Merge pull request #922 from smaarn/fix/747/improve-termination-signal-handling

[Python 3 only] Changed SIGTERM signal handling.

bazarr.py

@@ -55,34 +55,6 @@ class DaemonStatus(ProcessRegistry):
     def unregister(self, process):
         self.__processes.remove(process)
 
-    @staticmethod
-    def __wait_for_processes(processes, timeout):
-        """
-        Waits all the provided processes for the specified amount of time in seconds.
-        """
-        reference_ts = time.time()
-        elapsed = 0
-        remaining_processes = list(processes)
-        while elapsed < timeout and len(remaining_processes) > 0:
-            remaining_time = timeout - elapsed
-            for ep in list(remaining_processes):
-                if ep.poll() is not None:
-                    remaining_processes.remove(ep)
-                else:
-                    if remaining_time > 0:
-                        if PY3:
-                            try:
-                                ep.wait(remaining_time)
-                                remaining_processes.remove(ep)
-                            except subprocess.TimeoutExpired:
-                                pass
-                        else:
-                            # In python 2 there is no such thing as some mechanism to wait with a timeout
-                            time.sleep(1)
-                        elapsed = time.time() - reference_ts
-                        remaining_time = timeout - elapsed
-        return remaining_processes
-
     @staticmethod
     def __send_signal(processes, signal_no, live_processes=None):
         """
@@ -105,9 +77,11 @@ class DaemonStatus(ProcessRegistry):
         Flags this instance as should stop and terminates as smoothly as possible children processes.
         """
         self.__should_stop = True
-        live_processes = DaemonStatus.__send_signal(self.__processes, signal.SIGINT, list())
+        DaemonStatus.__send_signal(self.__processes, signal.SIGINT, list())
-        live_processes = DaemonStatus.__wait_for_processes(live_processes, 120)
+
-        DaemonStatus.__send_signal(live_processes, signal.SIGTERM)
+    def force_stop(self):
+        self.__should_stop = True
+        DaemonStatus.__send_signal(self.__processes, signal.SIGTERM)
 
     def should_stop(self):
         return self.__should_stop
@@ -170,11 +144,19 @@ if __name__ == '__main__':
     if PY3:
         daemonStatus = DaemonStatus()
 
+        def force_shutdown():
+            # force the killing of children processes
+            daemonStatus.force_stop()
+            # if a new SIGTERM signal is caught the standard behaviour should be followed
+            signal.signal(signal.SIGTERM, signal.SIG_DFL)
+            # emulate a Ctrl C command on itself (bypasses the signal thing but, then, emulates the "Ctrl+C break")
+            os.kill(os.getpid(), signal.SIGINT)
+    
         def shutdown():
             # indicates that everything should stop
             daemonStatus.stop()
-            # emulate a Ctrl C command on itself (bypasses the signal thing but, then, emulates the "Ctrl+C break")
+            # if a new sigterm signal is caught it should force the shutdown of children processes
-            os.kill(os.getpid(), signal.SIGINT)
+            signal.signal(signal.SIGTERM, lambda signal_no, frame: force_shutdown())
 
         signal.signal(signal.SIGTERM, lambda signal_no, frame: shutdown())