Windows: implement uv_poll

include/uv-private/uv-win.h

@@ -146,6 +146,8 @@ typedef struct _AFD_POLL_INFO {
   AFD_POLL_HANDLE_INFO Handles[1];
 } AFD_POLL_INFO, *PAFD_POLL_INFO;
 
+#define UV_MSAFD_PROVIDER_COUNT 3
+
 
 /**
  * It should be possible to cast uv_buf_t[] to WSABUF[]
@@ -158,6 +160,8 @@ typedef struct uv_buf_t {
 
 typedef int uv_file;
 
+typedef SOCKET uv_platform_socket_t;
+
 typedef HANDLE uv_thread_t;
 
 typedef CRITICAL_SECTION uv_mutex_t;
@@ -219,6 +223,9 @@ RB_HEAD(uv_timer_tree_s, uv_timer_s);
   uv_prepare_t* next_prepare_handle;                                          \
   uv_check_t* next_check_handle;                                              \
   uv_idle_t* next_idle_handle;                                                \
+  /* This handle holds the peer sockets for the fast variant of uv_poll_t */  \
+  SOCKET poll_peer_sockets[UV_MSAFD_PROVIDER_COUNT];                          \
+  /* State used by uv_ares. */                                                \
   ares_channel ares_chan;                                                     \
   int ares_active_sockets;                                                    \
   uv_timer_t ares_polling_timer;                                              \
@@ -237,6 +244,7 @@ RB_HEAD(uv_timer_tree_s, uv_timer_s);
   UV_ARES_CLEANUP_REQ,                    \
   UV_FS_EVENT_REQ,                        \
   UV_GETADDRINFO_REQ,                     \
+  UV_POLL_REQ,                            \
   UV_PROCESS_EXIT,                        \
   UV_PROCESS_CLOSE,                       \
   UV_READ,                                \
@@ -386,6 +394,21 @@ RB_HEAD(uv_timer_tree_s, uv_timer_s);
   COORD saved_position;                   \
   WORD saved_attributes;
 
+#define UV_POLL_PRIVATE_FIELDS            \
+  SOCKET socket;                          \
+  /* Used in fast mode */                 \
+  SOCKET peer_socket;                     \
+  AFD_POLL_INFO afd_poll_info_1;          \
+  AFD_POLL_INFO afd_poll_info_2;          \
+  /* Used in fast and slow mode. */       \
+  uv_req_t poll_req_1;                    \
+  uv_req_t poll_req_2;                    \
+  unsigned char submitted_events_1;       \
+  unsigned char submitted_events_2;       \
+  unsigned char mask_events_1;            \
+  unsigned char mask_events_2;            \
+  unsigned char events;
+
 #define UV_TIMER_PRIVATE_FIELDS           \
   RB_ENTRY(uv_timer_s) tree_entry;        \
   int64_t due;                            \

src/win/core.c

@@ -84,6 +84,8 @@ static void uv_loop_init(uv_loop_t* loop) {
   loop->next_check_handle = NULL;
   loop->next_idle_handle = NULL;
 
+  memset(&loop->poll_peer_sockets, 0, sizeof loop->poll_peer_sockets);
+
   loop->ares_active_sockets = 0;
   loop->ares_chan = NULL;
 
@@ -130,6 +132,14 @@ uv_loop_t* uv_loop_new(void) {
 
 void uv_loop_delete(uv_loop_t* loop) {
   if (loop != &uv_default_loop_) {
+    int i;
+    for (i = 0; i < ARRAY_SIZE(loop->poll_peer_sockets); i++) {
+      SOCKET sock = loop->poll_peer_sockets[i];
+      if (sock != 0 && sock != INVALID_SOCKET) {
+        closesocket(sock);
+      }
+    }
+
     free(loop);
   }
 }

src/win/handle.c

@@ -64,6 +64,9 @@ int uv_is_active(const uv_handle_t* handle) {
     case UV_CHECK:
       return (handle->flags & UV_HANDLE_ACTIVE) ? 1 : 0;
 
+    case UV_POLL:
+      return ((uv_poll_t*) handle)->events != 0;
+
     default:
       return 1;
   }
@@ -112,6 +115,10 @@ void uv_close(uv_handle_t* handle, uv_close_cb cb) {
       }
       return;
 
+    case UV_POLL:
+      uv_poll_close(handle->loop, (uv_poll_t*) handle);
+      return;
+
     case UV_TIMER:
       uv_timer_stop((uv_timer_t*)handle);
       uv_want_endgame(loop, handle);
@@ -195,6 +202,10 @@ void uv_process_endgames(uv_loop_t* loop) {
         uv_udp_endgame(loop, (uv_udp_t*) handle);
         break;
 
+      case UV_POLL:
+        uv_poll_endgame(loop, (uv_poll_t*) handle);
+        break;
+
       case UV_TIMER:
         uv_timer_endgame(loop, (uv_timer_t*) handle);
         break;

src/win/internal.h

@@ -84,6 +84,9 @@ void uv_process_timers(uv_loop_t* loop);
 #define UV_HANDLE_TTY_SAVED_POSITION            0x02000000
 #define UV_HANDLE_TTY_SAVED_ATTRIBUTES          0x04000000
 
+/* Only used by uv_poll_t handles. */
+#define UV_HANDLE_POLL_SLOW                     0x02000000
+
 
 void uv_want_endgame(uv_loop_t* loop, uv_handle_t* handle);
 void uv_process_endgames(uv_loop_t* loop);
@@ -230,6 +233,16 @@ void uv_process_tty_connect_req(uv_loop_t* loop, uv_tty_t* handle,
 void uv_tty_endgame(uv_loop_t* loop, uv_tty_t* handle);
 
 
+/*
+ * Poll watchers
+ */
+void uv_process_poll_req(uv_loop_t* loop, uv_poll_t* handle,
+    uv_req_t* req);
+
+void uv_poll_close(uv_loop_t* loop, uv_poll_t* handle);
+void uv_poll_endgame(uv_loop_t* loop, uv_poll_t* handle);
+
+
 /*
  * Loop watchers
  */

src/win/poll.c

@@ -0,0 +1,609 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+
+#include <assert.h>
+#include <io.h>
+
+#include "uv.h"
+#include "../uv-common.h"
+#include "internal.h"
+
+
+static const GUID uv_msafd_provider_ids[UV_MSAFD_PROVIDER_COUNT] = {
+  {0xe70f1aa0, 0xab8b, 0x11cf,
+      {0x8c, 0xa3, 0x00, 0x80, 0x5f, 0x48, 0xa1, 0x92}},
+  {0xf9eab0c0, 0x26d4, 0x11d0,
+      {0xbb, 0xbf, 0x00, 0xaa, 0x00, 0x6c, 0x34, 0xe4}},
+  {0x9fc48064, 0x7298, 0x43e4,
+      {0xb7, 0xbd, 0x18, 0x1f, 0x20, 0x89, 0x79, 0x2a}}
+};
+
+typedef struct uv_single_fd_set_s {
+  unsigned int fd_count;
+  SOCKET fd_array[1];
+} uv_single_fd_set_t;
+
+
+static void uv__fast_poll_submit_poll_req(uv_loop_t* loop, uv_poll_t* handle) {
+  uv_req_t* req;
+  AFD_POLL_INFO* afd_poll_info;
+  DWORD result;
+
+  /* Find a yet unsubmitted req to submit. */
+  if (handle->submitted_events_1 == 0) {
+    req = &handle->poll_req_1;
+    afd_poll_info = &handle->afd_poll_info_1;
+    handle->submitted_events_1 = handle->events;
+    handle->mask_events_1 = 0;
+    handle->mask_events_2 = handle->events;
+  } else if (handle->submitted_events_2 == 0) {
+    req = &handle->poll_req_2;
+    afd_poll_info = &handle->afd_poll_info_2;
+    handle->submitted_events_2 = handle->events;
+    handle->mask_events_1 = handle->events;
+    handle->mask_events_2 = 0;
+  } else {
+    assert(0);
+  }
+
+  /* Setting Exclusive to TRUE makes the other poll request return if there */
+  /* is any. */
+  afd_poll_info->Exclusive = TRUE;
+  afd_poll_info->NumberOfHandles = 1;
+  afd_poll_info->Timeout.QuadPart = INT64_MAX;
+  afd_poll_info->Handles[0].Handle = (HANDLE) handle->socket;
+  afd_poll_info->Handles[0].Status = 0;
+  afd_poll_info->Handles[0].Events = 0;
+
+  if (handle->events & UV_READABLE) {
+    afd_poll_info->Handles[0].Events |= AFD_POLL_RECEIVE |
+        AFD_POLL_DISCONNECT | AFD_POLL_ACCEPT | AFD_POLL_ABORT;
+  }
+  if (handle->events & UV_WRITABLE) {
+    afd_poll_info->Handles[0].Events |= AFD_POLL_SEND | AFD_POLL_CONNECT_FAIL;
+  }
+
+  memset(&req->overlapped, 0, sizeof req->overlapped);
+
+  result = uv_msafd_poll((SOCKET) handle->peer_socket,
+                         afd_poll_info,
+                         &req->overlapped);
+  if (result != 0 && WSAGetLastError() != WSA_IO_PENDING) {
+    /* Queue this req, reporting an error. */
+    SET_REQ_ERROR(req, WSAGetLastError());
+    uv_insert_pending_req(loop, req);
+  }
+}
+
+
+static int uv__fast_poll_cancel_poll_reqs(uv_loop_t* loop, uv_poll_t* handle) {
+  AFD_POLL_INFO afd_poll_info;
+  DWORD result;
+  HANDLE event;
+  OVERLAPPED overlapped;
+
+  event = CreateEvent(NULL, TRUE, FALSE, NULL);
+  if (event == NULL) {
+    uv__set_sys_error(loop, GetLastError());
+    return -1;
+  }
+
+  afd_poll_info.Exclusive = TRUE;
+  afd_poll_info.NumberOfHandles = 1;
+  afd_poll_info.Timeout.QuadPart = INT64_MAX;
+  afd_poll_info.Handles[0].Handle = (HANDLE) handle->socket;
+  afd_poll_info.Handles[0].Status = 0;
+  afd_poll_info.Handles[0].Events = AFD_POLL_ALL;
+
+  memset(&overlapped, 0, sizeof overlapped);
+  overlapped.hEvent = (HANDLE) ((uintptr_t) event & 1);
+
+  result = uv_msafd_poll(handle->socket,
+                         &afd_poll_info,
+                         &overlapped);
+
+  if (result == SOCKET_ERROR) {
+    DWORD error = WSAGetLastError();
+    if (error != WSA_IO_PENDING) {
+      uv__set_sys_error(loop, WSAGetLastError());
+      CloseHandle(event);
+      return -1;
+    }
+  }
+
+  CloseHandle(event);
+  return 0;
+}
+
+
+static void uv__fast_poll_process_poll_req(uv_loop_t* loop, uv_poll_t* handle,
+    uv_req_t* req) {
+  unsigned char mask_events;
+  AFD_POLL_INFO* afd_poll_info;
+
+  if (req == &handle->poll_req_1) {
+    afd_poll_info = &handle->afd_poll_info_1;
+    handle->submitted_events_1 = 0;
+    mask_events = handle->mask_events_1;
+  } else if (req == &handle->poll_req_2) {
+    afd_poll_info = &handle->afd_poll_info_2;
+    handle->submitted_events_2 = 0;
+    mask_events = handle->mask_events_2;
+  } else {
+    assert(0);
+  }
+
+  /* Report an error unless the select was just interrupted. */
+  if (!REQ_SUCCESS(req)) {
+    DWORD error = GET_REQ_SOCK_ERROR(req);
+    if (error != WSAEINTR && handle->events != 0) {
+      handle->events = 0; /* Stop the watcher */
+      uv__set_sys_error(loop, error);
+      handle->poll_cb(handle, -1, 0);
+    }
+
+  } else if (afd_poll_info->NumberOfHandles >= 1) {
+    unsigned char events = 0;
+
+    if ((afd_poll_info->Handles[0].Events & (AFD_POLL_RECEIVE |
+        AFD_POLL_DISCONNECT | AFD_POLL_ACCEPT | AFD_POLL_ABORT)) != 0) {
+      events |= UV_READABLE;
+    }
+    if ((afd_poll_info->Handles[0].Events & (AFD_POLL_SEND |
+        AFD_POLL_CONNECT_FAIL)) != 0) {
+      events |= UV_WRITABLE;
+    }
+
+    events &= handle->events & ~mask_events;
+
+    if (afd_poll_info->Handles[0].Events & AFD_POLL_LOCAL_CLOSE) {
+      /* Stop polling. */
+      handle->events = 0;
+    }
+
+    if (events != 0) {
+      handle->poll_cb(handle, 0, events);
+    }
+  }
+
+  if ((handle->events & ~(handle->submitted_events_1 |
+      handle->submitted_events_2)) != 0) {
+    uv__fast_poll_submit_poll_req(loop, handle);
+  } else if ((handle->flags & UV_HANDLE_CLOSING) &&
+             handle->submitted_events_1 == 0 &&
+             handle->submitted_events_2 == 0) {
+    uv_want_endgame(loop, (uv_handle_t*) handle);
+  }
+}
+
+
+static int uv__fast_poll_set(uv_loop_t* loop, uv_poll_t* handle, int events) {
+  assert(handle->type == UV_POLL);
+  assert(!(handle->flags & UV_HANDLE_CLOSING));
+  assert((events & ~(UV_READABLE | UV_WRITABLE)) == 0);
+
+  handle->events = events;
+  if ((handle->events & ~(handle->submitted_events_1 |
+      handle->submitted_events_2)) != 0) {
+    uv__fast_poll_submit_poll_req(handle->loop, handle);
+  }
+
+  return 0;
+}
+
+
+static void uv__fast_poll_close(uv_loop_t* loop, uv_poll_t* handle) {
+  handle->events = 0;
+
+  if (handle->submitted_events_1 == 0 &&
+      handle->submitted_events_2 == 0) {
+    uv_want_endgame(loop, (uv_handle_t*) handle);
+  } else {
+    /* Try to cancel outstanding poll requests. */
+    if (pCancelIoEx) {
+      /* Use CancelIoEx to cancel poll requests if available. */
+      if (handle->submitted_events_1)
+        pCancelIoEx((HANDLE) handle->socket, &handle->poll_req_1.overlapped);
+      if (handle->submitted_events_2)
+        pCancelIoEx((HANDLE) handle->socket, &handle->poll_req_2.overlapped);
+    } else if (handle->submitted_events_1 | handle->submitted_events_2) {
+      /* Execute another unique poll to force the others to return. */
+      uv__fast_poll_cancel_poll_reqs(loop, handle);
+    }
+  }
+}
+
+
+static SOCKET uv__fast_poll_create_peer_socket(HANDLE iocp,
+    WSAPROTOCOL_INFOW* protocol_info) {
+  SOCKET sock = 0;
+
+  sock = WSASocketW(protocol_info->iAddressFamily,
+                    protocol_info->iSocketType,
+                    protocol_info->iProtocol,
+                    protocol_info,
+                    0,
+                    WSA_FLAG_OVERLAPPED);
+  if (sock == INVALID_SOCKET) {
+    return INVALID_SOCKET;
+  }
+
+  if (!SetHandleInformation((HANDLE) sock, HANDLE_FLAG_INHERIT, 0)) {
+    goto error;
+  };
+
+  if (CreateIoCompletionPort((HANDLE) sock,
+                             iocp,
+                             (ULONG_PTR) sock,
+                             0) == NULL) {
+    goto error;
+  }
+
+  return sock;
+
+ error:
+  closesocket(sock);
+  return INVALID_SOCKET;
+}
+
+
+static SOCKET uv__fast_poll_get_peer_socket(uv_loop_t* loop,
