refactor(main): 优化主程序结构并添加信号处理支持

- 添加信号处理函数，实现优雅退出机制
- 引入signal模块，注册SIGINT和SIGTERM信号处理
- 添加全局停止标志用于控制程序终止
- 调整代码注释及格式，提升可读性
- 保持原有系统初始化与运行逻辑不变

dual_camera_system/main.py

@@ -17,6 +17,7 @@ import time
 import argparse
 import logging
 import threading
+import signal
 from typing import Optional
 
 import cv2
@@ -66,6 +67,18 @@ def setup_logging():
 setup_logging()
 logger = logging.getLogger(__name__)
 
+# 全局停止标志（用于信号处理）
+_shutdown_requested = False
+
+
+def _signal_handler(signum, frame):
+    """信号处理函数"""
+    global _shutdown_requested
+    sig_name = signal.Signals(signum).name
+    logger.info(f"接收到信号 {sig_name}，准备优雅退出...")
+    print(f"\n[信号] 接收到 {sig_name}，准备停止...")
+    _shutdown_requested = True
+
 
 class DualCameraSystem:
     """
@@ -680,8 +693,14 @@ def main():
 
 def run_multi_group_mode(args):
     """多组摄像头模式"""
+    global _shutdown_requested
     from multi_group_system import MultiGroupSystem
     
+    # 注册信号处理
+    signal.signal(signal.SIGINT, _signal_handler)
+    signal.signal(signal.SIGTERM, _signal_handler)
+    _shutdown_requested = False
+    
     print("\n" + "=" * 60)
     print("多组摄像头联动抓拍系统")
     print("=" * 60)
@@ -722,12 +741,14 @@ def run_multi_group_mode(args):
         print(f"\n多组摄像头系统运行中 ({len(system.groups)} 个组)")
         print("按 Ctrl+C 停止\n")
         
-        # 等待
-        system.wait()
+        # 等待（检查停止标志）
+        while system.running and not _shutdown_requested:
+            time.sleep(1)
         
     except KeyboardInterrupt:
         print("\n接收到停止信号")
     finally:
+        print("正在停止系统...")
         system.stop()
     
     return 0
@@ -735,6 +756,13 @@ def run_multi_group_mode(args):
 
 def run_single_group_mode(args):
     """单组摄像头模式（保持向后兼容）"""
+    global _shutdown_requested
+    
+    # 注册信号处理
+    signal.signal(signal.SIGINT, _signal_handler)
+    signal.signal(signal.SIGTERM, _signal_handler)
+    _shutdown_requested = False
+    
     # 构建配置
     config = {}
     
@@ -785,7 +813,7 @@ def run_single_group_mode(args):
                 return 1
             
             print("系统运行中,按Ctrl+C停止")
-            while True:
+            while not _shutdown_requested:
                 time.sleep(1)
                 results = system.get_results()
                 if results:
@@ -797,6 +825,7 @@ def run_single_group_mode(args):
         print("\n接收到停止信号")
     
     finally:
+        print("正在停止系统...")
         system.cleanup()
     
     return 0

dual_camera_system/scripts/dual-camera.service

@@ -27,9 +27,11 @@ StandardError=journal
 SyslogIdentifier=dual-camera
 
 # 优雅退出
-TimeoutStopSec=30
-KillSignal=SIGINT
-KillMode=process
+TimeoutStopSec=60
+KillSignal=SIGTERM
+KillMode=mixed
+# 如果正常终止失败，强制终止
+FinalKillSignal=SIGKILL
 
 [Install]
 WantedBy=multi-user.target