Revert "change pipeListener to unblocking poll loop"

This reverts commit 6ab3ecbf34.

listeners.py

@@ -1,5 +1,4 @@
-import logging, os, sys, stat, time
-from threading import Event
+import logging, os, sys, stat
 from exceptionThreading import ExceptionThread
 from evdev import InputDevice, ecodes
 from select import select
@@ -114,36 +113,14 @@ class KeypadListener(ExceptionThread):
 		except AttributeError:
 			pass
 			
+# TODO: these are not threadsafe
+# TODO: this code gets really confused if the pipe is deleted
 class PipeListener(ExceptionThread):
 	def __init__(self, callback, path):
 		self._path = path
-		self._stopper = Event()
-		self._makeFIFO()
 		
-		def listen():
-			while not self._stopper.isSet():
-				try:
-					fd = os.open(self._path, os.O_RDONLY | os.O_NONBLOCK)
-					msg = os.read(fd, 1024).decode().rstrip()
-					if msg != '':
-						callback(msg, logger)
-					os.close(fd)
-				except BlockingIOError:
-					pass
-				except FileNotFoundError:
-					# TODO: this might be easier with a watchdog
-					self._makeFIFO()
-				finally:
-					time.sleep(0.1)
-						
-		super().__init__(target=listen, daemon=False)
-		self.start()
-		logger.debug('Started pipe listener at path %s', self._path)
-
-	def _makeFIFO(self):
 		if os.path.exists(self._path):
 			if not stat.S_ISFIFO(os.stat(self._path)[0]):
-				logger.warn('%s exists but is not a pipe. Deleting', self._path)
 				os.remove(self._path)
 				os.mkfifo(self._path)
 		else:
@@ -151,8 +128,17 @@ class PipeListener(ExceptionThread):
 		
 		os.chmod(self._path, 0o0777)
 		
+		def listenForSecret():
+			while 1:
+				with open(self._path, 'r') as f:
+					msg = f.readline()[:-1]
+					callback(msg, logger)
+		
+		super().__init__(target=listenForSecret, daemon=True)
+		self.start()
+		logger.debug('Started pipe listener at path %s', self._path)
+		
 	def __del__(self):
-		self._stopper.set()
 		if os.path.exists(self._path):
 			os.remove(self._path)
 		logger.debug('Cleaned up pipe listener at path %s', self._path)