+    WSAPROTOCOL_INFOW* protocol_info) {
+  int index, i;
+  SOCKET peer_socket;
+
+  index = -1;
+  for (i = 0; i < ARRAY_SIZE(uv_msafd_provider_ids); i++) {
+    if (memcmp((void*) &protocol_info->ProviderId,
+               (void*) &uv_msafd_provider_ids[i],
+               sizeof protocol_info->ProviderId) == 0) {
+      index = i;
+    }
+  }
+
+  /* Check if the protocol uses an msafd socket. */
+  if (index < 0) {
+    return INVALID_SOCKET;
+  }
+
+  /* If we didn't (try) to create a peer socket yet, try to make one. Don't */
+  /* try again if the peer socket creation failed earlier for the same */
+  /* protocol. */
+  peer_socket = loop->poll_peer_sockets[index];
+  if (peer_socket == 0) {
+    peer_socket = uv__fast_poll_create_peer_socket(loop->iocp, protocol_info);
+    loop->poll_peer_sockets[index] = peer_socket;
+  }
+
+  return peer_socket;
+}
+
+
+static DWORD WINAPI uv__slow_poll_thread_proc(void* arg) {
+  uv_req_t* req = (uv_req_t*) arg;
+  uv_poll_t* handle = (uv_poll_t*) req->data;
+  unsigned char events, reported_events;
+  int r;
+  uv_single_fd_set_t rfds, wfds, efds;
+  struct timeval timeout;
+
+  assert(handle->type == UV_POLL);
+  assert(req->type == UV_POLL_REQ);
+
+  if (req == &handle->poll_req_1) {
+    events = handle->submitted_events_1;
+  } else if (req == &handle->poll_req_2) {
+    events = handle->submitted_events_2;
+  } else {
+    assert(0);
+  }
+
+  if (handle->events & UV_READABLE) {
+    rfds.fd_count = 1;
+    rfds.fd_array[0] = handle->socket;
+  } else {
+    rfds.fd_count = 0;
+  }
+
+  if (handle->events & UV_WRITABLE) {
+    wfds.fd_count = 1;
+    wfds.fd_array[0] = handle->socket;
+    efds.fd_count = 1;
+    efds.fd_array[0] = handle->socket;
+  } else {
+    wfds.fd_count = 0;
+    efds.fd_count = 0;
+  }
+
+  /* Make the select() time out after 3 minutes. If select() hangs because */
+  /* the user closed the socket, we will at least not hang indefinitely. */
+  timeout.tv_sec = 3 * 60;
+  timeout.tv_usec = 0;
+
+  r = select(1, (fd_set*) &rfds, (fd_set*) &wfds, (fd_set*) &efds, &timeout);
+  if (r == SOCKET_ERROR) {
+    /* Queue this req, reporting an error. */
+    SET_REQ_ERROR(&handle->poll_req_1, WSAGetLastError());
+    POST_COMPLETION_FOR_REQ(handle->loop, req);
+    return 0;
+  }
+
+  reported_events = 0;
+
+  if (r > 0) {
+    if (rfds.fd_count > 0) {
+      assert(rfds.fd_count == 1);
+      assert(rfds.fd_array[0] == handle->socket);
+      reported_events |= UV_READABLE;
+    }
+
+    if (wfds.fd_count > 0) {
+      assert(wfds.fd_count == 1);
+      assert(wfds.fd_array[0] == handle->socket);
+      reported_events |= UV_WRITABLE;
+    } else if (efds.fd_count > 0) {
+      assert(efds.fd_count == 1);
+      assert(efds.fd_array[0] == handle->socket);
+      reported_events |= UV_WRITABLE;
+    }
+  }
+
+  SET_REQ_SUCCESS(req);
+  req->overlapped.InternalHigh = (DWORD) reported_events;
+  POST_COMPLETION_FOR_REQ(handle->loop, req);
+
+  return 0;
+}
+
+
+static void uv__slow_poll_submit_poll_req(uv_loop_t* loop, uv_poll_t* handle) {
+  uv_req_t* req;
+
+  /* Find a yet unsubmitted req to submit. */
+  if (handle->submitted_events_1 == 0) {
+    req = &handle->poll_req_1;
+    handle->submitted_events_1 = handle->events;
+    handle->mask_events_1 = 0;
+    handle->mask_events_2 = handle->events;
+  } else if (handle->submitted_events_2 == 0) {
+    req = &handle->poll_req_2;
+    handle->submitted_events_2 = handle->events;
+    handle->mask_events_1 = handle->events;
+    handle->mask_events_2 = 0;
+  } else {
+    assert(0);
+  }
+
+  if (!QueueUserWorkItem(uv__slow_poll_thread_proc,
+                         (void*) req,
+                         WT_EXECUTELONGFUNCTION)) {
+    /* Make this req pending, reporting an error. */
+    SET_REQ_ERROR(req, GetLastError());
