--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-ping-pong.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,439 @@
+/* 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>
+#include <string.h> /* strlen */
+
+static int completed_pingers = 0;
+
+#if defined(__CYGWIN__) || defined(__MSYS__) || defined(__MVS__)
+#define NUM_PINGS 100 /* fewer pings to avoid timeout */
+#else
+#define NUM_PINGS 1000
+#endif
+
+static char PING[] = "PING\n";
+static char PONG[] = "PONG\n";
+static int pinger_on_connect_count;
+
+
+typedef struct {
+  int vectored_writes;
+  unsigned pongs;
+  unsigned state;
+  union {
+    uv_tcp_t tcp;
+    uv_pipe_t pipe;
+  } stream;
+  uv_connect_t connect_req;
+  char* pong;
+} pinger_t;
+
+
+static void alloc_cb(uv_handle_t* handle, size_t size, uv_buf_t* buf) {
+  buf->base = malloc(size);
+  buf->len = size;
+}
+
+
+static void ponger_on_close(uv_handle_t* handle) {
+  if (handle->data)
+    free(handle->data);
+  else
+    free(handle);
+}
+
+
+static void pinger_on_close(uv_handle_t* handle) {
+  pinger_t* pinger = (pinger_t*) handle->data;
+
+  ASSERT_EQ(NUM_PINGS, pinger->pongs);
+
+  if (handle == (uv_handle_t*) &pinger->stream.tcp) {
+    free(pinger); /* also frees handle */
+  } else {
+    uv_close((uv_handle_t*) &pinger->stream.tcp, ponger_on_close);
+    free(handle);
+  }
+
+  completed_pingers++;
+}
+
+
+static void pinger_after_write(uv_write_t* req, int status) {
+  ASSERT_OK(status);
+  free(req->data);
+  free(req);
+}
+
+
+static void pinger_write_ping(pinger_t* pinger) {
+  uv_stream_t* stream;
+  uv_write_t* req;
+  uv_buf_t bufs[sizeof PING - 1];
+  int i, nbufs;
+
+  stream = (uv_stream_t*) &pinger->stream.tcp;
+
+  if (!pinger->vectored_writes) {
+    /* Write a single buffer. */
+    nbufs = 1;
+    bufs[0] = uv_buf_init(PING, sizeof PING - 1);
+  } else {
+    /* Write multiple buffers, each with one byte in them. */
+    nbufs = sizeof PING - 1;
+    for (i = 0; i < nbufs; i++) {
+      bufs[i] = uv_buf_init(&PING[i], 1);
+    }
+  }
+
+  req = malloc(sizeof(*req));
+  ASSERT_NOT_NULL(req);
+  req->data = NULL;
+  ASSERT_OK(uv_write(req, stream, bufs, nbufs, pinger_after_write));
+
+  puts("PING");
+}
+
+
+static void pinger_read_cb(uv_stream_t* stream,
+                           ssize_t nread,
+                           const uv_buf_t* buf) {
+  ssize_t i;
+  pinger_t* pinger;
+
+  pinger = (pinger_t*) stream->data;
+
+  if (nread < 0) {
+    ASSERT_EQ(nread, UV_EOF);
+
+    puts("got EOF");
+    free(buf->base);
+
+    uv_close((uv_handle_t*) stream, pinger_on_close);
+
+    return;
+  }
+
+  /* Now we count the pongs */
+  for (i = 0; i < nread; i++) {
+    ASSERT_EQ(buf->base[i], pinger->pong[pinger->state]);
+    pinger->state = (pinger->state + 1) % strlen(pinger->pong);
+
+    if (pinger->state != 0)
+      continue;
+
+    printf("PONG %d\n", pinger->pongs);
+    pinger->pongs++;
+
+    if (pinger->pongs < NUM_PINGS) {
+      pinger_write_ping(pinger);
+    } else {
+      uv_close((uv_handle_t*) stream, pinger_on_close);
+      break;
+    }
+  }
+
+  free(buf->base);
+}
+
+
+static void ponger_read_cb(uv_stream_t* stream,
+                           ssize_t nread,
+                           const uv_buf_t* buf) {
+  uv_buf_t writebuf;
+  uv_write_t* req;
+  int i;
+
+  if (nread < 0) {
+    ASSERT_EQ(nread, UV_EOF);
+
+    puts("got EOF");
+    free(buf->base);
+
+    uv_close((uv_handle_t*) stream, ponger_on_close);
+
+    return;
+  }
+
+  /* Echo back */
+  for (i = 0; i < nread; i++) {
+    if (buf->base[i] == 'I')
+      buf->base[i] = 'O';
