--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-thread-name.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,193 @@
+/* Copyright libuv project 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 "../src/uv-common.h"
+
+#include <string.h>
+
+struct semaphores {
+  uv_sem_t main;
+  uv_sem_t worker;
+};
+
+static void thread_run(void* arg) {
+  int r;
+  char thread_name[16];
+  struct semaphores* sem;
+  uv_thread_t thread;
+
+  sem = arg;
+
+#ifdef _WIN32
+  /* uv_thread_self isn't defined for the main thread on Windows. */
+  thread = GetCurrentThread();
+#else
+  thread = uv_thread_self();
+#endif
+
+  r = uv_thread_setname("worker-thread");
+  ASSERT_OK(r);
+
+  uv_sem_post(&sem->worker);
+
+  r = uv_thread_getname(&thread, thread_name, sizeof(thread_name));
+  ASSERT_OK(r);
+
+  ASSERT_STR_EQ(thread_name, "worker-thread");
+
+  uv_sem_wait(&sem->main);
+}
+
+TEST_IMPL(thread_name) {
+  int r;
+  uv_thread_t threads[2];
+  char tn[UV_PTHREAD_MAX_NAMELEN_NP];
+  char thread_name[UV_PTHREAD_MAX_NAMELEN_NP];
+  char long_thread_name[UV_PTHREAD_MAX_NAMELEN_NP + 1];
+  struct semaphores sem;
+
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 26 || \
+    defined(_AIX) || \
+    defined(__MVS__) || \
+    defined(__PASE__)
+  RETURN_SKIP("API not available on this platform");
+#endif
+
+  ASSERT_OK(uv_sem_init(&sem.main, 0));
+  ASSERT_OK(uv_sem_init(&sem.worker, 0));
+
+  memset(thread_name, 'a', sizeof(thread_name) - 1);
+  thread_name[sizeof(thread_name) - 1] = '\0';
+
+  memset(long_thread_name, 'a', sizeof(long_thread_name) - 1);
+  long_thread_name[sizeof(long_thread_name) - 1] = '\0';
+
+#ifdef _WIN32
+  /* uv_thread_self isn't defined for the main thread on Windows. */
+  threads[0] = GetCurrentThread();
+#else
+  threads[0] = uv_thread_self();
+#endif
+
+  r = uv_thread_getname(&threads[0], tn, sizeof(tn));
+  ASSERT_OK(r);
+
+  r = uv_thread_setname(long_thread_name);
+  ASSERT_OK(r);
+
+  r = uv_thread_getname(&threads[0], tn, sizeof(tn));
+  ASSERT_OK(r);
+  ASSERT_STR_EQ(tn, thread_name);
+
+  r = uv_thread_setname(thread_name);
+  ASSERT_OK(r);
+
+  r = uv_thread_getname(&threads[0], tn, sizeof(tn));
+  ASSERT_OK(r);
+  ASSERT_STR_EQ(tn, thread_name);
+
+  r = uv_thread_getname(&threads[0], tn, 3);
+  ASSERT_OK(r);
+  ASSERT_EQ(strlen(tn), 2);
+  ASSERT_OK(memcmp(thread_name, tn, 2));
+
+  /* Illumos doesn't support non-ASCII thread names. */
+#ifndef __illumos__
+  r = uv_thread_setname("~½¬{½");
+  ASSERT_OK(r);
+
+  r = uv_thread_getname(&threads[0], tn, sizeof(tn));
+  ASSERT_OK(r);
+  ASSERT_STR_EQ(tn, "~½¬{½");
+#endif
+
+  ASSERT_OK(uv_thread_create(threads + 1, thread_run, &sem));
+
+  uv_sem_wait(&sem.worker);
+
+  r = uv_thread_getname(threads + 1, tn, sizeof(tn));
+  ASSERT_OK(r);
+
+  ASSERT_STR_EQ(tn, "worker-thread");
+
+  uv_sem_post(&sem.main);
+
+  ASSERT_OK(uv_thread_join(threads + 1));
+
+  uv_sem_destroy(&sem.main);
+  uv_sem_destroy(&sem.worker);
+
+  return 0;
+}
+
+#define MAX_THREADS 4
+
+static void* executedThreads[MAX_THREADS] = { NULL };
+static int size;
+static uv_loop_t* loop;
+
+static unsigned short int key_exists(void* key) {
+  size_t i;
+  for (i = 0; i < MAX_THREADS; i++) {
+    if (executedThreads[i] == key) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+static void work_cb(uv_work_t* req) {
+  uv_thread_t thread = uv_thread_self();
+  req->data = &thread;
+  char tn[UV_PTHREAD_MAX_NAMELEN_NP];
+  ASSERT_OK(uv_thread_getname(&thread, tn, sizeof(tn)));
+  ASSERT_STR_EQ(tn, "libuv-worker");
+}
+
+static void after_work_cb(uv_work_t* req, int status) {
+  ASSERT_OK(status);
+  if (!key_exists(req->data)) {
+    executedThreads[size++] = req->data;
+  }
+
+  if (size == MAX_THREADS) {
+    return;
+  }
+
+  uv_queue_work(loop, req, work_cb, after_work_cb);
+}
+
+TEST_IMPL(thread_name_threadpool) {
+
+#if defined(_AIX) || defined(__PASE__)
+  RETURN_SKIP("API not available on this platform");
+#endif
+  uv_work_t req;
+  loop = uv_default_loop();
+  // Just to make sure all workers will be executed
+  // with the correct thread name
+  ASSERT_OK(uv_queue_work(loop, &req, work_cb, after_work_cb));
+  uv_run(loop, UV_RUN_DEFAULT);
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}