[2244] introduced a new "Failed" state of Component.

src/lib/python/isc/bind10/component.py

@@ -45,6 +45,7 @@ COMPONENT_RESTART_DELAY = 10
 
 STATE_DEAD = 'dead'
 STATE_STOPPED = 'stopped'
+STATE_FAILED = 'failed'
 STATE_RUNNING = 'running'
 
 def get_signame(signal_number):
@@ -68,6 +69,7 @@ class BaseComponent:
       explicitly).
     - Running - after start() was called, it started successfully and is
       now running.
+    - Failed - the component failed (crashed) and is waiting for a restart
     - Dead - it failed and can not be resurrected.
 
     Init
@@ -79,11 +81,11 @@ class BaseComponent:
                     |            |                |
                     |failure     | failed()       |
                     |            |                |
-                    v            |                |
+                    v            |                | start()/restart()
                     +<-----------+                |
                     |                             |
                     |  kind == dispensable or kind|== needed and failed late
-                    +-----------------------------+
+                    +-----------------------> Failed
                     |
                     | kind == core or kind == needed and it failed too soon
                     v
@@ -236,7 +238,7 @@ class BaseComponent:
                      exit_str)
         if not self.running():
             raise ValueError("Can't fail component that isn't running")
-        self.__state = STATE_STOPPED
+        self.__state = STATE_FAILED
         self._failed_internal()
         # If it is a core component or the needed component failed to start
         # (including it stopped really soon)
@@ -296,6 +298,15 @@ class BaseComponent:
         """
         return self.__state == STATE_RUNNING
 
+    def is_failed(self):
+        """Informs if the component has failed and is waiting for a restart.
+
+        Unlike the case of running(), if this returns True it always means
+        the corresponding process has died and not yet restarted.
+
+        """
+        return self.__state == STATE_FAILED
+
     def _start_internal(self):
         """
         This method does the actual starting of a process. You need to override

src/lib/python/isc/bind10/tests/component_test.py

@@ -192,6 +192,7 @@ class ComponentTests(BossUtils, unittest.TestCase):
         self.assertFalse(self.__stop_called)
         self.assertFalse(self.__failed_called)
         self.assertFalse(component.running())
+        self.assertFalse(component.is_failed())
         # We can't stop or fail the component yet
         self.assertRaises(ValueError, component.stop)
         self.assertRaises(ValueError, component.failed, 1)
@@ -205,6 +206,7 @@ class ComponentTests(BossUtils, unittest.TestCase):
         self.assertFalse(self.__stop_called)
         self.assertFalse(self.__failed_called)
         self.assertTrue(component.running())
+        self.assertFalse(component.is_failed())
 
     def __check_dead(self, component):
         """
@@ -216,6 +218,7 @@ class ComponentTests(BossUtils, unittest.TestCase):
         self.assertTrue(self.__failed_called)
         self.assertEqual(1, self._exitcode)
         self.assertFalse(component.running())
+        self.assertFalse(component.is_failed())
         # Surely it can't be stopped when already dead
         self.assertRaises(ValueError, component.stop)
         # Nor started
@@ -235,6 +238,7 @@ class ComponentTests(BossUtils, unittest.TestCase):
         self.assertFalse(self.__stop_called)
         self.assertTrue(self.__failed_called)
         self.assertTrue(component.running())
+        self.assertFalse(component.is_failed())
         # Check it can't be started again
         self.assertRaises(ValueError, component.start)
 
@@ -247,6 +251,7 @@ class ComponentTests(BossUtils, unittest.TestCase):
         self.assertFalse(self.__stop_called)
         self.assertTrue(self.__failed_called)
         self.assertFalse(component.running())
+        self.assertTrue(component.is_failed())
 
     def __do_start_stop(self, kind):
         """
@@ -271,6 +276,7 @@ class ComponentTests(BossUtils, unittest.TestCase):
         self.assertTrue(self.__stop_called)
         self.assertFalse(self.__failed_called)
         self.assertFalse(component.running())
+        self.assertFalse(component.is_failed())
         # Check it can't be stopped twice
         self.assertRaises(ValueError, component.stop)
         # Or failed