--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/src/unix/core.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,2104 @@
+/* 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 "internal.h"
+#include "strtok.h"
+
+#include <stddef.h> /* NULL */
+#include <stdio.h> /* printf */
+#include <stdlib.h>
+#include <string.h> /* strerror */
+#include <errno.h>
+#include <assert.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>  /* O_CLOEXEC */
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <limits.h> /* INT_MAX, PATH_MAX, IOV_MAX */
+#include <sys/uio.h> /* writev */
+#include <sys/resource.h> /* getrusage */
+#include <pwd.h>
+#include <grp.h>
+#include <sys/utsname.h>
+#include <sys/time.h>
+#include <time.h> /* clock_gettime */
+
+#ifdef __sun
+# include <sys/filio.h>
+# include <sys/wait.h>
+#endif
+
+#if defined(__APPLE__)
+# include <mach/mach.h>
+# include <mach/thread_info.h>
+# include <sys/filio.h>
+# include <sys/sysctl.h>
+#endif /* defined(__APPLE__) */
+
+
+#if defined(__APPLE__) && !TARGET_OS_IPHONE
+# include <crt_externs.h>
+# include <mach-o/dyld.h> /* _NSGetExecutablePath */
+# define environ (*_NSGetEnviron())
+#else /* defined(__APPLE__) && !TARGET_OS_IPHONE */
+extern char** environ;
+#endif /* !(defined(__APPLE__) && !TARGET_OS_IPHONE) */
+
+
+#if defined(__DragonFly__)      || \
+    defined(__FreeBSD__)        || \
+    defined(__NetBSD__)         || \
+    defined(__OpenBSD__)
+# include <sys/sysctl.h>
+# include <sys/filio.h>
+# include <sys/wait.h>
+# include <sys/param.h>
+# if defined(__FreeBSD__)
+#  include <sys/cpuset.h>
+#  define uv__accept4 accept4
+# endif
+# if defined(__NetBSD__)
+#  define uv__accept4(a, b, c, d) paccept((a), (b), (c), NULL, (d))
+# endif
+#endif
+
+#if defined(__MVS__)
+# include <sys/ioctl.h>
+# include "zos-sys-info.h"
+#endif
+
+#if defined(__linux__)
+# include <sched.h>
+# include <sys/syscall.h>
+# define gettid() syscall(SYS_gettid)
+# define uv__accept4 accept4
+#endif
+
+#if defined(__FreeBSD__)
+# include <sys/param.h>
+# include <sys/cpuset.h>
+#endif
+
+#if defined(__NetBSD__)
+# include <sched.h>
+#endif
+
+#if defined(__linux__) && defined(__SANITIZE_THREAD__) && defined(__clang__)
+# include <sanitizer/linux_syscall_hooks.h>
+#endif
+
+static void uv__run_pending(uv_loop_t* loop);
+
+/* Verify that uv_buf_t is ABI-compatible with struct iovec. */
+STATIC_ASSERT(sizeof(uv_buf_t) == sizeof(struct iovec));
+STATIC_ASSERT(sizeof(((uv_buf_t*) 0)->base) ==
+              sizeof(((struct iovec*) 0)->iov_base));
+STATIC_ASSERT(sizeof(((uv_buf_t*) 0)->len) ==
+              sizeof(((struct iovec*) 0)->iov_len));
+STATIC_ASSERT(offsetof(uv_buf_t, base) == offsetof(struct iovec, iov_base));
+STATIC_ASSERT(offsetof(uv_buf_t, len) == offsetof(struct iovec, iov_len));
+
+
+/* https://github.com/libuv/libuv/issues/1674 */
+int uv_clock_gettime(uv_clock_id clock_id, uv_timespec64_t* ts) {
+  struct timespec t;
+  int r;
+
+  if (ts == NULL)
+    return UV_EFAULT;
+
+  switch (clock_id) {
+    default:
+      return UV_EINVAL;
+    case UV_CLOCK_MONOTONIC:
+      r = clock_gettime(CLOCK_MONOTONIC, &t);
+      break;
+    case UV_CLOCK_REALTIME:
+      r = clock_gettime(CLOCK_REALTIME, &t);
+      break;
+  }
+
+  if (r)
+    return UV__ERR(errno);
+
+  ts->tv_sec = t.tv_sec;
+  ts->tv_nsec = t.tv_nsec;
+
+  return 0;
+}
+
+
+uint64_t uv_hrtime(void) {
+  return uv__hrtime(UV_CLOCK_PRECISE);
+}
+
+
+void uv_close(uv_handle_t* handle, uv_close_cb close_cb) {
+  assert(!uv__is_closing(handle));
+
+  handle->flags |= UV_HANDLE_CLOSING;
+  handle->close_cb = close_cb;
+
+  switch (handle->type) {
+  case UV_NAMED_PIPE:
+    uv__pipe_close((uv_pipe_t*)handle);
+    break;
+
+  case UV_TTY:
+    uv__tty_close((uv_tty_t*)handle);
+    break;
+
+  case UV_TCP:
+    uv__tcp_close((uv_tcp_t*)handle);
+    break;
+
+  case UV_UDP:
+    uv__udp_close((uv_udp_t*)handle);
+    break;
+
+  case UV_PREPARE:
+    uv__prepare_close((uv_prepare_t*)handle);
+    break;
+
+  case UV_CHECK:
+    uv__check_close((uv_check_t*)handle);
+    break;
+
+  case UV_IDLE:
+    uv__idle_close((uv_idle_t*)handle);
+    break;
+
+  case UV_ASYNC:
+    uv__async_close((uv_async_t*)handle);
+    break;
+
+  case UV_TIMER:
+    uv__timer_close((uv_timer_t*)handle);
+    break;
+
+  case UV_PROCESS:
+    uv__process_close((uv_process_t*)handle);
+    break;
+
+  case UV_FS_EVENT:
+    uv__fs_event_close((uv_fs_event_t*)handle);
+#if defined(__sun) || defined(__MVS__)
+    /*
+     * On Solaris, illumos, and z/OS we will not be able to dissociate the
+     * watcher for an event which is pending delivery, so we cannot always call
+     * uv__make_close_pending() straight away. The backend will call the
+     * function once the event has cleared.
+     */
+    return;
+#endif
+    break;
+
+  case UV_POLL:
+    uv__poll_close((uv_poll_t*)handle);
+    break;
+
+  case UV_FS_POLL:
+    uv__fs_poll_close((uv_fs_poll_t*)handle);
+    /* Poll handles use file system requests, and one of them may still be
+     * running. The poll code will call uv__make_close_pending() for us. */
+    return;
+
+  case UV_SIGNAL:
+    uv__signal_close((uv_signal_t*) handle);
+    break;
+
+  default:
+    assert(0);
+  }
+
+  uv__make_close_pending(handle);
+}
+
+int uv__socket_sockopt(uv_handle_t* handle, int optname, int* value) {
+  int r;
+  int fd;
+  socklen_t len;
+
+  if (handle == NULL || value == NULL)
+    return UV_EINVAL;
+
+  if (handle->type == UV_TCP || handle->type == UV_NAMED_PIPE)
+    fd = uv__stream_fd((uv_stream_t*) handle);
+  else if (handle->type == UV_UDP)
+    fd = ((uv_udp_t *) handle)->io_watcher.fd;
+  else
+    return UV_ENOTSUP;
+
+  len = sizeof(*value);
+
+  if (*value == 0)
+    r = getsockopt(fd, SOL_SOCKET, optname, value, &len);
+  else
+    r = setsockopt(fd, SOL_SOCKET, optname, (const void*) value, len);
+
+  if (r < 0)
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+void uv__make_close_pending(uv_handle_t* handle) {
+  assert(handle->flags & UV_HANDLE_CLOSING);
+  assert(!(handle->flags & UV_HANDLE_CLOSED));
+  handle->next_closing = handle->loop->closing_handles;
+  handle->loop->closing_handles = handle;
+}
+
+int uv__getiovmax(void) {
+#if defined(IOV_MAX)
+  return IOV_MAX;
+#elif defined(_SC_IOV_MAX)
+  static _Atomic int iovmax_cached = -1;
+  int iovmax;
+
+  iovmax = atomic_load_explicit(&iovmax_cached, memory_order_relaxed);
+  if (iovmax != -1)
+    return iovmax;
+
+  /* On some embedded devices (arm-linux-uclibc based ip camera),
+   * sysconf(_SC_IOV_MAX) can not get the correct value. The return
+   * value is -1 and the errno is EINPROGRESS. Degrade the value to 1.