+  }
+
+  writebuf = uv_buf_init(buf->base, nread);
+  req = malloc(sizeof(*req));
+  ASSERT_NOT_NULL(req);
+  req->data = buf->base;
+  ASSERT_OK(uv_write(req, stream, &writebuf, 1, pinger_after_write));
+}
+
+
+static void pinger_on_connect(uv_connect_t* req, int status) {
+  pinger_t* pinger = (pinger_t*) req->handle->data;
+
+  pinger_on_connect_count++;
+
+  ASSERT_OK(status);
+
+  ASSERT_EQ(1, uv_is_readable(req->handle));
+  ASSERT_EQ(1, uv_is_writable(req->handle));
+  ASSERT_OK(uv_is_closing((uv_handle_t *) req->handle));
+
+  pinger_write_ping(pinger);
+
+  ASSERT_OK(uv_read_start((uv_stream_t*) req->handle,
+                          alloc_cb,
+                          pinger_read_cb));
+}
+
+
+/* same ping-pong test, but using IPv6 connection */
+static void tcp_pinger_v6_new(int vectored_writes) {
+  int r;
+  struct sockaddr_in6 server_addr;
+  pinger_t* pinger;
+
+
+  ASSERT_OK(uv_ip6_addr("::1", TEST_PORT, &server_addr));
+  pinger = malloc(sizeof(*pinger));
+  ASSERT_NOT_NULL(pinger);
+  pinger->vectored_writes = vectored_writes;
+  pinger->state = 0;
+  pinger->pongs = 0;
+  pinger->pong = PING;
+
+  /* Try to connect to the server and do NUM_PINGS ping-pongs. */
+  r = uv_tcp_init(uv_default_loop(), &pinger->stream.tcp);
+  pinger->stream.tcp.data = pinger;
+  ASSERT_OK(r);
+
+  /* We are never doing multiple reads/connects at a time anyway, so these
+   * handles can be pre-initialized. */
+  r = uv_tcp_connect(&pinger->connect_req,
+                     &pinger->stream.tcp,
+                     (const struct sockaddr*) &server_addr,
+                     pinger_on_connect);
+  ASSERT_OK(r);
+
+  /* Synchronous connect callbacks are not allowed. */
+  ASSERT_OK(pinger_on_connect_count);
+}
+
+
+static void tcp_pinger_new(int vectored_writes) {
+  int r;
+  struct sockaddr_in server_addr;
+  pinger_t* pinger;
+
+  ASSERT_OK(uv_ip4_addr("127.0.0.1", TEST_PORT, &server_addr));
+  pinger = malloc(sizeof(*pinger));
+  ASSERT_NOT_NULL(pinger);
+  pinger->vectored_writes = vectored_writes;
+  pinger->state = 0;
+  pinger->pongs = 0;
+  pinger->pong = PING;
+
+  /* Try to connect to the server and do NUM_PINGS ping-pongs. */
+  r = uv_tcp_init(uv_default_loop(), &pinger->stream.tcp);
+  pinger->stream.tcp.data = pinger;
+  ASSERT_OK(r);
+
+  /* We are never doing multiple reads/connects at a time anyway, so these
+   * handles can be pre-initialized. */
+  r = uv_tcp_connect(&pinger->connect_req,
+                     &pinger->stream.tcp,
+                     (const struct sockaddr*) &server_addr,
+                     pinger_on_connect);
+  ASSERT_OK(r);
+
+  /* Synchronous connect callbacks are not allowed. */
+  ASSERT_OK(pinger_on_connect_count);
+}
+
+
+static void pipe_pinger_new(int vectored_writes) {
+  int r;
+  pinger_t* pinger;
+
+  pinger = malloc(sizeof(*pinger));
+  ASSERT_NOT_NULL(pinger);
+  pinger->vectored_writes = vectored_writes;
+  pinger->state = 0;
+  pinger->pongs = 0;
+  pinger->pong = PING;
+
+  /* Try to connect to the server and do NUM_PINGS ping-pongs. */
+  r = uv_pipe_init(uv_default_loop(), &pinger->stream.pipe, 0);
+  pinger->stream.pipe.data = pinger;
+  ASSERT_OK(r);
+
+  /* We are never doing multiple reads/connects at a time anyway, so these
+   * handles can be pre-initialized. */
+  uv_pipe_connect(&pinger->connect_req, &pinger->stream.pipe, TEST_PIPENAME,
+      pinger_on_connect);
+
+  /* Synchronous connect callbacks are not allowed. */
+  ASSERT_OK(pinger_on_connect_count);
+}
+
+
+static void socketpair_pinger_new(int vectored_writes) {
+  pinger_t* pinger;
