task: program_units follows the executing G20/G21, like gcodes (#3627)

docs/src/config/python-interface.adoc

@@ -313,7 +313,10 @@ see <<python:reading-ini-values,ReadingINI file values>> for an example.
   flag, True if a probe operation is in progress.
 
 *program_units*:: '(returns integer)' -
-  one of CANON_UNITS_INCHES=1, CANON_UNITS_MM=2, CANON_UNITS_CM=3
+  one of CANON_UNITS_INCHES=1, CANON_UNITS_MM=2, CANON_UNITS_CM=3.
+  Follows the active G20/G21 reported in *gcodes*: the executing line while
+  a program runs, the interpreter otherwise. CANON_UNITS_CM is never reported:
+  G-code cannot select it and canterp maps it to mm.
 
 *queue*:: '(returns integer)' -
   current size of the trajectory planner queue.

src/emc/task/emctask.cc

@@ -29,6 +29,7 @@
 #include "nml_intf/interpl_nml.hh"		// NML_INTERP_LIST, interp_list
 #include "nml_intf/canon.hh"		// CANON_VECTOR, GET_PROGRAM_ORIGIN()
 #include "rs274ngc/rs274ngc_interp.hh"	// the interpreter
+#include "rs274ngc/interp_internal.hh"	// G_20, G_21
 #include "nml_intf/interp_return.hh"	// INTERP_FILE_NOT_OPEN
 #include <inifile.hh>
 
@@ -763,6 +764,17 @@ int emcTaskUpdate(EMC_TASK_STAT * stat)
         interp.active_settings(&stat->activeSettings[0]);
     }
 
+    // program_units follows the active G20/G21 above, so it describes the
+    // same point in the program as gcodes does: the executing move while a
+    // program runs, the interpreter otherwise.  Canon also sets it as the
+    // interpreter reads ahead, which alone reported a G20 read ahead of a
+    // still-running G21 move (issue #3627).  Canon's value stays when the
+    // interpreter reports no G20/G21 at all (canterp).
+    if (stat->activeGCodes[5] == G_20)
+        stat->programUnits = CANON_UNITS_INCHES;
+    else if (stat->activeGCodes[5] == G_21)
+        stat->programUnits = CANON_UNITS_MM;
+
     //update state of optional stop
     stat->optional_stop_state = GET_OPTIONAL_PROGRAM_STOP();
 

tests/program-units/.gitignore

@@ -0,0 +1 @@
+sim.var*

tests/program-units/README

@@ -0,0 +1,4 @@
+Issue #3627: linuxcnc.stat.program_units followed the interpreter's
+read-ahead, so it reported a G20 while a G21 move was still executing, and
+disagreed with gcodes. This runs a 5 s G21 move followed by G20 and checks,
+while the move executes, that program_units says mm whenever gcodes says G21.

tests/program-units/checkresult

@@ -0,0 +1,2 @@
+#!/bin/sh
+exit 0 # test failure is indicated by test.sh exit value

