The schedule module is not designed to run in a non-blocking fashion

This forces code to run sequentially on the scheduler thread.

fixes #231 (again)

Author: unode

mmpy_bot/scheduler.py

@@ -1,7 +1,6 @@
 from datetime import datetime
 from multiprocessing import Pipe, Process
 from multiprocessing.connection import Connection
-from threading import Thread
 from typing import Optional
 
 import schedule
@@ -38,26 +37,24 @@ def _run_job(self, job):
     event loop.
     """
 
-    def launch_and_wait():
-        # Launch job in a dedicated process and send the result through a pipe.
-        if "subprocess" in job.tags:
+    # Launch job in a dedicated process and send the result through a pipe.
+    if "subprocess" in job.tags:
 
-            def wrapped_run(pipe: Connection):
-                result = job.run()
-                pipe.send(result)
-
-            pipe, child_pipe = Pipe()
-            p = Process(target=wrapped_run, args=(child_pipe,))
-            p.start()
-            result = pipe.recv()
-        else:
-            # Or simply run the job in this thread
+        def wrapped_run(pipe: Connection):
             result = job.run()
-
-        if isinstance(result, schedule.CancelJob) or result is schedule.CancelJob:
-            self.cancel_job(job)
-
-    Thread(target=launch_and_wait).start()
+            pipe.send(result)
+
+        pipe, child_pipe = Pipe()
+        p = Process(target=wrapped_run, args=(child_pipe,))
+        p.start()
+        # This still blocks despite running in a subprocess
+        result = pipe.recv()
+    else:
+        # Or simply run the job in this thread
+        result = job.run()
+
+    if isinstance(result, schedule.CancelJob) or result is schedule.CancelJob:
+        self.cancel_job(job)
 
 
 def _once(trigger_time: Optional[datetime] = None):