scheduler: Add function to fork worker process.

It is much better to let some jobs run in their own process,
because that helps us to deal with memory-leaks and saves
the main process from being terminated by an unforeseen error.

diff --git a/backend/scheduler.py b/backend/scheduler.py
index 80f5fc4bb15c8f03f051cdb52a680b659e367d50..9e08362e4c5070fe53ec614aeea82c747fe30432 100644 (file)
--- a/backend/scheduler.py
+++ b/backend/scheduler.py
@@ -1,16 +1,20 @@
 #!/usr/bin/python
 
 import logging
+import multiprocessing
 import time
 import traceback
 
+import backend.main
+
 class Event(object):
        interval = None
 
        priority = 0
 
-       def __init__(self, *arguments):
-               self.arguments = arguments
+       def __init__(self, *args, **kwargs):
+               self.args = args
+               self.kwargs = kwargs
 
                self._next_start_time = 0
 
@@ -26,6 +30,30 @@ class Event(object):
        def run(self, *args, **kwargs):
                raise NotImplemented
 
+       def run_subprocess_background(self, method, *args):
+               arguments = [method,] + list(args)
+
+               process = multiprocessing.Process(target=self.fork, args=arguments)
+               process.daemon = False
+
+               # Start the process.
+               process.start()
+
+               return process
+
+       def run_subprocess(self, *args):
+               process = self.run_subprocess_background(*args)
+
+               # Wait until process has finished.
+               process.join()
+
+       @staticmethod
+       def fork(method, *args, **kwargs):
+               # Create new pakfire instance.
+               _pakfire = backend.main.Pakfire()
+
+               return method(_pakfire, *args, **kwargs)
+
 
 class Scheduler(object):
        def __init__(self):
@@ -48,6 +76,7 @@ class Scheduler(object):
        def run(self):
                while self._queue:
                        self.sort_queue()
+                       print self._queue
 
                        for event in self._queue:
                                # If the event has to be started some time in
@@ -56,7 +85,7 @@ class Scheduler(object):
                                        try:
                                                logging.info("Running %s..." % event)
 
-                                               event.run(*event.arguments)
+                                               event.run(*event.args, **event.kwargs)
 
                                        # In case the user interrupts the scheduler.
                                        except KeyboardInterrupt: