--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-eintr-handling.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,96 @@
+/* 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"
+
+#ifdef _WIN32
+
+TEST_IMPL(eintr_handling) {
+  RETURN_SKIP("Test not implemented on Windows.");
+}
+
+#else  /* !_WIN32 */
+
+#include <string.h>
+#include <unistd.h>
+
+static uv_loop_t* loop;
+static uv_fs_t read_req;
+static uv_buf_t iov;
+
+static char buf[32];
+static char test_buf[] = "test-buffer\n";
+int pipe_fds[2];
+
+struct thread_ctx {
+  uv_barrier_t barrier;
+  int fd;
+};
+
+static void thread_main(void* arg) {
+  int nwritten;
+  ASSERT_OK(kill(getpid(), SIGUSR1));
+
+  do
+    nwritten = write(pipe_fds[1], test_buf, sizeof(test_buf));
+  while (nwritten == -1 && errno == EINTR);
+
+  ASSERT_EQ(nwritten, sizeof(test_buf));
+}
+
+static void sig_func(uv_signal_t* handle, int signum) {
+  uv_signal_stop(handle);
+}
+
+TEST_IMPL(eintr_handling) {
+  struct thread_ctx ctx;
+  uv_thread_t thread;
+  uv_signal_t signal;
+  int nread;
+
+  iov = uv_buf_init(buf, sizeof(buf));
+  loop = uv_default_loop();
+
+  ASSERT_OK(uv_signal_init(loop, &signal));
+  ASSERT_OK(uv_signal_start(&signal, sig_func, SIGUSR1));
+
+  ASSERT_OK(pipe(pipe_fds));
+  ASSERT_OK(uv_thread_create(&thread, thread_main, &ctx));
+
+  nread = uv_fs_read(loop, &read_req, pipe_fds[0], &iov, 1, -1, NULL);
+
+  ASSERT_EQ(nread, sizeof(test_buf));
+  ASSERT_OK(strcmp(buf, test_buf));
+
+  ASSERT_OK(uv_run(loop, UV_RUN_DEFAULT));
+
+  ASSERT_OK(close(pipe_fds[0]));
+  ASSERT_OK(close(pipe_fds[1]));
+  uv_close((uv_handle_t*) &signal, NULL);
+
+  ASSERT_OK(uv_thread_join(&thread));
+
+  MAKE_VALGRIND_HAPPY(loop);
+  return 0;
+}
+
+#endif  /* !_WIN32 */