serialqueue: Rename stalled_bytes stat to upcoming_bytes

The stalled_bytes counter refers to the number of bytes that are not
yet eligible for transmission.  However, the naming leads to confusion
as it could be interpretted as an inability to transmit data.  Rename
to upcoming_bytes to try to avoid that confusion.

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

docs/Config_Changes.md

@@ -8,6 +8,9 @@ All dates in this document are approximate.
 
 ## Changes
 
+20230407: The `stalled_bytes` counter in the log and in the
+`printer.mcu.last_stats` field has been renamed to `upcoming_bytes`.
+
 20230304: The `SET_TMC_CURRENT` command now properly adjusts the globalscaler
 register for drivers that have it. This removes a limitation where on tmc5160,
 the currents could not be raised higher with `SET_TMC_CURRENT` than the

klippy/chelper/serialqueue.c

@@ -30,7 +30,7 @@
 #include "serialqueue.h" // struct queue_message
 
 struct command_queue {
-    struct list_head stalled_queue, ready_queue;
+    struct list_head upcoming_queue, ready_queue;
     struct list_node node;
 };
 
@@ -59,7 +59,7 @@ struct serialqueue {
     double srtt, rttvar, rto;
     // Pending transmission message queues
     struct list_head pending_queues;
-    int ready_bytes, stalled_bytes, need_ack_bytes, last_ack_bytes;
+    int ready_bytes, upcoming_bytes, need_ack_bytes, last_ack_bytes;
     uint64_t need_kick_clock;
     struct list_head notify_queue;
     // Received messages
@@ -458,7 +458,7 @@ build_and_send_command(struct serialqueue *sq, uint8_t *buf, int pending
         if (len + qm->len > MESSAGE_MAX - MESSAGE_TRAILER_SIZE)
             break;
         list_del(&qm->node);
-        if (list_empty(&cq->ready_queue) && list_empty(&cq->stalled_queue))
+        if (list_empty(&cq->ready_queue) && list_empty(&cq->upcoming_queue))
             list_del(&cq->node);
         memcpy(&buf[len], qm->msg, qm->len);
         len += qm->len;
@@ -523,10 +523,10 @@ check_send_command(struct serialqueue *sq, int pending, double eventtime)
     uint64_t min_stalled_clock = MAX_CLOCK, min_ready_clock = MAX_CLOCK;
     struct command_queue *cq;
     list_for_each_entry(cq, &sq->pending_queues, node) {
-        // Move messages from the stalled_queue to the ready_queue
+        // Move messages from the upcoming_queue to the ready_queue
-        while (!list_empty(&cq->stalled_queue)) {
+        while (!list_empty(&cq->upcoming_queue)) {
             struct queue_message *qm = list_first_entry(
-                &cq->stalled_queue, struct queue_message, node);
+                &cq->upcoming_queue, struct queue_message, node);
             if (ack_clock < qm->min_clock) {
                 if (qm->min_clock < min_stalled_clock)
                     min_stalled_clock = qm->min_clock;
@@ -534,7 +534,7 @@ check_send_command(struct serialqueue *sq, int pending, double eventtime)
             }
             list_del(&qm->node);
             list_add_tail(&qm->node, &cq->ready_queue);
-            sq->stalled_bytes -= qm->len;
+            sq->upcoming_bytes -= qm->len;
             sq->ready_bytes += qm->len;
         }
         // Update min_ready_clock
@@ -714,7 +714,7 @@ serialqueue_free(struct serialqueue *sq)
             &sq->pending_queues, struct command_queue, node);
         list_del(&cq->node);
         message_queue_free(&cq->ready_queue);
-        message_queue_free(&cq->stalled_queue);
+        message_queue_free(&cq->upcoming_queue);
     }
     pthread_mutex_unlock(&sq->lock);
     pollreactor_free(sq->pr);
@@ -728,7 +728,7 @@ serialqueue_alloc_commandqueue(void)
     struct command_queue *cq = malloc(sizeof(*cq));
     memset(cq, 0, sizeof(*cq));
     list_init(&cq->ready_queue);
-    list_init(&cq->stalled_queue);
+    list_init(&cq->upcoming_queue);
     return cq;
 }
 
@@ -738,7 +738,7 @@ serialqueue_free_commandqueue(struct command_queue *cq)
 {
     if (!cq)
         return;
-    if (!list_empty(&cq->ready_queue) || !list_empty(&cq->stalled_queue)) {
+    if (!list_empty(&cq->ready_queue) || !list_empty(&cq->upcoming_queue)) {
         errorf("Memory leak! Can't free non-empty commandqueue");
         return;
     }
@@ -784,12 +784,12 @@ serialqueue_send_batch(struct serialqueue *sq, struct command_queue *cq
         return;
     qm = list_first_entry(msgs, struct queue_message, node);
 
-    // Add list to cq->stalled_queue
+    // Add list to cq->upcoming_queue
     pthread_mutex_lock(&sq->lock);
-    if (list_empty(&cq->ready_queue) && list_empty(&cq->stalled_queue))
+    if (list_empty(&cq->ready_queue) && list_empty(&cq->upcoming_queue))
         list_add_tail(&cq->node, &sq->pending_queues);
-    list_join_tail(msgs, &cq->stalled_queue);
+    list_join_tail(msgs, &cq->upcoming_queue);
-    sq->stalled_bytes += len;
+    sq->upcoming_bytes += len;
     int mustwake = 0;
     if (qm->min_clock < sq->need_kick_clock) {
         sq->need_kick_clock = 0;
@@ -925,13 +925,13 @@ serialqueue_get_stats(struct serialqueue *sq, char *buf, int len)
              " bytes_retransmit=%u bytes_invalid=%u"
              " send_seq=%u receive_seq=%u retransmit_seq=%u"
              " srtt=%.3f rttvar=%.3f rto=%.3f"
-             " ready_bytes=%u stalled_bytes=%u"
+             " ready_bytes=%u upcoming_bytes=%u"
              , stats.bytes_write, stats.bytes_read
              , stats.bytes_retransmit, stats.bytes_invalid
              , (int)stats.send_seq, (int)stats.receive_seq
              , (int)stats.retransmit_seq
              , stats.srtt, stats.rttvar, stats.rto
-             , stats.ready_bytes, stats.stalled_bytes);
+             , stats.ready_bytes, stats.upcoming_bytes);
 }
 
 // Extract old messages stored in the debug queues