--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/benchmark-tcp-write-batch.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,144 @@
+/* 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 "uv.h"
+#include "task.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#define WRITE_REQ_DATA  "Hello, world."
+#define NUM_WRITE_REQS  (1000 * 1000)
+
+typedef struct {
+  uv_write_t req;
+  uv_buf_t buf;
+} write_req;
+
+
+static write_req* write_reqs;
+static uv_tcp_t tcp_client;
+static uv_connect_t connect_req;
+static uv_shutdown_t shutdown_req;
+
+static int shutdown_cb_called = 0;
+static int connect_cb_called = 0;
+static int write_cb_called = 0;
+static int close_cb_called = 0;
+
+static void connect_cb(uv_connect_t* req, int status);
+static void write_cb(uv_write_t* req, int status);
+static void shutdown_cb(uv_shutdown_t* req, int status);
+static void close_cb(uv_handle_t* handle);
+
+
+static void connect_cb(uv_connect_t* req, int status) {
+  write_req* w;
+  int i;
+  int r;
+
+  ASSERT_PTR_EQ(req->handle, (uv_stream_t*)&tcp_client);
+
+  for (i = 0; i < NUM_WRITE_REQS; i++) {
+    w = &write_reqs[i];
+    r = uv_write(&w->req, req->handle, &w->buf, 1, write_cb);
+    ASSERT_OK(r);
+  }
+
+  r = uv_shutdown(&shutdown_req, req->handle, shutdown_cb);
+  ASSERT_OK(r);
+
+  connect_cb_called++;
+}
+
+
+static void write_cb(uv_write_t* req, int status) {
+  ASSERT_NOT_NULL(req);
+  ASSERT_OK(status);
+  write_cb_called++;
+}
+
+
+static void shutdown_cb(uv_shutdown_t* req, int status) {
+  ASSERT_PTR_EQ(req->handle, (uv_stream_t*)&tcp_client);
+  ASSERT_OK(req->handle->write_queue_size);
+
+  uv_close((uv_handle_t*)req->handle, close_cb);
+  free(write_reqs);
+
+  shutdown_cb_called++;
+}
+
+
+static void close_cb(uv_handle_t* handle) {
+  ASSERT_PTR_EQ(handle, (uv_handle_t*)&tcp_client);
+  close_cb_called++;
+}
+
+
+BENCHMARK_IMPL(tcp_write_batch) {
+  struct sockaddr_in addr;
+  uv_loop_t* loop;
+  uint64_t start;
+  uint64_t stop;
+  int i;
+  int r;
+
+  write_reqs = malloc(sizeof(*write_reqs) * NUM_WRITE_REQS);
+  ASSERT_NOT_NULL(write_reqs);
+
+  /* Prepare the data to write out. */
+  for (i = 0; i < NUM_WRITE_REQS; i++) {
+    write_reqs[i].buf = uv_buf_init(WRITE_REQ_DATA,
+                                    sizeof(WRITE_REQ_DATA) - 1);
+  }
+
+  loop = uv_default_loop();
+  ASSERT_OK(uv_ip4_addr("127.0.0.1", TEST_PORT, &addr));
+
+  r = uv_tcp_init(loop, &tcp_client);
+  ASSERT_OK(r);
+
+  r = uv_tcp_connect(&connect_req,
+                     &tcp_client,
+                     (const struct sockaddr*) &addr,
+                     connect_cb);
+  ASSERT_OK(r);
+
+  start = uv_hrtime();
+
+  r = uv_run(loop, UV_RUN_DEFAULT);
+  ASSERT_OK(r);
+
+  stop = uv_hrtime();
+
+  ASSERT_EQ(1, connect_cb_called);
+  ASSERT_EQ(write_cb_called, NUM_WRITE_REQS);
+  ASSERT_EQ(1, shutdown_cb_called);
+  ASSERT_EQ(1, close_cb_called);
+
+  printf("%ld write requests in %.2fs.\n",
+         (long)NUM_WRITE_REQS,
+         (stop - start) / 1e9);
+
+  MAKE_VALGRIND_HAPPY(loop);
+  return 0;
+}