Clients: fix high CPU usage when launched via MultiProcessing (#4209)

* Core: make Utils.stream_input not consume all CPU for non-blocking streams

* Clients: ignore MultiProcessing pipe as input console

CommonClient.py

@@ -710,6 +710,11 @@ def run_gui(self):
 
     def run_cli(self):
         if sys.stdin:
+            if sys.stdin.fileno() != 0:
+                from multiprocessing import parent_process
+                if parent_process():
+                    return  # ignore MultiProcessing pipe
+
             # steam overlay breaks when starting console_loop
             if 'gameoverlayrenderer' in os.environ.get('LD_PRELOAD', ''):
                 logger.info("Skipping terminal input, due to conflicting Steam Overlay detected. Please use GUI only.")

Utils.py

@@ -18,6 +18,7 @@
 
 from argparse import Namespace
 from settings import Settings, get_settings
+from time import sleep
 from typing import BinaryIO, Coroutine, Optional, Set, Dict, Any, Union
 from typing_extensions import TypeGuard
 from yaml import load, load_all, dump
@@ -568,6 +569,8 @@ def queuer():
             else:
                 if text:
                     queue.put_nowait(text)
+                else:
+                    sleep(0.01)  # non-blocking stream
 
     from threading import Thread
     thread = Thread(target=queuer, name=f"Stream handler for {stream.name}", daemon=True)