Merge branch 'upstream-libuv' into update-libuv

* upstream-libuv:
  libuv 2021-11-09 (0f696da5)

58 files changed, 2005 insertions, 1256 deletions

diff --git a/Utilities/cmlibuv/include/uv.h b/Utilities/cmlibuv/include/uv.h
index 11891df8e2..48213e2077 100644
--- a/Utilities/cmlibuv/include/uv.h
+++ b/Utilities/cmlibuv/include/uv.h
@@ -130,6 +130,7 @@ extern "C" {
   XX(ENOTEMPTY, "directory not empty")                                        \
   XX(ENOTSOCK, "socket operation on non-socket")                              \
   XX(ENOTSUP, "operation not supported on socket")                            \
+  XX(EOVERFLOW, "value too large for defined data type")                      \
   XX(EPERM, "operation not permitted")                                        \
   XX(EPIPE, "broken pipe")                                                    \
   XX(EPROTO, "protocol error")                                                \
@@ -152,6 +153,7 @@ extern "C" {
   XX(ENOTTY, "inappropriate ioctl for device")                                \
   XX(EFTYPE, "inappropriate file type or format")                             \
   XX(EILSEQ, "illegal byte sequence")                                         \
+  XX(ESOCKTNOSUPPORT, "socket type not supported")                            \
 
 #define UV_HANDLE_TYPE_MAP(XX)                                                \
   XX(ASYNC, async)                                                            \
@@ -479,6 +481,12 @@ UV_EXTERN int uv_fileno(const uv_handle_t* handle, uv_os_fd_t* fd);
 
 UV_EXTERN uv_buf_t uv_buf_init(char* base, unsigned int len);
 
+UV_EXTERN int uv_pipe(uv_file fds[2], int read_flags, int write_flags);
+UV_EXTERN int uv_socketpair(int type,
+                            int protocol,
+                            uv_os_sock_t socket_vector[2],
+                            int flags0,
+                            int flags1);
 
 #define UV_STREAM_FIELDS                                                      \
   /* number of bytes queued for writing */                                    \
@@ -524,6 +532,10 @@ UV_EXTERN int uv_write2(uv_write_t* req,
 UV_EXTERN int uv_try_write(uv_stream_t* handle,
                            const uv_buf_t bufs[],
                            unsigned int nbufs);
+UV_EXTERN int uv_try_write2(uv_stream_t* handle,
+                            const uv_buf_t bufs[],
+                            unsigned int nbufs,
+                            uv_stream_t* send_handle);
 
 /* uv_write_t is a subclass of uv_req_t. */
 struct uv_write_s {
@@ -624,7 +636,14 @@ enum uv_udp_flags {
    * in uv_udp_recv_cb, nread will always be 0 and addr will always be NULL.
    */
   UV_UDP_MMSG_FREE = 16,
-
+  /*
+   * Indicates if IP_RECVERR/IPV6_RECVERR will be set when binding the handle.
+   * This sets IP_RECVERR for IPv4 and IPV6_RECVERR for IPv6 UDP sockets on
+   * Linux. This stops the Linux kernel from suppressing some ICMP error
+   * messages and enables full ICMP error reporting for faster failover.
+   * This flag is no-op on platforms other than Linux.
+   */
+  UV_UDP_LINUX_RECVERR = 32,
   /*
    * Indicates that recvmmsg should be used, if available.
    */
@@ -937,10 +956,13 @@ typedef enum {
   UV_WRITABLE_PIPE  = 0x20,
 
   /*
-   * Open the child pipe handle in overlapped mode on Windows.
-   * On Unix it is silently ignored.
+   * When UV_CREATE_PIPE is specified, specifying UV_NONBLOCK_PIPE opens the
+   * handle in non-blocking mode in the child. This may cause loss of data,
+   * if the child is not designed to handle to encounter this mode,
+   * but can also be significantly more efficient.
    */
-  UV_OVERLAPPED_PIPE = 0x40
+  UV_NONBLOCK_PIPE  = 0x40,
+  UV_OVERLAPPED_PIPE = 0x40 /* old name, for compatibility */
 } uv_stdio_flags;
 
 typedef struct uv_stdio_container_s {
diff --git a/Utilities/cmlibuv/include/uv/errno.h b/Utilities/cmlibuv/include/uv/errno.h
index 8d4d7686d2..71906b3f5e 100644
--- a/Utilities/cmlibuv/include/uv/errno.h
+++ b/Utilities/cmlibuv/include/uv/errno.h
@@ -317,7 +317,7 @@
 #if defined(EPROTO) && !defined(_WIN32)
 # define UV__EPROTO UV__ERR(EPROTO)
 #else
-# define UV__EPROTO UV__ERR(-4046)
+# define UV__EPROTO (-4046)
 #endif
 
 #if defined(EPROTONOSUPPORT) && !defined(_WIN32)
@@ -445,4 +445,16 @@
 # define UV__EILSEQ (-4027)
 #endif
 
+#if defined(EOVERFLOW) && !defined(_WIN32)
+# define UV__EOVERFLOW UV__ERR(EOVERFLOW)
+#else
+# define UV__EOVERFLOW (-4026)
+#endif
+
+#if defined(ESOCKTNOSUPPORT) && !defined(_WIN32)
+# define UV__ESOCKTNOSUPPORT UV__ERR(ESOCKTNOSUPPORT)
+#else
+# define UV__ESOCKTNOSUPPORT (-4025)
+#endif
+
 #endif /* UV_ERRNO_H_ */
diff --git a/Utilities/cmlibuv/include/uv/tree.h b/Utilities/cmlibuv/include/uv/tree.h
index f936416e3d..2b28835fde 100644
--- a/Utilities/cmlibuv/include/uv/tree.h
+++ b/Utilities/cmlibuv/include/uv/tree.h
@@ -251,7 +251,7 @@ void name##_SPLAY_MINMAX(struct name *head, int __comp)                       \
   SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;            \
   __left = __right = &__node;                                                 \
                                                                               \
-  while (1) {                                                                 \
+  for (;;) {                                                                  \
     if (__comp < 0) {                                                         \
       __tmp = SPLAY_LEFT((head)->sph_root, field);                            \
       if (__tmp == NULL)                                                      \
diff --git a/Utilities/cmlibuv/include/uv/unix.h b/Utilities/cmlibuv/include/uv/unix.h
index a59192fa41..7a5a3cb54b 100644
--- a/Utilities/cmlibuv/include/uv/unix.h
+++ b/Utilities/cmlibuv/include/uv/unix.h
@@ -72,12 +72,10 @@
 # include "bsd.h"
 #elif defined(__CYGWIN__) || \
       defined(__MSYS__)   || \
+      defined(__HAIKU__)  || \
+      defined(__QNX__)    || \
       defined(__GNU__)
 # include "posix.h"
-#elif defined(__HAIKU__)
-# include "posix.h"
-#elif defined(__QNX__)
-# include "posix.h"
 #endif
 
 #ifndef NI_MAXHOST
diff --git a/Utilities/cmlibuv/include/uv/version.h b/Utilities/cmlibuv/include/uv/version.h
index 96c1c130f2..ab5ed00954 100644
--- a/Utilities/cmlibuv/include/uv/version.h
+++ b/Utilities/cmlibuv/include/uv/version.h
@@ -31,7 +31,7 @@
  */
 
 #define UV_VERSION_MAJOR 1
-#define UV_VERSION_MINOR 39
+#define UV_VERSION_MINOR 42
 #define UV_VERSION_PATCH 1
 #define UV_VERSION_IS_RELEASE 0
 #define UV_VERSION_SUFFIX "dev"
diff --git a/Utilities/cmlibuv/include/uv/win.h b/Utilities/cmlibuv/include/uv/win.h
index f86357b4ed..9b5d5dc63a 100644
--- a/Utilities/cmlibuv/include/uv/win.h
+++ b/Utilities/cmlibuv/include/uv/win.h
@@ -45,7 +45,14 @@ typedef struct pollfd {
 #endif
 
 #include <mswsock.h>
+// Disable the typedef in mstcpip.h of MinGW.
+#define _TCP_INITIAL_RTO_PARAMETERS _TCP_INITIAL_RTO_PARAMETERS__AVOID
+#define TCP_INITIAL_RTO_PARAMETERS TCP_INITIAL_RTO_PARAMETERS__AVOID
+#define PTCP_INITIAL_RTO_PARAMETERS PTCP_INITIAL_RTO_PARAMETERS__AVOID
 #include <ws2tcpip.h>
+#undef _TCP_INITIAL_RTO_PARAMETERS
+#undef TCP_INITIAL_RTO_PARAMETERS
+#undef PTCP_INITIAL_RTO_PARAMETERS
 #include <windows.h>
 
 #include <process.h>
diff --git a/Utilities/cmlibuv/src/idna.c b/Utilities/cmlibuv/src/idna.c
index 13ffac6be8..b44cb16a1e 100644
--- a/Utilities/cmlibuv/src/idna.c
+++ b/Utilities/cmlibuv/src/idna.c
@@ -19,6 +19,7 @@
 
 #include "uv.h"
 #include "idna.h"
+#include <assert.h>
 #include <string.h>
 
 static unsigned uv__utf8_decode1_slow(const char** p,
@@ -32,7 +33,7 @@ static unsigned uv__utf8_decode1_slow(const char** p,
   if (a > 0xF7)
     return -1;
 
-  switch (*p - pe) {
+  switch (pe - *p) {
   default:
     if (a > 0xEF) {
       min = 0x10000;
@@ -62,6 +63,8 @@ static unsigned uv__utf8_decode1_slow(const char** p,
       a = 0;
       break;
     }
+    /* Fall through. */
+  case 0:
     return -1;  /* Invalid continuation byte. */
   }
 
@@ -88,6 +91,8 @@ static unsigned uv__utf8_decode1_slow(const char** p,
 unsigned uv__utf8_decode1(const char** p, const char* pe) {
   unsigned a;
 
+  assert(*p < pe);
+
   a = (unsigned char) *(*p)++;
 
   if (a < 128)
@@ -96,9 +101,6 @@ unsigned uv__utf8_decode1(const char** p, const char* pe) {
   return uv__utf8_decode1_slow(p, pe, a);
 }
 
-#define foreach_codepoint(c, p, pe) \
-  for (; (void) (*p <= pe && (c = uv__utf8_decode1(p, pe))), *p <= pe;)
-
 static int uv__idna_toascii_label(const char* s, const char* se,
                                   char** d, char* de) {
   static const char alphabet[] = "abcdefghijklmnopqrstuvwxyz0123456789";
@@ -121,15 +123,22 @@ static int uv__idna_toascii_label(const char* s, const char* se,
   ss = s;
   todo = 0;
 
-  foreach_codepoint(c, &s, se) {
+  /* Note: after this loop we've visited all UTF-8 characters and know
+   * they're legal so we no longer need to check for decode errors.
+   */
+  while (s < se) {
+    c = uv__utf8_decode1(&s, se);
+
+    if (c == -1u)
+      return UV_EINVAL;
+
     if (c < 128)
       h++;
-    else if (c == (unsigned) -1)
-      return UV_EINVAL;
     else
       todo++;
   }
 
+  /* Only write "xn--" when there are non-ASCII characters. */
   if (todo > 0) {
     if (*d < de) *(*d)++ = 'x';
     if (*d < de) *(*d)++ = 'n';
@@ -137,9 +146,13 @@ static int uv__idna_toascii_label(const char* s, const char* se,
     if (*d < de) *(*d)++ = '-';
   }
 
+  /* Write ASCII characters. */
   x = 0;
   s = ss;
-  foreach_codepoint(c, &s, se) {
+  while (s < se) {
+    c = uv__utf8_decode1(&s, se);
+    assert(c != -1u);
+
     if (c > 127)
       continue;
 
@@ -166,10 +179,15 @@ static int uv__idna_toascii_label(const char* s, const char* se,
   while (todo > 0) {
     m = -1;
     s = ss;
-    foreach_codepoint(c, &s, se)
+
+    while (s < se) {
+      c = uv__utf8_decode1(&s, se);
+      assert(c != -1u);
+
       if (c >= n)
         if (c < m)
           m = c;
+    }
 
     x = m - n;
     y = h + 1;
@@ -181,7 +199,10 @@ static int uv__idna_toascii_label(const char* s, const char* se,
     n = m;
 
     s = ss;
-    foreach_codepoint(c, &s, se) {
+    while (s < se) {
+      c = uv__utf8_decode1(&s, se);
+      assert(c != -1u);
+
       if (c < n)
         if (++delta == 0)
           return UV_E2BIG;  /* Overflow. */
@@ -245,8 +266,6 @@ static int uv__idna_toascii_label(const char* s, const char* se,
   return 0;
 }
 
-#undef foreach_codepoint
-
 long uv__idna_toascii(const char* s, const char* se, char* d, char* de) {
   const char* si;
   const char* st;
@@ -256,10 +275,14 @@ long uv__idna_toascii(const char* s, const char* se, char* d, char* de) {
 
   ds = d;
 
-  for (si = s; si < se; /* empty */) {
+  si = s;
+  while (si < se) {
     st = si;
     c = uv__utf8_decode1(&si, se);
 
+    if (c == -1u)
+      return UV_EINVAL;
+
     if (c != '.')
       if (c != 0x3002)  /* 。 */
         if (c != 0xFF0E)  /* ． */
diff --git a/Utilities/cmlibuv/src/inet.c b/Utilities/cmlibuv/src/inet.c
index 58238dcbb6..384c0f7261 100644
--- a/Utilities/cmlibuv/src/inet.c
+++ b/Utilities/cmlibuv/src/inet.c
@@ -141,8 +141,9 @@ static int inet_ntop6(const unsigned char *src, char *dst, size_t size) {
   if (best.base != -1 && (best.base + best.len) == ARRAY_SIZE(words))
     *tp++ = ':';
   *tp++ = '\0';
-  if (UV_E2BIG == uv__strscpy(dst, tmp, size))
+  if ((size_t) (tp - tmp) > size)
     return UV_ENOSPC;
+  uv__strscpy(dst, tmp, size);
   return 0;
 }
 
diff --git a/Utilities/cmlibuv/src/threadpool.c b/Utilities/cmlibuv/src/threadpool.c
index 0998938f3e..869ae95f58 100644
--- a/Utilities/cmlibuv/src/threadpool.c
+++ b/Utilities/cmlibuv/src/threadpool.c
@@ -161,7 +161,6 @@ static void post(QUEUE* q, enum uv__work_kind kind) {
 
 
 void uv__threadpool_cleanup(void) {
-#ifndef _WIN32
   unsigned int i;
 
   if (nthreads == 0)
@@ -181,7 +180,6 @@ void uv__threadpool_cleanup(void) {
 
   threads = NULL;
   nthreads = 0;
-#endif
 }
 
 
diff --git a/Utilities/cmlibuv/src/timer.c b/Utilities/cmlibuv/src/timer.c
index 1bea2a8bd2..bc680e71a9 100644
--- a/Utilities/cmlibuv/src/timer.c
+++ b/Utilities/cmlibuv/src/timer.c
@@ -58,6 +58,7 @@ static int timer_less_than(const struct heap_node* ha,
 int uv_timer_init(uv_loop_t* loop, uv_timer_t* handle) {
   uv__handle_init(loop, (uv_handle_t*)handle, UV_TIMER);
   handle->timer_cb = NULL;
+  handle->timeout = 0;
   handle->repeat = 0;
   return 0;
 }
diff --git a/Utilities/cmlibuv/src/unix/async.c b/Utilities/cmlibuv/src/unix/async.c
index 5f58fb88d6..e1805c3237 100644
--- a/Utilities/cmlibuv/src/unix/async.c
+++ b/Utilities/cmlibuv/src/unix/async.c
@@ -214,7 +214,7 @@ static int uv__async_start(uv_loop_t* loop) {
   pipefd[0] = err;
   pipefd[1] = -1;
 #else
-  err = uv__make_pipe(pipefd, UV__F_NONBLOCK);
+  err = uv__make_pipe(pipefd, UV_NONBLOCK_PIPE);
   if (err < 0)
     return err;
 #endif
diff --git a/Utilities/cmlibuv/src/unix/atomic-ops.h b/Utilities/cmlibuv/src/unix/atomic-ops.h
index 2518a0680f..63d8268ab5 100644
--- a/Utilities/cmlibuv/src/unix/atomic-ops.h
+++ b/Utilities/cmlibuv/src/unix/atomic-ops.h
@@ -58,9 +58,11 @@ UV_UNUSED(static int cmpxchgi(int* ptr, int oldval, int newval)) {
 
 UV_UNUSED(static void cpu_relax(void)) {
 #if defined(__i386__) || defined(__x86_64__)
-  __asm__ __volatile__ ("rep; nop");  /* a.k.a. PAUSE */
+  __asm__ __volatile__ ("rep; nop" ::: "memory");  /* a.k.a. PAUSE */
 #elif (defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__)
-  __asm__ volatile("yield");
+  __asm__ __volatile__ ("yield" ::: "memory");
+#elif defined(__powerpc64__) || defined(__ppc64__) || defined(__PPC64__)
+  __asm__ __volatile__ ("or 1,1,1; or 2,2,2" ::: "memory");
 #endif
 }
 
diff --git a/Utilities/cmlibuv/src/unix/bsd-ifaddrs.c b/Utilities/cmlibuv/src/unix/bsd-ifaddrs.c
index 5223ab4879..e48934bce2 100644
--- a/Utilities/cmlibuv/src/unix/bsd-ifaddrs.c
+++ b/Utilities/cmlibuv/src/unix/bsd-ifaddrs.c
@@ -42,8 +42,8 @@ static int uv__ifaddr_exclude(struct ifaddrs *ent, int exclude_type) {
     return 1;
 #if !defined(__CYGWIN__) && !defined(__MSYS__)
   /*
-   * If `exclude_type` is `UV__EXCLUDE_IFPHYS`, just see whether `sa_family`
-   * equals to `AF_LINK` or not. Otherwise, the result depends on the operation
+   * If `exclude_type` is `UV__EXCLUDE_IFPHYS`, return whether `sa_family`
+   * equals `AF_LINK`. Otherwise, the result depends on the operating
    * system with `AF_LINK` or `PF_INET`.
    */
   if (exclude_type == UV__EXCLUDE_IFPHYS)
@@ -53,7 +53,7 @@ static int uv__ifaddr_exclude(struct ifaddrs *ent, int exclude_type) {
     defined(__HAIKU__)
   /*
    * On BSD getifaddrs returns information related to the raw underlying
-   * devices.  We're not interested in this information.
+   * devices. We're not interested in this information.
    */
   if (ent->ifa_addr->sa_family == AF_LINK)
     return 1;
diff --git a/Utilities/cmlibuv/src/unix/bsd-proctitle.c b/Utilities/cmlibuv/src/unix/bsd-proctitle.c
index 723b81c01c..4f4e9e5183 100644
--- a/Utilities/cmlibuv/src/unix/bsd-proctitle.c
+++ b/Utilities/cmlibuv/src/unix/bsd-proctitle.c
@@ -38,9 +38,7 @@ static void init_process_title_mutex_once(void) {
 
 
 void uv__process_title_cleanup(void) {
-  /* TODO(bnoordhuis) uv_mutex_destroy(&process_title_mutex)
-   * and reset process_title_mutex_once?
-   */
+  uv_mutex_destroy(&process_title_mutex);
 }
 
 
diff --git a/Utilities/cmlibuv/src/unix/core.c b/Utilities/cmlibuv/src/unix/core.c
index 4245e027a6..225f775825 100644
--- a/Utilities/cmlibuv/src/unix/core.c
+++ b/Utilities/cmlibuv/src/unix/core.c
@@ -94,6 +94,10 @@ extern char** environ;
 # define uv__accept4 accept4
 #endif
 
+#if defined(__linux__) && defined(__SANITIZE_THREAD__) && defined(__clang__)
+# include <sanitizer/linux_syscall_hooks.h>
+#endif
+
 static int uv__run_pending(uv_loop_t* loop);
 
 /* Verify that uv_buf_t is ABI-compatible with struct iovec. */
@@ -545,7 +549,13 @@ int uv__close_nocancel(int fd) {
   return close$NOCANCEL$UNIX2003(fd);
 #endif
 #pragma GCC diagnostic pop
-#elif defined(__linux__)
+#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);
@@ -580,7 +590,7 @@ int uv__close(int fd) {
   return uv__close_nocheckstdio(fd);
 }
 
-
+#if UV__NONBLOCK_IS_IOCTL
 int uv__nonblock_ioctl(int fd, int set) {
   int r;
 
@@ -595,7 +605,6 @@ int uv__nonblock_ioctl(int fd, int set) {
 }
 
 
-#if !defined(__hpux) && !defined(__CYGWIN__) && !defined(__MSYS__) && !defined(__HAIKU__)
 int uv__cloexec_ioctl(int fd, int set) {
   int r;
 
@@ -931,13 +940,12 @@ void uv__io_stop(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
   if (w->pevents == 0) {
     QUEUE_REMOVE(&w->watcher_queue);
     QUEUE_INIT(&w->watcher_queue);
+    w->events = 0;
 
-    if (loop->watchers[w->fd] != NULL) {
-      assert(loop->watchers[w->fd] == w);
+    if (w == loop->watchers[w->fd]) {
       assert(loop->nfds > 0);
       loop->watchers[w->fd] = NULL;
       loop->nfds--;
-      w->events = 0;
     }
   }
   else if (QUEUE_EMPTY(&w->watcher_queue))
@@ -1181,7 +1189,9 @@ int uv__getpwuid_r(uv_passwd_t* pwd) {
     if (buf == NULL)
       return UV_ENOMEM;
 
-    r = getpwuid_r(uid, &pw, buf, bufsize, &result);
+    do
+      r = getpwuid_r(uid, &pw, buf, bufsize, &result);
+    while (r == EINTR);
 
     if (r != ERANGE)
       break;
@@ -1191,7 +1201,7 @@ int uv__getpwuid_r(uv_passwd_t* pwd) {
 
   if (r != 0) {
     uv__free(buf);
-    return -r;
+    return UV__ERR(r);
   }
 
   if (result == NULL) {
@@ -1586,7 +1596,7 @@ int uv__search_path(const char* prog, char* buf, size_t* buflen) {
     buf[*buflen] = '\0';
 
     return 0;
-  } 
+  }
 
   /* Case iii). Search PATH environment variable */
   cloned_path = NULL;
diff --git a/Utilities/cmlibuv/src/unix/darwin.c b/Utilities/cmlibuv/src/unix/darwin.c
index d0ecd452d8..a7be0dd2f3 100644
--- a/Utilities/cmlibuv/src/unix/darwin.c
+++ b/Utilities/cmlibuv/src/unix/darwin.c
@@ -33,9 +33,7 @@
 #include <sys/sysctl.h>
 #include <unistd.h>  /* sysconf */
 
