fix(bot): 🐛 Main process crashing on shard restart.

run.py

@@ -1,6 +1,6 @@
 from multiprocessing import managers
 
-from datetime import datetime, timezone
+from datetime import datetime, timezone, timedelta
 
 
 def shard(
@@ -8,6 +8,7 @@ def shard(
     shard_count: int,
     shutdown: managers.ValueProxy[bool],
     scheduled_shutdown: managers.ValueProxy[bool],
+    heartbeat: managers.ValueProxy[int]
 ) -> None:
     """Starts a new shard.
 
@@ -17,6 +18,7 @@ def shard(
         shutdown (ValueProxy[bool]): The flag for the main process to shut down all shards.
         scheduled_shutdown (ValueProxy[bool]): The flag for other shards to know the bot's gonna
           shut down soon.
+        heartbeat (ValueProxy[int]): A timestamp updated every second by the shard's process.
     """
 
     from payphone.bot import bot
@@ -26,6 +28,7 @@ def shard(
     bot.shard_count = shard_count
     bot.shutdown = shutdown
     bot.scheduled_shutdown = scheduled_shutdown
+    bot.heartbeat = heartbeat
 
     try:
         import uvloop  # pylint: disable=import-error
@@ -106,11 +109,14 @@ if __name__ == "__main__":
     manager = mp.Manager()
     shutdown = manager.Value("b", False)
     scheduled_shutdown = manager.Value("b", False)
+    heartbeats = [
+        manager.Value("i", 0) for i in range(shard_count)
+    ]
 
     print(f"Starting {shard_count} shard{"s" if shard_count != 1 else ""}.")
 
     ps: list[mp.Process] = [
-        mp.Process(target=shard, args=(i, shard_count, shutdown, scheduled_shutdown))
+        mp.Process(target=shard, args=(i, shard_count, shutdown, scheduled_shutdown, heartbeats[i]))
         for i in range(shard_count)
     ]
     flushing_p = mp.Process(target=flush_process)
@@ -142,11 +148,22 @@ if __name__ == "__main__":
                 raise ShutdownException()
 
             for i in range(shard_count):
+                is_heartbeat_updated = heartbeats[i].value > (datetime.now(timezone.utc) - timedelta(seconds=10)).timestamp()
+
+                if not ps[i].is_alive() or not is_heartbeat_updated:
                     if not ps[i].is_alive():
                         print(f"Shard {i}'s process exited. Restarting the shard...")
 
+                    else:
+                        print(f"Shard {i} did not update heartbeat. Terminating...")
+                        
+                        ps[i].terminate()
+                        ps[i].join()
+
+                        print(f"Shard {i}'s process was terminated. Restarting the shard...")
+
                     ps[i] = mp.Process(
-                        target=shard, args=(i, shard_count), name=f"payphone-shard-{i}"
+                        target=shard, args=(i, shard_count, shutdown, scheduled_shutdown, heartbeats[i]), name=f"payphone-shard-{i}"
                     )
                     ps[i].start()