+   */
+  iovmax = sysconf(_SC_IOV_MAX);
+  if (iovmax == -1)
+    iovmax = 1;
+
+  atomic_store_explicit(&iovmax_cached, iovmax, memory_order_relaxed);
+
+  return iovmax;
+#else
+  return 1024;
+#endif
+}
+
+
+static void uv__finish_close(uv_handle_t* handle) {
+  uv_signal_t* sh;
+
+  /* Note: while the handle is in the UV_HANDLE_CLOSING state now, it's still
+   * possible for it to be active in the sense that uv__is_active() returns
+   * true.
+   *
+   * A good example is when the user calls uv_shutdown(), immediately followed
+   * by uv_close(). The handle is considered active at this point because the
+   * completion of the shutdown req is still pending.
+   */
+  assert(handle->flags & UV_HANDLE_CLOSING);
+  assert(!(handle->flags & UV_HANDLE_CLOSED));
+  handle->flags |= UV_HANDLE_CLOSED;
+
+  switch (handle->type) {
+    case UV_PREPARE:
+    case UV_CHECK:
+    case UV_IDLE:
+    case UV_ASYNC:
+    case UV_TIMER:
+    case UV_PROCESS:
+    case UV_FS_EVENT:
+    case UV_FS_POLL:
+    case UV_POLL:
+      break;
+
+    case UV_SIGNAL:
+      /* If there are any caught signals "trapped" in the signal pipe,
+       * we can't call the close callback yet. Reinserting the handle
+       * into the closing queue makes the event loop spin but that's
+       * okay because we only need to deliver the pending events.
+       */
+      sh = (uv_signal_t*) handle;
+      if (sh->caught_signals > sh->dispatched_signals) {
+        handle->flags ^= UV_HANDLE_CLOSED;
+        uv__make_close_pending(handle);  /* Back into the queue. */
+        return;
+      }
+      break;
+
+    case UV_NAMED_PIPE:
+    case UV_TCP:
+    case UV_TTY:
+      uv__stream_destroy((uv_stream_t*)handle);
+      break;
+
+    case UV_UDP:
+      uv__udp_finish_close((uv_udp_t*)handle);
+      break;
+
+    default:
+      assert(0);
+      break;
+  }
+
+  uv__handle_unref(handle);
+  uv__queue_remove(&handle->handle_queue);
+
+  if (handle->close_cb) {
+    handle->close_cb(handle);
+  }
+}
+
+
+static void uv__run_closing_handles(uv_loop_t* loop) {
+  uv_handle_t* p;
+  uv_handle_t* q;
+
+  p = loop->closing_handles;
+  loop->closing_handles = NULL;
+
+  while (p) {
+    q = p->next_closing;
+    uv__finish_close(p);
+    p = q;
+  }
+}
+
+
+int uv_is_closing(const uv_handle_t* handle) {
+  return uv__is_closing(handle);
+}
+
+
+int uv_backend_fd(const uv_loop_t* loop) {
+  return loop->backend_fd;
+}
+
+
+static int uv__loop_alive(const uv_loop_t* loop) {
+  return uv__has_active_handles(loop) ||
+         uv__has_active_reqs(loop) ||
+         !uv__queue_empty(&loop->pending_queue) ||
+         loop->closing_handles != NULL;
+}
+
+
+static int uv__backend_timeout(const uv_loop_t* loop) {
+  if (loop->stop_flag == 0 &&
+      /* uv__loop_alive(loop) && */
+      (uv__has_active_handles(loop) || uv__has_active_reqs(loop)) &&
+      uv__queue_empty(&loop->pending_queue) &&
+      uv__queue_empty(&loop->idle_handles) &&
+      (loop->flags & UV_LOOP_REAP_CHILDREN) == 0 &&
+      loop->closing_handles == NULL)
+    return uv__next_timeout(loop);
+  return 0;
+}
+
+
+int uv_backend_timeout(const uv_loop_t* loop) {
+  if (uv__queue_empty(&loop->watcher_queue))
+    return uv__backend_timeout(loop);
+  /* Need to call uv_run to update the backend fd state. */
+  return 0;
+}
+
+
+int uv_loop_alive(const uv_loop_t* loop) {
+  return uv__loop_alive(loop);
+}
+
+
+int uv_run(uv_loop_t* loop, uv_run_mode mode) {
+  int timeout;
+  int r;
+  int can_sleep;
+
+  r = uv__loop_alive(loop);
+  if (!r)
+    uv__update_time(loop);
+
+  /* Maintain backwards compatibility by processing timers before entering the
+   * while loop for UV_RUN_DEFAULT. Otherwise timers only need to be executed
+   * once, which should be done after polling in order to maintain proper
+   * execution order of the conceptual event loop. */
+  if (mode == UV_RUN_DEFAULT && r != 0 && loop->stop_flag == 0) {
+    uv__update_time(loop);
+    uv__run_timers(loop);
+  }
+
+  while (r != 0 && loop->stop_flag == 0) {
+    can_sleep =
+        uv__queue_empty(&loop->pending_queue) &&
+        uv__queue_empty(&loop->idle_handles);
+
+    uv__run_pending(loop);
+    uv__run_idle(loop);
+    uv__run_prepare(loop);
+
+    timeout = 0;
+    if ((mode == UV_RUN_ONCE && can_sleep) || mode == UV_RUN_DEFAULT)
+      timeout = uv__backend_timeout(loop);
+
+    uv__metrics_inc_loop_count(loop);
+
+    uv__io_poll(loop, timeout);
+
+    /* Process immediate callbacks (e.g. write_cb) a small fixed number of
+     * times to avoid loop starvation.*/
+    for (r = 0; r < 8 && !uv__queue_empty(&loop->pending_queue); r++)
+      uv__run_pending(loop);
+
+    /* Run one final update on the provider_idle_time in case uv__io_poll
+     * returned because the timeout expired, but no events were received. This
+     * call will be ignored if the provider_entry_time was either never set (if
+     * the timeout == 0) or was already updated b/c an event was received.
+     */
+    uv__metrics_update_idle_time(loop);
+
+    uv__run_check(loop);
+    uv__run_closing_handles(loop);
+
+    uv__update_time(loop);
+    uv__run_timers(loop);
+
+    r = uv__loop_alive(loop);
+    if (mode == UV_RUN_ONCE || mode == UV_RUN_NOWAIT)
+      break;
+  }
+
+  /* The if statement lets gcc compile it to a conditional store. Avoids
+   * dirtying a cache line.
+   */
+  if (loop->stop_flag != 0)
+    loop->stop_flag = 0;
+
+  return r;
+}
+
+
+void uv_update_time(uv_loop_t* loop) {
+  uv__update_time(loop);
+}
+
+
+int uv_is_active(const uv_handle_t* handle) {
+  return uv__is_active(handle);
+}
+
+
+/* Open a socket in non-blocking close-on-exec mode, atomically if possible. */
+int uv__socket(int domain, int type, int protocol) {
+  int sockfd;
+  int err;
+
+#if defined(SOCK_NONBLOCK) && defined(SOCK_CLOEXEC)
+  sockfd = socket(domain, type | SOCK_NONBLOCK | SOCK_CLOEXEC, protocol);
+  if (sockfd != -1)
+    return sockfd;
+
+  if (errno != EINVAL)
+    return UV__ERR(errno);
+#endif
+
+  sockfd = socket(domain, type, protocol);
+  if (sockfd == -1)
+    return UV__ERR(errno);
+
+  err = uv__nonblock(sockfd, 1);
+  if (err == 0)
+    err = uv__cloexec(sockfd, 1);
+
+  if (err) {
+    uv__close(sockfd);
+    return err;
+  }
+
+#if defined(SO_NOSIGPIPE)
+  {
+    int on = 1;
+    setsockopt(sockfd, SOL_SOCKET, SO_NOSIGPIPE, &on, sizeof(on));
+  }
+#endif
+
+  return sockfd;
+}
+
+/* get a file pointer to a file in read-only and close-on-exec mode */
+FILE* uv__open_file(const char* path) {
+  int fd;
+  FILE* fp;
+
+  fd = uv__open_cloexec(path, O_RDONLY);
+  if (fd < 0)
+    return NULL;
+
+   fp = fdopen(fd, "r");
+   if (fp == NULL)
+     uv__close(fd);
+
+   return fp;
+}
+
+
+int uv__accept(int sockfd) {
+  int peerfd;
+  int err;
+
+  (void) &err;
+  assert(sockfd >= 0);
+
+  do
+#ifdef uv__accept4
+    peerfd = uv__accept4(sockfd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
+#else
+    peerfd = accept(sockfd, NULL, NULL);
+#endif
+  while (peerfd == -1 && errno == EINTR);
+
+  if (peerfd == -1)
+    return UV__ERR(errno);
+
+#ifndef uv__accept4
+  err = uv__cloexec(peerfd, 1);
+  if (err == 0)
+    err = uv__nonblock(peerfd, 1);
+
+  if (err != 0) {
+    uv__close(peerfd);
+    return err;
+  }
+#endif
+
+  return peerfd;
+}
+
+
+/* close() on macos has the "interesting" quirk that it fails with EINTR
+ * without closing the file descriptor when a thread is in the cancel state.
+ * That's why libuv calls close$NOCANCEL() instead.
+ *
+ * glibc on linux has a similar issue: close() is a cancellation point and
+ * will unwind the thread when it's in the cancel state. Work around that
+ * by making the system call directly. Musl libc is unaffected.
+ */
+int uv__close_nocancel(int fd) {
+#if defined(__APPLE__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdollar-in-identifier-extension"
+#if defined(__LP64__) || TARGET_OS_IPHONE
+  extern int close$NOCANCEL(int);
+  return close$NOCANCEL(fd);
+#else
+  extern int close$NOCANCEL$UNIX2003(int);
+  return close$NOCANCEL$UNIX2003(fd);
+#endif
+#pragma GCC diagnostic pop
+#elif defined(__linux__) && defined(__SANITIZE_THREAD__) && defined(__clang__)
+  long rc;
+  __sanitizer_syscall_pre_close(fd);
+  rc = syscall(SYS_close, fd);
+  __sanitizer_syscall_post_close(rc, fd);
+  return rc;
+#elif defined(__linux__) && !defined(__SANITIZE_THREAD__)
+  return syscall(SYS_close, fd);
+#else
+  return close(fd);
+#endif
+}
+
+
+int uv__close_nocheckstdio(int fd) {
+  int saved_errno;
+  int rc;
+
+  assert(fd > -1);  /* Catch uninitialized io_watcher.fd bugs. */
+
+  saved_errno = errno;
+  rc = uv__close_nocancel(fd);
+  if (rc == -1) {
+    rc = UV__ERR(errno);
+    if (rc == UV_EINTR || rc == UV__ERR(EINPROGRESS))
+      rc = 0;    /* The close is in progress, not an error. */
+    errno = saved_errno;
+  }
+
+  return rc;
+}
+
+
+int uv__close(int fd) {
+  assert(fd > STDERR_FILENO);  /* Catch stdio close bugs. */
+#if defined(__MVS__)
+  SAVE_ERRNO(epoll_file_close(fd));
+#endif
+  return uv__close_nocheckstdio(fd);
+}
+
+#if UV__NONBLOCK_IS_IOCTL
+int uv__nonblock_ioctl(int fd, int set) {
+  int r;
+
+  do
+    r = ioctl(fd, FIONBIO, &set);
+  while (r == -1 && errno == EINTR);
+
+  if (r)
+    return UV__ERR(errno);
+
+  return 0;
+}
+#endif
+
+
+int uv__nonblock_fcntl(int fd, int set) {
+  int flags;
+  int r;
+
+  do
+    r = fcntl(fd, F_GETFL);
+  while (r == -1 && errno == EINTR);
+
+  if (r == -1)
+    return UV__ERR(errno);
+
+  /* Bail out now if already set/clear. */
+  if (!!(r & O_NONBLOCK) == !!set)
+    return 0;
+
+  if (set)
+    flags = r | O_NONBLOCK;
+  else
+    flags = r & ~O_NONBLOCK;
+
+  do
+    r = fcntl(fd, F_SETFL, flags);
+  while (r == -1 && errno == EINTR);
+
+  if (r)
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+
+int uv__cloexec(int fd, int set) {
+  int flags;
+  int r;
+
+  flags = 0;
+  if (set)
+    flags = FD_CLOEXEC;
+
+  do
+    r = fcntl(fd, F_SETFD, flags);
+  while (r == -1 && errno == EINTR);
+
+  if (r)
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+
+ssize_t uv__recvmsg(int fd, struct msghdr* msg, int flags) {
+#if defined(__ANDROID__)   || \
+    defined(__DragonFly__) || \
+    defined(__FreeBSD__)   || \
+    defined(__NetBSD__)    || \
+    defined(__OpenBSD__)   || \
+    defined(__linux__)
+  ssize_t rc;
+  rc = recvmsg(fd, msg, flags | MSG_CMSG_CLOEXEC);
+  if (rc == -1)
+    return UV__ERR(errno);
+  return rc;
+#else
+  struct cmsghdr* cmsg;
+  int* pfd;
+  int* end;
+  ssize_t rc;
+  rc = recvmsg(fd, msg, flags);
+  if (rc == -1)
+    return UV__ERR(errno);
+  if (msg->msg_controllen == 0)
+    return rc;
+  for (cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg))
+    if (cmsg->cmsg_type == SCM_RIGHTS)
+      for (pfd = (int*) CMSG_DATA(cmsg),
+           end = (int*) ((char*) cmsg + cmsg->cmsg_len);
+           pfd < end;
+           pfd += 1)
+        uv__cloexec(*pfd, 1);
+  return rc;
+#endif
+}
+
+
+int uv_cwd(char* buffer, size_t* size) {
+  char scratch[1 + UV__PATH_MAX];
+
+  if (buffer == NULL || size == NULL || *size == 0)
+    return UV_EINVAL;
+
+  /* Try to read directly into the user's buffer first... */
+  if (getcwd(buffer, *size) != NULL)
+    goto fixup;
+
+  if (errno != ERANGE)
+    return UV__ERR(errno);
+
+  /* ...or into scratch space if the user's buffer is too small
+   * so we can report how much space to provide on the next try.
+   */
+  if (getcwd(scratch, sizeof(scratch)) == NULL)
+    return UV__ERR(errno);
+
+  buffer = scratch;
+
+fixup:
+
+  *size = strlen(buffer);
+
+  if (*size > 1 && buffer[*size - 1] == '/') {
+    *size -= 1;
+    buffer[*size] = '\0';
+  }
+
+  if (buffer == scratch) {
+    *size += 1;
+    return UV_ENOBUFS;
+  }
+
+  return 0;
+}
+
+
+int uv_chdir(const char* dir) {
+  if (chdir(dir))
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+
+void uv_disable_stdio_inheritance(void) {
+  int fd;
+
+  /* Set the CLOEXEC flag on all open descriptors. Unconditionally try the
+   * first 16 file descriptors. After that, bail out after the first error.