-#if !TARGET_OS_IPHONE
 #include "darwin-stub.h"
-#endif
 
 static uv_once_t once = UV_ONCE_INIT;
 static uint64_t (*time_func)(void);
@@ -223,10 +221,10 @@ static int uv__get_cpu_speed(uint64_t* speed) {
   err = UV_ENOENT;
   core_foundation_handle = dlopen("/System/Library/Frameworks/"
                                   "CoreFoundation.framework/"
-                                  "Versions/A/CoreFoundation",
+                                  "CoreFoundation",
                                   RTLD_LAZY | RTLD_LOCAL);
   iokit_handle = dlopen("/System/Library/Frameworks/IOKit.framework/"
-                        "Versions/A/IOKit",
+                        "IOKit",
                         RTLD_LAZY | RTLD_LOCAL);
 
   if (core_foundation_handle == NULL || iokit_handle == NULL)
@@ -304,6 +302,12 @@ static int uv__get_cpu_speed(uint64_t* speed) {
   pIOObjectRelease(it);
 
   err = 0;
+
+  if (device_type_str != NULL)
+    pCFRelease(device_type_str);
+  if (clock_frequency_str != NULL)
+    pCFRelease(clock_frequency_str);
+
 out:
   if (core_foundation_handle != NULL)
     dlclose(core_foundation_handle);
diff --git a/Utilities/cmlibuv/src/unix/epoll.c b/Utilities/cmlibuv/src/unix/epoll.c
new file mode 100644
index 0000000000..97348e254b
--- /dev/null
+++ b/Utilities/cmlibuv/src/unix/epoll.c
@@ -0,0 +1,422 @@
+/* Copyright libuv 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 <errno.h>
+#include <sys/epoll.h>
+
+int uv__epoll_init(uv_loop_t* loop) {
+  int fd;
+  fd = epoll_create1(O_CLOEXEC);
+
+  /* epoll_create1() can fail either because it's not implemented (old kernel)
+   * or because it doesn't understand the O_CLOEXEC flag.
+   */
+  if (fd == -1 && (errno == ENOSYS || errno == EINVAL)) {
+    fd = epoll_create(256);
+
+    if (fd != -1)
+      uv__cloexec(fd, 1);
+  }
+
+  loop->backend_fd = fd;
+  if (fd == -1)
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+
+void uv__platform_invalidate_fd(uv_loop_t* loop, int fd) {
+  struct epoll_event* events;
+  struct epoll_event dummy;
+  uintptr_t i;
+  uintptr_t nfds;
+
+  assert(loop->watchers != NULL);
+  assert(fd >= 0);
+
+  events = (struct epoll_event*) loop->watchers[loop->nwatchers];
+  nfds = (uintptr_t) loop->watchers[loop->nwatchers + 1];
+  if (events != NULL)
+    /* Invalidate events with same file descriptor */
+    for (i = 0; i < nfds; i++)
+      if (events[i].data.fd == fd)
+        events[i].data.fd = -1;
+
+  /* Remove the file descriptor from the epoll.
+   * This avoids a problem where the same file description remains open
+   * in another process, causing repeated junk epoll events.
+   *
+   * We pass in a dummy epoll_event, to work around a bug in old kernels.
+   */
+  if (loop->backend_fd >= 0) {
+    /* Work around a bug in kernels 3.10 to 3.19 where passing a struct that
+     * has the EPOLLWAKEUP flag set generates spurious audit syslog warnings.
+     */
+    memset(&dummy, 0, sizeof(dummy));
+    epoll_ctl(loop->backend_fd, EPOLL_CTL_DEL, fd, &dummy);
+  }
+}
+
+
+int uv__io_check_fd(uv_loop_t* loop, int fd) {
+  struct epoll_event e;
+  int rc;
+
+  memset(&e, 0, sizeof(e));
+  e.events = POLLIN;
+  e.data.fd = -1;
+
+  rc = 0;
+  if (epoll_ctl(loop->backend_fd, EPOLL_CTL_ADD, fd, &e))
+    if (errno != EEXIST)
+      rc = UV__ERR(errno);
+
+  if (rc == 0)
+    if (epoll_ctl(loop->backend_fd, EPOLL_CTL_DEL, fd, &e))
+      abort();
+
+  return rc;
+}
+
+
+void uv__io_poll(uv_loop_t* loop, int timeout) {
+  /* A bug in kernels < 2.6.37 makes timeouts larger than ~30 minutes
+   * effectively infinite on 32 bits architectures.  To avoid blocking
+   * indefinitely, we cap the timeout and poll again if necessary.
+   *
+   * Note that "30 minutes" is a simplification because it depends on
+   * the value of CONFIG_HZ.  The magic constant assumes CONFIG_HZ=1200,
+   * that being the largest value I have seen in the wild (and only once.)
+   */
+  static const int max_safe_timeout = 1789569;
+  static int no_epoll_pwait_cached;
+  static int no_epoll_wait_cached;
+  int no_epoll_pwait;
+  int no_epoll_wait;
+  struct epoll_event events[1024];
+  struct epoll_event* pe;
+  struct epoll_event e;
+  int real_timeout;
+  QUEUE* q;
+  uv__io_t* w;
+  sigset_t sigset;
+  uint64_t sigmask;
+  uint64_t base;
+  int have_signals;
+  int nevents;
+  int count;
+  int nfds;
+  int fd;
+  int op;
+  int i;
+  int user_timeout;
+  int reset_timeout;
+
+  if (loop->nfds == 0) {
+    assert(QUEUE_EMPTY(&loop->watcher_queue));
+    return;
+  }
+
+  memset(&e, 0, sizeof(e));
+
+  while (!QUEUE_EMPTY(&loop->watcher_queue)) {
+    q = QUEUE_HEAD(&loop->watcher_queue);
+    QUEUE_REMOVE(q);
+    QUEUE_INIT(q);
+
+    w = QUEUE_DATA(q, uv__io_t, watcher_queue);
+    assert(w->pevents != 0);
+    assert(w->fd >= 0);
+    assert(w->fd < (int) loop->nwatchers);
+
+    e.events = w->pevents;
+    e.data.fd = w->fd;
+
+    if (w->events == 0)
+      op = EPOLL_CTL_ADD;
+    else
+      op = EPOLL_CTL_MOD;
+
+    /* XXX Future optimization: do EPOLL_CTL_MOD lazily if we stop watching
+     * events, skip the syscall and squelch the events after epoll_wait().
+     */
+    if (epoll_ctl(loop->backend_fd, op, w->fd, &e)) {
+      if (errno != EEXIST)
+        abort();
+
+      assert(op == EPOLL_CTL_ADD);
+
+      /* We've reactivated a file descriptor that's been watched before. */
+      if (epoll_ctl(loop->backend_fd, EPOLL_CTL_MOD, w->fd, &e))
+        abort();
+    }
+
+    w->events = w->pevents;
+  }
+
+  sigmask = 0;
+  if (loop->flags & UV_LOOP_BLOCK_SIGPROF) {
+    sigemptyset(&sigset);
+    sigaddset(&sigset, SIGPROF);
+    sigmask |= 1 << (SIGPROF - 1);
+  }
+
+  assert(timeout >= -1);
+  base = loop->time;
+  count = 48; /* Benchmarks suggest this gives the best throughput. */
+  real_timeout = timeout;
+
+  if (uv__get_internal_fields(loop)->flags & UV_METRICS_IDLE_TIME) {
+    reset_timeout = 1;
+    user_timeout = timeout;
+    timeout = 0;
+  } else {
+    reset_timeout = 0;
+    user_timeout = 0;
+  }
+
+  /* You could argue there is a dependency between these two but
+   * ultimately we don't care about their ordering with respect
+   * to one another. Worst case, we make a few system calls that
+   * could have been avoided because another thread already knows
+   * they fail with ENOSYS. Hardly the end of the world.
+   */
+  no_epoll_pwait = uv__load_relaxed(&no_epoll_pwait_cached);
+  no_epoll_wait = uv__load_relaxed(&no_epoll_wait_cached);
+
+  for (;;) {
+    /* Only need to set the provider_entry_time if timeout != 0. The function
+     * will return early if the loop isn't configured with UV_METRICS_IDLE_TIME.
+     */
+    if (timeout != 0)
+      uv__metrics_set_provider_entry_time(loop);
+
+    /* See the comment for max_safe_timeout for an explanation of why
+     * this is necessary.  Executive summary: kernel bug workaround.
+     */
+    if (sizeof(int32_t) == sizeof(long) && timeout >= max_safe_timeout)
+      timeout = max_safe_timeout;
+
+    if (sigmask != 0 && no_epoll_pwait != 0)
+      if (pthread_sigmask(SIG_BLOCK, &sigset, NULL))
+        abort();
+
+    if (no_epoll_wait != 0 || (sigmask != 0 && no_epoll_pwait == 0)) {
+      nfds = epoll_pwait(loop->backend_fd,
+                         events,
+                         ARRAY_SIZE(events),
+                         timeout,
+                         &sigset);
+      if (nfds == -1 && errno == ENOSYS) {
+        uv__store_relaxed(&no_epoll_pwait_cached, 1);
+        no_epoll_pwait = 1;
+      }
+    } else {
+      nfds = epoll_wait(loop->backend_fd,
+                        events,
+                        ARRAY_SIZE(events),
+                        timeout);
+      if (nfds == -1 && errno == ENOSYS) {
+        uv__store_relaxed(&no_epoll_wait_cached, 1);
+        no_epoll_wait = 1;
+      }
+    }
+
+    if (sigmask != 0 && no_epoll_pwait != 0)
+      if (pthread_sigmask(SIG_UNBLOCK, &sigset, NULL))
+        abort();
+
+    /* Update loop->time unconditionally. It's tempting to skip the update when
+     * timeout == 0 (i.e. non-blocking poll) but there is no guarantee that the
+     * operating system didn't reschedule our process while in the syscall.
+     */
+    SAVE_ERRNO(uv__update_time(loop));
+
+    if (nfds == 0) {
+      assert(timeout != -1);
+
+      if (reset_timeout != 0) {
+        timeout = user_timeout;
+        reset_timeout = 0;
+      }
+
+      if (timeout == -1)
+        continue;
+
+      if (timeout == 0)
+        return;
+
+      /* We may have been inside the system call for longer than |timeout|
+       * milliseconds so we need to update the timestamp to avoid drift.
+       */
+      goto update_timeout;
+    }
+
+    if (nfds == -1) {
+      if (errno == ENOSYS) {
+        /* epoll_wait() or epoll_pwait() failed, try the other system call. */
+        assert(no_epoll_wait == 0 || no_epoll_pwait == 0);
+        continue;
+      }
+
+      if (errno != EINTR)
+        abort();
+
+      if (reset_timeout != 0) {
+        timeout = user_timeout;
+        reset_timeout = 0;
+      }
+
+      if (timeout == -1)
+        continue;
+
+      if (timeout == 0)
+        return;
+
+      /* Interrupted by a signal. Update timeout and poll again. */
+      goto update_timeout;
+    }
+
+    have_signals = 0;
+    nevents = 0;
+
+    {
+      /* Squelch a -Waddress-of-packed-member warning with gcc >= 9. */
+      union {
+        struct epoll_event* events;
+        uv__io_t* watchers;
+      } x;
+
+      x.events = events;
+      assert(loop->watchers != NULL);
+      loop->watchers[loop->nwatchers] = x.watchers;
+      loop->watchers[loop->nwatchers + 1] = (void*) (uintptr_t) nfds;
+    }
+
+    for (i = 0; i < nfds; i++) {
+      pe = events + i;
+      fd = pe->data.fd;
+
+      /* Skip invalidated events, see uv__platform_invalidate_fd */
+      if (fd == -1)
+        continue;
+
+      assert(fd >= 0);
+      assert((unsigned) fd < loop->nwatchers);
+
+      w = loop->watchers[fd];
+
+      if (w == NULL) {
+        /* File descriptor that we've stopped watching, disarm it.
+         *
+         * Ignore all errors because we may be racing with another thread
+         * when the file descriptor is closed.
+         */
+        epoll_ctl(loop->backend_fd, EPOLL_CTL_DEL, fd, pe);
+        continue;
+      }
+
+      /* Give users only events they're interested in. Prevents spurious
+       * callbacks when previous callback invocation in this loop has stopped
+       * the current watcher. Also, filters out events that users has not
+       * requested us to watch.
+       */
+      pe->events &= w->pevents | POLLERR | POLLHUP;
+
+      /* Work around an epoll quirk where it sometimes reports just the
+       * EPOLLERR or EPOLLHUP event.  In order to force the event loop to
+       * move forward, we merge in the read/write events that the watcher
+       * is interested in; uv__read() and uv__write() will then deal with
+       * the error or hangup in the usual fashion.
+       *
+       * Note to self: happens when epoll reports EPOLLIN|EPOLLHUP, the user
+       * reads the available data, calls uv_read_stop(), then sometime later
+       * calls uv_read_start() again.  By then, libuv has forgotten about the
+       * hangup and the kernel won't report EPOLLIN again because there's
+       * nothing left to read.  If anything, libuv is to blame here.  The
+       * current hack is just a quick bandaid; to properly fix it, libuv
+       * needs to remember the error/hangup event.  We should get that for
+       * free when we switch over to edge-triggered I/O.
+       */
+      if (pe->events == POLLERR || pe->events == POLLHUP)
+        pe->events |=
+          w->pevents & (POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
+
+      if (pe->events != 0) {
+        /* Run signal watchers last.  This also affects child process watchers
+         * because those are implemented in terms of signal watchers.
+         */
+        if (w == &loop->signal_io_watcher) {
+          have_signals = 1;
+        } else {
+          uv__metrics_update_idle_time(loop);
+          w->cb(loop, w, pe->events);
+        }
+
+        nevents++;
+      }
+    }
+
+    if (reset_timeout != 0) {
+      timeout = user_timeout;
+      reset_timeout = 0;
+    }
+
+    if (have_signals != 0) {
+      uv__metrics_update_idle_time(loop);
+      loop->signal_io_watcher.cb(loop, &loop->signal_io_watcher, POLLIN);
+    }
+
+    loop->watchers[loop->nwatchers] = NULL;
+    loop->watchers[loop->nwatchers + 1] = NULL;
+
+    if (have_signals != 0)
+      return;  /* Event loop should cycle now so don't poll again. */
+
+    if (nevents != 0) {
+      if (nfds == ARRAY_SIZE(events) && --count != 0) {
+        /* Poll for more events but don't block this time. */
+        timeout = 0;
+        continue;
+      }
+      return;
+    }
+
+    if (timeout == 0)
+      return;
+
+    if (timeout == -1)
+      continue;
+
+update_timeout:
+    assert(timeout > 0);
+
+    real_timeout -= (loop->time - base);
+    if (real_timeout <= 0)
+      return;
+
+    timeout = real_timeout;
+  }
+}
+
diff --git a/Utilities/cmlibuv/src/unix/freebsd.c b/Utilities/cmlibuv/src/unix/freebsd.c
index fe795a0e75..170b897e20 100644
--- a/Utilities/cmlibuv/src/unix/freebsd.c
+++ b/Utilities/cmlibuv/src/unix/freebsd.c
@@ -265,8 +265,11 @@ int uv_cpu_info(uv_cpu_info_t** cpu_infos, int* count) {
 
 
 int uv__sendmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen) {
-#if __FreeBSD__ >= 11
-  return sendmmsg(fd, mmsg, vlen, /* flags */ 0);
+#if __FreeBSD__ >= 11 && !defined(__DragonFly__)
+  return sendmmsg(fd,
+                  (struct mmsghdr*) mmsg,
+                  vlen,
+                  0 /* flags */);
 #else
   return errno = ENOSYS, -1;
 #endif
@@ -274,8 +277,12 @@ int uv__sendmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen) {
 
 
 int uv__recvmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen) {
-#if __FreeBSD__ >= 11
-  return recvmmsg(fd, mmsg, vlen, 0 /* flags */, NULL /* timeout */);
+#if __FreeBSD__ >= 11 && !defined(__DragonFly__)
+  return recvmmsg(fd,
+                  (struct mmsghdr*) mmsg,
+                  vlen,
+                  0 /* flags */,
+                  NULL /* timeout */);
 #else
   return errno = ENOSYS, -1;
 #endif
diff --git a/Utilities/cmlibuv/src/unix/fs.c b/Utilities/cmlibuv/src/unix/fs.c
index 6d57cee904..6b41f88ec5 100644
--- a/Utilities/cmlibuv/src/unix/fs.c
+++ b/Utilities/cmlibuv/src/unix/fs.c
@@ -56,8 +56,13 @@
 # define HAVE_PREADV 0
 #endif
 
+#if defined(__linux__)
+# include "sys/utsname.h"
+#endif
+
 #if defined(__linux__) || defined(__sun)
 # include <sys/sendfile.h>
+# include <sys/sysmacros.h>
 #endif
 
 #if defined(__APPLE__)
@@ -212,14 +217,30 @@ static ssize_t uv__fs_fdatasync(uv_fs_t* req) {
 UV_UNUSED(static struct timespec uv__fs_to_timespec(double time)) {
   struct timespec ts;
   ts.tv_sec  = time;
-  ts.tv_nsec = (uint64_t)(time * 1000000) % 1000000 * 1000;
+  ts.tv_nsec = (time - ts.tv_sec) * 1e9;
+
+ /* TODO(bnoordhuis) Remove this. utimesat() has nanosecond resolution but we
+  * stick to microsecond resolution for the sake of consistency with other
+  * platforms. I'm the original author of this compatibility hack but I'm
+  * less convinced it's useful nowadays.
+  */
+  ts.tv_nsec -= ts.tv_nsec % 1000;
+
+  if (ts.tv_nsec < 0) {
+    ts.tv_nsec += 1e9;
+    ts.tv_sec -= 1;
+  }
   return ts;
 }
 
 UV_UNUSED(static struct timeval uv__fs_to_timeval(double time)) {
   struct timeval tv;
   tv.tv_sec  = time;
-  tv.tv_usec = (uint64_t)(time * 1000000) % 1000000;
+  tv.tv_usec = (time - tv.tv_sec) * 1e6;
+  if (tv.tv_usec < 0) {
+    tv.tv_usec += 1e6;
+    tv.tv_sec -= 1;
+  }
   return tv;
 }
 
@@ -227,9 +248,6 @@ static ssize_t uv__fs_futime(uv_fs_t* req) {
 #if defined(__linux__)                                                        \
     || defined(_AIX71)                                                        \
     || defined(__HAIKU__)
-  /* utimesat() has nanosecond resolution but we stick to microseconds
-   * for the sake of consistency with other platforms.
-   */
   struct timespec ts[2];
   ts[0] = uv__fs_to_timespec(req->atime);
   ts[1] = uv__fs_to_timespec(req->mtime);
@@ -897,6 +915,115 @@ out:
 }
 
 
+#ifdef __linux__
+static unsigned uv__kernel_version(void) {
+  static unsigned cached_version;
+  struct utsname u;
+  unsigned version;
+  unsigned major;
+  unsigned minor;
+  unsigned patch;
+
+  version = uv__load_relaxed(&cached_version);
+  if (version != 0)
+    return version;
+
+  if (-1 == uname(&u))
+    return 0;
+
+  if (3 != sscanf(u.release, "%u.%u.%u", &major, &minor, &patch))
+    return 0;
+
+  version = major * 65536 + minor * 256 + patch;
+  uv__store_relaxed(&cached_version, version);
+
+  return version;
+}
+
+
+/* Pre-4.20 kernels have a bug where CephFS uses the RADOS copy-from command
+ * in copy_file_range() when it shouldn't. There is no workaround except to
+ * fall back to a regular copy.
+ */
+static int uv__is_buggy_cephfs(int fd) {
+  struct statfs s;
+
+  if (-1 == fstatfs(fd, &s))
+    return 0;
+
+  if (s.f_type != /* CephFS */ 0xC36400)
+    return 0;
+
+  return uv__kernel_version() < /* 4.20.0 */ 0x041400;
+}
+
+
+static int uv__is_cifs_or_smb(int fd) {
+  struct statfs s;
+
+  if (-1 == fstatfs(fd, &s))
+    return 0;
+
+  switch ((unsigned) s.f_type) {
+  case 0x0000517Bu:  /* SMB */
+  case 0xFE534D42u:  /* SMB2 */
+  case 0xFF534D42u:  /* CIFS */
+    return 1;
+  }
+
+  return 0;
+}
+
+
+static ssize_t uv__fs_try_copy_file_range(int in_fd, off_t* off,
+                                          int out_fd, size_t len) {
+  static int no_copy_file_range_support;
+  ssize_t r;
+
+  if (uv__load_relaxed(&no_copy_file_range_support)) {
+    errno = ENOSYS;
+    return -1;
+  }
+
+  r = uv__fs_copy_file_range(in_fd, off, out_fd, NULL, len, 0);
+
+  if (r != -1)
+    return r;
+
+  switch (errno) {
+  case EACCES:
+    /* Pre-4.20 kernels have a bug where CephFS uses the RADOS
+     * copy-from command when it shouldn't.
+     */
+    if (uv__is_buggy_cephfs(in_fd))
+      errno = ENOSYS;  /* Use fallback. */
+    break;
+  case ENOSYS:
+    uv__store_relaxed(&no_copy_file_range_support, 1);
+    break;
+  case EPERM:
+    /* It's been reported that CIFS spuriously fails.
+     * Consider it a transient error.
+     */
+    if (uv__is_cifs_or_smb(out_fd))
+      errno = ENOSYS;  /* Use fallback. */
+    break;
+  case ENOTSUP:
+  case EXDEV:
+    /* ENOTSUP - it could work on another file system type.
+     * EXDEV - it will not work when in_fd and out_fd are not on the same
+     *         mounted filesystem (pre Linux 5.3)
+     */
+    errno = ENOSYS;  /* Use fallback. */
+    break;
+  }
+
+  return -1;
+}
+
+#endif  /* __linux__ */
+
+
 static ssize_t uv__fs_sendfile(uv_fs_t* req) {
   int in_fd;
   int out_fd;
@@ -908,29 +1035,21 @@ static ssize_t uv__fs_sendfile(uv_fs_t* req) {
   {
     off_t off;
     ssize_t r;
+    size_t len;
+    int try_sendfile;
 
     off = req->off;
+    len = req->bufsml[0].len;
+    try_sendfile = 1;
 
 #ifdef __linux__
-    {
-      static int copy_file_range_support = 1;
-
-      if (copy_file_range_support) {
-        r = uv__fs_copy_file_range(in_fd, NULL, out_fd, &off, req->bufsml[0].len, 0);
-
-        if (r == -1 && errno == ENOSYS) {
-          errno = 0;
-          copy_file_range_support = 0;
-        } else {
-          goto ok;
-        }
-      }
-    }
+    r = uv__fs_try_copy_file_range(in_fd, &off, out_fd, len);
+    try_sendfile = (r == -1 && errno == ENOSYS);
 #endif
 
-    r = sendfile(out_fd, in_fd, &off, req->bufsml[0].len);
+    if (try_sendfile)
+      r = sendfile(out_fd, in_fd, &off, len);
 
-ok:
     /* sendfile() on SunOS returns EINVAL if the target fd is not a socket but
      * it still writes out data. Fortunately, we can detect it by checking if
      * the offset has been updated.
@@ -1020,9 +1139,6 @@ static ssize_t uv__fs_utime(uv_fs_t* req) {
     || defined(_AIX71)                                                         \
     || defined(__sun)                                                          \
     || defined(__HAIKU__)
-  /* utimesat() has nanosecond resolution but we stick to microseconds
-   * for the sake of consistency with other platforms.
-   */
   struct timespec ts[2];
   ts[0] = uv__fs_to_timespec(req->atime);
   ts[1] = uv__fs_to_timespec(req->mtime);
@@ -1217,22 +1333,15 @@ static ssize_t uv__fs_copyfile(uv_fs_t* req) {
   if (fchmod(dstfd, src_statsbuf.st_mode) == -1) {
     err = UV__ERR(errno);
 #ifdef __linux__
+    /* fchmod() on CIFS shares always fails with EPERM unless the share is
+     * mounted with "noperm". As fchmod() is a meaningless operation on such
+     * shares anyway, detect that condition and squelch the error.
+     */
     if (err != UV_EPERM)
       goto out;
 
-    {
-      struct statfs s;
-
-      /* fchmod() on CIFS shares always fails with EPERM unless the share is
-       * mounted with "noperm". As fchmod() is a meaningless operation on such
-       * shares anyway, detect that condition and squelch the error.
-       */
-      if (fstatfs(dstfd, &s) == -1)
-        goto out;
-
-      if (s.f_type != /* CIFS */ 0xFF534D42u)
-        goto out;
-    }
+    if (!uv__is_cifs_or_smb(dstfd))
+      goto out;
 
     err = 0;
 #else  /* !__linux__ */
@@ -1350,7 +1459,8 @@ static void uv__to_stat(struct stat* src, uv_stat_t* dst) {
   dst->st_birthtim.tv_nsec = src->st_ctimensec;
   dst->st_flags = 0;
   dst->st_gen = 0;
-#elif !defined(_AIX) && (       \
+#elif !defined(_AIX) &&         \
+    !defined(__MVS__) && (      \
     defined(__DragonFly__)   || \
     defined(__FreeBSD__)     || \
     defined(__OpenBSD__)     || \
@@ -1430,8 +1540,9 @@ static int uv__fs_statx(int fd,
   case -1:
     /* EPERM happens when a seccomp filter rejects the system call.
      * Has been observed with libseccomp < 2.3.3 and docker < 18.04.
+     * EOPNOTSUPP is used on DVS exported filesystems
      */
-    if (errno != EINVAL && errno != EPERM && errno != ENOSYS)
+    if (errno != EINVAL && errno != EPERM && errno != ENOSYS && errno != EOPNOTSUPP)
       return -1;
     /* Fall through. */
   default:
@@ -1444,12 +1555,12 @@ static int uv__fs_statx(int fd,
     return UV_ENOSYS;
   }
 
