OK, resetting error_count')
else:
- p.error_count += 1
+ p._error_count += 1
+ log.debug(u'ProcessManager.sigchild_handler: return'
+ u'not 0, error_count + 1 = %s', p._error_count)
del self.pidmap[pid]
p.restart()
self.pidmap[p.process.pid] = p
else: # is a pid
if name in self.pidmap:
return self.pidmap[name]
- return KeyError, name
+ raise KeyError, name
+ # Syntax sugar for self[name]
+ __getitem__ = get
def has(self, name):
if isinstance(name, basestring): # is a name
if name in self.pidmap:
return True
return False
+ # Syntax sugar for name in self
+ __contains__ = has
- def __getitem__(self, name):
- return self.get(name)
- def __contains__(self, name):
- return self.has(name)
+if __name__ == '__main__':
+ logging.basicConfig(
+ level = logging.DEBUG,
+ format = '%(asctime)s %(levelname)-8s %(message)s',
+ datefmt = '%H:%M:%S',
+ )
+
# Globals
manager = ProcessManager()
register = manager.register
unregister = manager.unregister
-call = manager.call
+once = manager.once
start = manager.start
stop = manager.stop
+restart = manager.restart
kill = manager.kill
get = manager.get
has = manager.has
print 'test-service count =', count
count += 1
if count > 4:
- print 'test-service not persistent anymore, start test2'
+ print 'set test-service non-persistent, start test-service-2'
pi.persist = False
- pm.start('test2')
+ assert 'test-service-2' not in manager.namemap
+ pm.start('test-service-2')
+ assert 'test-service-2' in manager.namemap
+ assert get('test-service-2').running
print 'died:', pi.name, pi.command
register('test-service', ('sleep', '2'), notify, True)
- register('test2', ('sleep', '3'), notify, False)
+ assert 'test-service' in manager.services
+ assert 'test-service' not in manager.namemap
+ assert not get('test-service').running
+ assert manager['test-service'] == get('test-service')
+ assert has('test-service')
+ assert 'test-service' in manager
+
+ register('test-service-2', ('sleep', '3'), notify, False)
+ assert 'test-service-2' in manager.services
+ assert 'test-service-2' not in manager.namemap
+ assert not get('test-service-2').running
signal.signal(signal.SIGCHLD, SIGCHLD_handler)
- call('test', ('sleep', '5'), notify)
+ once('test-once', ('sleep', '5'), notify)
+ assert 'test-once' not in manager.services
+ assert 'test-once' in manager.namemap
+ assert get('test-once').running
+ assert get('test-once').process.pid
+ pid = get('test-once').process.pid
+ restart('test-once')
+ assert pid != get('test-once').process.pid
+ assert pid != manager.pidmap[get('test-once').process.pid].process.pid
+
start('test-service')
+ assert 'test-service' in manager.namemap
+ assert get('test-service').running
+ assert get('test-service').process.pid
+ pid = get('test-service').process.pid
+ restart('test-service')
+ assert pid != get('test-service').process.pid
+ assert pid != manager.pidmap[get('test-service').process.pid].process.pid
- print "Esperando...", [pi.name for pi in manager.namemap.values()]
+ print "Known processes:", manager.services.keys()
+ print "Waiting...", manager.namemap.keys()
+ print "------------------------------------------------------------------"
while manager.pidmap:
signal.pause()
if sig == signal.SIGCHLD:
- sig = None
sigchild_handler(sig)
- print "Esperando...", [pi.name for pi in manager.namemap.values()]
+ sig = None
+ print "Known processes:", manager.services.keys()
+ print "Waiting...", manager.namemap.keys()
+ print "------------------------------------------------------------------"
+ assert 'test-service' not in manager.namemap
+ assert 'test-service-2' not in manager.namemap
+ assert 'test-once' not in manager.services
+ assert 'test-once' not in manager.namemap
+
+ restart('test-service')
+ assert get('test-service').process.pid
+ assert manager.pidmap[get('test-service').process.pid].process.pid
+
+ once('test-wait', ('sleep', '2'))
+ print 'test-wait running?', get('test-wait').running
+ assert get('test-wait').running
+ print 'Waiting test-wait to return...'
+ ret = get('test-wait').process.wait()
+ print 'Done! returned:', ret