* fix scan qrcode app can't release resource

Author: lxowalle

maix/__signal_handle__.py

@@ -5,18 +5,20 @@
 
 def force_exit():
     print("Force exit now")
-    _maix.util.do_exit_function()
     sys.exit(1)
 
 def signal_handle(signum, frame):
     _maix.app.set_exit_flag(True)
     signal.signal(signal.SIGINT, signal.SIG_DFL)
-
+    signal.signal(signal.SIGILL, signal.SIG_DFL)
+    signal.signal(signal.SIGABRT, signal.SIG_DFL)
     # set exit flag and wait force_exit_timeout seconds, then force exit
     t = threading.Timer(force_exit_timeout, force_exit)
     t.daemon = True
     t.start()
-
+    _maix.util.do_exit_function()
 
 def register_signal_handle():
-    signal.signal(signal.SIGINT, signal_handle)
+    signal.signal(signal.SIGINT, signal_handle)
+    signal.signal(signal.SIGILL, signal_handle)
+    signal.signal(signal.SIGABRT, signal_handle)

projects/app_scan_qrcode/main.py

@@ -2,7 +2,7 @@
 
 import struct
 from maix import image
-from maix import time
+from maix import app
 from maix.camera import Camera
 from maix.display import Display
 from maix.touchscreen import TouchScreen
@@ -231,7 +231,8 @@ def find_apriltags(img):
         return True
     else:
         return False
-while 1:
+
+while not app.need_exit():
     img = cam.read()
     if img:
         res = False