Opt: Stop thread gracefully

#883 #921

module/webui/app.py

@@ -1,5 +1,6 @@
 import argparse
 import queue
+import threading
 import time
 from datetime import datetime
 from typing import Dict, List
@@ -19,7 +20,7 @@ from module.webui.process_manager import ProcessManager
 from module.webui.setting import Setting
 from module.webui.translate import translate
 from module.webui.updater import updater
-from module.webui.utils import (Icon, Switch, TaskHandler, Thread, add_css,
+from module.webui.utils import (Icon, Switch, TaskHandler, add_css,
                                 filepath_css, get_localstorage,
                                 get_window_visibility_state, login,
                                 parse_pin_value, raise_exception, re_fullmatch)
@@ -843,13 +844,13 @@ class AlasGUI(Frame):
         self.show()
 
         # detect config change
-        _thread_wait_config_change = Thread(
+        _thread_wait_config_change = threading.Thread(
             target=self._alas_thread_wait_config_change)
         register_thread(_thread_wait_config_change)
         _thread_wait_config_change.start()
 
         # save config
-        _thread_save_config = Thread(
+        _thread_save_config = threading.Thread(
             target=self._alas_thread_update_config)
         register_thread(_thread_save_config)
         _thread_save_config.start()

module/webui/process_manager.py

@@ -8,7 +8,6 @@ from filelock import FileLock
 from module.config.utils import deep_get, filepath_config
 from module.logger import logger, set_file_logger, set_func_logger
 from module.webui.setting import Setting
-from module.webui.utils import Thread
 from rich.console import ConsoleRenderable
 
 
@@ -23,7 +22,7 @@ class ProcessManager:
         self.renderables_max_length = 400
         self.renderables_reduce_length = 80
         self._process: Process = None
-        self.thd_log_queue_handler: Thread = None
+        self.thd_log_queue_handler: threading.Thread = None
 
     def start(self, func: str, ev: threading.Event = None) -> None:
         if not self.alive:
@@ -31,9 +30,14 @@ class ProcessManager:
                 target=ProcessManager.run_process,
                 args=(self.config_name, func, self._renderable_queue, ev,))
             self._process.start()
-            self.thd_log_queue_handler = Thread(
+            self.start_log_queue_handler()
+
+    def start_log_queue_handler(self):
+        if self.thd_log_queue_handler is not None and self.thd_log_queue_handler.is_alive():
+            return
+        self.thd_log_queue_handler = threading.Thread(
                 target=self._thread_log_queue_handler)
-            self.thd_log_queue_handler.start()
+        self.thd_log_queue_handler.start()
 
     def stop(self) -> None:
         lock = FileLock(f"{filepath_config(self.config_name)}.lock")
@@ -42,13 +46,15 @@ class ProcessManager:
                 self._process.terminate()
                 self.renderables.append(
                     f"[{self.config_name}] exited. Reason: Manual stop\n")
-            if self.thd_log_queue_handler is not None:
-                self.thd_log_queue_handler.stop()
+            self.thd_log_queue_handler.join()
         logger.info(f"[{self.config_name}] exited")
 
     def _thread_log_queue_handler(self) -> None:
         while self.alive:
-            log = self._renderable_queue.get()
+            try:
+                log = self._renderable_queue.get(timeout=1)
+            except queue.Empty:
+                continue
             self.renderables.append(log)
             if len(self.renderables) > self.renderables_max_length:
                 self.renderables = self.renderables[self.renderables_reduce_length:]

module/webui/utils.py

@@ -1,4 +1,3 @@
-import ctypes
 import datetime
 import operator
 import re
@@ -92,26 +91,6 @@ class QueueHandler:
         self.queue.put(s)
 
 
-class Thread(threading.Thread):
-    # https://www.geeksforgeeks.org/python-different-ways-to-kill-a-thread/
-    def _get_id(self):
-        # returns id of the respective thread
-        if hasattr(self, '_thread_id'):
-            return self._thread_id
-        for thd_id, thread in threading._active.items():
-            if thread is self:
-                return thd_id
-
-    def stop(self):
-        if self.is_alive():
-            thread_id = self._get_id()
-            res = ctypes.pythonapi.PyThreadState_SetAsyncExc(thread_id,
-                                                             ctypes.py_object(SystemExit))
-            if res > 1:
-                ctypes.pythonapi.PyThreadState_SetAsyncExc(thread_id, 0)
-                logger.error('Exception raise failure')
-
-
 class Task:
     def __init__(self, g: Generator, delay: float, next_run: float = None, name: str = None) -> None:
         self.g = g
@@ -141,7 +120,8 @@ class TaskHandler:
         # Running task
         self._task = None
         # Task running thread
-        self._thread: Thread = None
+        self._thread: threading.Thread = None
+        self._alive = False
         self._lock = threading.Lock()
 
     def add(self, func, delay: float, pending_delete: bool = False) -> None:
@@ -215,7 +195,7 @@ class TaskHandler:
         Start task loop.
         You **should** run this function in an individual thread.
         """
-        while True:
+        while self._alive:
             if self.tasks:
                 with self._lock:
                     self.tasks.sort(key=operator.attrgetter('next_run'))
@@ -243,7 +223,7 @@ class TaskHandler:
                 time.sleep(0.5)
 
     def _get_thread(self) -> threading.Thread:
-        thread = Thread(target=self.loop, daemon=True)
+        thread = threading.Thread(target=self.loop, daemon=True)
         return thread
 
     def start(self) -> None:
@@ -259,8 +239,8 @@ class TaskHandler:
 
     def stop(self) -> None:
         self.remove_pending_task()
-        if self._thread.is_alive():
-            self._thread.stop()
+        self._alive = False
+        self._thread.join()
         logger.info("Finish task handler")