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 f6a393dc03325425ef03d84d72900583183f849e..0bfb721018c6a61d6d3a30e72bad6cf8c6f0d361 100644 (file)
--- a/pymin/procman.py
+++ b/pymin/procman.py
@@ -6,13 +6,13 @@ import signal
 import subprocess
 import logging ; log = logging.getLogger('pymin.procman')
 
 import subprocess
 import logging ; log = logging.getLogger('pymin.procman')
 

-__all__ = ('ProcessManager', 'manager', 'register', 'unregister', 'call',
+__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,
                  max_errors=3, args=None, kwargs=None):
            'start', 'stop', 'restart', 'kill', 'get', 'has', 'sigchild_handler')
 
 class ProcessInfo:
     def __init__(self, name, command, callback=None, persist=False,
                  max_errors=3, args=None, kwargs=None):

-        self.name = name
+        self._name = name

         self.command = command
         self.callback = callback
         if args is None: args = list()
         self.command = command
         self.callback = callback
         if args is None: args = list()


@@ -23,23 +23,22 @@ class ProcessInfo:
         self.max_errors = max_errors
         self.clear()
     def clear(self):
         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()
         log.debug(u'ProcessInfo.restart(): executing %s', self.command)
     def start(self):
         assert self.process is None
         self.restart()
     def restart(self):
         self.clear()
         log.debug(u'ProcessInfo.restart(): executing %s', self.command)

-        self.process = subprocess.Popen(self.command, *self.args, **self.kwargs)
-        self.running = True
+        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:
             # Allready stopped, kill it
             self.kill(signal.SIGKILL)
         else:


@@ -50,7 +49,19 @@ class ProcessInfo:
                       self.process.pid, signum)
         assert self.process is not None
         os.kill(self.process.pid, signum)
                       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:


@@ -71,51 +82,70 @@ class ProcessManager:
                 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)
                 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)

-        self.services[name] = ProcessInfo(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)
 
     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,
+    def once(self, name, command, callback=None, persist=False,

                 max_errors=3, *args, **kwargs):
                 max_errors=3, *args, **kwargs):

-        log.debug(u'ProcessManager.call(%s, %s, %s, %s, %s, %s, %s)',
+        log.debug(u'ProcessManager.once(%s, %s, %s, %s, %s, %s, %s)',

                   name, command, callback, persist, max_errors, args, kwargs)
                   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)
         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)
 
     def start(self, name):
         log.debug(u'ProcessManager.start(%s)', name)

-        assert name not in self.namemap
-        self._call(self.services[name])
+        if name not in self.namemap:
+            self._call(self.services[name])
+            return True
+        return False

 
     def stop(self, name):
         log.debug(u'ProcessManager.stop(%s)', name)
 
     def stop(self, name):
         log.debug(u'ProcessManager.stop(%s)', name)

-        assert name in self.namemap
-        self.namemap[name].stop()
+        if name in self.namemap:
+            self.namemap[name].stop()
+            return True
+        return False

 
     def restart(self, name):
         log.debug(u'ProcessManager.restart(%s)', name)
         # we have to check first in namemap in case is an unregistered
 
     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 call())
+        # process (added with once())

         if name in self.namemap:
             pi = self.namemap[name]
         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()
             pi.stop()
             pi.process.wait()
             pi.restart()

+            # add the new PID
+            self.pidmap[pi.process.pid] = pi
+            return True

         else:
         else:

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

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

 
     def sigchild_handler(self, signum, stack_frame=None):
         log.debug(u'ProcessManager.sigchild_handler(%s)', signum)
 
     def sigchild_handler(self, signum, stack_frame=None):
         log.debug(u'ProcessManager.sigchild_handler(%s)', signum)


@@ -137,24 +167,25 @@ class ProcessManager:
                     log.debug(u'ProcessManager.sigchild_handler: '
                                   u'calling %s(%s)', p.callback.__name__, p)
                     p.callback(self, p)
                     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, '
                     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)
+                            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:
                     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:
                         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'
                         log.debug(u'ProcessManager.sigchild_handler: return'

-                                u'not 0, error_count + 1 = %s', p.error_count)
+                                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


@@ -175,6 +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


@@ -186,12 +219,8 @@ class ProcessManager:
             if name in self.pidmap:
                 return True
         return False
             if name in self.pidmap:
                 return True
         return False

-
-    def __getitem__(self, name):
-        return self.get(name)
-
-    def __contains__(self, name):
-        return self.has(name)
+    # Syntax sugar for name in self
+    __contains__ = has

 
 
 if __name__ == '__main__':
 
 
 if __name__ == '__main__':


@@ -206,7 +235,7 @@ if __name__ == '__main__':
 manager = ProcessManager()
 register = manager.register
 unregister = manager.unregister
 manager = ProcessManager()
 register = manager.register
 unregister = manager.unregister

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

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


@@ -240,24 +269,42 @@ if __name__ == '__main__':
                 assert 'test-service-2' not in manager.namemap
                 pm.start('test-service-2')
                 assert 'test-service-2' in manager.namemap
                 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)
     assert 'test-service' in manager.services
     assert 'test-service' not in manager.namemap
         print 'died:', pi.name, pi.command
 
     register('test-service', ('sleep', '2'), notify, True)
     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
 
     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-once', ('sleep', '5'), notify)
+    once('test-once', ('sleep', '5'), notify)

     assert 'test-once' not in manager.services
     assert 'test-once' in manager.namemap
     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
 
     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 "Known processes:", manager.services.keys()
     print "Waiting...", manager.namemap.keys()
 
     print "Known processes:", manager.services.keys()
     print "Waiting...", manager.namemap.keys()


@@ -275,8 +322,13 @@ if __name__ == '__main__':
     assert 'test-once' not in manager.services
     assert 'test-once' not in manager.namemap
 
     assert 'test-once' not in manager.services
     assert 'test-once' not in manager.namemap
 

-    call('test-wait', ('sleep', '2'))
-    print 'test-wait returned?', get('test-wait').process.poll()
+    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
     print 'Waiting test-wait to return...'
     ret = get('test-wait').process.wait()
     print 'Done! returned:', ret