motion_queuing: Add new module to help with motion queues and flushing

Create a new module to assist with host management of motion queues.
Register all MCU_stepper objects with this module and use the module
for step generation.

All steppers will now automatically generate steps whenever
toolhead._advance_flush_time() is invoked.  It is no longer necessary
for callers to individually call stepper.generate_steps().

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

klippy/extras/force_move.py

@@ -85,14 +85,13 @@ class ForceMove:
         self.trapq_append(self.trapq, print_time, accel_t, cruise_t, accel_t,
                           0., 0., 0., axis_r, 0., 0., 0., cruise_v, accel)
         print_time = print_time + accel_t + cruise_t + accel_t
-        stepper.generate_steps(print_time)
-        self.trapq_finalize_moves(self.trapq, print_time + 99999.9,
-                                  print_time + 99999.9)
-        stepper.set_trapq(prev_trapq)
-        stepper.set_stepper_kinematics(prev_sk)
         toolhead.note_mcu_movequeue_activity(print_time)
         toolhead.dwell(accel_t + cruise_t + accel_t)
         toolhead.flush_step_generation()
+        stepper.set_trapq(prev_trapq)
+        stepper.set_stepper_kinematics(prev_sk)
+        self.trapq_finalize_moves(self.trapq, print_time + 99999.9,
+                                  print_time + 99999.9)
     def _lookup_stepper(self, gcmd):
         name = gcmd.get('STEPPER')
         if name not in self.steppers:

klippy/extras/manual_stepper.py

@@ -76,7 +76,6 @@ class ManualStepper:
         self.sync_print_time()
         self.next_cmd_time = self._submit_move(self.next_cmd_time, movepos,
                                                speed, accel)
-        self.rail.generate_steps(self.next_cmd_time)
         self.trapq_finalize_moves(self.trapq, self.next_cmd_time + 99999.9,
                                   self.next_cmd_time + 99999.9)
         toolhead = self.printer.lookup_object('toolhead')
@@ -138,7 +137,6 @@ class ManualStepper:
                 raise gcmd.error("Must unregister axis first")
             # Unregister
             toolhead.remove_extra_axis(self)
-            toolhead.unregister_step_generator(self.rail.generate_steps)
             self.axis_gcode_id = None
             return
         if (len(gcode_axis) != 1 or not gcode_axis.isupper()
@@ -155,7 +153,6 @@ class ManualStepper:
         self.gaxis_limit_velocity = limit_velocity
         self.gaxis_limit_accel = limit_accel
         toolhead.add_extra_axis(self, self.get_position()[0])
-        toolhead.register_step_generator(self.rail.generate_steps)
     def process_move(self, print_time, move, ea_index):
         axis_r = move.axes_r[ea_index]
         start_pos = move.start_pos[ea_index]
@@ -208,7 +205,7 @@ class ManualStepper:
                                     speed, self.homing_accel)
         # Drip updates to motors
         toolhead = self.printer.lookup_object('toolhead')
-        toolhead.drip_update_time(maxtime, drip_completion, self.steppers)
+        toolhead.drip_update_time(maxtime, drip_completion)
         # Clear trapq of any remaining parts of movement
         reactor = self.printer.get_reactor()
         self.trapq_finalize_moves(self.trapq, reactor.NEVER, 0)

klippy/extras/motion_queuing.py

@@ -0,0 +1,19 @@
+# Helper code for low-level motion queuing and flushing
+#
+# Copyright (C) 2025  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
+
+class PrinterMotionQueuing:
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.steppers = []
+    def register_stepper(self, config, stepper):
+        self.steppers.append(stepper)
+    def flush_motion_queues(self, must_flush_time, max_step_gen_time):
+        for stepper in self.steppers:
+            stepper.generate_steps(max_step_gen_time)
+
+def load_config(config):
+    return PrinterMotionQueuing(config)

klippy/kinematics/cartesian.py

@@ -36,7 +36,6 @@ class CartKinematics:
                         'safe_distance', None, minval=0.))
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         # Setup boundary checks
         max_velocity, max_accel = toolhead.get_max_velocity()
         self.max_z_velocity = config.getfloat('max_z_velocity', max_velocity,

klippy/kinematics/corexy.py

@@ -20,7 +20,6 @@ class CoreXYKinematics:
         self.rails[2].setup_itersolve('cartesian_stepper_alloc', b'z')
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         # Setup boundary checks
         max_velocity, max_accel = toolhead.get_max_velocity()
         self.max_z_velocity = config.getfloat(

klippy/kinematics/corexz.py

@@ -20,7 +20,6 @@ class CoreXZKinematics:
         self.rails[2].setup_itersolve('corexz_stepper_alloc', b'-')
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         # Setup boundary checks
         max_velocity, max_accel = toolhead.get_max_velocity()
         self.max_z_velocity = config.getfloat(

klippy/kinematics/delta.py

@@ -52,7 +52,6 @@ class DeltaKinematics:
             r.setup_itersolve('delta_stepper_alloc', a, t[0], t[1])
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         # Setup boundary checks
         self.need_home = True
         self.limit_xy2 = -1.

