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/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"
@@ -123,16 +122,16 @@ 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;
 }
 
 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);