+   */
+  for (fd = 0; ; fd++)
+    if (uv__cloexec(fd, 1) && fd > 15)
+      break;
+}
+
+
+int uv_fileno(const uv_handle_t* handle, uv_os_fd_t* fd) {
+  int fd_out;
+
+  switch (handle->type) {
+  case UV_TCP:
+  case UV_NAMED_PIPE:
+  case UV_TTY:
+    fd_out = uv__stream_fd((uv_stream_t*) handle);
+    break;
+
+  case UV_UDP:
+    fd_out = ((uv_udp_t *) handle)->io_watcher.fd;
+    break;
+
+  case UV_POLL:
+    fd_out = ((uv_poll_t *) handle)->io_watcher.fd;
+    break;
+
+  default:
+    return UV_EINVAL;
+  }
+
+  if (uv__is_closing(handle) || fd_out == -1)
+    return UV_EBADF;
+
+  *fd = fd_out;
+  return 0;
+}
+
+
+static void uv__run_pending(uv_loop_t* loop) {
+  struct uv__queue* q;
+  struct uv__queue pq;
+  uv__io_t* w;
+
+  uv__queue_move(&loop->pending_queue, &pq);
+
+  while (!uv__queue_empty(&pq)) {
+    q = uv__queue_head(&pq);
+    uv__queue_remove(q);
+    uv__queue_init(q);
+    w = uv__queue_data(q, uv__io_t, pending_queue);
+    w->cb(loop, w, POLLOUT);
+  }
+}
+
+
+static unsigned int next_power_of_two(unsigned int val) {
+  val -= 1;
+  val |= val >> 1;
+  val |= val >> 2;
+  val |= val >> 4;
+  val |= val >> 8;
+  val |= val >> 16;
+  val += 1;
+  return val;
+}
+
+static int maybe_resize(uv_loop_t* loop, unsigned int len) {
+  uv__io_t** watchers;
+  void* fake_watcher_list;
+  void* fake_watcher_count;
+  unsigned int nwatchers;
+  unsigned int i;
+
+  if (len <= loop->nwatchers)
+    return 0;
+
+  /* Preserve fake watcher list and count at the end of the watchers */
+  if (loop->watchers != NULL) {
+    fake_watcher_list = loop->watchers[loop->nwatchers];
+    fake_watcher_count = loop->watchers[loop->nwatchers + 1];
+  } else {
+    fake_watcher_list = NULL;
+    fake_watcher_count = NULL;
+  }
+
+  nwatchers = next_power_of_two(len + 2) - 2;
+  watchers = uv__reallocf(loop->watchers,
+                          (nwatchers + 2) * sizeof(loop->watchers[0]));
+
+  if (watchers == NULL)
+    return UV_ENOMEM;
+  for (i = loop->nwatchers; i < nwatchers; i++)
+    watchers[i] = NULL;
+  watchers[nwatchers] = fake_watcher_list;
+  watchers[nwatchers + 1] = fake_watcher_count;
+
+  loop->watchers = watchers;
+  loop->nwatchers = nwatchers;
+  return 0;
+}
+
+
+void uv__io_init(uv__io_t* w, uv__io_cb cb, int fd) {
+  assert(fd >= -1);
+  uv__queue_init(&w->pending_queue);
+  uv__queue_init(&w->watcher_queue);
+  w->cb = cb;
+  w->fd = fd;
+  w->events = 0;
+  w->pevents = 0;
+}
+
+
+int uv__io_start(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
+  int err;
+
+  assert(0 == (events & ~(POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI)));
+  assert(0 != events);
+  assert(w->fd >= 0);
+  assert(w->fd < INT_MAX);
+
+  w->pevents |= events;
+  err = maybe_resize(loop, w->fd + 1);
+  if (err)
+    return err;
+
+#if !defined(__sun)
+  /* The event ports backend needs to rearm all file descriptors on each and
+   * every tick of the event loop but the other backends allow us to
+   * short-circuit here if the event mask is unchanged.
+   */
+  if (w->events == w->pevents)
+    return 0;
+#endif
+
+  if (uv__queue_empty(&w->watcher_queue))
+    uv__queue_insert_tail(&loop->watcher_queue, &w->watcher_queue);
+
+  if (loop->watchers[w->fd] == NULL) {
+    loop->watchers[w->fd] = w;
+    loop->nfds++;
+  }
+
+  return 0;
+}
+
+
+int uv__io_init_start(uv_loop_t* loop,
+                      uv__io_t* w,
+                      uv__io_cb cb,
+                      int fd,
+                      unsigned int events) {
+  int err;
+
+  assert(cb != NULL);
+  assert(fd > -1);
+  uv__io_init(w, cb, fd);
+  err = uv__io_start(loop, w, events);
+  if (err)
+    uv__io_init(w, NULL, -1);
+  return err;
+}
+
+
+void uv__io_stop(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
+  assert(0 == (events & ~(POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI)));
+  assert(0 != events);
+
+  if (w->fd == -1)
+    return;
+
+  assert(w->fd >= 0);
+
+  /* Happens when uv__io_stop() is called on a handle that was never started. */
+  if ((unsigned) w->fd >= loop->nwatchers)
+    return;
+
+  w->pevents &= ~events;
+
+  if (w->pevents == 0) {
+    uv__queue_remove(&w->watcher_queue);
+    uv__queue_init(&w->watcher_queue);
+    w->events = 0;
+
+    if (w == loop->watchers[w->fd]) {
+      assert(loop->nfds > 0);
+      loop->watchers[w->fd] = NULL;
+      loop->nfds--;
+    }
+  }
+  else if (uv__queue_empty(&w->watcher_queue))
+    uv__queue_insert_tail(&loop->watcher_queue, &w->watcher_queue);
+}
+
+
+void uv__io_close(uv_loop_t* loop, uv__io_t* w) {
+  uv__io_stop(loop, w, POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
+  uv__queue_remove(&w->pending_queue);
+
+  /* Remove stale events for this file descriptor */
+  if (w->fd != -1)
+    uv__platform_invalidate_fd(loop, w->fd);
+}
+
+
+void uv__io_feed(uv_loop_t* loop, uv__io_t* w) {
+  if (uv__queue_empty(&w->pending_queue))
+    uv__queue_insert_tail(&loop->pending_queue, &w->pending_queue);
+}
+
+
+int uv__io_active(const uv__io_t* w, unsigned int events) {
+  assert(0 == (events & ~(POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI)));
+  assert(0 != events);
+  return 0 != (w->pevents & events);
+}
+
+
+int uv__fd_exists(uv_loop_t* loop, int fd) {
+  return (unsigned) fd < loop->nwatchers && loop->watchers[fd] != NULL;
+}
+
+
+static int uv__getrusage(int who, uv_rusage_t* rusage) {
+  struct rusage usage;
+
+  if (getrusage(who, &usage))
+    return UV__ERR(errno);
+
+  rusage->ru_utime.tv_sec = usage.ru_utime.tv_sec;
+  rusage->ru_utime.tv_usec = usage.ru_utime.tv_usec;
+
+  rusage->ru_stime.tv_sec = usage.ru_stime.tv_sec;
+  rusage->ru_stime.tv_usec = usage.ru_stime.tv_usec;
+
+#if !defined(__MVS__) && !defined(__HAIKU__)
+  rusage->ru_maxrss = usage.ru_maxrss;
+  rusage->ru_ixrss = usage.ru_ixrss;
+  rusage->ru_idrss = usage.ru_idrss;
+  rusage->ru_isrss = usage.ru_isrss;
+  rusage->ru_minflt = usage.ru_minflt;
+  rusage->ru_majflt = usage.ru_majflt;
+  rusage->ru_nswap = usage.ru_nswap;
+  rusage->ru_inblock = usage.ru_inblock;
+  rusage->ru_oublock = usage.ru_oublock;
+  rusage->ru_msgsnd = usage.ru_msgsnd;
+  rusage->ru_msgrcv = usage.ru_msgrcv;
+  rusage->ru_nsignals = usage.ru_nsignals;
+  rusage->ru_nvcsw = usage.ru_nvcsw;
+  rusage->ru_nivcsw = usage.ru_nivcsw;
+#endif
+
+  /* Most platforms report ru_maxrss in kilobytes; macOS and Solaris are
+   * the outliers because of course they are.