+  uv_os_sock_t fds[2];
+  uv_tcp_t* ponger;
+
+  pinger = malloc(sizeof(*pinger));
+  ASSERT_NOT_NULL(pinger);
+  pinger->vectored_writes = vectored_writes;
+  pinger->state = 0;
+  pinger->pongs = 0;
+  pinger->pong = PONG;
+
+  /* Try to make a socketpair and do NUM_PINGS ping-pongs. */
+  (void)uv_default_loop(); /* ensure WSAStartup has been performed */
+  ASSERT_OK(uv_socketpair(SOCK_STREAM, 0, fds, UV_NONBLOCK_PIPE, UV_NONBLOCK_PIPE));
+#ifndef _WIN32
+  /* On Windows, this is actually a UV_TCP, but libuv doesn't detect that. */
+  ASSERT_EQ(uv_guess_handle((uv_file) fds[0]), UV_NAMED_PIPE);
+  ASSERT_EQ(uv_guess_handle((uv_file) fds[1]), UV_NAMED_PIPE);
+#endif
+
+  ASSERT_OK(uv_tcp_init(uv_default_loop(), &pinger->stream.tcp));
+  pinger->stream.pipe.data = pinger;
+  ASSERT_OK(uv_tcp_open(&pinger->stream.tcp, fds[1]));
+
+  ponger = malloc(sizeof(*ponger));
+  ASSERT_NOT_NULL(ponger);
+  ponger->data = NULL;
+  ASSERT_OK(uv_tcp_init(uv_default_loop(), ponger));
+  ASSERT_OK(uv_tcp_open(ponger, fds[0]));
+
+  pinger_write_ping(pinger);
+
+  ASSERT_OK(uv_read_start((uv_stream_t*) &pinger->stream.tcp,
+                          alloc_cb,
+                          pinger_read_cb));
+  ASSERT_OK(uv_read_start((uv_stream_t*) ponger,
+                          alloc_cb,
+                          ponger_read_cb));
+}
+
+
+static void pipe2_pinger_new(int vectored_writes) {
+  uv_file fds[2];
+  pinger_t* pinger;
+  uv_pipe_t* ponger;
+
+  /* Try to make a pipe and do NUM_PINGS pings. */
+  ASSERT_OK(uv_pipe(fds, UV_NONBLOCK_PIPE, UV_NONBLOCK_PIPE));
+  ASSERT_EQ(uv_guess_handle(fds[0]), UV_NAMED_PIPE);
+  ASSERT_EQ(uv_guess_handle(fds[1]), UV_NAMED_PIPE);
+
+  ponger = malloc(sizeof(*ponger));
+  ASSERT_NOT_NULL(ponger);
+  ASSERT_OK(uv_pipe_init(uv_default_loop(), ponger, 0));
+  ASSERT_OK(uv_pipe_open(ponger, fds[0]));
+
+  pinger = malloc(sizeof(*pinger));
+  ASSERT_NOT_NULL(pinger);
+  pinger->vectored_writes = vectored_writes;
+  pinger->state = 0;
+  pinger->pongs = 0;
+  pinger->pong = PING;
+  ASSERT_OK(uv_pipe_init(uv_default_loop(), &pinger->stream.pipe, 0));
+  ASSERT_OK(uv_pipe_open(&pinger->stream.pipe, fds[1]));
+  pinger->stream.pipe.data = pinger; /* record for close_cb */
+  ponger->data = pinger; /* record for read_cb */
+
+  pinger_write_ping(pinger);
+
+  ASSERT_OK(uv_read_start((uv_stream_t*) ponger, alloc_cb, pinger_read_cb));
+}
+
+static int run_ping_pong_test(void) {
+  uv_run(uv_default_loop(), UV_RUN_DEFAULT);
+  ASSERT_EQ(1, completed_pingers);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}
+
+
+TEST_IMPL(tcp_ping_pong) {
+  tcp_pinger_new(0);
+  run_ping_pong_test();
+
+  completed_pingers = 0;
+  socketpair_pinger_new(0);
+  return run_ping_pong_test();
+}
+
+
+TEST_IMPL(tcp_ping_pong_vec) {
+  tcp_pinger_new(1);
+  run_ping_pong_test();
+
+  completed_pingers = 0;
+  socketpair_pinger_new(1);
+  return run_ping_pong_test();
+}
+
+
+TEST_IMPL(tcp6_ping_pong) {
+  if (!can_ipv6())
+    RETURN_SKIP("IPv6 not supported");
+  tcp_pinger_v6_new(0);
+  return run_ping_pong_test();
+}
+
+
+TEST_IMPL(tcp6_ping_pong_vec) {
+  if (!can_ipv6())
+    RETURN_SKIP("IPv6 not supported");
+  tcp_pinger_v6_new(1);
+  return run_ping_pong_test();
+}
+
+
+TEST_IMPL(pipe_ping_pong) {
+  pipe_pinger_new(0);
+  run_ping_pong_test();
+
+  completed_pingers = 0;
+  pipe2_pinger_new(0);
+  return run_ping_pong_test();
+}
+
+
+TEST_IMPL(pipe_ping_pong_vec) {
+  pipe_pinger_new(1);
+  run_ping_pong_test();
+
+  completed_pingers = 0;
+  pipe2_pinger_new(1);
+  return run_ping_pong_test();
+}