WIP locking & parking of plotter/scanner

sorteerhoed/central_management.py

@@ -36,6 +36,7 @@ class CentralManagement():
         self.eventQueue = Queue()
         self.isRunning = threading.Event()
         self.isScanning = threading.Event()
+        self.scanLock = threading.Lock()
 
         
     def loadConfig(self, filename):
@@ -77,7 +78,7 @@ class CentralManagement():
             sqsThread.start()
             
             # the plotter itself
-            self.plotter = Plotter(self.config, self.eventQueue, self.isRunning)
+            self.plotter = Plotter(self.config, self.eventQueue, self.isRunning, self.scanLock)
             plotterThread = threading.Thread(target=self.plotter.start, name='plotter')
             plotterThread.start()
             
@@ -130,9 +131,9 @@ class CentralManagement():
                     self.server.statusPage.set('state', self.currentHit.getStatus())
                     self.makeHit()
                 elif signal.name == 'scan.start':
-                    self.isScanning.set()
+                    pass
                 elif signal.name == 'scan.finished':
-                    self.isScanning.clear()
+                    pass
                 elif signal.name == 'hit.info':
                     if signal.params['hit_id'] != self.currentHit.id:
                         self.logger.warning(f"hit.info hit_id != currenthit.id: {signal}")
@@ -279,6 +280,7 @@ class CentralManagement():
             self.logger.debug(notification_info)
     
     def cleanDrawing(self):
+        with self.scanLock:
             self.eventQueue.put(Signal('scan.start'))
             # Scan to reset
             cmd = [
@@ -286,7 +288,7 @@ class CentralManagement():
             ]
             proc = subprocess.Popen(cmd, stdout=subprocess.DEVNULL, stderr=subprocess.PIPE)
             # opens connection to scanner, but only starts scanning when output becomes ready:
-        o, e = proc.communicate(80)
+            _, e = proc.communicate(80)
         if e:
             self.logger.critical(f"Scanner caused: {e.decode()}")
         
@@ -302,9 +304,7 @@ class CentralManagement():
         """
         Run scanimage on scaner and returns a string with the filename
         """
-        if self.isScanning.is_set():
+        with self.scanLock:
-            raise Exception("Already scanning!")
-        
             self.eventQueue.put(Signal('scan.start'))
             cmd = [
                 'sudo', 'scanimage', '-d', 'epkowa', '--format', 'jpeg',

sorteerhoed/plotter.py

@@ -2,12 +2,12 @@ import queue
 import logging
 from pyaxidraw import axidraw
 from queue import Queue
-from threading import Event
+from threading import Event, Lock
 from sorteerhoed.Signal import Signal
 import time
 
 class Plotter:
-    def __init__(self, config, eventQ: Queue, runningEvent: Event):
+    def __init__(self, config, eventQ: Queue, runningEvent: Event, scannerLock: Lock):
         #TODO: scanningEvent -> CentralManagement.isScanning -> prevent plotter move during scan, failsafe
         self.config = config
         self.eventQ = eventQ
@@ -21,12 +21,14 @@ class Plotter:
         self.xPadding = self.config['scanner']['left_padding'] / 10 / 2.54;
         self.yPadding = self.config['scanner']['top_padding'] / 10 / 2.54;
         self.logger.info(f"Paddings x: {self.xPadding} inch y: {self.yPadding} inch")
+        self.scannerLock = scannerLock
+        self.goPark = False
+        self.locked = False
+        self.ad = None
         
     def park(self):
         self.logger.info("Queue to park plotter")
-        
+        self.goPark = True
-        if self.config['dummy_plotter']:
-            # TODO: find a nice way to park the axidraw in the 0 position
         self.q.put([(-1/2.54)/self.plotWidth,0,0])
         
     def start(self):
@@ -60,6 +62,7 @@ class Plotter:
         finally:
             self.logger.warning("Close Axidraw connection")
             if self.ad:
+                with self.scannerLock:
                     self.ad.moveto(0,0)
                     self.ad.disconnect()
             
@@ -67,6 +70,11 @@ class Plotter:
             self.isRunning.clear()
     
     def draw_segments(self, segments = []):
+        if not self.locked:
+            # acquire lock if not already done so
+            self.scannerLock.acquire()
+            self.locked = True
+            
         coordinates = []
         for segment in segments:
             coordinate = [
@@ -140,6 +148,12 @@ class Plotter:
                 elif plotterRan:
                     plotterRan = False
                     self.eventQ.put(Signal('plotter.finished'))
+                    if self.goPark:
+                        self.eventQ.put(Signal('plotter.parked'))
+                        if self.locked:
+                            self.scannerLock.release()
+                            self.locked = False
+                        self.goPark = False
 #                 else:
 #                     time.sleep(.05)
 #                     self.logger.debug(f'Plotter move: {move}')