event/multiqueue.c: Rename "queue" to "multiqueue".

`lib/queue.h` implements a basic queue. `event/queue.c` implements
a specialized data structure on top of lib/queue.h; it is not a "normal"
queue.

Rename the specialized multi-level queue implemented in event/queue.c to
"multiqueue", to avoid confusion when reading the code.

Before this change one can eventually notice that "macros (uppercase
symbols) are for the normal queue, lowercase operations are for the
multi-level queue", but that is unnecessary friction for new developers
(or existing developers just visiting this part of the codebase).

1 files changed, 0 insertions, 208 deletions

diff --git a/src/nvim/event/queue.c b/src/nvim/event/queue.c
deleted file mode 100644
index ee224b0a25..0000000000
--- a/src/nvim/event/queue.c
+++ /dev/null
@@ -1,208 +0,0 @@
-// Queue for selective async event processing. Instances of this queue support a
-// parent/child relationship with the following properties:
-//
-// - pushing a node to a child queue will push a corresponding link node to the
-//   parent queue
-// - removing a link node from a parent queue will remove the next node
-//   in the linked child queue
-// - removing a node from a child queue will remove the corresponding link node
-//   in the parent queue
-//
-// These properties allow Nvim to organize and process events from different
-// sources with a certain degree of control. Here's how the queue is used:
-//
-//                         +----------------+
-//                         |   Main loop    |
-//                         +----------------+
-//                                  ^
-//                                  |
-//                         +----------------+
-//         +-------------->|   Event loop   |<------------+
-//         |               +--+-------------+             |
-//         |                  ^           ^               |
-//         |                  |           |               |
-//    +-----------+   +-----------+    +---------+    +---------+
-//    | Channel 1 |   | Channel 2 |    |  Job 1  |    |  Job 2  |
-//    +-----------+   +-----------+    +---------+    +---------+
-//
-//
-// The lower boxes represents event emitters, each with its own private queue
-// having the event loop queue as the parent.
-//
-// When idle, the main loop spins the event loop which queues events from many
-// sources (channels, jobs, user...). Each event emitter pushes events to its
-// private queue which is propagated to the event loop queue. When the main loop
-// consumes an event, the corresponding event is removed from the emitter's
-// queue.
-//
-// The main reason for this queue hierarchy is to allow focusing on a single
-// event emitter while blocking the main loop. For example, if the `jobwait`
-// VimL function is called on job1, the main loop will temporarily stop polling
-// the event loop queue and poll job1 queue instead. Same with channels, when
-// calling `rpcrequest` we want to temporarily stop processing events from
-// other sources and focus on a specific channel.
-
-#include <assert.h>
-#include <stdarg.h>
-#include <stdbool.h>
-#include <stdint.h>
-
-
-#include <uv.h>
-
-#include "nvim/event/queue.h"
-#include "nvim/memory.h"
-#include "nvim/os/time.h"
-
-typedef struct queue_item QueueItem;
-struct queue_item {
-  union {
-    Queue *queue;
-    struct {
-      Event event;
-      QueueItem *parent;
-    } item;
-  } data;
-  bool link;  // this is just a link to a node in a child queue
-  QUEUE node;
-};
-
-struct queue {
-  Queue *parent;
-  QUEUE headtail;
-  put_callback put_cb;
-  void *data;
-};
-
-#ifdef INCLUDE_GENERATED_DECLARATIONS
-# include "event/queue.c.generated.h"
-#endif
-
-static Event NILEVENT = {.handler = NULL, .argv = {NULL}};
-
-Queue *queue_new_parent(put_callback put_cb, void *data)
-{
-  return queue_new(NULL, put_cb, data);
-}
-
-Queue *queue_new_child(Queue *parent)
-  FUNC_ATTR_NONNULL_ALL
-{
-  assert(!parent->parent);
-  return queue_new(parent, NULL, NULL);
-}
-
-static Queue *queue_new(Queue *parent, put_callback put_cb, void *data)
-{
-  Queue *rv = xmalloc(sizeof(Queue));
-  QUEUE_INIT(&rv->headtail);
-  rv->parent = parent;
-  rv->put_cb = put_cb;
-  rv->data = data;
-  return rv;
-}
-
-void queue_free(Queue *queue)
-{
-  assert(queue);
-  while (!QUEUE_EMPTY(&queue->headtail)) {
-    QUEUE *q = QUEUE_HEAD(&queue->headtail);
-    QueueItem *item = queue_node_data(q);
-    if (queue->parent) {
-      QUEUE_REMOVE(&item->data.item.parent->node);
-      xfree(item->data.item.parent);
-    }
-    QUEUE_REMOVE(q);
-    xfree(item);
-  }
-
-  xfree(queue);
-}
-
-Event queue_get(Queue *queue)
-{
-  return queue_empty(queue) ? NILEVENT : queue_remove(queue);
-}
-
-void queue_put_event(Queue *queue, Event event)
-{
-  assert(queue);
-  queue_push(queue, event);
-  if (queue->parent && queue->parent->put_cb) {
-    queue->parent->put_cb(queue->parent, queue->parent->data);
-  }
-}
-
-void queue_process_events(Queue *queue)
-{
-  assert(queue);
-  while (!queue_empty(queue)) {
-    Event event = queue_get(queue);
-    if (event.handler) {
-      event.handler(event.argv);
-    }
-  }
-}
-
-bool queue_empty(Queue *queue)
-{
-  assert(queue);
-  return QUEUE_EMPTY(&queue->headtail);
-}
-
-void queue_replace_parent(Queue *queue, Queue *new_parent)
-{
-  assert(queue_empty(queue));
-  queue->parent = new_parent;
-}
-
-static Event queue_remove(Queue *queue)
-{
-  assert(!queue_empty(queue));
-  QUEUE *h = QUEUE_HEAD(&queue->headtail);
-  QUEUE_REMOVE(h);
-  QueueItem *item = queue_node_data(h);
-  Event rv;
-
-  if (item->link) {
-    assert(!queue->parent);
-    // remove the next node in the linked queue
-    Queue *linked = item->data.queue;
-    assert(!queue_empty(linked));
-    QueueItem *child =
-      queue_node_data(QUEUE_HEAD(&linked->headtail));
-    QUEUE_REMOVE(&child->node);
-    rv = child->data.item.event;
-    xfree(child);
-  } else {
-    if (queue->parent) {
-      // remove the corresponding link node in the parent queue
-      QUEUE_REMOVE(&item->data.item.parent->node);
-      xfree(item->data.item.parent);
-    }
-    rv = item->data.item.event;
-  }
-
-  xfree(item);
-  return rv;
-}
-
-static void queue_push(Queue *queue, Event event)
-{
-  QueueItem *item = xmalloc(sizeof(QueueItem));
-  item->link = false;
-  item->data.item.event = event;
-  QUEUE_INSERT_TAIL(&queue->headtail, &item->node);
-  if (queue->parent) {
-    // push link node to the parent queue
-    item->data.item.parent = xmalloc(sizeof(QueueItem));
-    item->data.item.parent->link = true;
-    item->data.item.parent->data.queue = queue;
-    QUEUE_INSERT_TAIL(&queue->parent->headtail, &item->data.item.parent->node);
-  }
-}
-
-static QueueItem *queue_node_data(QUEUE *q)
-{
-  return QUEUE_DATA(q, QueueItem, node);
-}