+   */
+#if defined(__APPLE__)
+  rusage->ru_maxrss /= 1024;                  /* macOS and iOS report bytes. */
+#elif defined(__sun)
+  rusage->ru_maxrss *= getpagesize() / 1024;  /* Solaris reports pages. */
+#endif
+
+  return 0;
+}
+
+
+int uv_getrusage(uv_rusage_t* rusage) {
+  return uv__getrusage(RUSAGE_SELF, rusage);
+}
+
+
+int uv_getrusage_thread(uv_rusage_t* rusage) {
+#if defined(__APPLE__)
+  mach_msg_type_number_t count;
+  thread_basic_info_data_t info;
+  kern_return_t kr;
+  thread_t thread;
+
+  thread = mach_thread_self();
+  count = THREAD_BASIC_INFO_COUNT;
+  kr = thread_info(thread,
+                   THREAD_BASIC_INFO,
+                   (thread_info_t)&info,
+                   &count);
+
+  if (kr != KERN_SUCCESS) {
+    mach_port_deallocate(mach_task_self(), thread);
+    return UV_EINVAL;
+  }
+
+  memset(rusage, 0, sizeof(*rusage));
+
+  rusage->ru_utime.tv_sec = info.user_time.seconds;
+  rusage->ru_utime.tv_usec = info.user_time.microseconds;
+  rusage->ru_stime.tv_sec = info.system_time.seconds;
+  rusage->ru_stime.tv_usec = info.system_time.microseconds;
+
+  mach_port_deallocate(mach_task_self(), thread);
+
+  return 0;
+
+#elif defined(RUSAGE_LWP)
+  return uv__getrusage(RUSAGE_LWP, rusage);
+#elif defined(RUSAGE_THREAD)
+  return uv__getrusage(RUSAGE_THREAD, rusage);
+#endif  /* defined(__APPLE__) */
+  return UV_ENOTSUP;
+}
+
+
+int uv__open_cloexec(const char* path, int flags) {
+#if defined(O_CLOEXEC)
+  int fd;
+
+  fd = open(path, flags | O_CLOEXEC);
+  if (fd == -1)
+    return UV__ERR(errno);
+
+  return fd;
+#else  /* O_CLOEXEC */
+  int err;
+  int fd;
+
+  fd = open(path, flags);
+  if (fd == -1)
+    return UV__ERR(errno);
+
+  err = uv__cloexec(fd, 1);
+  if (err) {
+    uv__close(fd);
+    return err;
+  }
+
+  return fd;
+#endif  /* O_CLOEXEC */
+}
+
+
+int uv__slurp(const char* filename, char* buf, size_t len) {
+  ssize_t n;
+  int fd;
+
+  assert(len > 0);
+
+  fd = uv__open_cloexec(filename, O_RDONLY);
+  if (fd < 0)
+    return fd;
+
+  do
+    n = read(fd, buf, len - 1);
+  while (n == -1 && errno == EINTR);
+
+  if (uv__close_nocheckstdio(fd))
+    abort();
+
+  if (n < 0)
+    return UV__ERR(errno);
+
+  buf[n] = '\0';
+
+  return 0;
+}
+
+
+int uv__dup2_cloexec(int oldfd, int newfd) {
+#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__linux__)
+  int r;
+
+  r = dup3(oldfd, newfd, O_CLOEXEC);
+  if (r == -1)
+    return UV__ERR(errno);
+
+  return r;
+#else
+  int err;
+  int r;
+
+  r = dup2(oldfd, newfd);  /* Never retry. */
+  if (r == -1)
+    return UV__ERR(errno);
+
+  err = uv__cloexec(newfd, 1);
+  if (err != 0) {
+    uv__close(newfd);
+    return err;
+  }
+
+  return r;
+#endif
+}
+
+
+int uv_os_homedir(char* buffer, size_t* size) {
+  uv_passwd_t pwd;
+  size_t len;
+  int r;
+
+  /* Check if the HOME environment variable is set first. The task of
+     performing input validation on buffer and size is taken care of by
+     uv_os_getenv(). */
+  r = uv_os_getenv("HOME", buffer, size);
+
+  if (r != UV_ENOENT)
+    return r;
+
+  /* HOME is not set, so call uv_os_get_passwd() */
+  r = uv_os_get_passwd(&pwd);
+
+  if (r != 0) {
+    return r;
+  }
+
+  len = strlen(pwd.homedir);
+
+  if (len >= *size) {
+    *size = len + 1;
+    uv_os_free_passwd(&pwd);
+    return UV_ENOBUFS;
+  }
+
+  memcpy(buffer, pwd.homedir, len + 1);
+  *size = len;
+  uv_os_free_passwd(&pwd);
+
+  return 0;
+}
+
+
+int uv_os_tmpdir(char* buffer, size_t* size) {
+  const char* buf;
+  size_t len;
+
+  if (buffer == NULL || size == NULL || *size == 0)
+    return UV_EINVAL;
+
+#define CHECK_ENV_VAR(name)                                                   \
+  do {                                                                        \
+    buf = getenv(name);                                                       \
+    if (buf != NULL)                                                          \
+      goto return_buffer;                                                     \
+  }                                                                           \
+  while (0)
+
+  /* Check the TMPDIR, TMP, TEMP, and TEMPDIR environment variables in order */
+  CHECK_ENV_VAR("TMPDIR");
+  CHECK_ENV_VAR("TMP");
+  CHECK_ENV_VAR("TEMP");
+  CHECK_ENV_VAR("TEMPDIR");
+
+#undef CHECK_ENV_VAR
+
+  /* No temp environment variables defined */
+  #if defined(__ANDROID__)
+    buf = "/data/local/tmp";
+  #else
+    buf = "/tmp";
+  #endif
+
+return_buffer:
+  len = strlen(buf);
+
+  if (len >= *size) {
+    *size = len + 1;
+    return UV_ENOBUFS;
+  }
+
+  /* The returned directory should not have a trailing slash. */
+  if (len > 1 && buf[len - 1] == '/') {
+    len--;
+  }
+
+  memcpy(buffer, buf, len + 1);
+  buffer[len] = '\0';
+  *size = len;
+
+  return 0;
+}
+
+
+static int uv__getpwuid_r(uv_passwd_t *pwd, uid_t uid) {
+  struct passwd pw;
+  struct passwd* result;
+  char* buf;
+  size_t bufsize;
+  size_t name_size;
+  size_t homedir_size;
+  size_t shell_size;
+  int r;
+
+  if (pwd == NULL)
+    return UV_EINVAL;
+
+  /* Calling sysconf(_SC_GETPW_R_SIZE_MAX) would get the suggested size, but it
+   * is frequently 1024 or 4096, so we can just use that directly. The pwent
+   * will not usually be large. */
+  for (bufsize = 2000;; bufsize *= 2) {
+    buf = uv__malloc(bufsize);
+
+    if (buf == NULL)
+      return UV_ENOMEM;
+
+    do
+      r = getpwuid_r(uid, &pw, buf, bufsize, &result);
+    while (r == EINTR);
+
+    if (r != 0 || result == NULL)
+      uv__free(buf);
+
+    if (r != ERANGE)
+      break;
+  }
+
+  if (r != 0)
+    return UV__ERR(r);
+
+  if (result == NULL)
+    return UV_ENOENT;
+
+  /* Allocate memory for the username, shell, and home directory */
+  name_size = strlen(pw.pw_name) + 1;
+  homedir_size = strlen(pw.pw_dir) + 1;
+  shell_size = strlen(pw.pw_shell) + 1;
+  pwd->username = uv__malloc(name_size + homedir_size + shell_size);
+
+  if (pwd->username == NULL) {
+    uv__free(buf);
+    return UV_ENOMEM;
+  }
+
+  /* Copy the username */
+  memcpy(pwd->username, pw.pw_name, name_size);
+
+  /* Copy the home directory */
