--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-timer-again.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,141 @@
+/* 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"
+
+
+static int close_cb_called = 0;
+static int repeat_1_cb_called = 0;
+static int repeat_2_cb_called = 0;
+
+static int repeat_2_cb_allowed = 0;
+
+static uv_timer_t dummy, repeat_1, repeat_2;
+
+static uint64_t start_time;
+
+
+static void close_cb(uv_handle_t* handle) {
+  ASSERT_NOT_NULL(handle);
+
+  close_cb_called++;
+}
+
+
+static void repeat_1_cb(uv_timer_t* handle) {
+  int r;
+
+  ASSERT_PTR_EQ(handle, &repeat_1);
+  ASSERT_EQ(50, uv_timer_get_repeat((uv_timer_t*)handle));
+
+  fprintf(stderr, "repeat_1_cb called after %ld ms\n",
+          (long int)(uv_now(uv_default_loop()) - start_time));
+  fflush(stderr);
+
+  repeat_1_cb_called++;
+
+  r = uv_timer_again(&repeat_2);
+  ASSERT_OK(r);
+
+  if (repeat_1_cb_called == 10) {
+    uv_close((uv_handle_t*)handle, close_cb);
+    /* We're not calling uv_timer_again on repeat_2 any more, so after this
+     * timer_2_cb is expected. */
+    repeat_2_cb_allowed = 1;
+    return;
+  }
+}
+
+
+static void repeat_2_cb(uv_timer_t* handle) {
+  ASSERT_PTR_EQ(handle, &repeat_2);
+  ASSERT(repeat_2_cb_allowed);
+
+  fprintf(stderr, "repeat_2_cb called after %ld ms\n",
+          (long int)(uv_now(uv_default_loop()) - start_time));
+  fflush(stderr);
+
+  repeat_2_cb_called++;
+
+  if (uv_timer_get_repeat(&repeat_2) == 0) {
+    ASSERT_OK(uv_is_active((uv_handle_t*) handle));
+    uv_close((uv_handle_t*)handle, close_cb);
+    return;
+  }
+
+  fprintf(stderr, "uv_timer_get_repeat %ld ms\n",
+          (long int)uv_timer_get_repeat(&repeat_2));
+  fflush(stderr);
+  ASSERT_EQ(100, uv_timer_get_repeat(&repeat_2));
+
+  /* This shouldn't take effect immediately. */
+  uv_timer_set_repeat(&repeat_2, 0);
+}
+
+
+TEST_IMPL(timer_again) {
+  int r;
+
+  start_time = uv_now(uv_default_loop());
+  ASSERT_LT(0, start_time);
+
+  /* Verify that it is not possible to uv_timer_again a never-started timer. */
+  r = uv_timer_init(uv_default_loop(), &dummy);
+  ASSERT_OK(r);
+  r = uv_timer_again(&dummy);
+  ASSERT_EQ(r, UV_EINVAL);
+  uv_unref((uv_handle_t*)&dummy);
+
+  /* Start timer repeat_1. */
+  r = uv_timer_init(uv_default_loop(), &repeat_1);
+  ASSERT_OK(r);
+  r = uv_timer_start(&repeat_1, repeat_1_cb, 50, 0);
+  ASSERT_OK(r);
+  ASSERT_OK(uv_timer_get_repeat(&repeat_1));
+
+  /* Actually make repeat_1 repeating. */
+  uv_timer_set_repeat(&repeat_1, 50);
+  ASSERT_EQ(50, uv_timer_get_repeat(&repeat_1));
+
+  /*
+   * Start another repeating timer. It'll be again()ed by the repeat_1 so
+   * it should not time out until repeat_1 stops.
+   */
+  r = uv_timer_init(uv_default_loop(), &repeat_2);
+  ASSERT_OK(r);
+  r = uv_timer_start(&repeat_2, repeat_2_cb, 100, 100);
+  ASSERT_OK(r);
+  ASSERT_EQ(100, uv_timer_get_repeat(&repeat_2));
+
+  uv_run(uv_default_loop(), UV_RUN_DEFAULT);
+
+  ASSERT_EQ(10, repeat_1_cb_called);
+  ASSERT_EQ(2, repeat_2_cb_called);
+  ASSERT_EQ(2, close_cb_called);
+
+  fprintf(stderr, "Test took %ld ms (expected ~700 ms)\n",
+          (long int)(uv_now(uv_default_loop()) - start_time));
+  fflush(stderr);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}