--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/benchmark-loop-count.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,134 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * 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.
+ */
+
+#include "task.h"
+#include "uv.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#define NUM_TICKS (2 * 1000 * 1000)
+#define NUM_TICKS2 (2 * 1000 * 1000 * 100)
+
+static unsigned long ticks;
+static uv_idle_t idle_handle;
+static uv_timer_t timer_handle;
+
+
+static void idle_cb(uv_idle_t* handle) {
+  if (++ticks == NUM_TICKS)
+    uv_idle_stop(handle);
+}
+
+static void idle_alive_cb(uv_idle_t* handle) {
+  int ticks = 0;
+
+  while (++ticks < NUM_TICKS2) {
+    int r = uv_loop_alive(handle->loop);
+    if (r == 0)
+      abort();
+  }
+
+  *(int*)handle->data = ticks;
+  uv_idle_stop(handle);
+}
+
+
+static void idle2_cb(uv_idle_t* handle) {
+  ticks++;
+}
+
+
+static void timer_cb(uv_timer_t* handle) {
+  uv_idle_stop(&idle_handle);
+  uv_timer_stop(&timer_handle);
+}
+
+
+BENCHMARK_IMPL(loop_count) {
+  uv_loop_t* loop = uv_default_loop();
+  uint64_t ns;
+
+  uv_idle_init(loop, &idle_handle);
+  uv_idle_start(&idle_handle, idle_cb);
+
+  ns = uv_hrtime();
+  uv_run(loop, UV_RUN_DEFAULT);
+  ns = uv_hrtime() - ns;
+
+  ASSERT_UINT64_EQ(ticks, NUM_TICKS);
+
+  fprintf(stderr, "loop_count: %d ticks in %.2fs (%.0f/s)\n",
+          NUM_TICKS,
+          ns / 1e9,
+          NUM_TICKS / (ns / 1e9));
+  fflush(stderr);
+
+  MAKE_VALGRIND_HAPPY(loop);
+  return 0;
+}
+
+
+BENCHMARK_IMPL(loop_count_timed) {
+  uv_loop_t* loop = uv_default_loop();
+
+  uv_idle_init(loop, &idle_handle);
+  uv_idle_start(&idle_handle, idle2_cb);
+
+  uv_timer_init(loop, &timer_handle);
+  uv_timer_start(&timer_handle, timer_cb, 5000, 0);
+
+  uv_run(loop, UV_RUN_DEFAULT);
+
+  fprintf(stderr, "loop_count: %lu ticks (%.0f ticks/s)\n", ticks, ticks / 5.0);
+  fflush(stderr);
+
+  MAKE_VALGRIND_HAPPY(loop);
+  return 0;
+}
+
+/* Measure the performance of running uv_loop_alive(). Adding this so we can get
+ * some sort of metric for the impact of switching active_reqs.count to use
+ * atomics. No other code sits in a hot path. */
+BENCHMARK_IMPL(loop_alive) {
+  uv_loop_t* loop = uv_default_loop();
+  int ticks = 0;
+  uint64_t ns;
+
+  uv_idle_init(loop, &idle_handle);
+  idle_handle.data = &ticks;
+  uv_idle_start(&idle_handle, idle_alive_cb);
+
+  ns = uv_hrtime();
+  uv_run(loop, UV_RUN_DEFAULT);
+  ns = uv_hrtime() - ns;
+
+  ASSERT_EQ(ticks, NUM_TICKS2);
+
+  fprintf(stderr, "loop_alive: %d ticks in %.2fs (%.0f/s)\n",
+          NUM_TICKS2,
+          ns / 1e9,
+          NUM_TICKS2 / (ns / 1e9));
+  fflush(stderr);
+
+  MAKE_VALGRIND_HAPPY(loop);
+  return 0;
+}