klippy: Add ability to restart the host software

Add a "restart" gcode command that will cause the host "klippy"
software to reload its config and restart.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/gcode.py

@@ -47,7 +47,7 @@ class GCodeParser:
     def build_handlers(self):
         handlers = ['G1', 'G4', 'G20', 'G21', 'G28', 'G90', 'G91', 'G92',
                     'M18', 'M82', 'M83', 'M105', 'M110', 'M114', 'M206',
-                    'HELP', 'QUERY_ENDSTOPS']
+                    'HELP', 'QUERY_ENDSTOPS', 'RESTART']
         if self.heater_nozzle is not None:
             handlers.extend(['M104', 'M109', 'PID_TUNE'])
         if self.heater_bed is not None:
@@ -62,10 +62,6 @@ class GCodeParser:
         for h, f in self.gcode_handlers.items():
             aliases = getattr(self, 'cmd_'+h+'_aliases', [])
             self.gcode_handlers.update(dict([(a, f) for a in aliases]))
-    def finish(self):
-        self.reactor.end()
-        self.toolhead.motor_off()
-        logging.debug('Completed translation by klippy')
     def stats(self, eventtime):
         return "gcodein=%d" % (self.bytes_read,)
     def set_printer_ready(self, is_ready):
@@ -75,7 +71,7 @@ class GCodeParser:
         self.build_handlers()
         if is_ready and self.is_fileinput and self.fd_handle is None:
             self.fd_handle = self.reactor.register_fd(self.fd, self.process_data)
-    def note_mcu_error(self):
+    def motor_heater_off(self):
         if self.toolhead is not None:
             self.toolhead.motor_off()
         if self.heater_nozzle is not None:
@@ -140,7 +136,8 @@ class GCodeParser:
         self.input_commands = lines
         self.process_commands(eventtime)
         if not data and self.is_fileinput:
-            self.finish()
+            self.motor_heater_off()
+            self.printer.request_exit_eof()
     # Response handling
     def ack(self, msg=None):
         if not self.need_ack or self.is_fileinput:
@@ -370,6 +367,11 @@ class GCodeParser:
         temp = float(params.get('S', '60'))
         heater.start_auto_tune(temp)
         self.bg_temp(heater)
+    cmd_RESTART_when_not_ready = True
+    cmd_RESTART_help = "Reload config file and restart host software"
+    def cmd_RESTART(self, params):
+        self.printer.request_restart()
+    cmd_HELP_when_not_ready = True
     def cmd_HELP(self, params):
         cmdhelp = ["// Available extended commands:"]
         for cmd in self.gcode_handlers:

klippy/klippy.py

@@ -14,9 +14,8 @@ Printer is not ready
 """
 
 message_restart = """
-This is an unrecoverable error.  Please correct the
-underlying issue and then manually restart the klippy host
-software.
+Once the underlying issue is corrected, use the "RESTART"
+command to reload the config and restart the host software.
 Printer is halted
 """
 
@@ -85,6 +84,7 @@ class Printer:
         self.need_dump_debug = False
         self.state_message = message_startup
         self.debugoutput = self.dictionary = None
+        self.run_result = None
         self.fileconfig = None
         self.mcu = None
         self.objects = {}
@@ -172,10 +172,7 @@ class Printer:
         except:
             logging.exception("Unhandled exception during run")
             return
-        # If gcode exits, then exit the MCU
-        self.stats(time.time())
-        self.mcu.disconnect()
-        self.stats(time.time())
+        return self.run_result
     def get_state_message(self):
         return self.state_message
     def note_shutdown(self, msg):
@@ -187,7 +184,17 @@ class Printer:
     def note_mcu_error(self, msg):
         self.state_message = "%s%s" % (msg, message_restart)
         self.gcode.set_printer_ready(False)
-        self.gcode.note_mcu_error()
+        self.gcode.motor_heater_off()
+    def disconnect(self):
+        if self.mcu is not None:
+            self.stats(time.time())
+            self.mcu.disconnect()
+    def request_restart(self):
+        self.run_result = "restart"
+        self.reactor.end()
+    def request_exit_eof(self):
+        self.run_result = "exit_eof"
+        self.reactor.end()
 
 
 ######################################################################
@@ -239,11 +246,21 @@ def main():
     logging.info("Starting Klippy...")
 
     # Start firmware
-    printer = Printer(conffile, input_fd, is_fileinput=debuginput is not None)
+    while 1:
+        is_fileinput = debuginput is not None
+        printer = Printer(conffile, input_fd, is_fileinput)
         if debugoutput:
             proto_dict = read_dictionary(options.read_dictionary)
             printer.set_fileoutput(debugoutput, proto_dict)
-    printer.run()
+        res = printer.run()
+        if res == 'restart':
+            printer.disconnect()
+            time.sleep(1.)
+            logging.info("Restarting printer")
+            continue
+        elif res == 'eof_stats':
+            printer.disconnect()
+        break
 
     if bglogger is not None:
         bglogger.stop()