Make procman.ProcessManager return True is an action could be taken (refs #11).

[software/pymin.git] / pymin / procman.py

diff --git a/pymin/procman.py b/pymin/procman.py
index 4478cb7c0eff9b7280b1049162fea17e066ff0c6..0bfb721018c6a61d6d3a30e72bad6cf8c6f0d361 100644 (file)
--- a/pymin/procman.py
+++ b/pymin/procman.py
@@ -4,49 +4,64 @@ import os
 import errno
 import signal
 import subprocess
 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,
 
 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
         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.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()
     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
     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):
             # 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)
         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:
     def __repr__(self):
         pid = None
         if self.process is not None:


@@ -61,66 +76,116 @@ class ProcessManager:
         self.services = dict()
         self.namemap = dict()
         self.pidmap = dict()
         self.services = dict()
         self.namemap = dict()
         self.pidmap = dict()

+        log.debug(u'ProcessManager()')

 
     def register(self, name, command, callback=None, persist=False,
 
     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):
 
     def unregister(self, name):

+        log.debug(u'ProcessManager.unregister(%s)', name)
+        pi = self.services[name]

         del 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, 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)
         self._call(pi)

+        return pi

 
     def start(self, name):
 
     def start(self, name):

-        assert name not in self.namemap
-        self._call(self.services[name])
+        log.debug(u'ProcessManager.start(%s)', name)
+        if name not in self.namemap:
+            self._call(self.services[name])
+            return True
+        return False

 
     def stop(self, name):
 
     def stop(self, name):

-        assert name in self.namemap
-        self.namemap[name].stop()
+        log.debug(u'ProcessManager.stop(%s)', name)
+        if name in self.namemap:
+            self.namemap[name].stop()
+            return True
+        return False

 
     def restart(self, name):
 
     def restart(self, name):

-        logging.debug(u'ProcessManager.restart(%s)', 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:
         if name in self.namemap:

-            self.namemap[name].stop()
-            self.namemap[name].wait()
-            self.namemap[name].restart()
+            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
+            return True

         else:
         else:

-            self.namemap[name].start()
+            self.start(name)
+            return False

 
     def kill(self, name, signum):
 
     def kill(self, name, signum):

-        assert name in self.namemap
-        self.namemap[name].kill(name, stop)
+        log.debug(u'ProcessManager.kill(%s, %s)', name, signum)
+        if name in self.namemap:
+            self.namemap[name].kill(name, stop)
+            return True
+        return False

 
     def sigchild_handler(self, signum, stack_frame=None):
 
     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:
         try:
             (pid, status) = os.waitpid(-1, os.WNOHANG)
         except OSError, e:

+            log.debug(u'ProcessManager.sigchild_handler(): OSError')

             if e.errno is errno.ECHILD:
             if e.errno is errno.ECHILD:

+                log.debug(u'ProcessManager.sigchild_handler(): OSError ECHILD')

                 return
             raise
                 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:
         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)
                     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:
                     del self.namemap[p.name]
                     del self.pidmap[pid]
                     p.clear()
                 else:

+                    log.debug(u'ProcessManager.sigchild_handler: persist')

                     if p.process.returncode == 0:
                     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:
                     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
                     del self.pidmap[pid]
                     p.restart()
                     self.pidmap[p.process.pid] = p


@@ -141,6 +206,8 @@ class ProcessManager:
             if name in self.pidmap:
                 return self.pidmap[name]
         raise KeyError, name
             if name in self.pidmap:
                 return self.pidmap[name]
         raise KeyError, name

+    # Syntax sugar for self[name]
+    __getitem__ = get

 
     def has(self, name):
         if isinstance(name, basestring): # is a name
 
     def has(self, name):
         if isinstance(name, basestring): # is a name


@@ -152,20 +219,26 @@ class ProcessManager:
             if name in self.pidmap:
                 return True
         return False
             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
 
 # Globals
 manager = ProcessManager()
 register = manager.register
 unregister = manager.unregister

-call = manager.call
+once = manager.once

 start = manager.start
 stop = manager.stop
 start = manager.start
 stop = manager.stop

+restart = manager.restart

 kill = manager.kill
 get = manager.get
 has = manager.has
 kill = manager.kill
 get = manager.get
 has = manager.has


@@ -191,24 +264,72 @@ if __name__ == '__main__':
             print 'test-service count =', count
             count += 1
             if count > 4:
             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
                 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)
         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)
 
 
     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')
     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:
             sigchild_handler(sig)
             sig = None
     while manager.pidmap:
         signal.pause()
         if sig == signal.SIGCHLD:
             sigchild_handler(sig)
             sig = None

-        print "Esperando...", [pi.name for pi in manager.namemap.values()]
+        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