Add ProcessManager.restart() method to block until the restart is done.

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

diff --git a/pymin/procman.py b/pymin/procman.py
index 423ace010cb647720443ee4cf85821ef3c123f05..5cea4d4e1760989126cb77d94483cc493b551e45 100644 (file)
--- a/pymin/procman.py
+++ b/pymin/procman.py
@@ -2,48 +2,128 @@
 
 import os
 import errno
 
 import os
 import errno

+import signal

 import subprocess
 
 import subprocess
 

+__ALL__ = ('ProcessManager', 'manager', 'register', 'unregister', 'call',
+           'start', 'stop', 'kill', 'get', 'has', 'sigchild_handler')
+

 class ProcessInfo:
 class ProcessInfo:

-    def __init__(self, name, process, args, kw, callback=None, persist=False):
+    def __init__(self, name, command, callback=None, persist=False,
+                       args=None, kw=None, max_errors=3):

         self.name = name
         self.name = name

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

         self.args = args
         self.args = args

+        if kw is None: kw = dict()

         self.kw = kw
         self.kw = kw

-        self.callback = callback

         self.persist = persist
         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
+    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
+    def stop(self):
+        assert self.process is not None
+        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):
+        assert self.process is not None
+        os.kill(self.process.pid, signum)
+        self.signal = signum

     def __repr__(self):
     def __repr__(self):

-        return 'ProcessInfo(name=%s, pid=%s, persist=%s, cb=%s, args=%s)' % (
-                    self.name, self.process.pid, self.persist,
-                    self.callback.__name__, self.args)
+        pid = None
+        if self.process is not None:
+            pid = self.process.pid
+        return 'ProcessInfo(name=%s, pid=%s command=%s, persist=%s, cb=%s)' % (
+                    self.name, pid, self.command, self.persist,
+                    self.callback.__name__)

 
 class ProcessManager:
 
     def __init__(self):
 
 class ProcessManager:
 
     def __init__(self):

+        self.services = dict()

         self.namemap = dict()
         self.pidmap = dict()
 
         self.namemap = dict()
         self.pidmap = dict()
 

-    def call(self, name, callback, persist, *args, **kw):
-        proc = subprocess.Popen(*args, **kw)
-        procinfo = ProcessInfo(name, proc, args, kw, callback, persist)
-        self.namemap[name] = self.pidmap[proc.pid] = procinfo
+    def register(self, name, command, callback=None, persist=False,
+                       *args, **kw):
+        self.services[name] = ProcessInfo(name, command, callback, persist,
+                                          args, kw)
+
+    def unregister(self, name):
+        del self.services[name]
+
+    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)
+        self._call(pi)
+
+    def start(self, name):
+        assert name not in self.namemap
+        self._call(self.services[name])
+
+    def stop(self, name):
+        assert name in self.namemap
+        self.namemap[name].stop()
+
+    def restart(self, name):
+        logging.debug(u'ProcessManager.restart(%s)', name)
+        if name in self.namemap:
+            self.namemap[name].stop()
+            self.namemap[name].wait()
+            self.namemap[name].restart()
+        else:
+            self.namemap[name].start()
+
+    def kill(self, name, signum):
+        assert name in self.namemap
+        self.namemap[name].kill(name, stop)

 
 

-    def sigchild_handler(self, signum):
+    def sigchild_handler(self, signum, stack_frame=None):

         try:
             (pid, status) = os.waitpid(-1, os.WNOHANG)
         except OSError, e:
         try:
             (pid, status) = os.waitpid(-1, os.WNOHANG)
         except OSError, e:

-            if e.errno is e.ECHILD:
+            if e.errno is errno.ECHILD:

                 return
             raise
         while pid:
             if pid in self.pidmap:
                 p = self.pidmap[pid]
                 return
             raise
         while pid:
             if pid in self.pidmap:
                 p = self.pidmap[pid]

-                del self.namemap[p.name]
-                del self.pidmap[pid]
+                p.process.returncode = status

                 if p.callback is not None:
                 if p.callback is not None:

-                    p.callback(p)
-                if p.persist:
-                    self.call(p.name, p.callback, True, *p.args, **p.kw)
+                    p.callback(self, p)
+                if p.dont_run or not p.persist or p.error_count >= p.max_errors:
+                    del self.namemap[p.name]
+                    del self.pidmap[pid]
+                    p.clear()
+                else:
+                    if p.process.returncode == 0:
+                        p.error_count = 0
+                    else:
+                        p.error_count += 1
+                    del self.pidmap[pid]
+                    p.restart()
+                    self.pidmap[p.process.pid] = p

             try:
                 (pid, status) = os.waitpid(-1, os.WNOHANG)
             except OSError, e:
             try:
                 (pid, status) = os.waitpid(-1, os.WNOHANG)
             except OSError, e:


@@ -51,17 +131,45 @@ class ProcessManager:
                     return
                 raise
 
                     return
                 raise
 

-    def __getitem__(self, name):
+    def get(self, name):

         if isinstance(name, basestring): # is a name
         if isinstance(name, basestring): # is a name

-            return self.namemap[name]
+            if name in self.namemap:
+                return self.namemap[name]
+            if name in self.services:
+                return self.services[name]

         else: # is a pid
         else: # is a pid

-            return self.pidmap[name]
+            if name in self.pidmap:
+                return self.pidmap[name]
+        raise KeyError, name

 
 

-    def __contains__(self, name):
+    def has(self, name):

         if isinstance(name, basestring): # is a name
         if isinstance(name, basestring): # is a name

-            return name in self.namemap
+            if name in self.namemap:
+                return True
+            if name in self.services:
+                return True

         else: # is a pid
         else: # is a pid

-            return name in self.pidmap
+            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)
+
+# Globals
+manager = ProcessManager()
+register = manager.register
+unregister = manager.unregister
+call = manager.call
+start = manager.start
+stop = manager.stop
+kill = manager.kill
+get = manager.get
+has = manager.has
+sigchild_handler = manager.sigchild_handler

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


@@ -70,29 +178,37 @@ if __name__ == '__main__':
     import time
 
     sig = None
     import time
 
     sig = None

+    count = 0

 
 

-    def sigchild_handler(signum, stacktrace):
+    def SIGCHLD_handler(signum, stacktrace):

         global sig
         sig = signum
         print 'SIGCHLD', signum
 
         global sig
         sig = signum
         print 'SIGCHLD', signum
 

-    def test_notify(proc):
-        print 'test died:', proc, proc.name, proc.process.pid
+    def notify(pm, pi):
+        global count
+        if pi.name == 'test-service':
+            print 'test-service count =', count
+            count += 1
+            if count > 4:
+                print 'test-service not persistent anymore, start test2'
+                pi.persist = False
+                pm.start('test2')
+        print 'died:', pi.name, pi.command

 
 

-    procman = ProcessManager()
+    register('test-service', ('sleep', '2'), notify, True)
+    register('test2', ('sleep', '3'), notify, False)

 
 

-    signal.signal(signal.SIGCHLD, sigchild_handler)
+    signal.signal(signal.SIGCHLD, SIGCHLD_handler)

 
 

-    procman.call('test', test_notify, True, ('sleep', '5'))
+    call('test', ('sleep', '5'), notify)
+    start('test-service')

 
 

-    while True:
-        time.sleep(1)
-        print "Esperando...",
-        if 'test' in procman:
-            print procman['test']
-        else:
-            print
+    print "Esperando...", [pi.name for pi in manager.namemap.values()]
+    while manager.pidmap:
+        signal.pause()

         if sig == signal.SIGCHLD:
             sig = None
         if sig == signal.SIGCHLD:
             sig = None

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