tests/program-units/core_sim.hal

@@ -0,0 +1,61 @@
+# core HAL config file for simulation
+
+# first load all the RT modules that will be needed
+# kinematics
+loadrt [KINS]KINEMATICS
+#autoconverted  trivkins
+# motion controller, get name and thread periods from INI file
+loadrt [EMCMOT]EMCMOT base_period_nsec=[EMCMOT]BASE_PERIOD servo_period_nsec=[EMCMOT]SERVO_PERIOD num_joints=[KINS]JOINTS 
+# load 6 differentiators (for velocity and accel signals
+loadrt ddt count=6
+# load additional blocks
+loadrt hypot count=2
+loadrt comp count=3
+loadrt or2 count=1
+
+# add motion controller functions to servo thread
+addf motion-command-handler servo-thread
+addf motion-controller servo-thread
+# link the differentiator functions into the code
+addf ddt.0 servo-thread
+addf ddt.1 servo-thread
+addf ddt.2 servo-thread
+addf ddt.3 servo-thread
+addf ddt.4 servo-thread
+addf ddt.5 servo-thread
+addf hypot.0 servo-thread
+addf hypot.1 servo-thread
+
+# create HAL signals for position commands from motion module
+# loop position commands back to motion module feedback
+net Xpos joint.0.motor-pos-cmd => joint.0.motor-pos-fb ddt.0.in
+net Ypos joint.1.motor-pos-cmd => joint.1.motor-pos-fb ddt.2.in
+net Zpos joint.2.motor-pos-cmd => joint.2.motor-pos-fb ddt.4.in
+
+# send the position commands thru differentiators to
+# generate velocity and accel signals
+net Xvel ddt.0.out => ddt.1.in hypot.0.in0
+net Xacc <= ddt.1.out 
+net Yvel ddt.2.out => ddt.3.in hypot.0.in1
+net Yacc <= ddt.3.out 
+net Zvel ddt.4.out => ddt.5.in hypot.1.in0
+net Zacc <= ddt.5.out 
+
+# Cartesian 2- and 3-axis velocities
+net XYvel hypot.0.out => hypot.1.in1
+net XYZvel <= hypot.1.out
+
+# estop loopback
+net estop-loop iocontrol.0.user-enable-out iocontrol.0.emc-enable-in
+
+# create signals for tool loading loopback
+net tool-prepare <= iocontrol.0.tool-prepare
+net tool-prepared => iocontrol.0.tool-prepared
+
+net tool-change <= iocontrol.0.tool-change
+net tool-changed => iocontrol.0.tool-changed
+
+net tool-number <= iocontrol.0.tool-number
+net tool-prep-number <= iocontrol.0.tool-prep-number
+net tool-prep-pocket <= iocontrol.0.tool-prep-pocket
+

tests/program-units/test-ui.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python3
+
+import linuxcnc
+import linuxcnc_util
+import time
+import sys
+
+
+l = linuxcnc_util.LinuxCNC()
+c, s = l.command, l.status
+l.wait_for_linuxcnc_startup()
+
+c.state(linuxcnc.STATE_ESTOP_RESET)
+c.state(linuxcnc.STATE_ON)
+c.home(-1)
+c.wait_complete()
+c.mode(linuxcnc.MODE_AUTO)
+c.wait_complete()
+c.program_open('test.ngc')
+c.wait_complete()
+s.poll()
+if s.task_mode != linuxcnc.MODE_AUTO or not s.file.endswith('test.ngc'):
+    print('FAIL: not in AUTO with test.ngc open (mode %d, file %r)' % (s.task_mode, s.file))
+    sys.exit(1)
+e = linuxcnc.error_channel()
+c.auto(linuxcnc.AUTO_RUN, 0)
+
+# While the G21 move executes, gcodes[5] (from the executing move) says G21.
+# program_units must agree: before the fix it already showed the G20 that the
+# interpreter had read ahead.
+in_g21 = mismatch = 0
+start = time.time()
+while time.time() - start < 30:
+    s.poll()
+    if s.interp_state == linuxcnc.INTERP_IDLE and time.time() - start > 1:
+        break
+    if s.gcodes[5] == 210 and s.interp_state != linuxcnc.INTERP_IDLE:
+        in_g21 += 1
+        if s.program_units != 2:  # CANON_UNITS_MM (no Python constant for it)
+            mismatch += 1
+    time.sleep(0.005)
+
+s.poll()
+while True:
+    msg = e.poll()
+    if not msg:
+        break
+    print('error channel: %s' % (msg[1],))
+if s.interp_state != linuxcnc.INTERP_IDLE:
+    print('FAIL: the program did not finish within 30 s')
+    sys.exit(1)
+print('samples while G21 executed: %d, program_units not mm in them: %d, end gcodes[5]=%d program_units=%d'
+      % (in_g21, mismatch, s.gcodes[5], s.program_units))
+if in_g21 < 100:
+    print('FAIL: the G21 move was not seen executing')
+    sys.exit(1)
+if mismatch:
+    print('FAIL: program_units disagreed with gcodes while the G21 move executed')
+    sys.exit(1)
+if (s.gcodes[5], s.program_units) != (200, 1):
+    print('FAIL: after the program, G20 should be active in both')
+    sys.exit(1)
+sys.exit(0)