-  buf->st_dev = 256 * statxbuf.stx_dev_major + statxbuf.stx_dev_minor;
+  buf->st_dev = makedev(statxbuf.stx_dev_major, statxbuf.stx_dev_minor);
   buf->st_mode = statxbuf.stx_mode;
   buf->st_nlink = statxbuf.stx_nlink;
   buf->st_uid = statxbuf.stx_uid;
   buf->st_gid = statxbuf.stx_gid;
-  buf->st_rdev = statxbuf.stx_rdev_major;
+  buf->st_rdev = makedev(statxbuf.stx_rdev_major, statxbuf.stx_rdev_minor);
   buf->st_ino = statxbuf.stx_ino;
   buf->st_size = statxbuf.stx_size;
   buf->st_blksize = statxbuf.stx_blksize;
diff --git a/Utilities/cmlibuv/src/unix/fsevents.c b/Utilities/cmlibuv/src/unix/fsevents.c
index a51f29b3f6..bf4f1f6a51 100644
--- a/Utilities/cmlibuv/src/unix/fsevents.c
+++ b/Utilities/cmlibuv/src/unix/fsevents.c
@@ -595,8 +595,7 @@ out:
 static int uv__fsevents_loop_init(uv_loop_t* loop) {
   CFRunLoopSourceContext ctx;
   uv__cf_loop_state_t* state;
-  pthread_attr_t attr_storage;
-  pthread_attr_t* attr;
+  pthread_attr_t attr;
   int err;
 
   if (loop->cf_state != NULL)
@@ -641,25 +640,19 @@ static int uv__fsevents_loop_init(uv_loop_t* loop) {
     goto fail_signal_source_create;
   }
 
-  /* In the unlikely event that pthread_attr_init() fails, create the thread
-   * with the default stack size. We'll use a little more address space but
-   * that in itself is not a fatal error.
-   */
-  attr = &attr_storage;
-  if (pthread_attr_init(attr))
-    attr = NULL;
+  if (pthread_attr_init(&attr))
+    abort();
 
-  if (attr != NULL)
-    if (pthread_attr_setstacksize(attr, 4 * PTHREAD_STACK_MIN))
-      abort();
+  if (pthread_attr_setstacksize(&attr, uv__thread_stack_size()))
+    abort();
 
   loop->cf_state = state;
 
   /* uv_thread_t is an alias for pthread_t. */
-  err = UV__ERR(pthread_create(&loop->cf_thread, attr, uv__cf_loop_runner, loop));
+  err = UV__ERR(pthread_create(&loop->cf_thread, &attr, uv__cf_loop_runner, loop));
 
-  if (attr != NULL)
-    pthread_attr_destroy(attr);
+  if (pthread_attr_destroy(&attr))
+    abort();
 
   if (err)
     goto fail_thread_create;
diff --git a/Utilities/cmlibuv/src/unix/getaddrinfo.c b/Utilities/cmlibuv/src/unix/getaddrinfo.c
index d7ca7d1a44..77337ace94 100644
--- a/Utilities/cmlibuv/src/unix/getaddrinfo.c
+++ b/Utilities/cmlibuv/src/unix/getaddrinfo.c
@@ -21,9 +21,6 @@
 /* Expose glibc-specific EAI_* error codes. Needs to be defined before we
  * include any headers.
  */
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE
-#endif
 
 #include "uv.h"
 #include "internal.h"
diff --git a/Utilities/cmlibuv/src/unix/ibmi.c b/Utilities/cmlibuv/src/unix/ibmi.c
index 73ab02a7ac..580ea1f3a8 100644
--- a/Utilities/cmlibuv/src/unix/ibmi.c
+++ b/Utilities/cmlibuv/src/unix/ibmi.c
@@ -26,7 +26,6 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
-#include <assert.h>
 #include <errno.h>
 
 #include <sys/types.h>
@@ -166,7 +165,7 @@ static void iconv_a2e(const char* src, unsigned char dst[], size_t length) {
 
   srclen = strlen(src);
   if (srclen > length)
-    abort();
+    srclen = length;
   for (i = 0; i < srclen; i++)
     dst[i] = a2e[src[i]];
   /* padding the remaining part with spaces */
@@ -360,6 +359,10 @@ static int get_ibmi_physical_address(const char* line, char (*phys_addr)[6]) {
   if (rc != 0)
     return rc;
 
+  if (err.bytes_available > 0) {
+    return -1;
+  }
+
   /* convert ebcdic loca_adapter_address to ascii first */
   iconv_e2a(rcvr.loca_adapter_address, mac_addr,
             sizeof(rcvr.loca_adapter_address));
@@ -443,9 +446,42 @@ int uv_interface_addresses(uv_interface_address_t** addresses, int* count) {
     }
     address->is_internal = cur->ifa_flags & IFF_LOOPBACK ? 1 : 0;
     if (!address->is_internal) {
-      int rc = get_ibmi_physical_address(address->name, &address->phys_addr);
-      if (rc != 0)
-        r = rc;
+      int rc = -1;
+      size_t name_len = strlen(address->name);
+      /* To get the associated MAC address, we must convert the address to a
+       * line description. Normally, the name field contains the line
+       * description name, but for VLANs it has the VLAN appended with a
+       * period. Since object names can also contain periods and numbers, there
+       * is no way to know if a returned name is for a VLAN or not. eg.
+       * *LIND ETH1.1 and *LIND ETH1, VLAN 1 both have the same name: ETH1.1
+       *
+       * Instead, we apply the same heuristic used by some of the XPF ioctls:
+       * - names > 10 *must* contain a VLAN
+       * - assume names <= 10 do not contain a VLAN and try directly
+       * - if >10 or QDCRLIND returned an error, try to strip off a VLAN
+       *   and try again
+       * - if we still get an error or couldn't find a period, leave the MAC as
+       *   00:00:00:00:00:00
+       */
+      if (name_len <= 10) {
+        /* Assume name does not contain a VLAN ID */
+        rc = get_ibmi_physical_address(address->name, &address->phys_addr);
+      }
+
+      if (name_len > 10 || rc != 0) {
+        /* The interface name must contain a VLAN ID suffix. Attempt to strip
+         * it off so we can get the line description to pass to QDCRLIND.
+         */
+        char* temp_name = uv__strdup(address->name);
+        char* dot = strrchr(temp_name, '.');
+        if (dot != NULL) {
+          *dot = '\0';
+          if (strlen(temp_name) <= 10) {
+            rc = get_ibmi_physical_address(temp_name, &address->phys_addr);
+          }
+        }
+        uv__free(temp_name);
+      }
     }
 
     address++;
@@ -499,3 +535,4 @@ int uv_get_process_title(char* buffer, size_t size) {
 
 void uv__process_title_cleanup(void) {
 }
+
diff --git a/Utilities/cmlibuv/src/unix/internal.h b/Utilities/cmlibuv/src/unix/internal.h
index 444dc85c59..586ae390d3 100644
--- a/Utilities/cmlibuv/src/unix/internal.h
+++ b/Utilities/cmlibuv/src/unix/internal.h
@@ -62,6 +62,17 @@
 # include <AvailabilityMacros.h>
 #endif
 
+/*
+ * Define common detection for active Thread Sanitizer
+ * - clang uses __has_feature(thread_sanitizer)
+ * - gcc-7+ uses __SANITIZE_THREAD__
+ */
+#if defined(__has_feature)
+# if __has_feature(thread_sanitizer)
+#  define __SANITIZE_THREAD__ 1
+# endif
+#endif
+
 #if defined(PATH_MAX)
 # define UV__PATH_MAX PATH_MAX
 #else
@@ -175,9 +186,11 @@ struct uv__stream_queued_fds_s {
     defined(__NetBSD__)
 #define uv__cloexec uv__cloexec_ioctl
 #define uv__nonblock uv__nonblock_ioctl
+#define UV__NONBLOCK_IS_IOCTL 1
 #else
 #define uv__cloexec uv__cloexec_fcntl
 #define uv__nonblock uv__nonblock_fcntl
+#define UV__NONBLOCK_IS_IOCTL 0
 #endif
 
 /* On Linux, uv__nonblock_fcntl() and uv__nonblock_ioctl() do not commute
@@ -256,6 +269,7 @@ int uv__signal_loop_fork(uv_loop_t* loop);
 /* platform specific */
 uint64_t uv__hrtime(uv_clocktype_t type);
 int uv__kqueue_init(uv_loop_t* loop);
+int uv__epoll_init(uv_loop_t* loop);
 int uv__platform_loop_init(uv_loop_t* loop);
 void uv__platform_loop_delete(uv_loop_t* loop);
 void uv__platform_invalidate_fd(uv_loop_t* loop, int fd);
@@ -271,6 +285,7 @@ void uv__prepare_close(uv_prepare_t* handle);
 void uv__process_close(uv_process_t* handle);
 void uv__stream_close(uv_stream_t* handle);
 void uv__tcp_close(uv_tcp_t* handle);
+size_t uv__thread_stack_size(void);
 void uv__udp_close(uv_udp_t* handle);
 void uv__udp_finish_close(uv_udp_t* handle);
 uv_handle_type uv__handle_type(int fd);
@@ -292,12 +307,6 @@ int uv___stream_fd(const uv_stream_t* handle);
 #define uv__stream_fd(handle) ((handle)->io_watcher.fd)
 #endif /* defined(__APPLE__) */
 
-#ifdef O_NONBLOCK
-# define UV__F_NONBLOCK O_NONBLOCK
-#else
-# define UV__F_NONBLOCK 1
-#endif
-
 int uv__make_pipe(int fds[2], int flags);
 
 #if defined(__APPLE__)
@@ -337,7 +346,8 @@ int uv__getsockpeername(const uv_handle_t* handle,
 
 #if defined(__linux__)            ||                                      \
     defined(__FreeBSD__)          ||                                      \
-    defined(__FreeBSD_kernel__)
+    defined(__FreeBSD_kernel__)   ||                                       \
+    defined(__DragonFly__)
 #define HAVE_MMSG 1
 struct uv__mmsghdr {
   struct msghdr msg_hdr;
@@ -350,5 +360,11 @@ int uv__sendmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen);
 #define HAVE_MMSG 0
 #endif
 
+#if defined(__sun)
+#if !defined(_POSIX_VERSION) || _POSIX_VERSION < 200809L
+size_t strnlen(const char* s, size_t maxlen);
+#endif
+#endif
+
 
 #endif /* UV_UNIX_INTERNAL_H_ */
diff --git a/Utilities/cmlibuv/src/unix/linux-core.c b/Utilities/cmlibuv/src/unix/linux-core.c
index 4db2f05053..8c9bbb75f7 100644
--- a/Utilities/cmlibuv/src/unix/linux-core.c
+++ b/Utilities/cmlibuv/src/unix/linux-core.c
@@ -82,29 +82,12 @@ static int read_times(FILE* statfile_fp,
 static void read_speeds(unsigned int numcpus, uv_cpu_info_t* ci);
 static uint64_t read_cpufreq(unsigned int cpunum);
 
-
 int uv__platform_loop_init(uv_loop_t* loop) {
-  int fd;
-  fd = epoll_create1(O_CLOEXEC);
-
-  /* epoll_create1() can fail either because it's not implemented (old kernel)
-   * or because it doesn't understand the O_CLOEXEC flag.
-   */
-  if (fd == -1 && (errno == ENOSYS || errno == EINVAL)) {
-    fd = epoll_create(256);
-
-    if (fd != -1)
-      uv__cloexec(fd, 1);
-  }
-
-  loop->backend_fd = fd;
+  
   loop->inotify_fd = -1;
   loop->inotify_watchers = NULL;
 
-  if (fd == -1)
-    return UV__ERR(errno);
-
-  return 0;
+  return uv__epoll_init(loop);
 }
 
 
@@ -134,380 +117,6 @@ void uv__platform_loop_delete(uv_loop_t* loop) {
 }
 
 
-void uv__platform_invalidate_fd(uv_loop_t* loop, int fd) {
-  struct epoll_event* events;
-  struct epoll_event dummy;
-  uintptr_t i;
-  uintptr_t nfds;
-
-  assert(loop->watchers != NULL);
-  assert(fd >= 0);
-
-  events = (struct epoll_event*) loop->watchers[loop->nwatchers];
-  nfds = (uintptr_t) loop->watchers[loop->nwatchers + 1];
-  if (events != NULL)
-    /* Invalidate events with same file descriptor */
-    for (i = 0; i < nfds; i++)
-      if (events[i].data.fd == fd)
-        events[i].data.fd = -1;
-
-  /* Remove the file descriptor from the epoll.
-   * This avoids a problem where the same file description remains open
-   * in another process, causing repeated junk epoll events.
-   *
-   * We pass in a dummy epoll_event, to work around a bug in old kernels.
-   */
-  if (loop->backend_fd >= 0) {
-    /* Work around a bug in kernels 3.10 to 3.19 where passing a struct that
-     * has the EPOLLWAKEUP flag set generates spurious audit syslog warnings.
-     */
-    memset(&dummy, 0, sizeof(dummy));
-    epoll_ctl(loop->backend_fd, EPOLL_CTL_DEL, fd, &dummy);
-  }
-}
-
-
-int uv__io_check_fd(uv_loop_t* loop, int fd) {
-  struct epoll_event e;
-  int rc;
-
-  memset(&e, 0, sizeof(e));
-  e.events = POLLIN;
-  e.data.fd = -1;
-
-  rc = 0;
-  if (epoll_ctl(loop->backend_fd, EPOLL_CTL_ADD, fd, &e))
-    if (errno != EEXIST)
-      rc = UV__ERR(errno);
-
-  if (rc == 0)
-    if (epoll_ctl(loop->backend_fd, EPOLL_CTL_DEL, fd, &e))
-      abort();
-
-  return rc;
-}
-
-
-void uv__io_poll(uv_loop_t* loop, int timeout) {
-  /* A bug in kernels < 2.6.37 makes timeouts larger than ~30 minutes
-   * effectively infinite on 32 bits architectures.  To avoid blocking
-   * indefinitely, we cap the timeout and poll again if necessary.
-   *
-   * Note that "30 minutes" is a simplification because it depends on
-   * the value of CONFIG_HZ.  The magic constant assumes CONFIG_HZ=1200,
-   * that being the largest value I have seen in the wild (and only once.)
-   */
-  static const int max_safe_timeout = 1789569;
-  static int no_epoll_pwait_cached;
-  static int no_epoll_wait_cached;
-  int no_epoll_pwait;
-  int no_epoll_wait;
-  struct epoll_event events[1024];
-  struct epoll_event* pe;
-  struct epoll_event e;
-  int real_timeout;
-  QUEUE* q;
-  uv__io_t* w;
-  sigset_t sigset;
-  uint64_t sigmask;
-  uint64_t base;
-  int have_signals;
-  int nevents;
-  int count;
-  int nfds;
-  int fd;
-  int op;
-  int i;
-  int user_timeout;
-  int reset_timeout;
-
-  if (loop->nfds == 0) {
-    assert(QUEUE_EMPTY(&loop->watcher_queue));
-    return;
-  }
-
-  memset(&e, 0, sizeof(e));
-
-  while (!QUEUE_EMPTY(&loop->watcher_queue)) {
-    q = QUEUE_HEAD(&loop->watcher_queue);
-    QUEUE_REMOVE(q);
-    QUEUE_INIT(q);
-
-    w = QUEUE_DATA(q, uv__io_t, watcher_queue);
-    assert(w->pevents != 0);
-    assert(w->fd >= 0);
-    assert(w->fd < (int) loop->nwatchers);
-
-    e.events = w->pevents;
-    e.data.fd = w->fd;
-
-    if (w->events == 0)
-      op = EPOLL_CTL_ADD;
-    else
-      op = EPOLL_CTL_MOD;
-
-    /* XXX Future optimization: do EPOLL_CTL_MOD lazily if we stop watching
-     * events, skip the syscall and squelch the events after epoll_wait().
-     */
-    if (epoll_ctl(loop->backend_fd, op, w->fd, &e)) {
-      if (errno != EEXIST)
-        abort();
-
-      assert(op == EPOLL_CTL_ADD);
-
-      /* We've reactivated a file descriptor that's been watched before. */
-      if (epoll_ctl(loop->backend_fd, EPOLL_CTL_MOD, w->fd, &e))
-        abort();
-    }
-
-    w->events = w->pevents;
-  }
-
-  sigmask = 0;
-  if (loop->flags & UV_LOOP_BLOCK_SIGPROF) {
-    sigemptyset(&sigset);
-    sigaddset(&sigset, SIGPROF);
-    sigmask |= 1 << (SIGPROF - 1);
-  }
-
-  assert(timeout >= -1);
-  base = loop->time;
-  count = 48; /* Benchmarks suggest this gives the best throughput. */
-  real_timeout = timeout;
-
-  if (uv__get_internal_fields(loop)->flags & UV_METRICS_IDLE_TIME) {
-    reset_timeout = 1;
-    user_timeout = timeout;
-    timeout = 0;
-  } else {
-    reset_timeout = 0;
-    user_timeout = 0;
-  }
-
-  /* You could argue there is a dependency between these two but
-   * ultimately we don't care about their ordering with respect
-   * to one another. Worst case, we make a few system calls that
-   * could have been avoided because another thread already knows
-   * they fail with ENOSYS. Hardly the end of the world.
-   */
-  no_epoll_pwait = uv__load_relaxed(&no_epoll_pwait_cached);
-  no_epoll_wait = uv__load_relaxed(&no_epoll_wait_cached);
-
-  for (;;) {
-    /* Only need to set the provider_entry_time if timeout != 0. The function
-     * will return early if the loop isn't configured with UV_METRICS_IDLE_TIME.
-     */
-    if (timeout != 0)
-      uv__metrics_set_provider_entry_time(loop);
-
-    /* See the comment for max_safe_timeout for an explanation of why
-     * this is necessary.  Executive summary: kernel bug workaround.
-     */
-    if (sizeof(int32_t) == sizeof(long) && timeout >= max_safe_timeout)
-      timeout = max_safe_timeout;
-
-    if (sigmask != 0 && no_epoll_pwait != 0)
-      if (pthread_sigmask(SIG_BLOCK, &sigset, NULL))
-        abort();
-
-    if (no_epoll_wait != 0 || (sigmask != 0 && no_epoll_pwait == 0)) {
-      nfds = epoll_pwait(loop->backend_fd,
-                         events,
-                         ARRAY_SIZE(events),
-                         timeout,
-                         &sigset);
-      if (nfds == -1 && errno == ENOSYS) {
-        uv__store_relaxed(&no_epoll_pwait_cached, 1);
-        no_epoll_pwait = 1;
-      }
-    } else {
-      nfds = epoll_wait(loop->backend_fd,
-                        events,
-                        ARRAY_SIZE(events),
-                        timeout);
-      if (nfds == -1 && errno == ENOSYS) {
-        uv__store_relaxed(&no_epoll_wait_cached, 1);
-        no_epoll_wait = 1;
-      }
-    }
-
-    if (sigmask != 0 && no_epoll_pwait != 0)
-      if (pthread_sigmask(SIG_UNBLOCK, &sigset, NULL))
-        abort();
-
-    /* Update loop->time unconditionally. It's tempting to skip the update when
-     * timeout == 0 (i.e. non-blocking poll) but there is no guarantee that the
-     * operating system didn't reschedule our process while in the syscall.
-     */
-    SAVE_ERRNO(uv__update_time(loop));
-
-    if (nfds == 0) {
-      assert(timeout != -1);
-
-      if (reset_timeout != 0) {
-        timeout = user_timeout;
-        reset_timeout = 0;
-      }
-
-      if (timeout == -1)
-        continue;
-
-      if (timeout == 0)
-        return;
-
-      /* We may have been inside the system call for longer than |timeout|
-       * milliseconds so we need to update the timestamp to avoid drift.
-       */
-      goto update_timeout;
-    }
-
-    if (nfds == -1) {
-      if (errno == ENOSYS) {
-        /* epoll_wait() or epoll_pwait() failed, try the other system call. */
-        assert(no_epoll_wait == 0 || no_epoll_pwait == 0);
-        continue;
-      }
-
-      if (errno != EINTR)
-        abort();
-
-      if (reset_timeout != 0) {
-        timeout = user_timeout;
-        reset_timeout = 0;
-      }
-
-      if (timeout == -1)
-        continue;
-
-      if (timeout == 0)
-        return;
-
-      /* Interrupted by a signal. Update timeout and poll again. */
-      goto update_timeout;
-    }
-
-    have_signals = 0;
-    nevents = 0;
-
-    {
-      /* Squelch a -Waddress-of-packed-member warning with gcc >= 9. */
-      union {
-        struct epoll_event* events;
-        uv__io_t* watchers;
-      } x;
-
-      x.events = events;
-      assert(loop->watchers != NULL);
-      loop->watchers[loop->nwatchers] = x.watchers;
-      loop->watchers[loop->nwatchers + 1] = (void*) (uintptr_t) nfds;
-    }
-
-    for (i = 0; i < nfds; i++) {
-      pe = events + i;
-      fd = pe->data.fd;
-
-      /* Skip invalidated events, see uv__platform_invalidate_fd */
-      if (fd == -1)
-        continue;
-
-      assert(fd >= 0);
-      assert((unsigned) fd < loop->nwatchers);
-
-      w = loop->watchers[fd];
-
-      if (w == NULL) {
-        /* File descriptor that we've stopped watching, disarm it.
-         *
-         * Ignore all errors because we may be racing with another thread
-         * when the file descriptor is closed.
-         */
-        epoll_ctl(loop->backend_fd, EPOLL_CTL_DEL, fd, pe);
-        continue;
-      }
-
-      /* Give users only events they're interested in. Prevents spurious
-       * callbacks when previous callback invocation in this loop has stopped
-       * the current watcher. Also, filters out events that users has not
-       * requested us to watch.
-       */
-      pe->events &= w->pevents | POLLERR | POLLHUP;
-
-      /* Work around an epoll quirk where it sometimes reports just the
-       * EPOLLERR or EPOLLHUP event.  In order to force the event loop to
-       * move forward, we merge in the read/write events that the watcher
-       * is interested in; uv__read() and uv__write() will then deal with
-       * the error or hangup in the usual fashion.
-       *
-       * Note to self: happens when epoll reports EPOLLIN|EPOLLHUP, the user
-       * reads the available data, calls uv_read_stop(), then sometime later
-       * calls uv_read_start() again.  By then, libuv has forgotten about the
-       * hangup and the kernel won't report EPOLLIN again because there's
-       * nothing left to read.  If anything, libuv is to blame here.  The
-       * current hack is just a quick bandaid; to properly fix it, libuv
-       * needs to remember the error/hangup event.  We should get that for
-       * free when we switch over to edge-triggered I/O.
-       */
-      if (pe->events == POLLERR || pe->events == POLLHUP)
-        pe->events |=
-          w->pevents & (POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
-
-      if (pe->events != 0) {
-        /* Run signal watchers last.  This also affects child process watchers
-         * because those are implemented in terms of signal watchers.
-         */
-        if (w == &loop->signal_io_watcher) {
-          have_signals = 1;
-        } else {
-          uv__metrics_update_idle_time(loop);
-          w->cb(loop, w, pe->events);
-        }
-
-        nevents++;
-      }
-    }
-
-    if (reset_timeout != 0) {
-      timeout = user_timeout;
-      reset_timeout = 0;
-    }
-
-    if (have_signals != 0) {
-      uv__metrics_update_idle_time(loop);
-      loop->signal_io_watcher.cb(loop, &loop->signal_io_watcher, POLLIN);
-    }
-
-    loop->watchers[loop->nwatchers] = NULL;
-    loop->watchers[loop->nwatchers + 1] = NULL;
-
-    if (have_signals != 0)
-      return;  /* Event loop should cycle now so don't poll again. */
-
-    if (nevents != 0) {
-      if (nfds == ARRAY_SIZE(events) && --count != 0) {
-        /* Poll for more events but don't block this time. */
-        timeout = 0;
-        continue;
-      }
-      return;
-    }
-
-    if (timeout == 0)
-      return;
-
-    if (timeout == -1)
-      continue;
-
-update_timeout:
-    assert(timeout > 0);
-
-    real_timeout -= (loop->time - base);
-    if (real_timeout <= 0)
-      return;
-
-    timeout = real_timeout;
-  }
-}
-
 
 uint64_t uv__hrtime(uv_clocktype_t type) {
   static clock_t fast_clock_id = -1;
@@ -602,22 +211,53 @@ err:
   return UV_EINVAL;
 }
 
+static 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_uptime(double* uptime) {
   static volatile int no_clock_boottime;
+  char buf[128];
   struct timespec now;
   int r;
 
