From 636d8e0faa99036eac770b72f5808b979f509361 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gina=20H=C3=A4u=C3=9Fge?= <gina@octoprint.org>
Date: Thu, 23 Feb 2017 16:50:04 +0100
Subject: [PATCH] Eventhandling: Wait for command to finish before triggering
 next

Should solve #733
---
 src/octoprint/events.py | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/src/octoprint/events.py b/src/octoprint/events.py
index a117c844..eb500a01 100644
--- a/src/octoprint/events.py
+++ b/src/octoprint/events.py
@@ -332,24 +332,31 @@ class CommandTrigger(GenericEventListener):
 			self._executeGcodeCommand(command, debug=debug)
 
 	def _executeSystemCommand(self, command, debug=False):
-		def commandExecutioner(command):
+		def commandExecutioner(cmd):
 			if debug:
-				self._logger.info("Executing system command: %s" % command)
+				self._logger.info("Executing system command: {}".format(cmd))
+			else:
+				self._logger.info("Executing a system command")
 			# we run this with shell=True since we have to trust whatever
 			# our admin configured as command and since we want to allow
 			# shell-alike handling here...
-			subprocess.Popen(command, shell=True)
+			subprocess.check_call(cmd, shell=True)
 
-		try:
-			if isinstance(command, (list, tuple, set)):
-				for c in command:
-					commandExecutioner(c)
-			else:
-				commandExecutioner(command)
-		except subprocess.CalledProcessError as e:
-			self._logger.warn("Command failed with return code %i: %s" % (e.returncode, str(e)))
-		except:
-			self._logger.exception("Command failed")
+		def process():
+			try:
+				if isinstance(command, (list, tuple, set)):
+					for c in command:
+						commandExecutioner(c)
+				else:
+					commandExecutioner(command)
+			except subprocess.CalledProcessError as e:
+				self._logger.warn("Command failed with return code %i: %s" % (e.returncode, str(e)))
+			except:
+				self._logger.exception("Command failed")
+
+		t = threading.Thread(target=process)
+		t.daemon = True
+		t.start()
 
 	def _executeGcodeCommand(self, command, debug=False):
 		commands = [command]