tests/program-units/test.ini

@@ -0,0 +1,117 @@
+# Simulated machine for tests/program-units (issue #3627), based on tests/abort/feed-rate.
+
+[EMC]
+# The version string for this INI file.
+VERSION = 1.1
+
+DEBUG = 0
+RCS_DEBUG = 0x05400f01
+
+[DISPLAY]
+DISPLAY = ./test-ui.py
+
+[FILTER]
+#No Content
+
+[RS274NGC]
+PARAMETER_FILE = sim.var
+
+[EMCMOT]
+EMCMOT = motmod
+COMM_TIMEOUT = 4.0
+BASE_PERIOD = 0
+SERVO_PERIOD = 1000000
+
+[TASK]
+TASK = milltask
+CYCLE_TIME = 0.001
+
+[HAL]
+HALUI = halui
+HALFILE = core_sim.hal
+
+[HALUI]
+#No Content
+[TRAJ]
+
+NO_FORCE_HOMING=1
+AXES =                  3
+COORDINATES =           X Y Z
+HOME =                  0 0 0
+LINEAR_UNITS =          inch
+ANGULAR_UNITS =         degree
+DEFAULT_LINEAR_VELOCITY =      1.2
+MAX_LINEAR_ACCELERATION =      123.45
+MAX_LINEAR_VELOCITY =          45.67
+
+[EMCIO]
+TOOL_TABLE = simpockets.tbl
+TOOL_CHANGE_QUILL_UP = 1
+RANDOM_TOOLCHANGER = 0
+
+
+
+[KINS]
+KINEMATICS = trivkins
+#This is a best-guess at the number of joints, it should be checked
+JOINTS = 3
+
+[AXIS_X]
+MIN_LIMIT = -40.0
+MAX_LIMIT = 40.0
+MAX_VELOCITY = 4
+MAX_ACCELERATION = 1000.0
+
+[JOINT_0]
+
+TYPE =             LINEAR
+HOME =             0.000
+MAX_VELOCITY =     4
+MAX_ACCELERATION = 1000.0
+BACKLASH =         0.000
+INPUT_SCALE =      4000
+OUTPUT_SCALE =     1.000
+MIN_LIMIT =        -40.0
+MAX_LIMIT =        40.0
+FERROR =           0.050
+MIN_FERROR =       0.010
+
+[AXIS_Y]
+MIN_LIMIT = -40.0
+MAX_LIMIT = 40.0
+MAX_VELOCITY = 4
+MAX_ACCELERATION = 1000.0
+
+[JOINT_1]
+
+TYPE =             LINEAR
+HOME =             0.000
+MAX_VELOCITY =     4
+MAX_ACCELERATION = 1000.0
+BACKLASH =         0.000
+INPUT_SCALE =      4000
+OUTPUT_SCALE =     1.000
+MIN_LIMIT =        -40.0
+MAX_LIMIT =        40.0
+FERROR =           0.050
+MIN_FERROR =       0.010
+
+[AXIS_Z]
+MIN_LIMIT = -40.0
+MAX_LIMIT = 40.0
+MAX_VELOCITY = 4
+MAX_ACCELERATION = 1000.0
+
+[JOINT_2]
+
+TYPE =             LINEAR
+HOME =             0.0
+MAX_VELOCITY =     4
+MAX_ACCELERATION = 1000.0
+BACKLASH =         0.000
+INPUT_SCALE =      4000
+OUTPUT_SCALE =     1.000
+MIN_LIMIT =        -40.0
+MAX_LIMIT =        40.0
+FERROR =           0.050
+MIN_FERROR =       0.010

tests/program-units/test.ngc

@@ -0,0 +1,5 @@
+G21 (this move runs in mm)
+G1 X25 F300 (about 5 s: the interpreter reads past it to the G20 long before it ends)
+G20
+G1 X0 F20
+M2

tests/program-units/test.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+rm -f sim.var
+linuxcnc -r test.ini
+