+  pwd->homedir = pwd->username + name_size;
+  memcpy(pwd->homedir, pw.pw_dir, homedir_size);
+
+  /* Copy the shell */
+  pwd->shell = pwd->homedir + homedir_size;
+  memcpy(pwd->shell, pw.pw_shell, shell_size);
+
+  /* Copy the uid and gid */
+  pwd->uid = pw.pw_uid;
+  pwd->gid = pw.pw_gid;
+
+  uv__free(buf);
+
+  return 0;
+}
+
+
+int uv_os_get_group(uv_group_t* grp, uv_uid_t gid) {
+#if defined(__ANDROID__) && __ANDROID_API__ < 24
+  /* This function getgrgid_r() was added in Android N (level 24) */
+  return UV_ENOSYS;
+#else
+  struct group gp;
+  struct group* result;
+  char* buf;
+  char* gr_mem;
+  size_t bufsize;
+  size_t name_size;
+  long members;
+  size_t mem_size;
+  int r;
+
+  if (grp == NULL)
+    return UV_EINVAL;
+
+  /* Calling sysconf(_SC_GETGR_R_SIZE_MAX) would get the suggested size, but it
+   * is frequently 1024 or 4096, so we can just use that directly. The pwent
+   * will not usually be large. */
+  for (bufsize = 2000;; bufsize *= 2) {
+    buf = uv__malloc(bufsize);
+
+    if (buf == NULL)
+      return UV_ENOMEM;
+
+    do
+      r = getgrgid_r(gid, &gp, buf, bufsize, &result);
+    while (r == EINTR);
+
+    if (r != 0 || result == NULL)
+      uv__free(buf);
+
+    if (r != ERANGE)
+      break;
+  }
+
+  if (r != 0)
+    return UV__ERR(r);
+
+  if (result == NULL)
+    return UV_ENOENT;
+
+  /* Allocate memory for the groupname and members. */
+  name_size = strlen(gp.gr_name) + 1;
+  members = 0;
+  mem_size = sizeof(char*);
+  for (r = 0; gp.gr_mem[r] != NULL; r++) {
+    mem_size += strlen(gp.gr_mem[r]) + 1 + sizeof(char*);
+    members++;
+  }
+
+  gr_mem = uv__malloc(name_size + mem_size);
+  if (gr_mem == NULL) {
+    uv__free(buf);
+    return UV_ENOMEM;
+  }
+
+  /* Copy the members */
+  grp->members = (char**) gr_mem;
+  grp->members[members] = NULL;
+  gr_mem = (char*) &grp->members[members + 1];
+  for (r = 0; r < members; r++) {
+    grp->members[r] = gr_mem;
+    strcpy(gr_mem, gp.gr_mem[r]);
+    gr_mem += strlen(gr_mem) + 1;
+  }
+  assert(gr_mem == (char*)grp->members + mem_size);
+
+  /* Copy the groupname */
+  grp->groupname = gr_mem;
+  memcpy(grp->groupname, gp.gr_name, name_size);
+  gr_mem += name_size;
+
+  /* Copy the gid */
+  grp->gid = gp.gr_gid;
+
+  uv__free(buf);
+
+  return 0;
+#endif
+}
+
+
+int uv_os_get_passwd(uv_passwd_t* pwd) {
+  return uv__getpwuid_r(pwd, geteuid());
+}
+
+
+int uv_os_get_passwd2(uv_passwd_t* pwd, uv_uid_t uid) {
+  return uv__getpwuid_r(pwd, uid);
+}
+
+
+int uv_translate_sys_error(int sys_errno) {
+  /* If < 0 then it's already a libuv error. */
+  return sys_errno <= 0 ? sys_errno : -sys_errno;
+}
+
+
+int uv_os_environ(uv_env_item_t** envitems, int* count) {
+  int i, j, cnt;
+  uv_env_item_t* envitem;
+
+  *envitems = NULL;
+  *count = 0;
+
+  for (i = 0; environ[i] != NULL; i++);
+
+  *envitems = uv__calloc(i, sizeof(**envitems));
+
+  if (*envitems == NULL)
+    return UV_ENOMEM;
+
+  for (j = 0, cnt = 0; j < i; j++) {
+    char* buf;
+    char* ptr;
+
+    if (environ[j] == NULL)
+      break;
+
+    buf = uv__strdup(environ[j]);
+    if (buf == NULL)
+      goto fail;
+
+    ptr = strchr(buf, '=');
+    if (ptr == NULL) {
+      uv__free(buf);
+      continue;
+    }
+
+    *ptr = '\0';
+
+    envitem = &(*envitems)[cnt];
+    envitem->name = buf;
+    envitem->value = ptr + 1;
+
+    cnt++;
+  }
+
+  *count = cnt;
+  return 0;
+
+fail:
+  for (i = 0; i < cnt; i++) {
+    envitem = &(*envitems)[cnt];
+    uv__free(envitem->name);
+  }
+  uv__free(*envitems);
+
+  *envitems = NULL;
+  *count = 0;
+  return UV_ENOMEM;
+}
+
+
+int uv_os_getenv(const char* name, char* buffer, size_t* size) {
+  char* var;
+  size_t len;
+
+  if (name == NULL || buffer == NULL || size == NULL || *size == 0)
+    return UV_EINVAL;
+
+  var = getenv(name);
+
+  if (var == NULL)
+    return UV_ENOENT;
+
+  len = strlen(var);
+
+  if (len >= *size) {
+    *size = len + 1;
+    return UV_ENOBUFS;
+  }
+
+  memcpy(buffer, var, len + 1);
+  *size = len;
+
+  return 0;
+}
+
+
+int uv_os_setenv(const char* name, const char* value) {
+  if (name == NULL || value == NULL)
+    return UV_EINVAL;
+
+  if (setenv(name, value, 1) != 0)
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+
+int uv_os_unsetenv(const char* name) {
+  if (name == NULL)
+    return UV_EINVAL;
+
+  if (unsetenv(name) != 0)
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+
+int uv_os_gethostname(char* buffer, size_t* size) {
+  /*
+    On some platforms, if the input buffer is not large enough, gethostname()
+    succeeds, but truncates the result. libuv can detect this and return ENOBUFS
+    instead by creating a large enough buffer and comparing the hostname length
+    to the size input.
+  */
+  char buf[UV_MAXHOSTNAMESIZE];
+  size_t len;
+
+  if (buffer == NULL || size == NULL || *size == 0)
+    return UV_EINVAL;
+
+  if (gethostname(buf, sizeof(buf)) != 0)
+    return UV__ERR(errno);
+
+  buf[sizeof(buf) - 1] = '\0'; /* Null terminate, just to be safe. */
+  len = strlen(buf);
+
+  if (len >= *size) {
+    *size = len + 1;
+    return UV_ENOBUFS;
+  }
+
+  memcpy(buffer, buf, len + 1);
+  *size = len;
+  return 0;
+}
+
+
+uv_os_fd_t uv_get_osfhandle(int fd) {
+  return fd;
+}
+
+int uv_open_osfhandle(uv_os_fd_t os_fd) {
+  return os_fd;
+}
+
+uv_pid_t uv_os_getpid(void) {
+  return getpid();
+}
+
+
+uv_pid_t uv_os_getppid(void) {
+  return getppid();
+}
+
+int uv_cpumask_size(void) {
+#if UV__CPU_AFFINITY_SUPPORTED
+  return CPU_SETSIZE;
+#else
+  return UV_ENOTSUP;
+#endif
+}
+
+int uv_os_getpriority(uv_pid_t pid, int* priority) {
+  int r;
+
+  if (priority == NULL)
+    return UV_EINVAL;
+
+  errno = 0;
+  r = getpriority(PRIO_PROCESS, (int) pid);
+
+  if (r == -1 && errno != 0)
+    return UV__ERR(errno);
+
+  *priority = r;
+  return 0;
+}
+
+
+int uv_os_setpriority(uv_pid_t pid, int priority) {
+  if (priority < UV_PRIORITY_HIGHEST || priority > UV_PRIORITY_LOW)
+    return UV_EINVAL;
+
+  if (setpriority(PRIO_PROCESS, (int) pid, priority) != 0)
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+/**
+ * If the function succeeds, the return value is 0.