+  /* Try /proc/uptime first, then fallback to clock_gettime(). */
+  
+  if (0 == uv__slurp("/proc/uptime", buf, sizeof(buf)))
+    if (1 == sscanf(buf, "%lf", uptime))
+      return 0;
+
   /* Try CLOCK_BOOTTIME first, fall back to CLOCK_MONOTONIC if not available
    * (pre-2.6.39 kernels). CLOCK_MONOTONIC doesn't increase when the system
    * is suspended.
    */
   if (no_clock_boottime) {
-    retry: r = clock_gettime(CLOCK_MONOTONIC, &now);
+    retry_clock_gettime: r = clock_gettime(CLOCK_MONOTONIC, &now);
   }
   else if ((r = clock_gettime(CLOCK_BOOTTIME, &now)) && errno == EINVAL) {
     no_clock_boottime = 1;
-    goto retry;
+    goto retry_clock_gettime;
   }
 
   if (r)
@@ -709,35 +349,47 @@ static void read_speeds(unsigned int numcpus, uv_cpu_info_t* ci) {
 }
 
 
-/* Also reads the CPU frequency on x86. The other architectures only have
- * a BogoMIPS field, which may not be very accurate.
+/* Also reads the CPU frequency on ppc and x86. The other architectures only
+ * have a BogoMIPS field, which may not be very accurate.
  *
  * Note: Simply returns on error, uv_cpu_info() takes care of the cleanup.
  */
 static int read_models(unsigned int numcpus, uv_cpu_info_t* ci) {
+#if defined(__PPC__)
+  static const char model_marker[] = "cpu\t\t: ";
+  static const char speed_marker[] = "clock\t\t: ";
+#else
   static const char model_marker[] = "model name\t: ";
   static const char speed_marker[] = "cpu MHz\t\t: ";
+#endif
   const char* inferred_model;
   unsigned int model_idx;
   unsigned int speed_idx;
+  unsigned int part_idx;
   char buf[1024];
   char* model;
   FILE* fp;
+  int model_id;
 
   /* Most are unused on non-ARM, non-MIPS and non-x86 architectures. */
   (void) &model_marker;
   (void) &speed_marker;
   (void) &speed_idx;
+  (void) &part_idx;
   (void) &model;
   (void) &buf;
   (void) &fp;
+  (void) &model_id;
 
   model_idx = 0;
   speed_idx = 0;
+  part_idx = 0;
 
 #if defined(__arm__) || \
     defined(__i386__) || \
     defined(__mips__) || \
+    defined(__aarch64__) || \
+    defined(__PPC__) || \
     defined(__x86_64__)
   fp = uv__open_file("/proc/cpuinfo");
   if (fp == NULL)
@@ -756,11 +408,96 @@ static int read_models(unsigned int numcpus, uv_cpu_info_t* ci) {
         continue;
       }
     }
-#if defined(__arm__) || defined(__mips__)
+#if defined(__arm__) || defined(__mips__) || defined(__aarch64__)
     if (model_idx < numcpus) {
 #if defined(__arm__)
       /* Fallback for pre-3.8 kernels. */
       static const char model_marker[] = "Processor\t: ";
+#elif defined(__aarch64__)
+      static const char part_marker[] = "CPU part\t: ";
+
+      /* Adapted from: https://github.com/karelzak/util-linux */
+      struct vendor_part {
+        const int id;
+        const char* name;
+      };
+
+      static const struct vendor_part arm_chips[] = {
+        { 0x811, "ARM810" },
+        { 0x920, "ARM920" },
+        { 0x922, "ARM922" },
+        { 0x926, "ARM926" },
+        { 0x940, "ARM940" },
+        { 0x946, "ARM946" },
+        { 0x966, "ARM966" },
+        { 0xa20, "ARM1020" },
+        { 0xa22, "ARM1022" },
+        { 0xa26, "ARM1026" },
+        { 0xb02, "ARM11 MPCore" },
+        { 0xb36, "ARM1136" },
+        { 0xb56, "ARM1156" },
+        { 0xb76, "ARM1176" },
+        { 0xc05, "Cortex-A5" },
+        { 0xc07, "Cortex-A7" },
+        { 0xc08, "Cortex-A8" },
+        { 0xc09, "Cortex-A9" },
+        { 0xc0d, "Cortex-A17" },  /* Originally A12 */
+        { 0xc0f, "Cortex-A15" },
+        { 0xc0e, "Cortex-A17" },
+        { 0xc14, "Cortex-R4" },
+        { 0xc15, "Cortex-R5" },
+        { 0xc17, "Cortex-R7" },
+        { 0xc18, "Cortex-R8" },
+        { 0xc20, "Cortex-M0" },
+        { 0xc21, "Cortex-M1" },
+        { 0xc23, "Cortex-M3" },
+        { 0xc24, "Cortex-M4" },
+        { 0xc27, "Cortex-M7" },
+        { 0xc60, "Cortex-M0+" },
+        { 0xd01, "Cortex-A32" },
+        { 0xd03, "Cortex-A53" },
+        { 0xd04, "Cortex-A35" },
+        { 0xd05, "Cortex-A55" },
+        { 0xd06, "Cortex-A65" },
+        { 0xd07, "Cortex-A57" },
+        { 0xd08, "Cortex-A72" },
+        { 0xd09, "Cortex-A73" },
+        { 0xd0a, "Cortex-A75" },
+        { 0xd0b, "Cortex-A76" },
+        { 0xd0c, "Neoverse-N1" },
+        { 0xd0d, "Cortex-A77" },
+        { 0xd0e, "Cortex-A76AE" },
+        { 0xd13, "Cortex-R52" },
+        { 0xd20, "Cortex-M23" },
+        { 0xd21, "Cortex-M33" },
+        { 0xd41, "Cortex-A78" },
+        { 0xd42, "Cortex-A78AE" },
+        { 0xd4a, "Neoverse-E1" },
+        { 0xd4b, "Cortex-A78C" },
+      };
+
+      if (strncmp(buf, part_marker, sizeof(part_marker) - 1) == 0) {
+        model = buf + sizeof(part_marker) - 1;
+
+        errno = 0;
+        model_id = strtol(model, NULL, 16);
+        if ((errno != 0) || model_id < 0) {
+          fclose(fp);
+          return UV_EINVAL;
+        }
+
+        for (part_idx = 0; part_idx < ARRAY_SIZE(arm_chips); part_idx++) {
+          if (model_id == arm_chips[part_idx].id) {
+            model = uv__strdup(arm_chips[part_idx].name);
+            if (model == NULL) {
+              fclose(fp);
+              return UV_ENOMEM;
+            }
+            ci[model_idx++].model = model;
+            break;
+          }
+        }
+      }
 #else	/* defined(__mips__) */
       static const char model_marker[] = "cpu model\t\t: ";
 #endif
@@ -775,18 +512,18 @@ static int read_models(unsigned int numcpus, uv_cpu_info_t* ci) {
         continue;
       }
     }
-#else  /* !__arm__ && !__mips__ */
+#else  /* !__arm__ && !__mips__ && !__aarch64__ */
     if (speed_idx < numcpus) {
       if (strncmp(buf, speed_marker, sizeof(speed_marker) - 1) == 0) {
         ci[speed_idx++].speed = atoi(buf + sizeof(speed_marker) - 1);
         continue;
       }
     }
-#endif  /* __arm__ || __mips__ */
+#endif  /* __arm__ || __mips__ || __aarch64__ */
   }
 
   fclose(fp);
-#endif  /* __arm__ || __i386__ || __mips__ || __x86_64__ */
+#endif  /* __arm__ || __i386__ || __mips__ || __PPC__ || __x86_64__ || __aarch__ */
 
   /* Now we want to make sure that all the models contain *something* because
    * it's not safe to leave them as null. Copy the last entry unless there
@@ -824,9 +561,9 @@ static int read_times(FILE* statfile_fp,
   char buf[1024];
 
   ticks = (unsigned int)sysconf(_SC_CLK_TCK);
-  multiplier = ((uint64_t)1000L / ticks);
   assert(ticks != (unsigned int) -1);
   assert(ticks != 0);
+  multiplier = ((uint64_t)1000L / ticks);
 
   rewind(statfile_fp);
 
@@ -1025,32 +762,6 @@ void uv__set_process_title(const char* title) {
 }
 
 
-static 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;
-}
-
-
 static uint64_t uv__read_proc_meminfo(const char* what) {
   uint64_t rc;
   char* p;
diff --git a/Utilities/cmlibuv/src/unix/linux-inotify.c b/Utilities/cmlibuv/src/unix/linux-inotify.c
index 42b601adbf..c1bd260e16 100644
--- a/Utilities/cmlibuv/src/unix/linux-inotify.c
+++ b/Utilities/cmlibuv/src/unix/linux-inotify.c
@@ -178,7 +178,7 @@ static void uv__inotify_read(uv_loop_t* loop,
   /* needs to be large enough for sizeof(inotify_event) + strlen(path) */
   char buf[4096];
 
-  while (1) {
+  for (;;) {
     do
       size = read(loop->inotify_fd, buf, sizeof(buf));
     while (size == -1 && errno == EINTR);
diff --git a/Utilities/cmlibuv/src/unix/linux-syscalls.c b/Utilities/cmlibuv/src/unix/linux-syscalls.c
index 44daaf12d4..5071cd56d1 100644
--- a/Utilities/cmlibuv/src/unix/linux-syscalls.c
+++ b/Utilities/cmlibuv/src/unix/linux-syscalls.c
@@ -194,37 +194,37 @@ int uv__recvmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen) {
 
 
 ssize_t uv__preadv(int fd, const struct iovec *iov, int iovcnt, int64_t offset) {
-#if defined(__NR_preadv)
-  return syscall(__NR_preadv, fd, iov, iovcnt, (long)offset, (long)(offset >> 32));
-#else
+#if !defined(__NR_preadv) || defined(__ANDROID_API__) && __ANDROID_API__ < 24
   return errno = ENOSYS, -1;
+#else
+  return syscall(__NR_preadv, fd, iov, iovcnt, (long)offset, (long)(offset >> 32));
 #endif
 }
 
 
 ssize_t uv__pwritev(int fd, const struct iovec *iov, int iovcnt, int64_t offset) {
-#if defined(__NR_pwritev)
-  return syscall(__NR_pwritev, fd, iov, iovcnt, (long)offset, (long)(offset >> 32));
-#else
+#if !defined(__NR_pwritev) || defined(__ANDROID_API__) && __ANDROID_API__ < 24
   return errno = ENOSYS, -1;
+#else
+  return syscall(__NR_pwritev, fd, iov, iovcnt, (long)offset, (long)(offset >> 32));
 #endif
 }
 
 
 int uv__dup3(int oldfd, int newfd, int flags) {
-#if defined(__NR_dup3)
-  return syscall(__NR_dup3, oldfd, newfd, flags);
-#else
+#if !defined(__NR_dup3) || defined(__ANDROID_API__) && __ANDROID_API__ < 21
   return errno = ENOSYS, -1;
+#else
+  return syscall(__NR_dup3, oldfd, newfd, flags);
 #endif
 }
 
 
 ssize_t
 uv__fs_copy_file_range(int fd_in,
-                       ssize_t* off_in,
+                       off_t* off_in,
                        int fd_out,
-                       ssize_t* off_out,
+                       off_t* off_out,
                        size_t len,
                        unsigned int flags)
 {
@@ -247,21 +247,18 @@ int uv__statx(int dirfd,
               int flags,
               unsigned int mask,
               struct uv__statx* statxbuf) {
-  /* __NR_statx make Android box killed by SIGSYS.
-   * That looks like a seccomp2 sandbox filter rejecting the system call.
-   */
-#if defined(__NR_statx) && !defined(__ANDROID__)
-  return syscall(__NR_statx, dirfd, path, flags, mask, statxbuf);
-#else
+#if !defined(__NR_statx) || defined(__ANDROID_API__) && __ANDROID_API__ < 30
   return errno = ENOSYS, -1;
+#else
+  return syscall(__NR_statx, dirfd, path, flags, mask, statxbuf);
 #endif
 }
 
 
 ssize_t uv__getrandom(void* buf, size_t buflen, unsigned flags) {
-#if defined(__NR_getrandom)
-  return syscall(__NR_getrandom, buf, buflen, flags);
-#else
+#if !defined(__NR_getrandom) || defined(__ANDROID_API__) && __ANDROID_API__ < 28
   return errno = ENOSYS, -1;
+#else
+  return syscall(__NR_getrandom, buf, buflen, flags);
 #endif
 }
diff --git a/Utilities/cmlibuv/src/unix/linux-syscalls.h b/Utilities/cmlibuv/src/unix/linux-syscalls.h
index 761ff32e21..b4d9082d46 100644
--- a/Utilities/cmlibuv/src/unix/linux-syscalls.h
+++ b/Utilities/cmlibuv/src/unix/linux-syscalls.h
@@ -22,9 +22,6 @@
 #ifndef UV_LINUX_SYSCALL_H_
 #define UV_LINUX_SYSCALL_H_
 
-#undef  _GNU_SOURCE
-#define _GNU_SOURCE
-
 #include <stdint.h>
 #include <signal.h>
 #include <sys/types.h>
@@ -66,9 +63,9 @@ ssize_t uv__pwritev(int fd, const struct iovec *iov, int iovcnt, int64_t offset)
 int uv__dup3(int oldfd, int newfd, int flags);
 ssize_t
 uv__fs_copy_file_range(int fd_in,
-                       ssize_t* off_in,
+                       off_t* off_in,
                        int fd_out,
-                       ssize_t* off_out,
+                       off_t* off_out,
                        size_t len,
                        unsigned int flags);
 int uv__statx(int dirfd,
diff --git a/Utilities/cmlibuv/src/unix/os390-proctitle.c b/Utilities/cmlibuv/src/unix/os390-proctitle.c
new file mode 100644
index 0000000000..ccda97c9ac
--- /dev/null
+++ b/Utilities/cmlibuv/src/unix/os390-proctitle.c
@@ -0,0 +1,136 @@
+/* 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 "internal.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+static uv_mutex_t process_title_mutex;
+static uv_once_t process_title_mutex_once = UV_ONCE_INIT;
+static char* process_title = NULL;
+static void* args_mem = NULL;
+
+
+static void init_process_title_mutex_once(void) {
+  uv_mutex_init(&process_title_mutex);
+}
+
+
+char** uv_setup_args(int argc, char** argv) {
+  char** new_argv;
+  size_t size;
+  char* s;
+  int i;
+
+  if (argc <= 0)
+    return argv;
+
+  /* Calculate how much memory we need for the argv strings. */
+  size = 0;
+  for (i = 0; i < argc; i++)
+    size += strlen(argv[i]) + 1;
+
+  /* Add space for the argv pointers. */
+  size += (argc + 1) * sizeof(char*);
+
+  new_argv = uv__malloc(size);
+  if (new_argv == NULL)
+    return argv;
+
+  /* Copy over the strings and set up the pointer table. */
+  s = (char*) &new_argv[argc + 1];
+  for (i = 0; i < argc; i++) {
+    size = strlen(argv[i]) + 1;
+    memcpy(s, argv[i], size);
+    new_argv[i] = s;
+    s += size;
+  }
+  new_argv[i] = NULL;
+
+  args_mem = new_argv;
+  process_title = uv__strdup(argv[0]);
+
+  return new_argv;
+}
+
+
+int uv_set_process_title(const char* title) {
+  char* new_title;
+
+  /* If uv_setup_args wasn't called or failed, we can't continue. */
+  if (args_mem == NULL)
+    return UV_ENOBUFS;
+
+  /* We cannot free this pointer when libuv shuts down,
+   * the process may still be using it.
+   */
+  new_title = uv__strdup(title);
+  if (new_title == NULL)
+    return UV_ENOMEM;
+
+  uv_once(&process_title_mutex_once, init_process_title_mutex_once);
+  uv_mutex_lock(&process_title_mutex);
+
+  if (process_title != NULL)
+    uv__free(process_title);
+
+  process_title = new_title;
+
+  uv_mutex_unlock(&process_title_mutex);
+
+  return 0;
+}
+
+
+int uv_get_process_title(char* buffer, size_t size) {
+  size_t len;
+
+  if (buffer == NULL || size == 0)
+    return UV_EINVAL;
+
+  /* If uv_setup_args wasn't called or failed, we can't continue. */
+  if (args_mem == NULL || process_title == NULL)
+    return UV_ENOBUFS;
+
+  uv_once(&process_title_mutex_once, init_process_title_mutex_once);
+  uv_mutex_lock(&process_title_mutex);
+
+  len = strlen(process_title);
+
+  if (size <= len) {
+    uv_mutex_unlock(&process_title_mutex);
+    return UV_ENOBUFS;
+  }
+
+  strcpy(buffer, process_title);
+
+  uv_mutex_unlock(&process_title_mutex);
+
+  return 0;
+}
+
+
+void uv__process_title_cleanup(void) {
+  uv__free(args_mem);  /* Keep valgrind happy. */
+  args_mem = NULL;
+}
diff --git a/Utilities/cmlibuv/src/unix/os390-syscalls.c b/Utilities/cmlibuv/src/unix/os390-syscalls.c
index 491e950c50..c19155339c 100644
--- a/Utilities/cmlibuv/src/unix/os390-syscalls.c
+++ b/Utilities/cmlibuv/src/unix/os390-syscalls.c
@@ -27,12 +27,6 @@
 #include <termios.h>
 #include <sys/msg.h>
 
-#define CW_INTRPT 1
-#define CW_CONDVAR 32
-
-#pragma linkage(BPX4CTW, OS)
-#pragma linkage(BPX1CTW, OS)
-
 static QUEUE global_epoll_queue;
 static uv_mutex_t global_epoll_lock;
 static uv_once_t once = UV_ONCE_INIT;
@@ -55,7 +49,7 @@ int scandir(const char* maindir, struct dirent*** namelist,
   if (!mdir)
     return -1;
 
-  while (1) {
+  for (;;) {
     dirent = readdir(mdir);
     if (!dirent)
       break;
@@ -381,46 +375,6 @@ void epoll_queue_close(uv__os390_epoll* lst) {
 }
 
 
-int nanosleep(const struct timespec* req, struct timespec* rem) {
-  unsigned nano;
-  unsigned seconds;
-  unsigned events;
-  unsigned secrem;
-  unsigned nanorem;
-  int rv;
-  int err;
-  int rsn;
-
-  nano = (int)req->tv_nsec;
-  seconds = req->tv_sec;
-  events = CW_CONDVAR | CW_INTRPT;
-  secrem = 0;
-  nanorem = 0;
-
-#if defined(_LP64)
-  BPX4CTW(&seconds, &nano, &events, &secrem, &nanorem, &rv, &err, &rsn);
-#else
-  BPX1CTW(&seconds, &nano, &events, &secrem, &nanorem, &rv, &err, &rsn);
-#endif
-
-  /* Don't clobber errno unless BPX1CTW/BPX4CTW errored.
-   * Don't leak EAGAIN, that just means the timeout expired.
-   */
-  if (rv == -1)
-    if (err == EAGAIN)
-      rv = 0;
-    else
-      errno = err;
-
-  if (rem != NULL && (rv == 0 || err == EINTR)) {
-    rem->tv_nsec = nanorem;
-    rem->tv_sec = secrem;
-  }
-
-  return rv;
-}
-
-
 char* mkdtemp(char* path) {
   static const char* tempchars =
     "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
@@ -550,15 +504,6 @@ ssize_t os390_readlink(const char* path, char* buf, size_t len) {
 }
 
 
-size_t strnlen(const char* str, size_t maxlen) {
-  char* p = memchr(str, 0, maxlen);
-  if (p == NULL)
-    return maxlen;
-  else
-    return p - str;
-}
-
-
 int sem_init(UV_PLATFORM_SEM_T* semid, int pshared, unsigned int value) {
   UNREACHABLE();
 }
diff --git a/Utilities/cmlibuv/src/unix/os390-syscalls.h b/Utilities/cmlibuv/src/unix/os390-syscalls.h
index 86416bbc55..7d59b75e47 100644
--- a/Utilities/cmlibuv/src/unix/os390-syscalls.h
+++ b/Utilities/cmlibuv/src/unix/os390-syscalls.h
@@ -28,6 +28,7 @@
 #include <dirent.h>
 #include <poll.h>
 #include <pthread.h>
+#include "zos-base.h"
 
 #define EPOLL_CTL_ADD             1
 #define EPOLL_CTL_DEL             2
@@ -57,7 +58,6 @@ int epoll_wait(uv__os390_epoll* ep, struct epoll_event *events, int maxevents, i
 int epoll_file_close(int fd);
 
 /* utility functions */
-int nanosleep(const struct timespec* req, struct timespec* rem);
 int scandir(const char* maindir, struct dirent*** namelist,
             int (*filter)(const struct dirent *),
             int (*compar)(const struct dirent **,
diff --git a/Utilities/cmlibuv/src/unix/os390.c b/Utilities/cmlibuv/src/unix/os390.c
index 3bb44266d9..bf0448b519 100644
--- a/Utilities/cmlibuv/src/unix/os390.c
+++ b/Utilities/cmlibuv/src/unix/os390.c
@@ -28,6 +28,8 @@
 #include <builtins.h>
 #include <termios.h>
 #include <sys/msg.h>
+#include <sys/resource.h>
+#include "zos-base.h"
 #if defined(__clang__)
 #include "csrsic.h"
 #else
@@ -61,12 +63,6 @@
 /* Address of the rsm control and enumeration area. */
 #define CVTRCEP_OFFSET    0x490
 
-/*
-    Number of frames currently available to system.
-    Excluded are frames backing perm storage, frames offline, and bad frames.
-*/
-#define RCEPOOL_OFFSET    0x004
-
 /* Total number of frames currently on all available frame queues. */
 #define RCEAFC_OFFSET     0x088
 
@@ -144,102 +140,8 @@ uint64_t uv__hrtime(uv_clocktype_t type) {
 }
 
 
-/*
-    Get the exe path using the thread entry information
-    in the address space.
-*/
-static int getexe(const int pid, char* buf, size_t len) {
-  struct {
-    int pid;
-    int thid[2];
-    char accesspid;
-    char accessthid;
-    char asid[2];
-    char loginname[8];
-    char flag;
-    char len;
-  } Input_data;
-
-  union {
-    struct {
-      char gthb[4];
-      int pid;
-      int thid[2];
-      char accesspid;
-      char accessthid[3];
-      int lenused;
-      int offsetProcess;
-      int offsetConTTY;
-      int offsetPath;
-      int offsetCommand;
-      int offsetFileData;
-      int offsetThread;
-    } Output_data;
-    char buf[2048];
-  } Output_buf;
-
-  struct Output_path_type {
-    char gthe[4];
-    short int len;
-    char path[1024];
-  };
-
-  int Input_length;
-  int Output_length;
-  void* Input_address;
-  void* Output_address;
-  struct Output_path_type* Output_path;
-  int rv;
-  int rc;
-  int rsn;
-
-  Input_length = PGTH_LEN;
-  Output_length = sizeof(Output_buf);
-  Output_address = &Output_buf;
-  Input_address = &Input_data;
-  memset(&Input_data, 0, sizeof Input_data);
-  Input_data.flag |= PGTHAPATH;
-  Input_data.pid = pid;
-  Input_data.accesspid = PGTH_CURRENT;
-
-#ifdef _LP64
-  BPX4GTH(&Input_length,
-          &Input_address,
-          &Output_length,
-          &Output_address,
-          &rv,
-          &rc,
-          &rsn);
-#else
-  BPX1GTH(&Input_length,
-          &Input_address,
-          &Output_length,
-          &Output_address,
-          &rv,
-          &rc,
-          &rsn);
-#endif
-
-  if (rv == -1) {
-    errno = rc;
-    return -1;
-  }
-
-  /* Check highest byte to ensure data availability */
-  assert(((Output_buf.Output_data.offsetPath >>24) & 0xFF) == 'A');
-
-  /* Get the offset from the lowest 3 bytes */
-  Output_path = (struct Output_path_type*) ((char*) (&Output_buf) +
-      (Output_buf.Output_data.offsetPath & 0x00FFFFFF));
-
-  if (Output_path->len >= len) {
-    errno = ENOBUFS;
-    return -1;
-  }
-
-  uv__strscpy(buf, Output_path->path, len);
-
-  return 0;
+static int getexe(char* buf, size_t len) {
+  return uv__strscpy(buf, __getargv()[0], len);
 }
 
 
@@ -259,8 +161,7 @@ int uv_exepath(char* buffer, size_t* size) {
   if (buffer == NULL || size == NULL || *size == 0)
     return UV_EINVAL;
 
-  pid = getpid();
-  res = getexe(pid, args, sizeof(args));
+  res = getexe(args, sizeof(args));
   if (res < 0)
     return UV_EINVAL;
 
