--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-pipe-set-non-blocking.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,131 @@
+/* Copyright (c) 2015, Ben Noordhuis <[email protected]>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "uv.h"
+#include "task.h"
+
+#include <string.h> /* memset */
+#ifndef _WIN32
+#include <unistd.h> /* close */
+#endif
+
+struct thread_ctx {
+  uv_barrier_t barrier;
+  uv_file fd;
+};
+
+static void thread_main(void* arg) {
+  struct thread_ctx* ctx;
+  uv_fs_t req;
+  uv_buf_t bufs[1];
+  char buf[4096];
+  ssize_t n;
+  int uv_errno;
+
+  bufs[0] = uv_buf_init(buf, sizeof(buf));
+
+  ctx = arg;
+  uv_barrier_wait(&ctx->barrier);
+
+  uv_sleep(100); /* make sure we are forcing the writer to block a bit */
+  do {
+    uv_errno = uv_fs_read(NULL, &req, ctx->fd, bufs, 1, -1, NULL);
+    n = req.result;
+    uv_fs_req_cleanup(&req);
+  } while (n > 0 || (n == -1 && uv_errno == UV_EINTR));
+
+  ASSERT_OK(n);
+}
+
+
+#ifdef _WIN32
+static void write_cb(uv_write_t* req, int status) {
+  ASSERT_OK(status);
+  req->handle = NULL; /* signal completion of write_cb */
+}
+#endif
+
+#ifdef _WIN32
+#define NWRITES (10 << 16)
+#else
+#define NWRITES (10 << 20)
+#endif
+
+
+TEST_IMPL(pipe_set_non_blocking) {
+  struct thread_ctx ctx;
+  uv_pipe_t pipe_handle;
+  uv_thread_t thread;
+  size_t nwritten;
+  char data[4096];
+  uv_buf_t buf;
+  uv_file fd[2];
+  int n;
+#ifdef _WIN32
+  uv_write_t write_req;
+#endif
+
+  ASSERT_OK(uv_pipe_init(uv_default_loop(), &pipe_handle, 0));
+  ASSERT_OK(uv_pipe(fd, 0, 0));
+  ASSERT_OK(uv_pipe_open(&pipe_handle, fd[1]));
+  ASSERT_OK(uv_stream_set_blocking((uv_stream_t*) &pipe_handle, 1));
+  fd[1] = -1; /* fd[1] is owned by pipe_handle now. */
+
+  ctx.fd = fd[0];
+  ASSERT_OK(uv_barrier_init(&ctx.barrier, 2));
+  ASSERT_OK(uv_thread_create(&thread, thread_main, &ctx));
+  uv_barrier_wait(&ctx.barrier);
+
+  buf.len = sizeof(data);
+  buf.base = data;
+  memset(data, '.', sizeof(data));
+
+  nwritten = 0;
+  while (nwritten < NWRITES) {
+    /* The stream is in blocking mode so uv_try_write() should always succeed
+     * with the exact number of bytes that we wanted written.
+     */
+    n = uv_try_write((uv_stream_t*) &pipe_handle, &buf, 1);
+#ifdef _WIN32
+    ASSERT_EQ(n, UV_EAGAIN); /* E_NOTIMPL */
+    ASSERT_OK(uv_write(&write_req,
+                       (uv_stream_t*) &pipe_handle,
+                       &buf,
+                       1,
+                       write_cb));
+    ASSERT_NOT_NULL(write_req.handle);
+    ASSERT_OK(uv_run(uv_default_loop(), UV_RUN_ONCE));
+    ASSERT_NULL(write_req.handle); /* check for signaled completion of write_cb */
+    n = buf.len;
+#endif
+    ASSERT_EQ(n, sizeof(data));
+    nwritten += n;
+  }
+
+  uv_close((uv_handle_t*) &pipe_handle, NULL);
+  ASSERT_OK(uv_run(uv_default_loop(), UV_RUN_DEFAULT));
+
+  ASSERT_OK(uv_thread_join(&thread));
+#ifdef _WIN32
+  ASSERT_OK(_close(fd[0]));  /* fd[1] is closed by uv_close(). */
+#else
+  ASSERT_OK(close(fd[0]));  /* fd[1] is closed by uv_close(). */
+#endif
+  fd[0] = -1;
+  uv_barrier_destroy(&ctx.barrier);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}