+ * If the function fails, the return value is non-zero.
+ * for Linux, when schedule policy is SCHED_OTHER (default), priority is 0.
+ * So the output parameter priority is actually the nice value.
+*/
+int uv_thread_getpriority(uv_thread_t tid, int* priority) {
+  int r;
+  int policy;
+  struct sched_param param;
+#ifdef __linux__
+  pid_t pid = gettid();
+#endif
+
+  if (priority == NULL)
+    return UV_EINVAL;
+
+  r = pthread_getschedparam(tid, &policy, &param);
+  if (r != 0)
+    return UV__ERR(errno);
+
+#ifdef __linux__
+  if (SCHED_OTHER == policy && pthread_equal(tid, pthread_self())) {
+    errno = 0;
+    r = getpriority(PRIO_PROCESS, pid);
+    if (r == -1 && errno != 0)
+      return UV__ERR(errno);
+    *priority = r;
+    return 0;
+  }
+#endif
+
+  *priority = param.sched_priority;
+  return 0;
+}
+
+#ifdef __linux__
+static int set_nice_for_calling_thread(int priority) {
+  int r;
+  int nice;
+
+  if (priority < UV_THREAD_PRIORITY_LOWEST || priority > UV_THREAD_PRIORITY_HIGHEST)
+    return UV_EINVAL;
+
+  pid_t pid = gettid();
+  nice = 0 - priority * 2;
+  r = setpriority(PRIO_PROCESS, pid, nice);
+  if (r != 0)
+    return UV__ERR(errno);
+  return 0;
+}
+#endif
+
+/**
+ * If the function succeeds, the return value is 0.
+ * If the function fails, the return value is non-zero.
+*/
+int uv_thread_setpriority(uv_thread_t tid, int priority) {
+#if !defined(__GNU__)
+  int r;
+  int min;
+  int max;
+  int range;
+  int prio;
+  int policy;
+  struct sched_param param;
+
+  if (priority < UV_THREAD_PRIORITY_LOWEST || priority > UV_THREAD_PRIORITY_HIGHEST)
+    return UV_EINVAL;
+
+  r = pthread_getschedparam(tid, &policy, &param);
+  if (r != 0)
+    return UV__ERR(errno);
+
+#ifdef __linux__
+/**
+ * for Linux, when schedule policy is SCHED_OTHER (default), priority must be 0,
+ * we should set the nice value in this case.
+*/
+  if (SCHED_OTHER == policy && pthread_equal(tid, pthread_self()))
+    return set_nice_for_calling_thread(priority);
+#endif
+
+#ifdef __PASE__
+  min = 1;
+  max = 127;
+#else
+  min = sched_get_priority_min(policy);
+  max = sched_get_priority_max(policy);
+#endif
+
+  if (min == -1 || max == -1)
+    return UV__ERR(errno);
+
+  range = max - min;
+
+  switch (priority) {
+    case UV_THREAD_PRIORITY_HIGHEST:
+      prio = max;
+      break;
+    case UV_THREAD_PRIORITY_ABOVE_NORMAL:
+      prio = min + range * 3 / 4;
+      break;
+    case UV_THREAD_PRIORITY_NORMAL:
+      prio = min + range / 2;
+      break;
+    case UV_THREAD_PRIORITY_BELOW_NORMAL:
+      prio = min + range / 4;
+      break;
+    case UV_THREAD_PRIORITY_LOWEST:
+      prio = min;
+      break;
+    default:
+      return 0;
+  }
+
+  if (param.sched_priority != prio) {
+    param.sched_priority = prio;
+    r = pthread_setschedparam(tid, policy, &param);
+    if (r != 0)
+      return UV__ERR(errno);
+  }
+
+  return 0;
+#else  /* !defined(__GNU__) */
+  /* Simulate success on systems where thread priority is not implemented. */
+  return 0;
+#endif  /* !defined(__GNU__) */
+}
+
+int uv_os_uname(uv_utsname_t* buffer) {
+  struct utsname buf;
+  int r;
+
+  if (buffer == NULL)
+    return UV_EINVAL;
+
+  if (uname(&buf) == -1) {
+    r = UV__ERR(errno);
+    goto error;
+  }
+
+  r = uv__strscpy(buffer->sysname, buf.sysname, sizeof(buffer->sysname));
+  if (r == UV_E2BIG)
+    goto error;
+
+#ifdef _AIX
+  r = snprintf(buffer->release,
+               sizeof(buffer->release),
+               "%s.%s",
+               buf.version,
+               buf.release);
+  if (r >= sizeof(buffer->release)) {
+    r = UV_E2BIG;
+    goto error;
+  }
+#else
+  r = uv__strscpy(buffer->release, buf.release, sizeof(buffer->release));
+  if (r == UV_E2BIG)
+    goto error;
+#endif
+
+  r = uv__strscpy(buffer->version, buf.version, sizeof(buffer->version));
+  if (r == UV_E2BIG)
+    goto error;
+
+#if defined(_AIX) || defined(__PASE__)
+  r = uv__strscpy(buffer->machine, "ppc64", sizeof(buffer->machine));
+#else
+  r = uv__strscpy(buffer->machine, buf.machine, sizeof(buffer->machine));
+#endif
+
+  if (r == UV_E2BIG)
+    goto error;
+
+  return 0;
+
+error:
+  buffer->sysname[0] = '\0';
+  buffer->release[0] = '\0';
+  buffer->version[0] = '\0';
+  buffer->machine[0] = '\0';
+  return r;
+}
+
+int uv__getsockpeername(const uv_handle_t* handle,
+                        uv__peersockfunc func,
+                        struct sockaddr* name,
+                        int* namelen) {
+  socklen_t socklen;
+  uv_os_fd_t fd;
+  int r;
+
+  r = uv_fileno(handle, &fd);
+  if (r < 0)
+    return r;
+
+  /* sizeof(socklen_t) != sizeof(int) on some systems. */
+  socklen = (socklen_t) *namelen;
+
+  if (func(fd, name, &socklen))
+    return UV__ERR(errno);
+
+  *namelen = (int) socklen;
+  return 0;
+}
+
+int uv_gettimeofday(uv_timeval64_t* tv) {
+  struct timeval time;
+
+  if (tv == NULL)
+    return UV_EINVAL;
+
+  if (gettimeofday(&time, NULL) != 0)
+    return UV__ERR(errno);
+
+  tv->tv_sec = (int64_t) time.tv_sec;
+  tv->tv_usec = (int32_t) time.tv_usec;
+  return 0;
+}
+
+void uv_sleep(unsigned int msec) {
+  struct timespec timeout;
+  int rc;
+
+  timeout.tv_sec = msec / 1000;
+  timeout.tv_nsec = (msec % 1000) * 1000 * 1000;
+
+  do
+    rc = nanosleep(&timeout, &timeout);
+  while (rc == -1 && errno == EINTR);
+
+  assert(rc == 0);
+}
+
+int uv__search_path(const char* prog, char* buf, size_t* buflen) {
+  char abspath[UV__PATH_MAX];
+  size_t abspath_size;
+  char trypath[UV__PATH_MAX];
+  char* cloned_path;
+  char* path_env;
+  char* token;
+  char* itr;
+
+  if (buf == NULL || buflen == NULL || *buflen == 0)
+    return UV_EINVAL;
+
+  /*
+   * Possibilities for prog:
+   * i) an absolute path such as: /home/user/myprojects/nodejs/node
+   * ii) a relative path such as: ./node or ../myprojects/nodejs/node
+   * iii) a bare filename such as "node", after exporting PATH variable
+   *     to its location.