@@ -275,25 +176,25 @@ uint64_t uv_get_free_memory(void) {
   data_area_ptr rcep = {0};
   cvt.assign = *(data_area_ptr_assign_type*)(CVT_PTR);
   rcep.assign = *(data_area_ptr_assign_type*)(cvt.deref + CVTRCEP_OFFSET);
-  freeram = *((uint64_t*)(rcep.deref + RCEAFC_OFFSET)) * 4;
+  freeram = (uint64_t)*((uint32_t*)(rcep.deref + RCEAFC_OFFSET)) * 4096;
   return freeram;
 }
 
 
 uint64_t uv_get_total_memory(void) {
-  uint64_t totalram;
-
-  data_area_ptr cvt = {0};
-  data_area_ptr rcep = {0};
-  cvt.assign = *(data_area_ptr_assign_type*)(CVT_PTR);
-  rcep.assign = *(data_area_ptr_assign_type*)(cvt.deref + CVTRCEP_OFFSET);
-  totalram = *((uint64_t*)(rcep.deref + RCEPOOL_OFFSET)) * 4;
-  return totalram;
+  /* Use CVTRLSTG to get the size of actual real storage online at IPL in K. */
+  return (uint64_t)((int)((char *__ptr32 *__ptr32 *)0)[4][214]) * 1024;
 }
 
 
 uint64_t uv_get_constrained_memory(void) {
-  return 0;  /* Memory constraints are unknown. */
+  struct rlimit rl;
+
+  /* RLIMIT_MEMLIMIT return value is in megabytes rather than bytes. */
+  if (getrlimit(RLIMIT_MEMLIMIT, &rl) == 0)
+    return rl.rlim_cur * 1024 * 1024;
+
+  return 0; /* There is no memory limit set. */
 }
 
 
@@ -733,6 +634,10 @@ static int os390_message_queue_handler(uv__os390_epoll* ep) {
     /* Some event that we are not interested in. */
     return 0;
 
+  /* `__rfim_utok` is treated as text when it should be treated as binary while
+   * running in ASCII mode, resulting in an unwanted autoconversion.
+   */
+  __a2e_l(msg.__rfim_utok, sizeof(msg.__rfim_utok));
   handle = *(uv_fs_event_t**)(msg.__rfim_utok);
   handle->cb(handle, uv__basename_r(handle->path), events, 0);
   return 1;
@@ -959,9 +864,6 @@ update_timeout:
   }
 }
 
-void uv__set_process_title(const char* title) {
-  /* do nothing */
-}
 
 int uv__io_fork(uv_loop_t* loop) {
   /*
diff --git a/Utilities/cmlibuv/src/unix/pipe.c b/Utilities/cmlibuv/src/unix/pipe.c
index 52a8fd52fa..fc7c4eae8d 100644
--- a/Utilities/cmlibuv/src/unix/pipe.c
+++ b/Utilities/cmlibuv/src/unix/pipe.c
@@ -377,3 +377,57 @@ int uv_pipe_chmod(uv_pipe_t* handle, int mode) {
 
   return r != -1 ? 0 : UV__ERR(errno);
 }
+
+
+int uv_pipe(uv_os_fd_t fds[2], int read_flags, int write_flags) {
+  uv_os_fd_t temp[2];
+  int err;
+#if defined(__FreeBSD__) || defined(__linux__)
+  int flags = O_CLOEXEC;
+
+  if ((read_flags & UV_NONBLOCK_PIPE) && (write_flags & UV_NONBLOCK_PIPE))
+    flags |= UV_FS_O_NONBLOCK;
+
+  if (pipe2(temp, flags))
+    return UV__ERR(errno);
+
+  if (flags & UV_FS_O_NONBLOCK) {
+    fds[0] = temp[0];
+    fds[1] = temp[1];
+    return 0;
+  }
+#else
+  if (pipe(temp))
+    return UV__ERR(errno);
+
+  if ((err = uv__cloexec(temp[0], 1)))
+    goto fail;
+
+  if ((err = uv__cloexec(temp[1], 1)))
+    goto fail;
+#endif
+
+  if (read_flags & UV_NONBLOCK_PIPE)
+    if ((err = uv__nonblock(temp[0], 1)))
+      goto fail;
+
+  if (write_flags & UV_NONBLOCK_PIPE)
+    if ((err = uv__nonblock(temp[1], 1)))
+      goto fail;
+
+  fds[0] = temp[0];
+  fds[1] = temp[1];
+  return 0;
+
+fail:
+  uv__close(temp[0]);
+  uv__close(temp[1]);
+  return err;
+}
+
+
+int uv__make_pipe(int fds[2], int flags) {
+  return uv_pipe(fds,
+                 flags & UV_NONBLOCK_PIPE,
+                 flags & UV_NONBLOCK_PIPE);
+}
diff --git a/Utilities/cmlibuv/src/unix/poll.c b/Utilities/cmlibuv/src/unix/poll.c
index 3d5022b22e..7a12e2d148 100644
--- a/Utilities/cmlibuv/src/unix/poll.c
+++ b/Utilities/cmlibuv/src/unix/poll.c
@@ -79,9 +79,10 @@ int uv_poll_init(uv_loop_t* loop, uv_poll_t* handle, int fd) {
    * Workaround for e.g. kqueue fds not supporting ioctls.
    */
   err = uv__nonblock(fd, 1);
+#if UV__NONBLOCK_IS_IOCTL
   if (err == UV_ENOTTY)
-    if (uv__nonblock == uv__nonblock_ioctl)
-      err = uv__nonblock_fcntl(fd, 1);
+    err = uv__nonblock_fcntl(fd, 1);
+#endif
 
   if (err)
     return err;
@@ -116,12 +117,21 @@ int uv_poll_stop(uv_poll_t* handle) {
 
 
 int uv_poll_start(uv_poll_t* handle, int pevents, uv_poll_cb poll_cb) {
+  uv__io_t** watchers;
+  uv__io_t* w;
   int events;
 
   assert((pevents & ~(UV_READABLE | UV_WRITABLE | UV_DISCONNECT |
                       UV_PRIORITIZED)) == 0);
   assert(!uv__is_closing(handle));
 
+  watchers = handle->loop->watchers;
+  w = &handle->io_watcher;
+
+  if (uv__fd_exists(handle->loop, w->fd))
+    if (watchers[w->fd] != w)
+      return UV_EEXIST;
+
   uv__poll_stop(handle);
 
   if (pevents == 0)
diff --git a/Utilities/cmlibuv/src/unix/process.c b/Utilities/cmlibuv/src/unix/process.c
index 08aa2f3cc6..2af2088f90 100644
--- a/Utilities/cmlibuv/src/unix/process.c
+++ b/Utilities/cmlibuv/src/unix/process.c
@@ -26,6 +26,7 @@
 #include <stdlib.h>
 #include <assert.h>
 #include <errno.h>
+#include <signal.h>
 
 #include <sys/types.h>
 #include <sys/wait.h>
@@ -45,6 +46,10 @@ extern char **environ;
 # include <grp.h>
 #endif
 
+#if defined(__MVS__)
+# include "zos-base.h"
+#endif
+
 #ifndef CMAKE_BOOTSTRAP
 #if defined(__linux__)
 # define uv__cpu_set_t cpu_set_t
@@ -122,68 +127,6 @@ static void uv__chld(uv_signal_t* handle, int signum) {
   assert(QUEUE_EMPTY(&pending));
 }
 
-
-static int uv__make_socketpair(int fds[2]) {
-#if defined(__FreeBSD__) || defined(__linux__)
-  if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, fds))
-    return UV__ERR(errno);
-
-  return 0;
-#else
-  int err;
-
-  if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds))
-    return UV__ERR(errno);
-
-  err = uv__cloexec(fds[0], 1);
-  if (err == 0)
-    err = uv__cloexec(fds[1], 1);
-
-  if (err != 0) {
-    uv__close(fds[0]);
-    uv__close(fds[1]);
-    return UV__ERR(errno);
-  }
-
-  return 0;
-#endif
-}
-
-
-int uv__make_pipe(int fds[2], int flags) {
-#if defined(__FreeBSD__) || defined(__linux__)
-  if (pipe2(fds, flags | O_CLOEXEC))
-    return UV__ERR(errno);
-
-  return 0;
-#else
-  if (pipe(fds))
-    return UV__ERR(errno);
-
-  if (uv__cloexec(fds[0], 1))
-    goto fail;
-
-  if (uv__cloexec(fds[1], 1))
-    goto fail;
-
-  if (flags & UV__F_NONBLOCK) {
-    if (uv__nonblock(fds[0], 1))
-      goto fail;
-
-    if (uv__nonblock(fds[1], 1))
-      goto fail;
-  }
-
-  return 0;
-
-fail:
-  uv__close(fds[0]);
-  uv__close(fds[1]);
-  return UV__ERR(errno);
-#endif
-}
-
-
 /*
  * Used for initializing stdio streams like options.stdin_stream. Returns
  * zero on success. See also the cleanup section in uv_spawn().
@@ -203,7 +146,7 @@ static int uv__process_init_stdio(uv_stdio_container_t* container, int fds[2]) {
     if (container->data.stream->type != UV_NAMED_PIPE)
       return UV_EINVAL;
     else
-      return uv__make_socketpair(fds);
+      return uv_socketpair(SOCK_STREAM, 0, fds, 0, 0);
 
   case UV_INHERIT_FD:
   case UV_INHERIT_STREAM:
@@ -270,6 +213,12 @@ static void uv__write_int(int fd, int val) {
 }
 
 
+static void uv__write_errno(int error_fd) {
+  uv__write_int(error_fd, UV__ERR(errno));
+  _exit(127);
+}
+
+
 #if !(defined(__APPLE__) && (TARGET_OS_TV || TARGET_OS_WATCH))
 /* execvp is marked __WATCHOS_PROHIBITED __TVOS_PROHIBITED, so must be
  * avoided. Since this isn't called on those targets, the function
@@ -279,10 +228,9 @@ static void uv__process_child_init(const uv_process_options_t* options,
                                    int stdio_count,
                                    int (*pipes)[2],
                                    int error_fd) {
-  sigset_t set;
+  sigset_t signewset;
   int close_fd;
   int use_fd;
-  int err;
   int fd;
   int n;
 #ifndef CMAKE_BOOTSTRAP
@@ -294,6 +242,26 @@ static void uv__process_child_init(const uv_process_options_t* options,
 #endif
 #endif
 
+  /* Reset signal disposition first. Use a hard-coded limit because NSIG is not
+   * fixed on Linux: it's either 32, 34 or 64, depending on whether RT signals
+   * are enabled. We are not allowed to touch RT signal handlers, glibc uses
+   * them internally.
+   */
+  for (n = 1; n < 32; n += 1) {
+    if (n == SIGKILL || n == SIGSTOP)
+      continue;  /* Can't be changed. */
+
+#if defined(__HAIKU__)
+    if (n == SIGKILLTHR)
+      continue;  /* Can't be changed. */
+#endif
+
+    if (SIG_ERR != signal(n, SIG_DFL))
+      continue;
+
+    uv__write_errno(error_fd);
+  }
+
   if (options->flags & UV_PROCESS_DETACHED)
     setsid();
 
@@ -306,10 +274,8 @@ static void uv__process_child_init(const uv_process_options_t* options,
     if (use_fd < 0 || use_fd >= fd)
       continue;
     pipes[fd][1] = fcntl(use_fd, F_DUPFD, stdio_count);
-    if (pipes[fd][1] == -1) {
-      uv__write_int(error_fd, UV__ERR(errno));
-      _exit(127);
-    }
+    if (pipes[fd][1] == -1)
+      uv__write_errno(error_fd);
   }
 
   for (fd = 0; fd < stdio_count; fd++) {
@@ -326,10 +292,8 @@ static void uv__process_child_init(const uv_process_options_t* options,
         use_fd = open("/dev/null", fd == 0 ? O_RDONLY : O_RDWR);
         close_fd = use_fd;
 
-        if (use_fd < 0) {
-          uv__write_int(error_fd, UV__ERR(errno));
-          _exit(127);
-        }
+        if (use_fd < 0)
+          uv__write_errno(error_fd);
       }
     }
 
@@ -338,10 +302,8 @@ static void uv__process_child_init(const uv_process_options_t* options,
     else
       fd = dup2(use_fd, fd);
 
-    if (fd == -1) {
-      uv__write_int(error_fd, UV__ERR(errno));
-      _exit(127);
-    }
+    if (fd == -1)
+      uv__write_errno(error_fd);
 
     if (fd <= 2)
       uv__nonblock_fcntl(fd, 0);
@@ -357,10 +319,8 @@ static void uv__process_child_init(const uv_process_options_t* options,
       uv__close(use_fd);
   }
 
-  if (options->cwd != NULL && chdir(options->cwd)) {
-    uv__write_int(error_fd, UV__ERR(errno));
-    _exit(127);
-  }
+  if (options->cwd != NULL && chdir(options->cwd))
+    uv__write_errno(error_fd);
 
   if (options->flags & (UV_PROCESS_SETUID | UV_PROCESS_SETGID)) {
     /* When dropping privileges from root, the `setgroups` call will
@@ -373,15 +333,11 @@ static void uv__process_child_init(const uv_process_options_t* options,
     SAVE_ERRNO(setgroups(0, NULL));
   }
 
-  if ((options->flags & UV_PROCESS_SETGID) && setgid(options->gid)) {
-    uv__write_int(error_fd, UV__ERR(errno));
-    _exit(127);
-  }
+  if ((options->flags & UV_PROCESS_SETGID) && setgid(options->gid))
+    uv__write_errno(error_fd);
 
-  if ((options->flags & UV_PROCESS_SETUID) && setuid(options->uid)) {
-    uv__write_int(error_fd, UV__ERR(errno));
-    _exit(127);
-  }
+  if ((options->flags & UV_PROCESS_SETUID) && setuid(options->uid))
+    uv__write_errno(error_fd);
 
 #ifndef CMAKE_BOOTSTRAP
 #if defined(__linux__) || defined(__FreeBSD__)
@@ -409,39 +365,19 @@ static void uv__process_child_init(const uv_process_options_t* options,
     environ = options->env;
   }
 
-  /* Reset signal disposition.  Use a hard-coded limit because NSIG
-   * is not fixed on Linux: it's either 32, 34 or 64, depending on
-   * whether RT signals are enabled.  We are not allowed to touch
-   * RT signal handlers, glibc uses them internally.
-   */
-  for (n = 1; n < 32; n += 1) {
-    if (n == SIGKILL || n == SIGSTOP)
-      continue;  /* Can't be changed. */
+  /* Reset signal mask just before exec. */
+  sigemptyset(&signewset);
+  if (sigprocmask(SIG_SETMASK, &signewset, NULL) != 0)
+    abort();
 
-#if defined(__HAIKU__)
-    if (n == SIGKILLTHR)
-      continue;  /* Can't be changed. */
+#ifdef __MVS__
+  execvpe(options->file, options->args, environ);
+#else
+  execvp(options->file, options->args);
 #endif
 
-    if (SIG_ERR != signal(n, SIG_DFL))
-      continue;
-
-    uv__write_int(error_fd, UV__ERR(errno));
-    _exit(127);
-  }
-
-  /* Reset signal mask. */
-  sigemptyset(&set);
-  err = pthread_sigmask(SIG_SETMASK, &set, NULL);
-
-  if (err != 0) {
-    uv__write_int(error_fd, UV__ERR(err));
-    _exit(127);
-  }
-
-  execvp(options->file, options->args);
-  uv__write_int(error_fd, UV__ERR(errno));
-  _exit(127);
+  uv__write_errno(error_fd);
+  abort();
 }
 #endif
 
@@ -453,6 +389,8 @@ int uv_spawn(uv_loop_t* loop,
   /* fork is marked __WATCHOS_PROHIBITED __TVOS_PROHIBITED. */
   return UV_ENOSYS;
 #else
+  sigset_t signewset;
+  sigset_t sigoldset;
   int signal_pipe[2] = { -1, -1 };
   int pipes_storage[8][2];
   int (*pipes)[2];
@@ -541,25 +479,41 @@ int uv_spawn(uv_loop_t* loop,
 
   /* Acquire write lock to prevent opening new fds in worker threads */
   uv_rwlock_wrlock(&loop->cloexec_lock);
-  pid = fork();
 
-  if (pid == -1) {
+  /* Start the child with most signals blocked, to avoid any issues before we
+   * can reset them, but allow program failures to exit (and not hang). */
+  sigfillset(&signewset);
+  sigdelset(&signewset, SIGKILL);
+  sigdelset(&signewset, SIGSTOP);
+  sigdelset(&signewset, SIGTRAP);
+  sigdelset(&signewset, SIGSEGV);
+  sigdelset(&signewset, SIGBUS);
+  sigdelset(&signewset, SIGILL);
+  sigdelset(&signewset, SIGSYS);
+  sigdelset(&signewset, SIGABRT);
+  if (pthread_sigmask(SIG_BLOCK, &signewset, &sigoldset) != 0)
+    abort();
+
+  pid = fork();
+  if (pid == -1)
     err = UV__ERR(errno);
-    uv_rwlock_wrunlock(&loop->cloexec_lock);
-    uv__close(signal_pipe[0]);
-    uv__close(signal_pipe[1]);
-    goto error;
-  }
 
-  if (pid == 0) {
+  if (pid == 0)
     uv__process_child_init(options, stdio_count, pipes, signal_pipe[1]);
+
+  if (pthread_sigmask(SIG_SETMASK, &sigoldset, NULL) != 0)
     abort();
-  }
 
   /* Release lock in parent process */
   uv_rwlock_wrunlock(&loop->cloexec_lock);
+
   uv__close(signal_pipe[1]);
 
+  if (pid == -1) {
+    uv__close(signal_pipe[0]);
+    goto error;
+  }
+
   process->status = 0;
   exec_errorno = 0;
   do
diff --git a/Utilities/cmlibuv/src/unix/proctitle.c b/Utilities/cmlibuv/src/unix/proctitle.c
index 9ffe5b629c..9d1f00ddf6 100644
--- a/Utilities/cmlibuv/src/unix/proctitle.c
+++ b/Utilities/cmlibuv/src/unix/proctitle.c
@@ -84,10 +84,7 @@ char** uv_setup_args(int argc, char** argv) {
   }
   new_argv[i] = NULL;
 
-  /* argv is not adjacent on z/os, we use just argv[0] on that platform. */
-#ifndef __MVS__
   pt.cap = argv[i - 1] + size - argv[0];
-#endif
 
   args_mem = new_argv;
   process_title = pt;
@@ -119,6 +116,7 @@ int uv_set_process_title(const char* title) {
   memcpy(pt->str, title, len);
   memset(pt->str + len, '\0', pt->cap - len);
   pt->len = len;
+  uv__set_process_title(pt->str);
 
   uv_mutex_unlock(&process_title_mutex);
 
diff --git a/Utilities/cmlibuv/src/unix/signal.c b/Utilities/cmlibuv/src/unix/signal.c
index f40a3e54eb..1133c73a95 100644
--- a/Utilities/cmlibuv/src/unix/signal.c
+++ b/Utilities/cmlibuv/src/unix/signal.c
@@ -265,7 +265,7 @@ static int uv__signal_loop_once_init(uv_loop_t* loop) {
   if (loop->signal_pipefd[0] != -1)
     return 0;
 
-  err = uv__make_pipe(loop->signal_pipefd, UV__F_NONBLOCK);
+  err = uv__make_pipe(loop->signal_pipefd, UV_NONBLOCK_PIPE);
   if (err)
     return err;
 
diff --git a/Utilities/cmlibuv/src/unix/stream.c b/Utilities/cmlibuv/src/unix/stream.c
index 3b6da8d464..dd0e0f7f58 100644
--- a/Utilities/cmlibuv/src/unix/stream.c
+++ b/Utilities/cmlibuv/src/unix/stream.c
@@ -164,7 +164,7 @@ static void uv__stream_osx_select(void* arg) {
   else
     max_fd = s->int_fd;
 
-  while (1) {
+  for (;;) {
     /* Terminate on semaphore */
     if (uv_sem_trywait(&s->close_sem) == 0)
       break;
@@ -195,7 +195,7 @@ static void uv__stream_osx_select(void* arg) {
 
     /* Empty socketpair's buffer in case of interruption */
     if (FD_ISSET(s->int_fd, s->sread))
-      while (1) {
+      for (;;) {
         r = read(s->int_fd, buf, sizeof(buf));
 
         if (r == sizeof(buf))
@@ -799,33 +799,21 @@ static int uv__handle_fd(uv_handle_t* handle) {
   }
 }
 
-static void uv__write(uv_stream_t* stream) {
+static int uv__try_write(uv_stream_t* stream,
+                         const uv_buf_t bufs[],
+                         unsigned int nbufs,
+                         uv_stream_t* send_handle) {
   struct iovec* iov;
-  QUEUE* q;
-  uv_write_t* req;
   int iovmax;
   int iovcnt;
   ssize_t n;
-  int err;
-
-start:
-
-  assert(uv__stream_fd(stream) >= 0);
-
-  if (QUEUE_EMPTY(&stream->write_queue))
-    return;
-
-  q = QUEUE_HEAD(&stream->write_queue);
-  req = QUEUE_DATA(q, uv_write_t, queue);
-  assert(req->handle == stream);
 
   /*
    * Cast to iovec. We had to have our own uv_buf_t instead of iovec
    * because Windows's WSABUF is not an iovec.
    */
-  assert(sizeof(uv_buf_t) == sizeof(struct iovec));
-  iov = (struct iovec*) &(req->bufs[req->write_index]);
-  iovcnt = req->nbufs - req->write_index;
+  iov = (struct iovec*) bufs;
+  iovcnt = nbufs;
 
   iovmax = uv__getiovmax();
 
@@ -837,8 +825,7 @@ start:
    * Now do the actual writev. Note that we've been updating the pointers
    * inside the iov each time we write. So there is no need to offset it.
    */
-
-  if (req->send_handle) {
+  if (send_handle != NULL) {
     int fd_to_send;
     struct msghdr msg;
     struct cmsghdr *cmsg;
@@ -847,12 +834,10 @@ start:
       struct cmsghdr alias;
     } scratch;
 
-    if (uv__is_closing(req->send_handle)) {
-      err = UV_EBADF;
-      goto error;
-    }
+    if (uv__is_closing(send_handle))
+      return UV_EBADF;
 
-    fd_to_send = uv__handle_fd((uv_handle_t*) req->send_handle);
+    fd_to_send = uv__handle_fd((uv_handle_t*) send_handle);
 
     memset(&scratch, 0, sizeof(scratch));
 
@@ -882,44 +867,68 @@ start:
     do
       n = sendmsg(uv__stream_fd(stream), &msg, 0);
     while (n == -1 && RETRY_ON_WRITE_ERROR(errno));
-
-    /* Ensure the handle isn't sent again in case this is a partial write. */
-    if (n >= 0)
-      req->send_handle = NULL;
   } else {
     do
       n = uv__writev(uv__stream_fd(stream), iov, iovcnt);
     while (n == -1 && RETRY_ON_WRITE_ERROR(errno));
   }
 
-  if (n == -1 && !IS_TRANSIENT_WRITE_ERROR(errno, req->send_handle)) {
-    err = UV__ERR(errno);
-    goto error;
-  }
+  if (n >= 0)
+    return n;
 
-  if (n >= 0 && uv__write_req_update(stream, req, n)) {
-    uv__write_req_finish(req);
-    return;  /* TODO(bnoordhuis) Start trying to write the next request. */
-  }
+  if (IS_TRANSIENT_WRITE_ERROR(errno, send_handle))
+    return UV_EAGAIN;
 
-  /* If this is a blocking stream, try again. */
-  if (stream->flags & UV_HANDLE_BLOCKING_WRITES)
-    goto start;
+  return UV__ERR(errno);
+}
 
-  /* We're not done. */
-  uv__io_start(stream->loop, &stream->io_watcher, POLLOUT);
+static void uv__write(uv_stream_t* stream) {
+  QUEUE* q;
+  uv_write_t* req;
+  ssize_t n;
 
-  /* Notify select() thread about state change */
-  uv__stream_osx_interrupt_select(stream);
+  assert(uv__stream_fd(stream) >= 0);
+
+  for (;;) {
+    if (QUEUE_EMPTY(&stream->write_queue))
+      return;
+
+    q = QUEUE_HEAD(&stream->write_queue);
+    req = QUEUE_DATA(q, uv_write_t, queue);
+    assert(req->handle == stream);
+
+    n = uv__try_write(stream,
+                      &(req->bufs[req->write_index]),
+                      req->nbufs - req->write_index,
+                      req->send_handle);
+
+    /* Ensure the handle isn't sent again in case this is a partial write. */
+    if (n >= 0) {
+      req->send_handle = NULL;
+      if (uv__write_req_update(stream, req, n)) {
+        uv__write_req_finish(req);
+        return;  /* TODO(bnoordhuis) Start trying to write the next request. */
+      }
+    } else if (n != UV_EAGAIN)
+      break;
+
+    /* If this is a blocking stream, try again. */
+    if (stream->flags & UV_HANDLE_BLOCKING_WRITES)
+      continue;
+
+    /* We're not done. */
+    uv__io_start(stream->loop, &stream->io_watcher, POLLOUT);
 
-  return;
+    /* Notify select() thread about state change */
+    uv__stream_osx_interrupt_select(stream);
+
+    return;
+  }
 
-error:
-  req->error = err;
+  req->error = n;
+  // XXX(jwn): this must call uv__stream_flush_write_queue(stream, n) here, since we won't generate any more events
   uv__write_req_finish(req);
   uv__io_stop(stream->loop, &stream->io_watcher, POLLOUT);
-  if (!uv__io_active(&stream->io_watcher, POLLIN))
-    uv__handle_stop(stream);
   uv__stream_osx_interrupt_select(stream);
 }
 
@@ -1001,9 +1010,9 @@ uv_handle_type uv__handle_type(int fd) {
 static void uv__stream_eof(uv_stream_t* stream, const uv_buf_t* buf) {
   stream->flags |= UV_HANDLE_READ_EOF;
   stream->flags &= ~UV_HANDLE_READING;
+  stream->flags &= ~UV_HANDLE_READABLE;
   uv__io_stop(stream->loop, &stream->io_watcher, POLLIN);
-  if (!uv__io_active(&stream->io_watcher, POLLOUT))
-    uv__handle_stop(stream);
+  uv__handle_stop(stream);
   uv__stream_osx_interrupt_select(stream);
   stream->read_cb(stream, UV_EOF, buf);
 }
@@ -1188,12 +1197,12 @@ static void uv__read(uv_stream_t* stream) {
 #endif
       } else {
         /* Error. User should call uv_close(). */
+        stream->flags &= ~(UV_HANDLE_READABLE | UV_HANDLE_WRITABLE);
         stream->read_cb(stream, UV__ERR(errno), &buf);
         if (stream->flags & UV_HANDLE_READING) {
           stream->flags &= ~UV_HANDLE_READING;
           uv__io_stop(stream->loop, &stream->io_watcher, POLLIN);
-          if (!uv__io_active(&stream->io_watcher, POLLOUT))
-            uv__handle_stop(stream);
+          uv__handle_stop(stream);
           uv__stream_osx_interrupt_select(stream);
         }
       }
@@ -1276,6 +1285,7 @@ int uv_shutdown(uv_shutdown_t* req, uv_stream_t* stream, uv_shutdown_cb cb) {
   req->cb = cb;
   stream->shutdown_req = req;
   stream->flags |= UV_HANDLE_SHUTTING;
+  stream->flags &= ~UV_HANDLE_WRITABLE;
 
   uv__io_start(stream->loop, &stream->io_watcher, POLLOUT);
   uv__stream_osx_interrupt_select(stream);
@@ -1390,14 +1400,9 @@ static void uv__stream_connect(uv_stream_t* stream) {
 }
 
 
-int uv_write2(uv_write_t* req,
-              uv_stream_t* stream,
-              const uv_buf_t bufs[],
-              unsigned int nbufs,
-              uv_stream_t* send_handle,
-              uv_write_cb cb) {
-  int empty_queue;
-
+static int uv__check_before_write(uv_stream_t* stream,
+                                  unsigned int nbufs,
+                                  uv_stream_t* send_handle) {
   assert(nbufs > 0);
   assert((stream->type == UV_TCP ||
           stream->type == UV_NAMED_PIPE ||
@@ -1410,7 +1415,7 @@ int uv_write2(uv_write_t* req,
   if (!(stream->flags & UV_HANDLE_WRITABLE))
     return UV_EPIPE;
 
-  if (send_handle) {
+  if (send_handle != NULL) {
     if (stream->type != UV_NAMED_PIPE || !((uv_pipe_t*)stream)->ipc)
       return UV_EINVAL;
 
@@ -1430,6 +1435,22 @@ int uv_write2(uv_write_t* req,
 #endif
   }
 
+  return 0;
+}
+
+int uv_write2(uv_write_t* req,
+              uv_stream_t* stream,
+              const uv_buf_t bufs[],
+              unsigned int nbufs,
+              uv_stream_t* send_handle,
+              uv_write_cb cb) {
+  int empty_queue;
+  int err;
+
+  err = uv__check_before_write(stream, nbufs, send_handle);
+  if (err < 0)
+    return err;
+
   /* It's legal for write_queue_size > 0 even when the write_queue is empty;
    * it means there are error-state requests in the write_completed_queue that
    * will touch up write_queue_size later, see also uv__write_req_finish().
@@ -1498,72 +1519,37 @@ int uv_write(uv_write_t* req,
 }
 
 
-void uv_try_write_cb(uv_write_t* req, int status) {
-  /* Should not be called */
-  abort();
-}
-
-
 int uv_try_write(uv_stream_t* stream,
                  const uv_buf_t bufs[],
                  unsigned int nbufs) {
-  int r;
-  int has_pollout;
-  size_t written;
-  size_t req_size;
-  uv_write_t req;
+  return uv_try_write2(stream, bufs, nbufs, NULL);
+}
+
+
+int uv_try_write2(uv_stream_t* stream,
+                  const uv_buf_t bufs[],
+                  unsigned int nbufs,
+                  uv_stream_t* send_handle) {
+  int err;
 
   /* Connecting or already writing some data */
   if (stream->connect_req != NULL || stream->write_queue_size != 0)
     return UV_EAGAIN;
 
-  has_pollout = uv__io_active(&stream->io_watcher, POLLOUT);
+  err = uv__check_before_write(stream, nbufs, NULL);
+  if (err < 0)
+    return err;
 
-  r = uv_write(&req, stream, bufs, nbufs, uv_try_write_cb);
-  if (r != 0)
-    return r;
-
-  /* Remove not written bytes from write queue size */
-  written = uv__count_bufs(bufs, nbufs);
-  if (req.bufs != NULL)
-    req_size = uv__write_req_size(&req);
-  else
-    req_size = 0;
-  written -= req_size;
-  stream->write_queue_size -= req_size;
-
-  /* Unqueue request, regardless of immediateness */
-  QUEUE_REMOVE(&req.queue);
-  uv__req_unregister(stream->loop, &req);
-  if (req.bufs != req.bufsml)
-    uv__free(req.bufs);
-  req.bufs = NULL;
-
-  /* Do not poll for writable, if we wasn't before calling this */
-  if (!has_pollout) {
-    uv__io_stop(stream->loop, &stream->io_watcher, POLLOUT);
-    uv__stream_osx_interrupt_select(stream);
-  }
-
-  if (written == 0 && req_size != 0)
-    return req.error < 0 ? req.error : UV_EAGAIN;
-  else
-    return written;
+  return uv__try_write(stream, bufs, nbufs, send_handle);
 }
 
 
-int uv_read_start(uv_stream_t* stream,
-                  uv_alloc_cb alloc_cb,
-                  uv_read_cb read_cb) {
+int uv__read_start(uv_stream_t* stream,
+                   uv_alloc_cb alloc_cb,
+                   uv_read_cb read_cb) {
   assert(stream->type == UV_TCP || stream->type == UV_NAMED_PIPE ||
       stream->type == UV_TTY);
 
-  if (stream->flags & UV_HANDLE_CLOSING)
-    return UV_EINVAL;
-
-  if (!(stream->flags & UV_HANDLE_READABLE))
-    return UV_ENOTCONN;
-
   /* The UV_HANDLE_READING flag is irrelevant of the state of the tcp - it just
    * expresses the desired state of the user.
    */
@@ -1593,8 +1579,7 @@ int uv_read_stop(uv_stream_t* stream) {
 
   stream->flags &= ~UV_HANDLE_READING;
   uv__io_stop(stream->loop, &stream->io_watcher, POLLIN);
-  if (!uv__io_active(&stream->io_watcher, POLLOUT))
-    uv__handle_stop(stream);
+  uv__handle_stop(stream);
   uv__stream_osx_interrupt_select(stream);
 
   stream->read_cb = NULL;
diff --git a/Utilities/cmlibuv/src/unix/sunos.c b/Utilities/cmlibuv/src/unix/sunos.c
index 2166e8f08e..eab2e40a67 100644
--- a/Utilities/cmlibuv/src/unix/sunos.c
+++ b/Utilities/cmlibuv/src/unix/sunos.c
@@ -869,3 +869,14 @@ void uv_free_interface_addresses(uv_interface_address_t* addresses,
 
   uv__free(addresses);
 }
+
+
+#if !defined(_POSIX_VERSION) || _POSIX_VERSION < 200809L
+size_t strnlen(const char* s, size_t maxlen) {
+  const char* end;
+  end = memchr(s, '\0', maxlen);
+  if (end == NULL)
+    return maxlen;
+  return end - s;
+}
+#endif
diff --git a/Utilities/cmlibuv/src/unix/tcp.c b/Utilities/cmlibuv/src/unix/tcp.c
index 18acd20df1..bc0fb661f1 100644
--- a/Utilities/cmlibuv/src/unix/tcp.c
+++ b/Utilities/cmlibuv/src/unix/tcp.c
@@ -214,14 +214,15 @@ int uv__tcp_connect(uv_connect_t* req,
   if (handle->connect_req != NULL)
     return UV_EALREADY;  /* FIXME(bnoordhuis) UV_EINVAL or maybe UV_EBUSY. */
 
+  if (handle->delayed_error != 0)
+    goto out;
+
   err = maybe_new_socket(handle,
                          addr->sa_family,
                          UV_HANDLE_READABLE | UV_HANDLE_WRITABLE);
   if (err)
     return err;
 
-  handle->delayed_error = 0;
-
   do {
     errno = 0;
     r = connect(uv__stream_fd(handle), addr, addrlen);
@@ -249,6 +250,8 @@ int uv__tcp_connect(uv_connect_t* req,
       return UV__ERR(errno);
   }
 
+out:
+
   uv__req_init(handle->loop, req, UV_CONNECT);
   req->cb = cb;
   req->handle = (uv_stream_t*) handle;
@@ -459,3 +462,49 @@ int uv_tcp_simultaneous_accepts(uv_tcp_t* handle, int enable) {
 void uv__tcp_close(uv_tcp_t* handle) {
   uv__stream_close((uv_stream_t*)handle);
 }
+
+
+int uv_socketpair(int type, int protocol, uv_os_sock_t fds[2], int flags0, int flags1) {
+  uv_os_sock_t temp[2];
+  int err;
+#if defined(__FreeBSD__) || defined(__linux__)
+  int flags;
+
+  flags = type | SOCK_CLOEXEC;
+  if ((flags0 & UV_NONBLOCK_PIPE) && (flags1 & UV_NONBLOCK_PIPE))
+    flags |= SOCK_NONBLOCK;
+
+  if (socketpair(AF_UNIX, flags, protocol, temp))
+    return UV__ERR(errno);
+
+  if (flags & UV_FS_O_NONBLOCK) {
+    fds[0] = temp[0];
+    fds[1] = temp[1];
+    return 0;
+  }
+#else
+  if (socketpair(AF_UNIX, type, protocol, temp))
+    return UV__ERR(errno);
+
+  if ((err = uv__cloexec(temp[0], 1)))
+    goto fail;
+  if ((err = uv__cloexec(temp[1], 1)))
+    goto fail;
+#endif
+
+  if (flags0 & UV_NONBLOCK_PIPE)
+    if ((err = uv__nonblock(temp[0], 1)))
+        goto fail;
+  if (flags1 & UV_NONBLOCK_PIPE)
+    if ((err = uv__nonblock(temp[1], 1)))
+      goto fail;
+
+  fds[0] = temp[0];
+  fds[1] = temp[1];
+  return 0;
+
+fail:
+  uv__close(temp[0]);
+  uv__close(temp[1]);
+  return err;
+}
diff --git a/Utilities/cmlibuv/src/unix/thread.c b/Utilities/cmlibuv/src/unix/thread.c
index 8aeb0ca382..cbddf173f7 100644
--- a/Utilities/cmlibuv/src/unix/thread.c
+++ b/Utilities/cmlibuv/src/unix/thread.c
@@ -107,8 +107,7 @@ int uv_barrier_wait(uv_barrier_t* barrier) {
   }
 
   last = (--b->out == 0);
-  if (!last)
-    uv_cond_signal(&b->cond);  /* Not needed for last thread. */
+  uv_cond_signal(&b->cond);
 
   uv_mutex_unlock(&b->mutex);
   return last;
@@ -122,9 +121,10 @@ void uv_barrier_destroy(uv_barrier_t* barrier) {
   uv_mutex_lock(&b->mutex);
 
   assert(b->in == 0);
-  assert(b->out == 0);
+  while (b->out != 0)
+    uv_cond_wait(&b->cond, &b->mutex);
 
-  if (b->in != 0 || b->out != 0)
+  if (b->in != 0)
     abort();
 
   uv_mutex_unlock(&b->mutex);
@@ -168,7 +168,7 @@ void uv_barrier_destroy(uv_barrier_t* barrier) {
  * On Linux, threads created by musl have a much smaller stack than threads
  * created by glibc (80 vs. 2048 or 4096 kB.)  Follow glibc for consistency.
  */
-static size_t thread_stack_size(void) {
+size_t uv__thread_stack_size(void) {
 #if defined(__APPLE__) || defined(__linux__)
   struct rlimit lim;
 
@@ -234,7 +234,7 @@ int uv_thread_create_ex(uv_thread_t* tid,
 
   attr = NULL;
   if (stack_size == 0) {
-    stack_size = thread_stack_size();
+    stack_size = uv__thread_stack_size();
   } else {
     pagesize = (size_t)getpagesize();
     /* Round up to the nearest page boundary. */
diff --git a/Utilities/cmlibuv/src/unix/tty.c b/Utilities/cmlibuv/src/unix/tty.c
index 82cd723d74..8cefc150bb 100644
--- a/Utilities/cmlibuv/src/unix/tty.c
+++ b/Utilities/cmlibuv/src/unix/tty.c
@@ -239,6 +239,24 @@ static void uv__tty_make_raw(struct termios* tio) {
   tio->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
   tio->c_cflag &= ~(CSIZE | PARENB);
   tio->c_cflag |= CS8;
+
+  /*
+   * By default, most software expects a pending read to block until at
+   * least one byte becomes available.  As per termio(7I), this requires
+   * setting the MIN and TIME parameters appropriately.
+   *
+   * As a somewhat unfortunate artifact of history, the MIN and TIME slots
+   * in the control character array overlap with the EOF and EOL slots used
+   * for canonical mode processing.  Because the EOF character needs to be
+   * the ASCII EOT value (aka Control-D), it has the byte value 4.  When
+   * switching to raw mode, this is interpreted as a MIN value of 4; i.e.,
+   * reads will block until at least four bytes have been input.
+   *
+   * Other platforms with a distinct MIN slot like Linux and FreeBSD appear
+   * to default to a MIN value of 1, so we'll force that value here:
+   */
+  tio->c_cc[VMIN] = 1;
+  tio->c_cc[VTIME] = 0;
 #else
   cfmakeraw(tio);
 #endif /* #ifdef __sun */
diff --git a/Utilities/cmlibuv/src/unix/udp.c b/Utilities/cmlibuv/src/unix/udp.c
index 7d699a1675..71bfbf7f79 100644
--- a/Utilities/cmlibuv/src/unix/udp.c
+++ b/Utilities/cmlibuv/src/unix/udp.c
@@ -32,8 +32,6 @@
 #endif
 #include <sys/un.h>
 
-#define UV__UDP_DGRAM_MAXSIZE (64 * 1024)
-
 #if defined(IPV6_JOIN_GROUP) && !defined(IPV6_ADD_MEMBERSHIP)
 # define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
 #endif
@@ -377,8 +375,11 @@ write_queue_drain:
     return;
   }
 
+  /* Safety: npkts known to be >0 below. Hence cast from ssize_t
+   * to size_t safe.
+   */
   for (i = 0, q = QUEUE_HEAD(&handle->write_queue);
-       i < pkts && q != &handle->write_queue;
+       i < (size_t)npkts && q != &handle->write_queue;
        ++i, q = QUEUE_HEAD(&handle->write_queue)) {
     assert(q != NULL);
     req = QUEUE_DATA(q, uv_udp_send_t, queue);
@@ -504,6 +505,28 @@ static int uv__set_reuse(int fd) {
   return 0;
 }
 
+/*
+ * The Linux kernel suppresses some ICMP error messages by default for UDP
+ * sockets. Setting IP_RECVERR/IPV6_RECVERR on the socket enables full ICMP
+ * error reporting, hopefully resulting in faster failover to working name
+ * servers.
+ */
+static int uv__set_recverr(int fd, sa_family_t ss_family) {
+#if defined(__linux__)
+  int yes;
+
+  yes = 1;
+  if (ss_family == AF_INET) {
+    if (setsockopt(fd, IPPROTO_IP, IP_RECVERR, &yes, sizeof(yes)))
+      return UV__ERR(errno);
+  } else if (ss_family == AF_INET6) {
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVERR, &yes, sizeof(yes)))
+       return UV__ERR(errno);
+  }
+#endif
+  return 0;
+}
+
 
 int uv__udp_bind(uv_udp_t* handle,
                  const struct sockaddr* addr,
@@ -514,7 +537,7 @@ int uv__udp_bind(uv_udp_t* handle,
   int fd;
 
   /* Check for bad flags. */
-  if (flags & ~(UV_UDP_IPV6ONLY | UV_UDP_REUSEADDR))
+  if (flags & ~(UV_UDP_IPV6ONLY | UV_UDP_REUSEADDR | UV_UDP_LINUX_RECVERR))
     return UV_EINVAL;
 
   /* Cannot set IPv6-only mode on non-IPv6 socket. */
@@ -530,6 +553,12 @@ int uv__udp_bind(uv_udp_t* handle,
     handle->io_watcher.fd = fd;
   }
 
+  if (flags & UV_UDP_LINUX_RECVERR) {
+    err = uv__set_recverr(fd, addr->sa_family);
+    if (err)
+      return err;
+  }
+
   if (flags & UV_UDP_REUSEADDR) {
     err = uv__set_reuse(fd);
     if (err)
@@ -854,7 +883,7 @@ static int uv__udp_set_membership6(uv_udp_t* handle,
 #if !defined(__OpenBSD__) &&                                        \
     !defined(__NetBSD__) &&                                         \
     !defined(__ANDROID__) &&                                        \
-    !defined(__DragonFly__) &                                       \
+    !defined(__DragonFly__) &&                                      \
     !defined(__QNX__)
 static int uv__udp_set_source_membership4(uv_udp_t* handle,
                                           const struct sockaddr_in* multicast_addr,
diff --git a/Utilities/cmlibuv/src/uv-common.c b/Utilities/cmlibuv/src/uv-common.c
index 213c7c638b..8bce62edf6 100644
--- a/Utilities/cmlibuv/src/uv-common.c
+++ b/Utilities/cmlibuv/src/uv-common.c
@@ -834,6 +834,25 @@ void uv_loop_delete(uv_loop_t* loop) {
 }
 
 
+int uv_read_start(uv_stream_t* stream,
+                  uv_alloc_cb alloc_cb,
+                  uv_read_cb read_cb) {
+  if (stream == NULL || alloc_cb == NULL || read_cb == NULL)
+    return UV_EINVAL;
+
+  if (stream->flags & UV_HANDLE_CLOSING)
+    return UV_EINVAL;
+
+  if (stream->flags & UV_HANDLE_READING)
+    return UV_EALREADY;
+
+  if (!(stream->flags & UV_HANDLE_READABLE))
+    return UV_ENOTCONN;
+
+  return uv__read_start(stream, alloc_cb, read_cb);
+}
+
+
 void uv_os_free_environ(uv_env_item_t* envitems, int count) {
   int i;
 
@@ -855,7 +874,11 @@ void uv_free_cpu_info(uv_cpu_info_t* cpu_infos, int count) {
 }
 
 
-#ifdef __GNUC__  /* Also covers __clang__, __LCC__, and __INTEL_COMPILER. */
+/* Also covers __clang__ and __INTEL_COMPILER. Disabled on Windows because
+ * threads have already been forcibly terminated by the operating system
+ * by the time destructors run, ergo, it's not safe to try to clean them up.
+ */
+#if defined(__GNUC__) && !defined(_WIN32)
 __attribute__((destructor))
 #endif
 void uv_library_shutdown(void) {
diff --git a/Utilities/cmlibuv/src/uv-common.h b/Utilities/cmlibuv/src/uv-common.h
index e851291cc0..8a190bf8fa 100644
--- a/Utilities/cmlibuv/src/uv-common.h
+++ b/Utilities/cmlibuv/src/uv-common.h
@@ -68,6 +68,8 @@ extern int snprintf(char*, size_t, const char*, ...);
 #define uv__store_relaxed(p, v) do *p = v; while (0)
 #endif
 
+#define UV__UDP_DGRAM_MAXSIZE (64 * 1024)
+
 /* Handle flags. Some flags are specific to Windows or UNIX. */
 enum {
   /* Used by all handles. */
@@ -106,8 +108,7 @@ enum {
   UV_HANDLE_TCP_KEEPALIVE               = 0x02000000,
   UV_HANDLE_TCP_SINGLE_ACCEPT           = 0x04000000,
   UV_HANDLE_TCP_ACCEPT_STATE_CHANGING   = 0x08000000,
-  UV_HANDLE_TCP_SOCKET_CLOSED           = 0x10000000,
-  UV_HANDLE_SHARED_TCP_SOCKET           = 0x20000000,
+  UV_HANDLE_SHARED_TCP_SOCKET           = 0x10000000,
 
   /* Only used by uv_udp_t handles. */
   UV_HANDLE_UDP_PROCESSING              = 0x01000000,
@@ -136,6 +137,10 @@ int uv__loop_configure(uv_loop_t* loop, uv_loop_option option, va_list ap);
 
 void uv__loop_close(uv_loop_t* loop);
 
+int uv__read_start(uv_stream_t* stream,
+                   uv_alloc_cb alloc_cb,
+                   uv_read_cb read_cb);
+
 int uv__tcp_bind(uv_tcp_t* tcp,
                  const struct sockaddr* addr,
                  unsigned int addrlen,
diff --git a/Utilities/cmlibuv/src/win/error.c b/Utilities/cmlibuv/src/win/error.c
index 3ec984c83e..3a269da87a 100644
--- a/Utilities/cmlibuv/src/win/error.c
+++ b/Utilities/cmlibuv/src/win/error.c
@@ -105,7 +105,6 @@ int uv_translate_sys_error(int sys_errno) {
     case ERROR_SYMLINK_NOT_SUPPORTED:       return UV_EINVAL;
     case WSAEINVAL:                         return UV_EINVAL;
     case WSAEPFNOSUPPORT:                   return UV_EINVAL;
-    case WSAESOCKTNOSUPPORT:                return UV_EINVAL;
     case ERROR_BEGINNING_OF_MEDIA:          return UV_EIO;
     case ERROR_BUS_RESET:                   return UV_EIO;
     case ERROR_CRC:                         return UV_EIO;
@@ -168,6 +167,7 @@ int uv_translate_sys_error(int sys_errno) {
     case ERROR_NOT_SAME_DEVICE:             return UV_EXDEV;
     case ERROR_INVALID_FUNCTION:            return UV_EISDIR;
     case ERROR_META_EXPANSION_TOO_LONG:     return UV_E2BIG;
+    case WSAESOCKTNOSUPPORT:                return UV_ESOCKTNOSUPPORT;
     default:                                return UV_UNKNOWN;
   }
 }
diff --git a/Utilities/cmlibuv/src/win/fs-event.c b/Utilities/cmlibuv/src/win/fs-event.c
index 0126c5eded..76da077551 100644
--- a/Utilities/cmlibuv/src/win/fs-event.c
+++ b/Utilities/cmlibuv/src/win/fs-event.c
@@ -574,10 +574,10 @@ void uv_process_fs_event_req(uv_loop_t* loop, uv_req_t* req,
     handle->cb(handle, NULL, 0, uv_translate_sys_error(err));
   }
 
-  if (!(handle->flags & UV_HANDLE_CLOSING)) {
-    uv_fs_event_queue_readdirchanges(loop, handle);
-  } else {
+  if (handle->flags & UV_HANDLE_CLOSING) {
     uv_want_endgame(loop, (uv_handle_t*)handle);
+  } else if (uv__is_active(handle)) {
+    uv_fs_event_queue_readdirchanges(loop, handle);
   }
 }
 
diff --git a/Utilities/cmlibuv/src/win/fs.c b/Utilities/cmlibuv/src/win/fs.c
index d6ff7ed291..903764144f 100644
--- a/Utilities/cmlibuv/src/win/fs.c
+++ b/Utilities/cmlibuv/src/win/fs.c
@@ -92,30 +92,24 @@
     return;                                                                 \
   }
 
-#define MILLIONu (1000U * 1000U)
-#define BILLIONu (1000U * 1000U * 1000U)
+#define MILLION ((int64_t) 1000 * 1000)
+#define BILLION ((int64_t) 1000 * 1000 * 1000)
 
-#define FILETIME_TO_UINT(filetime)                                          \
-   (*((uint64_t*) &(filetime)) - (uint64_t) 116444736 * BILLIONu)
-
-#define FILETIME_TO_TIME_T(filetime)                                        \
-   (FILETIME_TO_UINT(filetime) / (10u * MILLIONu))
-
-#define FILETIME_TO_TIME_NS(filetime, secs)                                 \
-   ((FILETIME_TO_UINT(filetime) - (secs * (uint64_t) 10 * MILLIONu)) * 100U)
-
-#define FILETIME_TO_TIMESPEC(ts, filetime)                                  \
-   do {                                                                     \
-     (ts).tv_sec = (long) FILETIME_TO_TIME_T(filetime);                     \
-     (ts).tv_nsec = (long) FILETIME_TO_TIME_NS(filetime, (ts).tv_sec);      \
-   } while(0)
+static void uv__filetime_to_timespec(uv_timespec_t *ts, int64_t filetime) {
+  filetime -= 116444736 * BILLION;
+  ts->tv_sec = (long) (filetime / (10 * MILLION));
+  ts->tv_nsec = (long) ((filetime - ts->tv_sec * 10 * MILLION) * 100U);
+  if (ts->tv_nsec < 0) {
+    ts->tv_sec -= 1;
+    ts->tv_nsec += 1e9;
+  }
+}
 
 #define TIME_T_TO_FILETIME(time, filetime_ptr)                              \
   do {                                                                      \
-    uint64_t bigtime = ((uint64_t) ((time) * (uint64_t) 10 * MILLIONu)) +   \
-                       (uint64_t) 116444736 * BILLIONu;                     \
-    (filetime_ptr)->dwLowDateTime = bigtime & 0xFFFFFFFF;                   \
-    (filetime_ptr)->dwHighDateTime = bigtime >> 32;                         \
+    int64_t bigtime = ((time) * 10 * MILLION + 116444736 * BILLION);        \
+    (filetime_ptr)->dwLowDateTime = (uint64_t) bigtime & 0xFFFFFFFF;        \
+    (filetime_ptr)->dwHighDateTime = (uint64_t) bigtime >> 32;              \
   } while(0)
 
 #define IS_SLASH(c) ((c) == L'\\' || (c) == L'/')
@@ -764,7 +758,7 @@ void fs__read_filemap(uv_fs_t* req, struct uv__fd_info_s* fd_info) {
   void* view;
 
   if (rw_flags == UV_FS_O_WRONLY) {
-    SET_REQ_WIN32_ERROR(req, ERROR_ACCESS_DENIED);
+    SET_REQ_WIN32_ERROR(req, ERROR_INVALID_FLAGS);
     return;
   }
   if (fd_info->is_directory) {
@@ -918,6 +912,11 @@ void fs__read(uv_fs_t* req) {
     SET_REQ_RESULT(req, bytes);
   } else {
     error = GetLastError();
+
+    if (error == ERROR_ACCESS_DENIED) {
+      error = ERROR_INVALID_FLAGS;
+    }
+
     if (error == ERROR_HANDLE_EOF) {
       SET_REQ_RESULT(req, bytes);
     } else {
@@ -942,7 +941,7 @@ void fs__write_filemap(uv_fs_t* req, HANDLE file,
   FILETIME ft;
 
   if (rw_flags == UV_FS_O_RDONLY) {
-    SET_REQ_WIN32_ERROR(req, ERROR_ACCESS_DENIED);
+    SET_REQ_WIN32_ERROR(req, ERROR_INVALID_FLAGS);
     return;
   }
   if (fd_info->is_directory) {
@@ -1058,6 +1057,7 @@ void fs__write(uv_fs_t* req) {
   OVERLAPPED overlapped, *overlapped_ptr;
   LARGE_INTEGER offset_;
   DWORD bytes;
+  DWORD error;
   int result;
   unsigned int index;
   LARGE_INTEGER original_position;
@@ -1117,7 +1117,13 @@ void fs__write(uv_fs_t* req) {
   if (result || bytes > 0) {
     SET_REQ_RESULT(req, bytes);
   } else {
-    SET_REQ_WIN32_ERROR(req, GetLastError());
+    error = GetLastError();
+
+    if (error == ERROR_ACCESS_DENIED) {
+      error = ERROR_INVALID_FLAGS;
+    }
+
+    SET_REQ_WIN32_ERROR(req, error);
   }
 }
 
@@ -1224,7 +1230,8 @@ void fs__mkdir(uv_fs_t* req) {
     SET_REQ_RESULT(req, 0);
   } else {
     SET_REQ_WIN32_ERROR(req, GetLastError());
-    if (req->sys_errno_ == ERROR_INVALID_NAME)
+    if (req->sys_errno_ == ERROR_INVALID_NAME ||
+        req->sys_errno_ == ERROR_DIRECTORY)
       req->result = UV_EINVAL;
   }
 }
@@ -1791,10 +1798,14 @@ INLINE static int fs__stat_handle(HANDLE handle, uv_stat_t* statbuf,
     statbuf->st_mode |= (_S_IREAD | _S_IWRITE) | ((_S_IREAD | _S_IWRITE) >> 3) |
                         ((_S_IREAD | _S_IWRITE) >> 6);
 
-  FILETIME_TO_TIMESPEC(statbuf->st_atim, file_info.BasicInformation.LastAccessTime);
-  FILETIME_TO_TIMESPEC(statbuf->st_ctim, file_info.BasicInformation.ChangeTime);
-  FILETIME_TO_TIMESPEC(statbuf->st_mtim, file_info.BasicInformation.LastWriteTime);
-  FILETIME_TO_TIMESPEC(statbuf->st_birthtim, file_info.BasicInformation.CreationTime);
+  uv__filetime_to_timespec(&statbuf->st_atim,
+                           file_info.BasicInformation.LastAccessTime.QuadPart);
+  uv__filetime_to_timespec(&statbuf->st_ctim,
+                           file_info.BasicInformation.ChangeTime.QuadPart);
+  uv__filetime_to_timespec(&statbuf->st_mtim,
+                           file_info.BasicInformation.LastWriteTime.QuadPart);
+  uv__filetime_to_timespec(&statbuf->st_birthtim,
+                           file_info.BasicInformation.CreationTime.QuadPart);
 
   statbuf->st_ino = file_info.InternalInformation.IndexNumber.QuadPart;
 
diff --git a/Utilities/cmlibuv/src/win/internal.h b/Utilities/cmlibuv/src/win/internal.h
index 3f56777c61..7e1aef444a 100644
--- a/Utilities/cmlibuv/src/win/internal.h
+++ b/Utilities/cmlibuv/src/win/internal.h
@@ -119,8 +119,8 @@ void uv_udp_endgame(uv_loop_t* loop, uv_udp_t* handle);
 /*
  * Pipes
  */
-int uv_stdio_pipe_server(uv_loop_t* loop, uv_pipe_t* handle, DWORD access,
-    char* name, size_t nameSize);
+int uv__create_stdio_pipe_pair(uv_loop_t* loop,
+    uv_pipe_t* parent_pipe, HANDLE* child_pipe_ptr, unsigned int flags);
 
 int uv_pipe_listen(uv_pipe_t* handle, int backlog, uv_connection_cb cb);
 int uv_pipe_accept(uv_pipe_t* server, uv_stream_t* client);
diff --git a/Utilities/cmlibuv/src/win/pipe.c b/Utilities/cmlibuv/src/win/pipe.c
index f81245ec60..912aed9b62 100644
--- a/Utilities/cmlibuv/src/win/pipe.c
+++ b/Utilities/cmlibuv/src/win/pipe.c
@@ -202,17 +202,17 @@ static void close_pipe(uv_pipe_t* pipe) {
 }
 
 
-int uv_stdio_pipe_server(uv_loop_t* loop, uv_pipe_t* handle, DWORD access,
-    char* name, size_t nameSize) {
+static int uv__pipe_server(
+    HANDLE* pipeHandle_ptr, DWORD access,
+    char* name, size_t nameSize, char* random) {
   HANDLE pipeHandle;
   int err;
-  char* ptr = (char*)handle;
 
   for (;;) {
-    uv_unique_pipe_name(ptr, name, nameSize);
+    uv_unique_pipe_name(random, name, nameSize);
 
     pipeHandle = CreateNamedPipeA(name,
-      access | FILE_FLAG_OVERLAPPED | FILE_FLAG_FIRST_PIPE_INSTANCE | WRITE_DAC,
+      access | FILE_FLAG_FIRST_PIPE_INSTANCE,
       PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_WAIT, 1, 65536, 65536, 0,
       NULL);
 
@@ -226,26 +226,225 @@ int uv_stdio_pipe_server(uv_loop_t* loop, uv_pipe_t* handle, DWORD access,
       goto error;
     }
 
-    /* Pipe name collision.  Increment the pointer and try again. */
-    ptr++;
+    /* Pipe name collision.  Increment the random number and try again. */
+    random++;
   }
 
-  if (CreateIoCompletionPort(pipeHandle,
+  *pipeHandle_ptr = pipeHandle;
+
+  return 0;
+
+ error:
+  if (pipeHandle != INVALID_HANDLE_VALUE)
+    CloseHandle(pipeHandle);
+
+  return err;
+}
+
+
+static int uv__create_pipe_pair(
+    HANDLE* server_pipe_ptr, HANDLE* client_pipe_ptr,
+    unsigned int server_flags, unsigned int client_flags,
+    int inherit_client, char* random) {
+  /* allowed flags are: UV_READABLE_PIPE | UV_WRITABLE_PIPE | UV_NONBLOCK_PIPE */
+  char pipe_name[64];
+  SECURITY_ATTRIBUTES sa;
+  DWORD server_access;
+  DWORD client_access;
+  HANDLE server_pipe;
+  HANDLE client_pipe;
+  int err;
+
+  server_pipe = INVALID_HANDLE_VALUE;
+  client_pipe = INVALID_HANDLE_VALUE;
+
+  server_access = 0;
+  if (server_flags & UV_READABLE_PIPE)
+    server_access |= PIPE_ACCESS_INBOUND;
+  if (server_flags & UV_WRITABLE_PIPE)
+    server_access |= PIPE_ACCESS_OUTBOUND;
+  if (server_flags & UV_NONBLOCK_PIPE)
+    server_access |= FILE_FLAG_OVERLAPPED;
+  server_access |= WRITE_DAC;
+
+  client_access = 0;
+  if (client_flags & UV_READABLE_PIPE)
+    client_access |= GENERIC_READ;
+  else
+    client_access |= FILE_READ_ATTRIBUTES;
+  if (client_flags & UV_WRITABLE_PIPE)
+    client_access |= GENERIC_WRITE;
+  else
+    client_access |= FILE_WRITE_ATTRIBUTES;
+  client_access |= WRITE_DAC;
+
+  /* Create server pipe handle. */
+  err = uv__pipe_server(&server_pipe,
+                        server_access,
+                        pipe_name,
+                        sizeof(pipe_name),
+                        random);
+  if (err)
+    goto error;
+
+  /* Create client pipe handle. */
+  sa.nLength = sizeof sa;
+  sa.lpSecurityDescriptor = NULL;
+  sa.bInheritHandle = inherit_client;
+
+  client_pipe = CreateFileA(pipe_name,
+                            client_access,
+                            0,
+                            &sa,
+                            OPEN_EXISTING,
+                            (client_flags & UV_NONBLOCK_PIPE) ? FILE_FLAG_OVERLAPPED : 0,
+                            NULL);
+  if (client_pipe == INVALID_HANDLE_VALUE) {
+    err = GetLastError();
+    goto error;
+  }
+
+#ifndef NDEBUG
+  /* Validate that the pipe was opened in the right mode. */
+  {
+    DWORD mode;
+    BOOL r;
+    r = GetNamedPipeHandleState(client_pipe, &mode, NULL, NULL, NULL, NULL, 0);
+    if (r == TRUE) {
+      assert(mode == (PIPE_READMODE_BYTE | PIPE_WAIT));
+    } else {
+      fprintf(stderr, "libuv assertion failure: GetNamedPipeHandleState failed\n");
+    }
+  }
+#endif
+
+  /* Do a blocking ConnectNamedPipe.  This should not block because we have
+   * both ends of the pipe created. */
+  if (!ConnectNamedPipe(server_pipe, NULL)) {
+    if (GetLastError() != ERROR_PIPE_CONNECTED) {
+      err = GetLastError();
+      goto error;
+    }
+  }
+
+  *client_pipe_ptr = client_pipe;
+  *server_pipe_ptr = server_pipe;
+  return 0;
+
+ error:
+  if (server_pipe != INVALID_HANDLE_VALUE)
+    CloseHandle(server_pipe);
+
+  if (client_pipe != INVALID_HANDLE_VALUE)
+    CloseHandle(client_pipe);
+
+  return err;
+}
+
+
+int uv_pipe(uv_file fds[2], int read_flags, int write_flags) {
+  uv_file temp[2];
+  int err;
+  HANDLE readh;
+  HANDLE writeh;
+
+  /* Make the server side the inbound (read) end, */
+  /* so that both ends will have FILE_READ_ATTRIBUTES permission. */
+  /* TODO: better source of local randomness than &fds? */
+  read_flags |= UV_READABLE_PIPE;
+  write_flags |= UV_WRITABLE_PIPE;
+  err = uv__create_pipe_pair(&readh, &writeh, read_flags, write_flags, 0, (char*) &fds[0]);
+  if (err != 0)
+    return err;
+  temp[0] = _open_osfhandle((intptr_t) readh, 0);
+  if (temp[0] == -1) {
+    if (errno == UV_EMFILE)
+      err = UV_EMFILE;
+    else
+      err = UV_UNKNOWN;
+    CloseHandle(readh);
+    CloseHandle(writeh);
+    return err;
+  }
+  temp[1] = _open_osfhandle((intptr_t) writeh, 0);
+  if (temp[1] == -1) {
+    if (errno == UV_EMFILE)
+      err = UV_EMFILE;
+    else
+      err = UV_UNKNOWN;
+    _close(temp[0]);
+    CloseHandle(writeh);
+    return err;
+  }
+  fds[0] = temp[0];
+  fds[1] = temp[1];
+  return 0;
+}
+
+
+int uv__create_stdio_pipe_pair(uv_loop_t* loop,
+    uv_pipe_t* parent_pipe, HANDLE* child_pipe_ptr, unsigned int flags) {
+  /* The parent_pipe is always the server_pipe and kept by libuv.
+   * The child_pipe is always the client_pipe and is passed to the child.
+   * The flags are specified with respect to their usage in the child. */
+  HANDLE server_pipe;
+  HANDLE client_pipe;
+  unsigned int server_flags;
+  unsigned int client_flags;
+  int err;
+
+  server_pipe = INVALID_HANDLE_VALUE;
+  client_pipe = INVALID_HANDLE_VALUE;
+
+  server_flags = 0;
+  client_flags = 0;
+  if (flags & UV_READABLE_PIPE) {
+    /* The server needs inbound (read) access too, otherwise CreateNamedPipe()
+     * won't give us the FILE_READ_ATTRIBUTES permission. We need that to probe
+     * the state of the write buffer when we're trying to shutdown the pipe. */
+    server_flags |= UV_READABLE_PIPE | UV_WRITABLE_PIPE;
+    client_flags |= UV_READABLE_PIPE;
+  }
+  if (flags & UV_WRITABLE_PIPE) {
+    server_flags |= UV_READABLE_PIPE;
+    client_flags |= UV_WRITABLE_PIPE;
+  }
+  server_flags |= UV_NONBLOCK_PIPE;
+  if (flags & UV_NONBLOCK_PIPE || parent_pipe->ipc) {
+    client_flags |= UV_NONBLOCK_PIPE;
+  }
+
+  err = uv__create_pipe_pair(&server_pipe, &client_pipe,
+          server_flags, client_flags, 1, (char*) server_pipe);
+  if (err)
+    goto error;
+
+  if (CreateIoCompletionPort(server_pipe,
                              loop->iocp,
-                             (ULONG_PTR)handle,
+                             (ULONG_PTR) parent_pipe,
                              0) == NULL) {
     err = GetLastError();
     goto error;
   }
 
-  uv_pipe_connection_init(handle);
-  handle->handle = pipeHandle;
+  uv_pipe_connection_init(parent_pipe);
+  parent_pipe->handle = server_pipe;
+  *child_pipe_ptr = client_pipe;
+
+  /* The server end is now readable and/or writable. */
+  if (flags & UV_READABLE_PIPE)
+    parent_pipe->flags |= UV_HANDLE_WRITABLE;
+  if (flags & UV_WRITABLE_PIPE)
+    parent_pipe->flags |= UV_HANDLE_READABLE;
 
   return 0;
 
  error:
-  if (pipeHandle != INVALID_HANDLE_VALUE)
-    CloseHandle(pipeHandle);
+  if (server_pipe != INVALID_HANDLE_VALUE)
+    CloseHandle(server_pipe);
+
+  if (client_pipe != INVALID_HANDLE_VALUE)
+    CloseHandle(client_pipe);
 
   return err;
 }
@@ -712,9 +911,8 @@ error:
     handle->name = NULL;
   }
 
-  if (pipeHandle != INVALID_HANDLE_VALUE) {
+  if (pipeHandle != INVALID_HANDLE_VALUE)
     CloseHandle(pipeHandle);
-  }
 
   /* Make this req pending reporting an error. */
   SET_REQ_ERROR(req, err);
@@ -1054,7 +1252,6 @@ static DWORD WINAPI uv_pipe_writefile_thread_proc(void* parameter) {
   assert(req != NULL);
   assert(req->type == UV_WRITE);
   assert(handle->type == UV_NAMED_PIPE);
-  assert(req->write_buffer.base);
 
   result = WriteFile(handle->handle,
                      req->write_buffer.base,
diff --git a/Utilities/cmlibuv/src/win/poll.c b/Utilities/cmlibuv/src/win/poll.c
index 87858590c8..9d37759606 100644
--- a/Utilities/cmlibuv/src/win/poll.c
+++ b/Utilities/cmlibuv/src/win/poll.c
@@ -488,7 +488,8 @@ static int uv__poll_set(uv_poll_t* handle, int events, uv_poll_cb cb) {
 
   assert(handle->type == UV_POLL);
   assert(!(handle->flags & UV_HANDLE_CLOSING));
-  assert((events & ~(UV_READABLE | UV_WRITABLE | UV_DISCONNECT)) == 0);
+  assert((events & ~(UV_READABLE | UV_WRITABLE | UV_DISCONNECT |
+                     UV_PRIORITIZED)) == 0);
 
   handle->events = events;
   handle->poll_cb = cb;
diff --git a/Utilities/cmlibuv/src/win/process-stdio.c b/Utilities/cmlibuv/src/win/process-stdio.c
index 355d618808..0db3572373 100644
--- a/Utilities/cmlibuv/src/win/process-stdio.c
+++ b/Utilities/cmlibuv/src/win/process-stdio.c
@@ -95,102 +95,6 @@ void uv_disable_stdio_inheritance(void) {
 }
 
 
-static int uv__create_stdio_pipe_pair(uv_loop_t* loop,
-    uv_pipe_t* server_pipe, HANDLE* child_pipe_ptr, unsigned int flags) {
-  char pipe_name[64];
-  SECURITY_ATTRIBUTES sa;
-  DWORD server_access = 0;
-  DWORD client_access = 0;
-  HANDLE child_pipe = INVALID_HANDLE_VALUE;
-  int err;
-  int overlap;
-
-  if (flags & UV_READABLE_PIPE) {
-    /* The server needs inbound access too, otherwise CreateNamedPipe() won't
-     * give us the FILE_READ_ATTRIBUTES permission. We need that to probe the
-     * state of the write buffer when we're trying to shutdown the pipe. */
-    server_access |= PIPE_ACCESS_OUTBOUND | PIPE_ACCESS_INBOUND;
-    client_access |= GENERIC_READ | FILE_WRITE_ATTRIBUTES;
-  }
-  if (flags & UV_WRITABLE_PIPE) {
-    server_access |= PIPE_ACCESS_INBOUND;
-    client_access |= GENERIC_WRITE | FILE_READ_ATTRIBUTES;
-  }
-
-  /* Create server pipe handle. */
-  err = uv_stdio_pipe_server(loop,
-                             server_pipe,
-                             server_access,
-                             pipe_name,
-                             sizeof(pipe_name));
-  if (err)
-    goto error;
-
-  /* Create child pipe handle. */
-  sa.nLength = sizeof sa;
-  sa.lpSecurityDescriptor = NULL;
-  sa.bInheritHandle = TRUE;
-
-  overlap = server_pipe->ipc || (flags & UV_OVERLAPPED_PIPE);
-  child_pipe = CreateFileA(pipe_name,
-                           client_access,
-                           0,
-                           &sa,
-                           OPEN_EXISTING,
-                           overlap ? FILE_FLAG_OVERLAPPED : 0,
-                           NULL);
-  if (child_pipe == INVALID_HANDLE_VALUE) {
-    err = GetLastError();
-    goto error;
-  }
-
-#ifndef NDEBUG
-  /* Validate that the pipe was opened in the right mode. */
-  {
-    DWORD mode;
-    BOOL r = GetNamedPipeHandleState(child_pipe,
-                                     &mode,
-                                     NULL,
-                                     NULL,
-                                     NULL,
-                                     NULL,
-                                     0);
-    assert(r == TRUE);
-    assert(mode == (PIPE_READMODE_BYTE | PIPE_WAIT));
-  }
-#endif
-
-  /* Do a blocking ConnectNamedPipe. This should not block because we have both
-   * ends of the pipe created. */
-  if (!ConnectNamedPipe(server_pipe->handle, NULL)) {
-    if (GetLastError() != ERROR_PIPE_CONNECTED) {
-      err = GetLastError();
-      goto error;
-    }
-  }
-
-  /* The server end is now readable and/or writable. */
-  if (flags & UV_READABLE_PIPE)
-    server_pipe->flags |= UV_HANDLE_WRITABLE;
-  if (flags & UV_WRITABLE_PIPE)
-    server_pipe->flags |= UV_HANDLE_READABLE;
-
-  *child_pipe_ptr = child_pipe;
-  return 0;
-
- error:
-  if (server_pipe->handle != INVALID_HANDLE_VALUE) {
-    uv_pipe_cleanup(loop, server_pipe);
-  }
-
-  if (child_pipe != INVALID_HANDLE_VALUE) {
-    CloseHandle(child_pipe);
-  }
-
-  return err;
-}
-
-
 static int uv__duplicate_handle(uv_loop_t* loop, HANDLE handle, HANDLE* dup) {
   HANDLE current_process;
 
diff --git a/Utilities/cmlibuv/src/win/process.c b/Utilities/cmlibuv/src/win/process.c
index aada889e16..9ca4122caa 100644
--- a/Utilities/cmlibuv/src/win/process.c
+++ b/Utilities/cmlibuv/src/win/process.c
@@ -169,10 +169,9 @@ static WCHAR* search_path_join_test(const WCHAR* dir,
                                     size_t cwd_len) {
   WCHAR *result, *result_pos;
   DWORD attrs;
-  if (
-    (dir_len > 2 && dir[0] == L'\\' && dir[1] == L'\\') ||
-    (dir_len > 2 && dir[0] == L'/' && dir[1] == L'/') 
-   ) {
+  if (dir_len > 2 &&
+      ((dir[0] == L'\\' || dir[0] == L'/') &&
+       (dir[1] == L'\\' || dir[1] == L'/'))) {
     /* It's a UNC path so ignore cwd */
     cwd_len = 0;
   } else if (dir_len >= 1 && (dir[0] == L'/' || dir[0] == L'\\')) {
@@ -645,7 +644,7 @@ int env_strncmp(const wchar_t* a, int na, const wchar_t* b) {
   assert(r==nb);
   B[nb] = L'\0';
 
