refactor(event): change last use of klist to kvec

loop->children might have been a linked list because used to be
modified in place while looped over. However the loops that exists
rather schedules events to be processed later, outside of the loop,
so this can not happen anymore.

When a linked list is otherwise useful it is better to use
lib/queue_defs.h which defines an _intrusive_ linked list (i e it
doesn't need to do allocations for list items like klist ).

src/klib/klist.h

@@ -1,144 +0,0 @@
-/* The MIT License
-
-   Copyright (c) 2008-2009, by Attractive Chaos <attractor@live.co.uk>
-
-   Permission is hereby granted, free of charge, to any person obtaining
-   a copy of this software and associated documentation files (the
-   "Software"), to deal in the Software without restriction, including
-   without limitation the rights to use, copy, modify, merge, publish,
-   distribute, sublicense, and/or sell copies of the Software, and to
-   permit persons to whom the Software is furnished to do so, subject to
-   the following conditions:
-
-   The above copyright notice and this permission notice shall be
-   included in all copies or substantial portions of the Software.
-
-   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
-   BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
-   ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-   SOFTWARE.
- */
-
-#ifndef _AC_KLIST_H
-#define _AC_KLIST_H
-
-#include <assert.h>
-#include <stdlib.h>
-
-#include "nvim/func_attr.h"
-#include "nvim/memory.h"
-
-#define KMEMPOOL_INIT(name, kmptype_t, kmpfree_f) \
-  typedef struct { \
-    size_t cnt, n, max; \
-    kmptype_t **buf; \
-  } kmp_##name##_t; \
-  static inline kmp_##name##_t *kmp_init_##name(void) { \
-    return (kmp_##name##_t *)xcalloc(1, sizeof(kmp_##name##_t)); \
-  } \
-  static inline void kmp_destroy_##name(kmp_##name##_t *mp) \
-  REAL_FATTR_UNUSED; \
-  static inline void kmp_destroy_##name(kmp_##name##_t *mp) { \
-    size_t k; \
-    for (k = 0; k < mp->n; k++) { \
-      kmpfree_f(mp->buf[k]); XFREE_CLEAR(mp->buf[k]); \
-    } \
-    XFREE_CLEAR(mp->buf); XFREE_CLEAR(mp); \
-  } \
-  static inline kmptype_t *kmp_alloc_##name(kmp_##name##_t *mp) { \
-    mp->cnt++; \
-    if (mp->n == 0) { \
-      return (kmptype_t *)xcalloc(1, sizeof(kmptype_t)); \
-    } \
-    return mp->buf[--mp->n]; \
-  } \
-  static inline void kmp_free_##name(kmp_##name##_t *mp, kmptype_t *p) { \
-    mp->cnt--; \
-    if (mp->n == mp->max) { \
-      mp->max = mp->max ? (mp->max << 1) : 16; \
-      mp->buf = (kmptype_t **)xrealloc(mp->buf, sizeof(kmptype_t *) * mp->max); \
-    } \
-    mp->buf[mp->n++] = p; \
-  }
-
-#define kmempool_t(name) kmp_##name##_t
-#define kmp_init(name) kmp_init_##name()
-#define kmp_destroy(name, mp) kmp_destroy_##name(mp)
-#define kmp_alloc(name, mp) kmp_alloc_##name(mp)
-#define kmp_free(name, mp, p) kmp_free_##name(mp, p)
-
-#define KLIST_INIT(name, kltype_t, kmpfree_t) \
-  struct __kl1_##name { \
-    kltype_t data; \
-    struct __kl1_##name *next; \
-  }; \
-  typedef struct __kl1_##name kl1_##name; \
-  KMEMPOOL_INIT(name, kl1_##name, kmpfree_t) \
-  typedef struct { \
-    kl1_##name *head, *tail; \
-    kmp_##name##_t *mp; \
-    size_t size; \
-  } kl_##name##_t; \
-  static inline kl_##name##_t *kl_init_##name(void) { \
-    kl_##name##_t *kl = (kl_##name##_t *)xcalloc(1, sizeof(kl_##name##_t)); \
-    kl->mp = kmp_init(name); \
-    kl->head = kl->tail = kmp_alloc(name, kl->mp); \
-    kl->head->next = 0; \
-    return kl; \
-  } \
-  static inline void kl_destroy_##name(kl_##name##_t *kl) \
-  REAL_FATTR_UNUSED; \
-  static inline void kl_destroy_##name(kl_##name##_t *kl) { \
-    kl1_##name *p; \
-    for (p = kl->head; p != kl->tail; p = p->next) { \
-      kmp_free(name, kl->mp, p); \
-    } \
-    kmp_free(name, kl->mp, p); \
-    kmp_destroy(name, kl->mp); \
-    XFREE_CLEAR(kl); \
-  } \
-  static inline void kl_push_##name(kl_##name##_t *kl, kltype_t d) { \
-    kl1_##name *q, *p = kmp_alloc(name, kl->mp); \
-    q = kl->tail; p->next = 0; kl->tail->next = p; kl->tail = p; \
-    kl->size++; \
-    q->data = d; \
-  } \
-  static inline kltype_t kl_shift_at_##name(kl_##name##_t *kl, \
-                                            kl1_##name **n) { \
-    assert((*n)->next); \
-    kl1_##name *p; \
-    kl->size--; \
-    p = *n; \
-    *n = (*n)->next; \
-    if (p == kl->head) { \
-      kl->head = *n; \
-    } \
-    kltype_t d = p->data; \
-    kmp_free(name, kl->mp, p); \
-    return d; \
-  }
-
-#define kliter_t(name) kl1_##name
-#define klist_t(name) kl_##name##_t
-#define kl_val(iter) ((iter)->data)
-#define kl_next(iter) ((iter)->next)
-#define kl_begin(kl) ((kl)->head)
-#define kl_end(kl) ((kl)->tail)
-
-#define kl_init(name) kl_init_##name()
-#define kl_destroy(name, kl) kl_destroy_##name(kl)
-#define kl_push(name, kl, d) kl_push_##name(kl, d)
-#define kl_shift_at(name, kl, node) kl_shift_at_##name(kl, node)
-#define kl_shift(name, kl) kl_shift_at(name, kl, &kl->head)
-#define kl_empty(kl) ((kl)->size == 0)
-// Iteration macros. It's ok to modify the list while iterating as long as a
-// `break` statement is executed before the next iteration.
-#define kl_iter(name, kl, p) kl_iter_at(name, kl, p, NULL)
-#define kl_iter_at(name, kl, p, h) \
-  for (kl1_##name **p = h ? h : &kl->head; *p != kl->tail; p = &(*p)->next)
-
-#endif