+   */
+
+  /* Case i) and ii) absolute or relative paths */
+  if (strchr(prog, '/') != NULL) {
+    if (realpath(prog, abspath) != abspath)
+      return UV__ERR(errno);
+
+    abspath_size = strlen(abspath);
+
+    *buflen -= 1;
+    if (*buflen > abspath_size)
+      *buflen = abspath_size;
+
+    memcpy(buf, abspath, *buflen);
+    buf[*buflen] = '\0';
+
+    return 0;
+  }
+
+  /* Case iii). Search PATH environment variable */
+  cloned_path = NULL;
+  token = NULL;
+  path_env = getenv("PATH");
+
+  if (path_env == NULL)
+    return UV_EINVAL;
+
+  cloned_path = uv__strdup(path_env);
+  if (cloned_path == NULL)
+    return UV_ENOMEM;
+
+  token = uv__strtok(cloned_path, ":", &itr);
+  while (token != NULL) {
+    snprintf(trypath, sizeof(trypath) - 1, "%s/%s", token, prog);
+    if (realpath(trypath, abspath) == abspath) {
+      /* Check the match is executable */
+      if (access(abspath, X_OK) == 0) {
+        abspath_size = strlen(abspath);
+
+        *buflen -= 1;
+        if (*buflen > abspath_size)
+          *buflen = abspath_size;
+
+        memcpy(buf, abspath, *buflen);
+        buf[*buflen] = '\0';
+
+        uv__free(cloned_path);
+        return 0;
+      }
+    }
+    token = uv__strtok(NULL, ":", &itr);
+  }
+  uv__free(cloned_path);
+
+  /* Out of tokens (path entries), and no match found */
+  return UV_EINVAL;
+}
+
+#if defined(__linux__) || defined (__FreeBSD__)
+# define uv__cpu_count(cpuset) CPU_COUNT(cpuset)
+#elif defined(__NetBSD__)
+static int uv__cpu_count(cpuset_t* set) {
+  int rc;
+  cpuid_t i;
+
+  rc = 0;
+  for (i = 0;; i++) {
+    int r = cpuset_isset(i, set);
+    if (r < 0)
+      break;
+    if (r)
+      rc++;
+  }
+
+  return rc;
+}
+#endif /* __NetBSD__ */
+
+unsigned int uv_available_parallelism(void) {
+  long rc = -1;
+
+#ifdef __linux__
+  cpu_set_t set;
+
+  memset(&set, 0, sizeof(set));
+
+  /* sysconf(_SC_NPROCESSORS_ONLN) in musl calls sched_getaffinity() but in
+   * glibc it's... complicated... so for consistency try sched_getaffinity()
+   * before falling back to sysconf(_SC_NPROCESSORS_ONLN).
+   */
+  if (0 == sched_getaffinity(0, sizeof(set), &set))
+    rc = uv__cpu_count(&set);
+#elif defined(__MVS__)
+  rc = __get_num_online_cpus();
+  if (rc < 1)
+    rc = 1;
+
+  return (unsigned) rc;
+#elif defined(__FreeBSD__)
+  cpuset_t set;
+
+  memset(&set, 0, sizeof(set));
+
+  if (0 == cpuset_getaffinity(CPU_LEVEL_WHICH, CPU_WHICH_PID, -1, sizeof(set), &set))
+    rc = uv__cpu_count(&set);
+#elif defined(__NetBSD__)
+  cpuset_t* set = cpuset_create();
+  if (set != NULL) {
+    if (0 == sched_getaffinity_np(getpid(), sizeof(set), &set))
+      rc = uv__cpu_count(&set);
+    cpuset_destroy(set);
+  }
+#elif defined(__APPLE__)
+  int nprocs;
+  size_t i;
+  size_t len = sizeof(nprocs);
+  static const char *mib[] = {
+    "hw.activecpu",
+    "hw.logicalcpu",
+    "hw.ncpu"
+  };
+
+  for (i = 0; i < ARRAY_SIZE(mib); i++) {
+    if (0 == sysctlbyname(mib[i], &nprocs, &len, NULL, 0) &&
+	      len == sizeof(nprocs) &&
+	      nprocs > 0) {
+      rc = nprocs;
+      break;
+    }
+  }
+#elif defined(__OpenBSD__)
+  int nprocs;
+  size_t i;
+  size_t len = sizeof(nprocs);
+  static int mib[][2] = {
+# ifdef HW_NCPUONLINE
+    { CTL_HW, HW_NCPUONLINE },
+# endif
+    { CTL_HW, HW_NCPU }
+  };
+
+  for (i = 0; i < ARRAY_SIZE(mib); i++) {
+    if (0 == sysctl(mib[i], ARRAY_SIZE(mib[i]), &nprocs, &len, NULL, 0) &&
+	len == sizeof(nprocs) &&
+        nprocs > 0) {
+      rc = nprocs;
+      break;
+    }
+  }
+#endif /* __linux__ */
+
+  if (rc < 0)
+    rc = sysconf(_SC_NPROCESSORS_ONLN);
+
+#ifdef __linux__
+  {
+    long long quota = 0;
+
+    if (uv__get_constrained_cpu(&quota) == 0)
+      if (quota > 0 && quota < rc)
+        rc = quota;
+  }
+#endif  /* __linux__ */
+
+  if (rc < 1)
+    rc = 1;
+
+  return (unsigned) rc;
+}
+
+int uv__sock_reuseport(int fd) {
+  int on = 1;
+#if defined(__FreeBSD__) && __FreeBSD__ >= 12 && defined(SO_REUSEPORT_LB)
+  /* FreeBSD 12 introduced a new socket option named SO_REUSEPORT_LB
+   * with the capability of load balancing, it's the substitution of
+   * the SO_REUSEPORTs on Linux and DragonFlyBSD. */
+  if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT_LB, &on, sizeof(on)))
+    return UV__ERR(errno);
+#elif (defined(__linux__) || \
+      defined(_AIX73) || \
+      (defined(__DragonFly__) && __DragonFly_version >= 300600) || \
+      (defined(UV__SOLARIS_11_4) && UV__SOLARIS_11_4)) && \
+      defined(SO_REUSEPORT)
+  /* On Linux 3.9+, the SO_REUSEPORT implementation distributes connections
+   * evenly across all of the threads (or processes) that are blocked in
+   * accept() on the same port. As with TCP, SO_REUSEPORT distributes datagrams
+   * evenly across all of the receiving threads (or process).
+   *
+   * DragonFlyBSD 3.6.0 extended SO_REUSEPORT to distribute workload to
+   * available sockets, which made it the equivalent of Linux's SO_REUSEPORT.
+   *
+   * AIX 7.2.5 added the feature that would add the capability to distribute
+   * incoming connections or datagrams across all listening ports for SO_REUSEPORT.
+   *
+   * Solaris 11 supported SO_REUSEPORT, but it's implemented only for
+   * binding to the same address and port, without load balancing.
+   * Solaris 11.4 extended SO_REUSEPORT with the capability of load balancing.
+   */
+  if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &on, sizeof(on)))
+    return UV__ERR(errno);
+#else
+  (void) (fd);
+  (void) (on);
+  /* SO_REUSEPORTs do not have the capability of load balancing on platforms
+   * other than those mentioned above. The semantics are completely different,
+   * therefore we shouldn't enable it, but fail this operation to indicate that
+   * UV_[TCP/UDP]_REUSEPORT is not supported on these platforms. */
+  return UV_ENOTSUP;
+#endif
+
+  return 0;
+}