klippy/kinematics/deltesian.py

@@ -40,7 +40,6 @@ class DeltesianKinematics:
         self.rails[2].setup_itersolve('cartesian_stepper_alloc', b'y')
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         self.limits = [(1.0, -1.0)] * 3
         # X axis limits
         min_angle = config.getfloat('min_angle', MIN_ANGLE,

klippy/kinematics/extruder.py

@@ -39,8 +39,6 @@ class ExtruderStepper:
                                    self.name, self.cmd_SYNC_EXTRUDER_MOTION,
                                    desc=self.cmd_SYNC_EXTRUDER_MOTION_help)
     def _handle_connect(self):
-        toolhead = self.printer.lookup_object('toolhead')
-        toolhead.register_step_generator(self.stepper.generate_steps)
         self._set_pressure_advance(self.config_pa, self.config_smooth_time)
     def get_status(self, eventtime):
         return {'pressure_advance': self.pressure_advance,

klippy/kinematics/generic_cartesian.py

@@ -108,7 +108,6 @@ class GenericCartesianKinematics:
         self._load_kinematics(config)
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         self.dc_module = None
         if self.dc_carriages:
             pcs = [dc.get_dual_carriage() for dc in self.dc_carriages]

klippy/kinematics/hybrid_corexy.py

@@ -39,7 +39,6 @@ class HybridCoreXYKinematics:
                         'safe_distance', None, minval=0.))
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         # Setup boundary checks
         max_velocity, max_accel = toolhead.get_max_velocity()
         self.max_z_velocity = config.getfloat(

klippy/kinematics/hybrid_corexz.py

@@ -39,7 +39,6 @@ class HybridCoreXZKinematics:
                         'safe_distance', None, minval=0.))
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         # Setup boundary checks
         max_velocity, max_accel = toolhead.get_max_velocity()
         self.max_z_velocity = config.getfloat(

klippy/kinematics/polar.py

@@ -21,7 +21,6 @@ class PolarKinematics:
                                           for s in r.get_steppers() ]
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         # Setup boundary checks
         max_velocity, max_accel = toolhead.get_max_velocity()
         self.max_z_velocity = config.getfloat(

klippy/kinematics/rotary_delta.py

@@ -52,7 +52,6 @@ class RotaryDeltaKinematics:
                               math.radians(a), ua, la)
         for s in self.get_steppers():
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         # Setup boundary checks
         self.need_home = True
         self.limit_xy2 = -1.

klippy/kinematics/winch.py

@@ -21,7 +21,6 @@ class WinchKinematics:
             self.anchors.append(a)
             s.setup_itersolve('winch_stepper_alloc', *a)
             s.set_trapq(toolhead.get_trapq())
-            toolhead.register_step_generator(s.generate_steps)
         # Setup boundary checks
         acoords = list(zip(*self.anchors))
         self.axes_min = toolhead.Coord(*[min(a) for a in acoords], e=0.)

klippy/stepper.py

@@ -273,7 +273,8 @@ def PrinterStepper(config, units_in_radians=False):
                               rotation_dist, steps_per_rotation,
                               step_pulse_duration, units_in_radians)
     # Register with helper modules
-    for mname in ['stepper_enable', 'force_move', 'motion_report']:
+    mods = ['stepper_enable', 'force_move', 'motion_report', 'motion_queuing']
+    for mname in mods:
         m = printer.load_object(config, mname)
         m.register_stepper(config, mcu_stepper)
     return mcu_stepper
@@ -442,9 +443,6 @@ class GenericPrinterRail:
     def setup_itersolve(self, alloc_func, *params):
         for stepper in self.steppers:
             stepper.setup_itersolve(alloc_func, *params)
-    def generate_steps(self, flush_time):
-        for stepper in self.steppers:
-            stepper.generate_steps(flush_time)
     def set_trapq(self, trapq):
         for stepper in self.steppers:
             stepper.set_trapq(trapq)

klippy/toolhead.py

@@ -251,7 +251,7 @@ class ToolHead:
         self.trapq_append = ffi_lib.trapq_append
         self.trapq_finalize_moves = ffi_lib.trapq_finalize_moves
         # Motion flushing
-        self.step_generators = []
+        self.motion_queuing = self.printer.load_object(config, 'motion_queuing')
         self.flush_trapqs = [self.trapq]
         # Create kinematics class
         gcode = self.printer.lookup_object('gcode')
@@ -280,8 +280,7 @@ class ToolHead:
         sg_flush_want = min(flush_time + STEPCOMPRESS_FLUSH_TIME,
                             self.print_time - self.kin_flush_delay)
         sg_flush_time = max(sg_flush_want, flush_time)
-        for sg in self.step_generators:
+        self.motion_queuing.flush_motion_queues(flush_time, sg_flush_time)
-            sg(sg_flush_time)
         self.min_restart_time = max(self.min_restart_time, sg_flush_time)
         # Free trapq entries that are no longer needed
         clear_history_time = self.clear_history_time
@@ -517,7 +516,7 @@ class ToolHead:
     def get_extra_axes(self):
         return [None, None, None] + self.extra_axes
     # Homing "drip move" handling
-    def drip_update_time(self, next_print_time, drip_completion, addstepper=()):
+    def drip_update_time(self, next_print_time, drip_completion):
         # Transition from "NeedPrime"/"Priming"/main state to "Drip" state
         self.special_queuing_state = "Drip"
         self.need_check_pause = self.reactor.NEVER
@@ -539,8 +538,6 @@ class ToolHead:
                 continue
             npt = min(self.print_time + DRIP_SEGMENT_TIME, next_print_time)
             self.note_mcu_movequeue_activity(npt + self.kin_flush_delay)
-            for stepper in addstepper:
-                stepper.generate_steps(npt)
             self._advance_move_time(npt)
         # Exit "Drip" state
         self.reactor.update_timer(self.flush_timer, self.reactor.NOW)
@@ -617,11 +614,6 @@ class ToolHead:
         return self.kin
     def get_trapq(self):
         return self.trapq
-    def register_step_generator(self, handler):
-        self.step_generators.append(handler)
-    def unregister_step_generator(self, handler):
-        if handler in self.step_generators:
-            self.step_generators.remove(handler)
     def note_step_generation_scan_time(self, delay, old_delay=0.):
         self.flush_step_generation()
         if old_delay: