src/modules/robot/Conveyor.cpp

   1 /*
   2       This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl) with additions from Sungeun K. Jeon (https://github.com/chamnit/grbl)
   3       Smoothie is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
   4       Smoothie is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
   5       You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>.
   6 */
   7
   8 #include "nuts_bolts.h"
   9 #include "Gcode.h"
  10 #include "Module.h"
  11 #include "Kernel.h"
  12 #include "Timer.h" // mbed.h lib
  13 #include "wait_api.h" // mbed.h lib
  14 #include "Block.h"
  15 #include "Conveyor.h"
  16 #include "Planner.h"
  17 #include "mri.h"
  18 #include "checksumm.h"
  19 #include "Config.h"
  20 #include "StreamOutputPool.h"
  21 #include "ConfigValue.h"
  22 #include "StepTicker.h"
  23 #include "Robot.h"
  24 #include "StepperMotor.h"
  25
  26 #include <functional>
  27 #include <vector>
  28
  29 #include "mbed.h"
  30
  31 #define planner_queue_size_checksum CHECKSUM("planner_queue_size")
  32 #define queue_delay_time_ms_checksum CHECKSUM("queue_delay_time_ms")
  33
  34 /*
  35  * The conveyor holds the queue of blocks, takes care of creating them, and starting the executing chain of blocks
  36  *
  37  * The Queue is implemented as a ringbuffer- with a twist
  38  *
  39  * Since delete() is not thread-safe, we must marshall deletable items out of ISR context
  40  *
  41  * To do this, we have implmented a *double* ringbuffer- two ringbuffers sharing the same ring, and one index pointer
  42  *
  43  * as in regular ringbuffers, HEAD always points to a clean, free block. We are free to prepare it as we see fit, at our leisure.
  44  * When the block is fully prepared, we increment the head pointer, and from that point we must not touch it anymore.
  45  *
  46  * also, as in regular ringbuffers, we can 'use' the TAIL block, and increment tail pointer when we're finished with it
  47  *
  48  * Both of these are implemented here- see queue_head_block() (where head is pushed) and on_idle() (where tail is consumed)
  49  *
  50  * The double ring is implemented by adding a third index pointer that lives in between head and tail. We call it isr_tail_i.
  51  *
  52  * in ISR context, we use HEAD as the head pointer, and isr_tail_i as the tail pointer.
  53  * As HEAD increments, ISR context can consume the new blocks which appear, and when we're finished with a block, we increment isr_tail_i to signal that they're finished, and ready to be cleaned
  54  *
  55  * in IDLE context, we use isr_tail_i as the head pointer, and TAIL as the tail pointer.
  56  * When isr_tail_i != tail, we clean up the tail block (performing ISR-unsafe delete operations) and consume it (increment tail pointer), returning it to the pool of clean, unused blocks which HEAD is allowed to prepare for queueing
  57  *
  58  * Thus, our two ringbuffers exist sharing the one ring of blocks, and we safely marshall used blocks from ISR context to IDLE context for safe cleanup.
  59  */
  60
  61
  62 Conveyor::Conveyor()
  63 {
  64     running = false;
  65     allow_fetch = false;
  66     flush= false;
  67 }
  68
  69 void Conveyor::on_module_loaded()
  70 {
  71     register_for_event(ON_IDLE);
  72     register_for_event(ON_HALT);
  73
  74     // Attach to the end_of_move stepper event
  75     //THEKERNEL->step_ticker->finished_fnc = std::bind( &Conveyor::all_moves_finished, this);
  76     queue_size = THEKERNEL->config->value(planner_queue_size_checksum)->by_default(32)->as_number();
  77     queue_delay_time_ms = THEKERNEL->config->value(queue_delay_time_ms_checksum)->by_default(100)->as_number();
  78 }
  79
  80 // we allocate the queue here after config is completed so we do not run out of memory during config
  81 void Conveyor::start(uint8_t n)
  82 {
  83     Block::init(n); // set the number of motors which determines how big the tick info vector is
  84     queue.resize(queue_size);
  85     running = true;
  86 }
  87
  88 void Conveyor::on_halt(void* argument)
  89 {
  90     if(argument == nullptr) {
  91         flush_queue();
  92     }
  93 }
  94
  95 void Conveyor::on_idle(void*)
  96 {
  97     if (running) {
  98         check_queue();
  99     }
 100
 101     // we can garbage collect the block queue here
 102     if (queue.tail_i != queue.isr_tail_i) {
 103         if (queue.is_empty()) {
 104             __debugbreak();
 105         } else {
 106             // Cleanly delete block
 107             Block* block = queue.tail_ref();
 108             //block->debug();
 109             block->clear();
 110             queue.consume_tail();
 111         }
 112     }
 113 }
 114
 115 // see if we are idle
 116 // this checks the block queue is empty, and that the step queue is empty and
 117 // checks that all motors are no longer moving
 118 bool Conveyor::is_idle() const
 119 {
 120     if(queue.is_empty()) {
 121         for(auto &a : THEROBOT->actuators) {
 122             if(a->is_moving()) return false;
 123         }
 124         return true;
 125     }
 126
 127     return false;
 128 }
 129
 130 // Wait for the queue to be empty and for all the jobs to finish in step ticker
 131 void Conveyor::wait_for_idle(bool wait_for_motors)
 132 {
 133     // wait for the job queue to empty, this means cycling everything on the block queue into the job queue
 134     // forcing them to be jobs
 135     running = false; // stops on_idle calling check_queue
 136     while (!queue.is_empty()) {
 137         check_queue(true); // forces queue to be made available to stepticker
 138         THEKERNEL->call_event(ON_IDLE, this);
 139     }
 140
 141     if(wait_for_motors) {
 142         // now we wait for all motors to stop moving
 143         while(!is_idle()) {
 144             THEKERNEL->call_event(ON_IDLE, this);
 145         }
 146     }
 147
 148     running = true;
 149     // returning now means that everything has totally finished
 150 }
 151
 152 /*
 153  * push the pre-prepared head block onto the queue
 154  */
 155 void Conveyor::queue_head_block()
 156 {
 157     // upstream caller will block on this until there is room in the queue
 158     while (queue.is_full() && !THEKERNEL->is_halted()) {
 159         //check_queue();
 160         THEKERNEL->call_event(ON_IDLE, this); // will call check_queue();
 161     }
 162
 163     if(THEKERNEL->is_halted()) {
 164         // we do not want to stick more stuff on the queue if we are in halt state
 165         // clear and release the block on the head
 166         queue.head_ref()->clear();
 167         return; // if we got a halt then we are done here
 168     }
 169
 170     queue.produce_head();
 171
 172     // not sure if this is the correct place but we need to turn on the motors if they were not already on
 173     THEKERNEL->call_event(ON_ENABLE, (void*)1); // turn all enable pins on
 174 }
 175
 176 void Conveyor::check_queue(bool force)
 177 {
 178     static uint32_t last_time_check = us_ticker_read();
 179
 180     if(queue.is_empty()) {
 181         allow_fetch = false;
 182         last_time_check = us_ticker_read(); // reset timeout
 183         return;
 184     }
 185
 186     // if we have been waiting for more than the required waiting time and the queue is not empty, or the queue is full, then allow stepticker to get the tail
 187     // we do this to allow an idle system to pre load the queue a bit so the first few blocks run smoothly.
 188     if(force || queue.is_full() || (us_ticker_read() - last_time_check) >= (queue_delay_time_ms * 1000)) {
 189         last_time_check = us_ticker_read(); // reset timeout
 190         if(!flush) allow_fetch = true;
 191         return;
 192     }
 193 }
 194
 195 // called from step ticker ISR
 196 bool Conveyor::get_next_block(Block **block)
 197 {
 198     // mark entire queue for GC if flush flag is asserted
 199     if (flush){
 200         while (queue.isr_tail_i != queue.head_i) {
 201             queue.isr_tail_i = queue.next(queue.isr_tail_i);
 202         }
 203     }
 204
 205     // default the feerate to zero if there is no block available
 206     this->current_feedrate= 0;
 207
 208     if(THEKERNEL->is_halted() || queue.isr_tail_i == queue.head_i) return false; // we do not have anything to give
 209
 210     // wait for queue to fill up, optimizes planning
 211     if(!allow_fetch) return false;
 212
 213     Block *b= queue.item_ref(queue.isr_tail_i);
 214     // we cannot use this now if it is being updated
 215     if(!b->locked) {
 216         if(!b->is_ready) __debugbreak(); // should never happen
 217
 218         b->is_ticking= true;
 219         b->recalculate_flag= false;
 220         this->current_feedrate= b->nominal_speed;
 221         *block= b;
 222         return true;
 223     }
 224
 225     return false;
 226 }
 227
 228 // called from step ticker ISR when block is finished, do not do anything slow here
 229 void Conveyor::block_finished()
 230 {
 231     // we increment the isr_tail_i so we can get the next block
 232     queue.isr_tail_i= queue.next(queue.isr_tail_i);
 233 }
 234
 235 /*
 236     In most cases this will not totally flush the queue, as when streaming
 237     gcode there is one stalled waiting for space in the queue, in
 238     queue_head_block() so after this flush, once main_loop runs again one more
 239     gcode gets stuck in the queue, this is bad. Current work around is to call
 240     this when the queue in not full and streaming has stopped
 241 */
 242 void Conveyor::flush_queue()
 243 {
 244     allow_fetch = false;
 245     flush= true;
 246
 247     // TODO force deceleration of last block
 248
 249     // now wait until the block queue has been flushed
 250     wait_for_idle(false);
 251
 252     flush= false;
 253 }
 254
 255 // Debug function
 256 void Conveyor::dump_queue()
 257 {
 258     for (unsigned int index = queue.tail_i, i = 0; true; index = queue.next(index), i++ ) {
 259         THEKERNEL->streams->printf("block %03d > ", i);
 260         queue.item_ref(index)->debug();
 261
 262         if (index == queue.head_i)
 263             break;
 264     }
 265 }