src/nvim/event/loop.c

@@ -20,7 +20,7 @@ void loop_init(Loop *loop, void *data)
   loop->recursive = 0;
   loop->closing = false;
   loop->uv.data = loop;
-  loop->children = kl_init(WatcherPtr);
+  kv_init(loop->children);
   loop->events = multiqueue_new_parent(loop_on_put, loop);
   loop->fast_events = multiqueue_new_child(loop->events);
   loop->thread_events = multiqueue_new_parent(NULL, NULL);
@@ -187,7 +187,7 @@ bool loop_close(Loop *loop, bool wait)
   multiqueue_free(loop->fast_events);
   multiqueue_free(loop->thread_events);
   multiqueue_free(loop->events);
-  kl_destroy(WatcherPtr, loop->children);
+  kv_destroy(loop->children);
   return rv;
 }
 

src/nvim/event/loop.h

@@ -3,15 +3,10 @@
 #include <stdbool.h>
 #include <uv.h>
 
-#include "klib/klist.h"
+#include "klib/kvec.h"
 #include "nvim/event/defs.h"  // IWYU pragma: keep
 #include "nvim/types_defs.h"  // IWYU pragma: keep
 
-typedef void *WatcherPtr;
-
-#define NOOP(x)
-KLIST_INIT(WatcherPtr, WatcherPtr, NOOP)
-
 struct loop {
   uv_loop_t uv;
   MultiQueue *events;
@@ -27,7 +22,7 @@ struct loop {
   MultiQueue *fast_events;
 