-  while (1) {
+  for (;;) {
     wchar_t AA = *A++;
     wchar_t BB = *B++;
     if (AA < BB) {
diff --git a/Utilities/cmlibuv/src/win/stream.c b/Utilities/cmlibuv/src/win/stream.c
index 46a0709a38..abf477f644 100644
--- a/Utilities/cmlibuv/src/win/stream.c
+++ b/Utilities/cmlibuv/src/win/stream.c
@@ -65,18 +65,11 @@ int uv_accept(uv_stream_t* server, uv_stream_t* client) {
 }
 
 
-int uv_read_start(uv_stream_t* handle, uv_alloc_cb alloc_cb,
-    uv_read_cb read_cb) {
+int uv__read_start(uv_stream_t* handle,
+                   uv_alloc_cb alloc_cb,
+                   uv_read_cb read_cb) {
   int err;
 
-  if (handle->flags & UV_HANDLE_READING) {
-    return UV_EALREADY;
-  }
-
-  if (!(handle->flags & UV_HANDLE_READABLE)) {
-    return UV_ENOTCONN;
-  }
-
   err = ERROR_INVALID_PARAMETER;
   switch (handle->type) {
     case UV_TCP:
@@ -195,6 +188,16 @@ int uv_try_write(uv_stream_t* stream,
 }
 
 
+int uv_try_write2(uv_stream_t* stream,
+                  const uv_buf_t bufs[],
+                  unsigned int nbufs,
+                  uv_stream_t* send_handle) {
+  if (send_handle != NULL)
+    return UV_EAGAIN;
+  return uv_try_write(stream, bufs, nbufs);
+}
+
+
 int uv_shutdown(uv_shutdown_t* req, uv_stream_t* handle, uv_shutdown_cb cb) {
   uv_loop_t* loop = handle->loop;
 
diff --git a/Utilities/cmlibuv/src/win/tcp.c b/Utilities/cmlibuv/src/win/tcp.c
index 0dcaa97df7..cf2dbd85fd 100644
--- a/Utilities/cmlibuv/src/win/tcp.c
+++ b/Utilities/cmlibuv/src/win/tcp.c
@@ -236,12 +236,7 @@ void uv_tcp_endgame(uv_loop_t* loop, uv_tcp_t* handle) {
   if (handle->flags & UV_HANDLE_CLOSING &&
       handle->reqs_pending == 0) {
     assert(!(handle->flags & UV_HANDLE_CLOSED));
-
-    if (!(handle->flags & UV_HANDLE_TCP_SOCKET_CLOSED)) {
-      closesocket(handle->socket);
-      handle->socket = INVALID_SOCKET;
-      handle->flags |= UV_HANDLE_TCP_SOCKET_CLOSED;
-    }
+    assert(handle->socket == INVALID_SOCKET);
 
     if (!(handle->flags & UV_HANDLE_CONNECTION) && handle->tcp.serv.accept_reqs) {
       if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
@@ -599,6 +594,7 @@ int uv_tcp_listen(uv_tcp_t* handle, int backlog, uv_connection_cb cb) {
     }
   }
 
+  /* If this flag is set, we already made this listen call in xfer. */
   if (!(handle->flags & UV_HANDLE_SHARED_TCP_SOCKET) &&
       listen(handle->socket, backlog) == SOCKET_ERROR) {
     return WSAGetLastError();
@@ -769,7 +765,7 @@ static int uv__is_loopback(const struct sockaddr_storage* storage) {
 }
 
 // Check if Windows version is 10.0.16299 or later
-static int uv__is_fast_loopback_fail_supported() {
+static int uv__is_fast_loopback_fail_supported(void) {
   OSVERSIONINFOW os_info;
   if (!pRtlGetVersion)
     return 0;
@@ -800,9 +796,8 @@ static int uv_tcp_try_connect(uv_connect_t* req,
   if (err)
     return err;
 
-  if (handle->delayed_error) {
-    return handle->delayed_error;
-  }
+  if (handle->delayed_error != 0)
+    goto out;
 
   if (!(handle->flags & UV_HANDLE_BOUND)) {
     if (addrlen == sizeof(uv_addr_ip4_any_)) {
@@ -815,8 +810,8 @@ static int uv_tcp_try_connect(uv_connect_t* req,
     err = uv_tcp_try_bind(handle, bind_addr, addrlen, 0);
     if (err)
       return err;
-    if (handle->delayed_error)
-      return handle->delayed_error;
+    if (handle->delayed_error != 0)
+      goto out;
   }
 
   if (!handle->tcp.conn.func_connectex) {
@@ -844,11 +839,21 @@ static int uv_tcp_try_connect(uv_connect_t* req,
              NULL);
   }
 
+out:
+
   UV_REQ_INIT(req, UV_CONNECT);
   req->handle = (uv_stream_t*) handle;
   req->cb = cb;
   memset(&req->u.io.overlapped, 0, sizeof(req->u.io.overlapped));
 
+  if (handle->delayed_error != 0) {
+    /* Process the req without IOCP. */
+    handle->reqs_pending++;
+    REGISTER_HANDLE_REQ(loop, handle, req);
+    uv_insert_pending_req(loop, (uv_req_t*)req);
+    return 0;
+  }
+
   success = handle->tcp.conn.func_connectex(handle->socket,
                                             (const struct sockaddr*) &converted,
                                             addrlen,
@@ -1015,6 +1020,7 @@ void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
          */
         err = WSAECONNRESET;
       }
+      handle->flags &= ~(UV_HANDLE_READABLE | UV_HANDLE_WRITABLE);
 
       handle->read_cb((uv_stream_t*)handle,
                       uv_translate_sys_error(err),
@@ -1096,6 +1102,7 @@ void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
              * Unix. */
             err = WSAECONNRESET;
           }
+          handle->flags &= ~(UV_HANDLE_READABLE | UV_HANDLE_WRITABLE);
 
           handle->read_cb((uv_stream_t*)handle,
                           uv_translate_sys_error(err),
@@ -1149,9 +1156,14 @@ void uv_process_tcp_write_req(uv_loop_t* loop, uv_tcp_t* handle,
   }
 
   handle->stream.conn.write_reqs_pending--;
-  if (handle->stream.conn.shutdown_req != NULL &&
-      handle->stream.conn.write_reqs_pending == 0) {
-    uv_want_endgame(loop, (uv_handle_t*)handle);
+  if (handle->stream.conn.write_reqs_pending == 0) {
+    if (handle->flags & UV_HANDLE_CLOSING) {
+      closesocket(handle->socket);
+      handle->socket = INVALID_SOCKET;
+    }
+    if (handle->stream.conn.shutdown_req != NULL) {
+      uv_want_endgame(loop, (uv_handle_t*)handle);
+    }
   }
 
   DECREASE_PENDING_REQ_COUNT(handle);
@@ -1215,7 +1227,14 @@ void uv_process_tcp_connect_req(uv_loop_t* loop, uv_tcp_t* handle,
   UNREGISTER_HANDLE_REQ(loop, handle, req);
 
   err = 0;
-  if (REQ_SUCCESS(req)) {
+  if (handle->delayed_error) {
+    /* To smooth over the differences between unixes errors that
+     * were reported synchronously on the first connect can be delayed
+     * until the next tick--which is now.
+     */
+    err = handle->delayed_error;
+    handle->delayed_error = 0;
+  } else if (REQ_SUCCESS(req)) {
     if (handle->flags & UV_HANDLE_CLOSING) {
       /* use UV_ECANCELED for consistency with Unix */
       err = ERROR_OPERATION_ABORTED;
@@ -1320,7 +1339,7 @@ int uv_tcp_nodelay(uv_tcp_t* handle, int enable) {
   if (handle->socket != INVALID_SOCKET) {
     err = uv__tcp_nodelay(handle, handle->socket, enable);
     if (err)
-      return err;
+      return uv_translate_sys_error(err);
   }
 
   if (enable) {
@@ -1339,7 +1358,7 @@ int uv_tcp_keepalive(uv_tcp_t* handle, int enable, unsigned int delay) {
   if (handle->socket != INVALID_SOCKET) {
     err = uv__tcp_keepalive(handle, handle->socket, enable, delay);
     if (err)
-      return err;
+      return uv_translate_sys_error(err);
   }
 
   if (enable) {
@@ -1386,9 +1405,24 @@ int uv_tcp_simultaneous_accepts(uv_tcp_t* handle, int enable) {
 }
 
 
-static int uv_tcp_try_cancel_io(uv_tcp_t* tcp) {
-  SOCKET socket = tcp->socket;
+static void uv_tcp_try_cancel_reqs(uv_tcp_t* tcp) {
+  SOCKET socket;
   int non_ifs_lsp;
+  int reading;
+  int writing;
+
+  socket = tcp->socket;
+  reading = tcp->flags & UV_HANDLE_READING;
+  writing = tcp->stream.conn.write_reqs_pending > 0;
+  if (!reading && !writing)
+    return;
+
+  /* TODO: in libuv v2, keep explicit track of write_reqs, so we can cancel
+   * them each explicitly with CancelIoEx (like unix). */
+  if (reading)
+    CancelIoEx((HANDLE) socket, &tcp->read_req.u.io.overlapped);
+  if (writing)
+    CancelIo((HANDLE) socket);
 
   /* Check if we have any non-IFS LSPs stacked on top of TCP */
   non_ifs_lsp = (tcp->flags & UV_HANDLE_IPV6) ? uv_tcp_non_ifs_lsp_ipv6 :
@@ -1408,71 +1442,41 @@ static int uv_tcp_try_cancel_io(uv_tcp_t* tcp) {
                  NULL,
                  NULL) != 0) {
       /* Failed. We can't do CancelIo. */
-      return -1;
+      return;
     }
   }
 
   assert(socket != 0 && socket != INVALID_SOCKET);
 
-  if (!CancelIo((HANDLE) socket)) {
-    return GetLastError();
+  if (socket != tcp->socket) {
+    if (reading)
+      CancelIoEx((HANDLE) socket, &tcp->read_req.u.io.overlapped);
+    if (writing)
+      CancelIo((HANDLE) socket);
   }
-
-  /* It worked. */
-  return 0;
 }
 
 
 void uv_tcp_close(uv_loop_t* loop, uv_tcp_t* tcp) {
-  int close_socket = 1;
-
-  if (tcp->flags & UV_HANDLE_READ_PENDING) {
-    /* In order for winsock to do a graceful close there must not be any any
-     * pending reads, or the socket must be shut down for writing */
-    if (!(tcp->flags & UV_HANDLE_SHARED_TCP_SOCKET)) {
-      /* Just do shutdown on non-shared sockets, which ensures graceful close. */
-      shutdown(tcp->socket, SD_SEND);
-
-    } else if (uv_tcp_try_cancel_io(tcp) == 0) {
-      /* In case of a shared socket, we try to cancel all outstanding I/O,. If
-       * that works, don't close the socket yet - wait for the read req to
-       * return and close the socket in uv_tcp_endgame. */
-      close_socket = 0;
-
-    } else {
-      /* When cancelling isn't possible - which could happen when an LSP is
-       * present on an old Windows version, we will have to close the socket
-       * with a read pending. That is not nice because trailing sent bytes may
-       * not make it to the other side. */
+  if (tcp->flags & UV_HANDLE_CONNECTION) {
+    uv_tcp_try_cancel_reqs(tcp);
+    if (tcp->flags & UV_HANDLE_READING) {
+      uv_read_stop((uv_stream_t*) tcp);
     }
-
-  } else if ((tcp->flags & UV_HANDLE_SHARED_TCP_SOCKET) &&
-             tcp->tcp.serv.accept_reqs != NULL) {
-    /* Under normal circumstances closesocket() will ensure that all pending
-     * accept reqs are canceled. However, when the socket is shared the
-     * presence of another reference to the socket in another process will keep
-     * the accept reqs going, so we have to ensure that these are canceled. */
-    if (uv_tcp_try_cancel_io(tcp) != 0) {
-      /* When cancellation is not possible, there is another option: we can
-       * close the incoming sockets, which will also cancel the accept
-       * operations. However this is not cool because we might inadvertently
-       * close a socket that just accepted a new connection, which will cause
-       * the connection to be aborted. */
+  } else {
+    if (tcp->tcp.serv.accept_reqs != NULL) {
+      /* First close the incoming sockets to cancel the accept operations before
+       * we free their resources. */
       unsigned int i;
       for (i = 0; i < uv_simultaneous_server_accepts; i++) {
         uv_tcp_accept_t* req = &tcp->tcp.serv.accept_reqs[i];
-        if (req->accept_socket != INVALID_SOCKET &&
-            !HasOverlappedIoCompleted(&req->u.io.overlapped)) {
+        if (req->accept_socket != INVALID_SOCKET) {
           closesocket(req->accept_socket);
           req->accept_socket = INVALID_SOCKET;
         }
       }
     }
-  }
-
-  if (tcp->flags & UV_HANDLE_READING) {
-    tcp->flags &= ~UV_HANDLE_READING;
-    DECREASE_ACTIVE_COUNT(loop, tcp);
+    assert(!(tcp->flags & UV_HANDLE_READING));
   }
 
   if (tcp->flags & UV_HANDLE_LISTENING) {
@@ -1480,10 +1484,15 @@ void uv_tcp_close(uv_loop_t* loop, uv_tcp_t* tcp) {
     DECREASE_ACTIVE_COUNT(loop, tcp);
   }
 
-  if (close_socket) {
+  /* If any overlapped req failed to cancel, calling `closesocket` now would
+   * cause Win32 to send an RST packet. Try to avoid that for writes, if
+   * possibly applicable, by waiting to process the completion notifications
+   * first (which typically should be cancellations). There's not much we can
+   * do about canceled reads, which also will generate an RST packet. */
+  if (!(tcp->flags & UV_HANDLE_CONNECTION) ||
+      tcp->stream.conn.write_reqs_pending == 0) {
     closesocket(tcp->socket);
     tcp->socket = INVALID_SOCKET;
-    tcp->flags |= UV_HANDLE_TCP_SOCKET_CLOSED;
   }
 
   tcp->flags &= ~(UV_HANDLE_READABLE | UV_HANDLE_WRITABLE);
@@ -1571,3 +1580,118 @@ int uv__tcp_connect(uv_connect_t* req,
 
   return 0;
 }
+
+#ifndef WSA_FLAG_NO_HANDLE_INHERIT
+/* Added in Windows 7 SP1. Specify this to avoid race conditions, */
+/* but also manually clear the inherit flag in case this failed. */
+#define WSA_FLAG_NO_HANDLE_INHERIT 0x80
+#endif
+
+int uv_socketpair(int type, int protocol, uv_os_sock_t fds[2], int flags0, int flags1) {
+  SOCKET server = INVALID_SOCKET;
+  SOCKET client0 = INVALID_SOCKET;
+  SOCKET client1 = INVALID_SOCKET;
+  SOCKADDR_IN name;
+  LPFN_ACCEPTEX func_acceptex;
+  WSAOVERLAPPED overlap;
+  char accept_buffer[sizeof(struct sockaddr_storage) * 2 + 32];
+  int namelen;
+  int err;
+  DWORD bytes;
+  DWORD flags;
+  DWORD client0_flags = WSA_FLAG_NO_HANDLE_INHERIT;
+  DWORD client1_flags = WSA_FLAG_NO_HANDLE_INHERIT;
+
+  if (flags0 & UV_NONBLOCK_PIPE)
+      client0_flags |= WSA_FLAG_OVERLAPPED;
+  if (flags1 & UV_NONBLOCK_PIPE)
+      client1_flags |= WSA_FLAG_OVERLAPPED;
+
+  server = WSASocketW(AF_INET, type, protocol, NULL, 0,
+                      WSA_FLAG_OVERLAPPED | WSA_FLAG_NO_HANDLE_INHERIT);
+  if (server == INVALID_SOCKET)
+    goto wsaerror;
+  if (!SetHandleInformation((HANDLE) server, HANDLE_FLAG_INHERIT, 0))
+    goto error;
+  name.sin_family = AF_INET;
+  name.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+  name.sin_port = 0;
+  if (bind(server, (SOCKADDR*) &name, sizeof(name)) != 0)
+    goto wsaerror;
+  if (listen(server, 1) != 0)
+    goto wsaerror;
+  namelen = sizeof(name);
+  if (getsockname(server, (SOCKADDR*) &name, &namelen) != 0)
+    goto wsaerror;
+  client0 = WSASocketW(AF_INET, type, protocol, NULL, 0, client0_flags);
+  if (client0 == INVALID_SOCKET)
+    goto wsaerror;
+  if (!SetHandleInformation((HANDLE) client0, HANDLE_FLAG_INHERIT, 0))
+    goto error;
+  if (connect(client0, (SOCKADDR*) &name, sizeof(name)) != 0)
+    goto wsaerror;
+  client1 = WSASocketW(AF_INET, type, protocol, NULL, 0, client1_flags);
+  if (client1 == INVALID_SOCKET)
+    goto wsaerror;
+  if (!SetHandleInformation((HANDLE) client1, HANDLE_FLAG_INHERIT, 0))
+    goto error;
+  if (!uv_get_acceptex_function(server, &func_acceptex)) {
+    err = WSAEAFNOSUPPORT;
+    goto cleanup;
+  }
+  memset(&overlap, 0, sizeof(overlap));
+  if (!func_acceptex(server,
+                     client1,
+                     accept_buffer,
+                     0,
+                     sizeof(struct sockaddr_storage),
+                     sizeof(struct sockaddr_storage),
+                     &bytes,
+                     &overlap)) {
+    err = WSAGetLastError();
+    if (err == ERROR_IO_PENDING) {
+      /* Result should complete immediately, since we already called connect,
+       * but emperically, we sometimes have to poll the kernel a couple times
+       * until it notices that. */
+      while (!WSAGetOverlappedResult(client1, &overlap, &bytes, FALSE, &flags)) {
+        err = WSAGetLastError();
+        if (err != WSA_IO_INCOMPLETE)
+          goto cleanup;
+        SwitchToThread();
+      }
+    }
+    else {
+      goto cleanup;
+    }
+  }
+  if (setsockopt(client1, SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT,
+                  (char*) &server, sizeof(server)) != 0) {
+    goto wsaerror;
+  }
+
+  closesocket(server);
+
+  fds[0] = client0;
+  fds[1] = client1;
+
+  return 0;
+
+ wsaerror:
+    err = WSAGetLastError();
+    goto cleanup;
+
+ error:
+    err = GetLastError();
+    goto cleanup;
+
+ cleanup:
+    if (server != INVALID_SOCKET)
+      closesocket(server);
+    if (client0 != INVALID_SOCKET)
+      closesocket(client0);
+    if (client1 != INVALID_SOCKET)
+      closesocket(client1);
+
+    assert(err);
+    return uv_translate_sys_error(err);
+}
diff --git a/Utilities/cmlibuv/src/win/udp.c b/Utilities/cmlibuv/src/win/udp.c
index 68ca728aa5..3043f2da88 100644
--- a/Utilities/cmlibuv/src/win/udp.c
+++ b/Utilities/cmlibuv/src/win/udp.c
@@ -284,7 +284,7 @@ static void uv_udp_queue_recv(uv_loop_t* loop, uv_udp_t* handle) {
     handle->flags &= ~UV_HANDLE_ZERO_READ;
 
     handle->recv_buffer = uv_buf_init(NULL, 0);
-    handle->alloc_cb((uv_handle_t*) handle, 65536, &handle->recv_buffer);
+    handle->alloc_cb((uv_handle_t*) handle, UV__UDP_DGRAM_MAXSIZE, &handle->recv_buffer);
     if (handle->recv_buffer.base == NULL || handle->recv_buffer.len == 0) {
       handle->recv_cb(handle, UV_ENOBUFS, &handle->recv_buffer, NULL, 0);
       return;
@@ -501,7 +501,7 @@ void uv_process_udp_recv_req(uv_loop_t* loop, uv_udp_t* handle,
     /* Do a nonblocking receive.
      * TODO: try to read multiple datagrams at once. FIONREAD maybe? */
     buf = uv_buf_init(NULL, 0);
-    handle->alloc_cb((uv_handle_t*) handle, 65536, &buf);
+    handle->alloc_cb((uv_handle_t*) handle, UV__UDP_DGRAM_MAXSIZE, &buf);
     if (buf.base == NULL || buf.len == 0) {
       handle->recv_cb(handle, UV_ENOBUFS, &buf, NULL, 0);
       goto done;
diff --git a/Utilities/cmlibuv/src/win/util.c b/Utilities/cmlibuv/src/win/util.c
index aad8f1a15e..33e874ac44 100644
--- a/Utilities/cmlibuv/src/win/util.c
+++ b/Utilities/cmlibuv/src/win/util.c
@@ -1664,26 +1664,36 @@ int uv_os_unsetenv(const char* name) {
 
 
 int uv_os_gethostname(char* buffer, size_t* size) {
-  char buf[UV_MAXHOSTNAMESIZE];
+  WCHAR buf[UV_MAXHOSTNAMESIZE];
   size_t len;
+  char* utf8_str;
+  int convert_result;
 
   if (buffer == NULL || size == NULL || *size == 0)
     return UV_EINVAL;
 
   uv__once_init(); /* Initialize winsock */
 
-  if (gethostname(buf, sizeof(buf)) != 0)
+  if (pGetHostNameW == NULL)
+    return UV_ENOSYS;
+
+  if (pGetHostNameW(buf, UV_MAXHOSTNAMESIZE) != 0)
     return uv_translate_sys_error(WSAGetLastError());
 
-  buf[sizeof(buf) - 1] = '\0'; /* Null terminate, just to be safe. */
-  len = strlen(buf);
+  convert_result = uv__convert_utf16_to_utf8(buf, -1, &utf8_str);
+
+  if (convert_result != 0)
+    return convert_result;
 
+  len = strlen(utf8_str);
   if (len >= *size) {
     *size = len + 1;
+    uv__free(utf8_str);
     return UV_ENOBUFS;
   }
 
-  memcpy(buffer, buf, len + 1);
+  memcpy(buffer, utf8_str, len + 1);
+  uv__free(utf8_str);
   *size = len;
   return 0;
 }
diff --git a/Utilities/cmlibuv/src/win/winapi.c b/Utilities/cmlibuv/src/win/winapi.c
index bb86ec8cea..bf306cd83b 100644
--- a/Utilities/cmlibuv/src/win/winapi.c
+++ b/Utilities/cmlibuv/src/win/winapi.c
@@ -45,12 +45,15 @@ sPowerRegisterSuspendResumeNotification pPowerRegisterSuspendResumeNotification;
 /* User32.dll function pointer */
 sSetWinEventHook pSetWinEventHook;
 
+/* ws2_32.dll function pointer */
+uv_sGetHostNameW pGetHostNameW;
 
 void uv_winapi_init(void) {
   HMODULE ntdll_module;
   HMODULE powrprof_module;
   HMODULE user32_module;
   HMODULE kernel32_module;
+  HMODULE ws2_32_module;
 
   ntdll_module = GetModuleHandleA("ntdll.dll");
   if (ntdll_module == NULL) {
@@ -134,4 +137,11 @@ void uv_winapi_init(void) {
     pSetWinEventHook = (sSetWinEventHook)
       GetProcAddress(user32_module, "SetWinEventHook");
   }
+
+  ws2_32_module = LoadLibraryA("ws2_32.dll");
+  if (ws2_32_module != NULL) {
+    pGetHostNameW = (uv_sGetHostNameW) GetProcAddress(
+        ws2_32_module,
+        "GetHostNameW");
+  }
 }
diff --git a/Utilities/cmlibuv/src/win/winapi.h b/Utilities/cmlibuv/src/win/winapi.h
index 9bc455934a..e815f8f95e 100644
--- a/Utilities/cmlibuv/src/win/winapi.h
+++ b/Utilities/cmlibuv/src/win/winapi.h
@@ -4768,4 +4768,11 @@ extern sPowerRegisterSuspendResumeNotification pPowerRegisterSuspendResumeNotifi
 /* User32.dll function pointer */
 extern sSetWinEventHook pSetWinEventHook;
 
+/* ws2_32.dll function pointer */
+/* mingw doesn't have this definition, so let's declare it here locally */
+typedef int (WINAPI *uv_sGetHostNameW)
+            (PWSTR,
+             int);
+extern uv_sGetHostNameW pGetHostNameW;
+
 #endif /* UV_WIN_WINAPI_H_ */