perf: reduce RTN parsing chunk size to 20 and rework ProcessPoolExecutor system

comet/core/execution.py

@@ -1,17 +1,42 @@
+import atexit
+import multiprocessing
+import os
+import signal
 from concurrent.futures import ProcessPoolExecutor
 
+_mp_context = None
+try:
+    _mp_context = multiprocessing.get_context("forkserver")
+except ValueError:
+    _mp_context = multiprocessing.get_context("spawn")
+
 app_executor = None
 
 
-def setup_executor():
+def worker_initializer():
+    signal.signal(signal.SIGINT, signal.SIG_IGN)
+
+
+def setup_executor(max_workers: int | None = None):
     global app_executor
-    app_executor = ProcessPoolExecutor()
+
+    if max_workers is None:
+        cpu_count = os.cpu_count() or 1
+        max_workers = min(cpu_count, 4)
+
+    app_executor = ProcessPoolExecutor(
+        max_workers=max_workers, mp_context=_mp_context, initializer=worker_initializer
+    )
 
 
 def shutdown_executor():
     global app_executor
     if app_executor:
-        app_executor.shutdown()
+        app_executor.shutdown(wait=True, cancel_futures=True)
+        app_executor = None
+
+
+atexit.register(shutdown_executor)
 
 
 def get_executor():

comet/services/orchestration.py

@@ -172,7 +172,7 @@ class TorrentManager:
             return
 
         loop = asyncio.get_running_loop()
-        chunk_size = 50
+        chunk_size = 20
         tasks = [
             loop.run_in_executor(
                 get_executor(),