   // used by process/job-control subsystem
-  klist_t(WatcherPtr) *children;
+  kvec_t(Proc *) children;
   uv_signal_t children_watcher;
   uv_timer_t children_kill_timer;
 

src/nvim/event/proc.c

@@ -3,7 +3,6 @@
 #include <signal.h>
 #include <uv.h>
 
-#include "klib/klist.h"
 #include "nvim/event/libuv_proc.h"
 #include "nvim/event/loop.h"
 #include "nvim/event/multiqueue.h"
@@ -123,7 +122,7 @@ int proc_spawn(Proc *proc, bool in, bool out, bool err)
   proc->internal_exit_cb = on_proc_exit;
   proc->internal_close_cb = decref;
   proc->refcount++;
-  kl_push(WatcherPtr, proc->loop->children, proc);
+  kv_push(proc->loop->children, proc);
   DLOG("new: pid=%d exepath=[%s]", proc->pid, proc_get_exepath(proc));
   return 0;
 }
@@ -131,8 +130,8 @@ int proc_spawn(Proc *proc, bool in, bool out, bool err)
 void proc_teardown(Loop *loop) FUNC_ATTR_NONNULL_ALL
 {
   proc_is_tearing_down = true;
-  kl_iter(WatcherPtr, loop->children, current) {
-    Proc *proc = (*current)->data;
+  for (size_t i = 0; i < kv_size(loop->children); i++) {
+    Proc *proc = kv_A(loop->children, i);
     if (proc->detach || proc->type == kProcTypePty) {
       // Close handles to process without killing it.
       CREATE_EVENT(loop->events, proc_close_handles, proc);
@@ -143,7 +142,7 @@ void proc_teardown(Loop *loop) FUNC_ATTR_NONNULL_ALL
 
   // Wait until all children exit and all close events are processed.
   LOOP_PROCESS_EVENTS_UNTIL(loop, loop->events, -1,
-                            kl_empty(loop->children) && multiqueue_empty(loop->events));
+                            kv_size(loop->children) == 0 && multiqueue_empty(loop->events));
   pty_proc_teardown(loop);
 }
 
@@ -254,8 +253,8 @@ static void children_kill_cb(uv_timer_t *handle)
 {
   Loop *loop = handle->loop->data;
 
-  kl_iter(WatcherPtr, loop->children, current) {
-    Proc *proc = (*current)->data;
+  for (size_t i = 0; i < kv_size(loop->children); i++) {
+    Proc *proc = kv_A(loop->children, i);
     bool exited = (proc->status >= 0);
     if (exited || !proc->stopped_time) {
       continue;
@@ -294,15 +293,19 @@ static void decref(Proc *proc)
   }
 
   Loop *loop = proc->loop;
-  kliter_t(WatcherPtr) **node = NULL;
-  kl_iter(WatcherPtr, loop->children, current) {
-    if ((*current)->data == proc) {
-      node = current;
+  size_t i;
+  for (i = 0; i < kv_size(loop->children); i++) {
+    Proc *current = kv_A(loop->children, i);
+    if (current == proc) {
       break;
     }
   }
-  assert(node);
-  kl_shift_at(WatcherPtr, loop->children, node);
+  assert(i < kv_size(loop->children));  // element found
+  if (i < kv_size(loop->children) - 1) {
+    memmove(&kv_A(loop->children, i), &kv_A(loop->children, i + 1),
+            sizeof(&kv_A(loop->children, i)) * (kv_size(loop->children) - (i + 1)));
+  }
+  kv_size(loop->children)--;
   CREATE_EVENT(proc->events, proc_close_event, proc);
 }
 

src/nvim/os/pty_proc_unix.c

@@ -30,7 +30,6 @@
 #endif
 
 #include "auto/config.h"
-#include "klib/klist.h"
 #include "nvim/eval/typval.h"
 #include "nvim/event/defs.h"
 #include "nvim/event/loop.h"
@@ -387,8 +386,8 @@ static void chld_handler(uv_signal_t *handle, int signum)
 
   Loop *loop = handle->loop->data;
 
-  kl_iter(WatcherPtr, loop->children, current) {
-    Proc *proc = (*current)->data;
+  for (size_t i = 0; i < kv_size(loop->children); i++) {
+    Proc *proc = kv_A(loop->children, i);
     do {
       pid = waitpid(proc->pid, &stat, WNOHANG);
     } while (pid < 0 && errno == EINTR);