--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/benchmark-spawn.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,164 @@
+/* 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.
+ */
+
+/* This benchmark spawns itself 1000 times. */
+
+#include "task.h"
+#include "uv.h"
+
+static uv_loop_t* loop;
+
+static int N = 1000;
+static int done;
+
+static uv_process_t process;
+static uv_process_options_t options;
+static char exepath[1024];
+static size_t exepath_size = 1024;
+static char* args[3];
+static uv_pipe_t out;
+
+#define OUTPUT_SIZE 1024
+static char output[OUTPUT_SIZE];
+static int output_used;
+
+static int process_open;
+static int pipe_open;
+
+
+static void spawn(void);
+
+
+static void maybe_spawn(void) {
+  if (process_open == 0 && pipe_open == 0) {
+    done++;
+    if (done < N) {
+      spawn();
+    }
+  }
+}
+
+
+static void process_close_cb(uv_handle_t* handle) {
+  ASSERT_EQ(1, process_open);
+  process_open = 0;
+  maybe_spawn();
+}
+
+
+static void exit_cb(uv_process_t* process,
+                    int64_t exit_status,
+                    int term_signal) {
+  ASSERT_EQ(42, exit_status);
+  ASSERT_OK(term_signal);
+  uv_close((uv_handle_t*)process, process_close_cb);
+}
+
+
+static void on_alloc(uv_handle_t* handle,
+                     size_t suggested_size,
+                     uv_buf_t* buf) {
+  buf->base = output + output_used;
+  buf->len = OUTPUT_SIZE - output_used;
+}
+
+
+static void pipe_close_cb(uv_handle_t* pipe) {
+  ASSERT_EQ(1, pipe_open);
+  pipe_open = 0;
+  maybe_spawn();
+}
+
+
+static void on_read(uv_stream_t* pipe, ssize_t nread, const uv_buf_t* buf) {
+  if (nread > 0) {
+    ASSERT_EQ(1, pipe_open);
+    output_used += nread;
+  } else if (nread < 0) {
+    if (nread == UV_EOF) {
+      uv_close((uv_handle_t*)pipe, pipe_close_cb);
+    }
+  }
+}
+
+
+static void spawn(void) {
+  uv_stdio_container_t stdio[2];
+  int r;
+
+  ASSERT_OK(process_open);
+  ASSERT_OK(pipe_open);
+
+  args[0] = exepath;
+  args[1] = "spawn_helper";
+  args[2] = NULL;
+  options.file = exepath;
+  options.args = args;
+  options.exit_cb = exit_cb;
+
+  uv_pipe_init(loop, &out, 0);
+
+  options.stdio = stdio;
+  options.stdio_count = 2;
+  options.stdio[0].flags = UV_IGNORE;
+  options.stdio[1].flags = UV_CREATE_PIPE | UV_WRITABLE_PIPE;
+  options.stdio[1].data.stream = (uv_stream_t*)&out;
+
+  r = uv_spawn(loop, &process, &options);
+  ASSERT_OK(r);
+
+  process_open = 1;
+  pipe_open = 1;
+  output_used = 0;
+
+  r = uv_read_start((uv_stream_t*) &out, on_alloc, on_read);
+  ASSERT_OK(r);
+}
+
+
+BENCHMARK_IMPL(spawn) {
+  int r;
+  static int64_t start_time, end_time;
+
+  loop = uv_default_loop();
+
+  r = uv_exepath(exepath, &exepath_size);
+  ASSERT_OK(r);
+  exepath[exepath_size] = '\0';
+
+  uv_update_time(loop);
+  start_time = uv_now(loop);
+
+  spawn();
+
+  r = uv_run(loop, UV_RUN_DEFAULT);
+  ASSERT_OK(r);
+
+  uv_update_time(loop);
+  end_time = uv_now(loop);
+
+  fprintf(stderr, "spawn: %.0f spawns/s\n",
+          (double) N / (double) (end_time - start_time) * 1000.0);
+  fflush(stderr);
+
+  MAKE_VALGRIND_HAPPY(loop);
+  return 0;
+}