From 7f10c317f1950c0b611d68d15f44b00c3ad9f852 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gina=20H=C3=A4u=C3=9Fge?= <osd@foosel.net>
Date: Thu, 13 Aug 2015 17:15:01 +0200
Subject: [PATCH] Properly handle serial close on Macs

Readline could still be stuck in a read loop, leading to an exception on Mac
when closing the connection from another thread. This should now be captured
correctly.

Fixes #1021
(cherry picked from commit c829b27)
---
 src/octoprint/util/comm.py | 34 +++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/src/octoprint/util/comm.py b/src/octoprint/util/comm.py
index e36e6e92..6f3cd1e4 100644
--- a/src/octoprint/util/comm.py
+++ b/src/octoprint/util/comm.py
@@ -151,6 +151,7 @@ class MachineCom(object):
 
 		self._long_running_command = False
 		self._heating = False
+		self._connection_closing = False
 
 		self._timeout = None
 
@@ -400,11 +401,15 @@ class MachineCom(object):
 
 		printing = self.isPrinting() or self.isPaused()
 		if self._serial is not None:
+			try:
+				self._serial.close()
+			except:
+				self._logger.exception("Error while trying to close serial port")
+				isError = True
 			if isError:
 				self._changeState(self.STATE_CLOSED_WITH_ERROR)
 			else:
 				self._changeState(self.STATE_CLOSED)
-			self._serial.close()
 		self._serial = None
 
 		if settings().get(["feature", "sdSupport"]):
@@ -1317,15 +1322,17 @@ class MachineCom(object):
 		return line
 
 	def _readline(self):
-		if self._serial == None:
+		if self._serial == None or self._connection_closing:
 			return None
+
 		try:
 			ret = self._serial.readline()
 		except:
-			self._logger.exception("Unexpected error while reading from serial port")
-			self._log("Unexpected error while reading serial port, please consult octoprint.log for details: %s" % (get_exception_string()))
-			self._errorValue = get_exception_string()
-			self.close(True)
+			if not self._connection_closing:
+				self._logger.exception("Unexpected error while reading from serial port")
+				self._log("Unexpected error while reading serial port, please consult octoprint.log for details: %s" % (get_exception_string()))
+				self._errorValue = get_exception_string()
+				self.close(True)
 			return None
 		if ret == '':
 			#self._log("Recv: TIMEOUT")
@@ -1635,6 +1642,9 @@ class MachineCom(object):
 		self._doSendWithoutChecksum(commandToSend)
 
 	def _doSendWithoutChecksum(self, cmd):
+		if self._serial is None or self._connection_closing:
+			return
+
 		self._log("Send: %s" % cmd)
 		try:
 			self._serial.write(cmd + '\n')
@@ -1643,15 +1653,17 @@ class MachineCom(object):
 			try:
 				self._serial.write(cmd + '\n')
 			except:
+				if not self._connection_closing:
+					self._logger.exception("Unexpected error while writing to serial port")
+					self._log("Unexpected error while writing to serial port: %s" % (get_exception_string()))
+					self._errorValue = get_exception_string()
+					self.close(True)
+		except:
+			if not self._connection_closing:
 				self._logger.exception("Unexpected error while writing to serial port")
 				self._log("Unexpected error while writing to serial port: %s" % (get_exception_string()))
 				self._errorValue = get_exception_string()
 				self.close(True)
-		except:
-			self._logger.exception("Unexpected error while writing to serial port")
-			self._log("Unexpected error while writing to serial port: %s" % (get_exception_string()))
-			self._errorValue = get_exception_string()
-			self.close(True)
 
 	##~~ command handlers