+    uv_insert_pending_req(loop, req);
+  }
+}
+
+
+
+static void uv__slow_poll_process_poll_req(uv_loop_t* loop, uv_poll_t* handle,
+    uv_req_t* req) {
+  unsigned char mask_events;
+  if (req == &handle->poll_req_1) {
+    handle->submitted_events_1 = 0;
+    mask_events = handle->mask_events_1;
+  } else if (req == &handle->poll_req_2) {
+    handle->submitted_events_2 = 0;
+    mask_events = handle->mask_events_2;
+  } else {
+    assert(0);
+  }
+
+  if (!REQ_SUCCESS(req)) {
+    /* Error. */
+    if (handle->events != 0) {
+      handle->events = 0; /* Stop the watcher */
+      uv__set_sys_error(loop, GET_REQ_ERROR(req));
+      handle->poll_cb(handle, -1, 0);
+    }
+  } else {
+    /* Got some events. */
+    int events = req->overlapped.InternalHigh & handle->events & ~mask_events;
+    if (events != 0) {
+      handle->poll_cb(handle, 0, events);
+    }
+  }
+
+  if ((handle->events & ~(handle->submitted_events_1 |
+      handle->submitted_events_2)) != 0) {
+    uv__slow_poll_submit_poll_req(loop, handle);
+  } else if ((handle->flags & UV_HANDLE_CLOSING) &&
+             handle->submitted_events_1 == 0 &&
+             handle->submitted_events_2 == 0) {
+    uv_want_endgame(loop, (uv_handle_t*) handle);
+  }
+}
+
+
+static int uv__slow_poll_set(uv_loop_t* loop, uv_poll_t* handle, int events) {
+  assert(handle->type == UV_POLL);
+  assert(!(handle->flags & UV_HANDLE_CLOSING));
+  assert((events & ~(UV_READABLE | UV_WRITABLE)) == 0);
+
+  handle->events = events;
+  if ((handle->events &
+      ~(handle->submitted_events_1 | handle->submitted_events_2)) != 0) {
+    uv__slow_poll_submit_poll_req(handle->loop, handle);
+  }
+
+  return 0;
+}
+
+
+static void uv__slow_poll_close(uv_loop_t* loop, uv_poll_t* handle) {
+  handle->events = 0;
+
+  if (handle->submitted_events_1 == 0 &&
+      handle->submitted_events_2 == 0) {
+    uv_want_endgame(loop, (uv_handle_t*) handle);
+  }
+}
+
+
+int uv_poll_init(uv_loop_t* loop, uv_poll_t* handle, int fd) {
+  return uv_poll_init_socket(loop, handle, (SOCKET) _get_osfhandle(fd));
+}
+
+
+int uv_poll_init_socket(uv_loop_t* loop, uv_poll_t* handle,
+    uv_platform_socket_t socket) {
+  WSAPROTOCOL_INFOW protocol_info;
+  int len;
+  SOCKET peer_socket, base_socket;
+  DWORD bytes;
+
+  /* Try to obtain a base handle for the socket. This increases this chances */
+  /* that we find an AFD handle and are able to use the fast poll mechanism. */
+  /* This will always fail on windows XP/2k3, since they don't support the */
+  /* SIO_BASE_HANDLE ioctl. */
+#ifndef NDEBUG
+  base_socket = INVALID_SOCKET;
+#endif
+
+  if (WSAIoctl(socket,
+               SIO_BASE_HANDLE,
+               NULL,
+               0,
+               &base_socket,
+               sizeof base_socket,
+               &bytes,
+               NULL,
+               NULL) == 0) {
+    assert(base_socket != 0 && base_socket != INVALID_SOCKET);
+    socket = base_socket;
+  }
+
+  handle->type = UV_POLL;
+  handle->socket = socket;
+  handle->loop = loop;
+  handle->flags = 0;
+  handle->events = 0;
+
+  /* Obtain protocol information about the socket. */
+  len = sizeof protocol_info;
+  if (getsockopt(socket,
+                 SOL_SOCKET,
+                 SO_PROTOCOL_INFOW,
+                 (char*) &protocol_info,
+                 &len) != 0) {
+    uv__set_sys_error(loop, WSAGetLastError());
+    return -1;
+  }
+
+  /* Get the peer socket that is needed to enable fast poll. If the returned */
+  /* value is NULL, the protocol is not implemented by MSAFD and we'll have */
+  /* to use slow mode. */
+  peer_socket = uv__fast_poll_get_peer_socket(loop, &protocol_info);
+
+  if (peer_socket != INVALID_SOCKET) {
+    /* Initialize fast poll specific fields. */
+    handle->peer_socket = peer_socket;
+  } else {
+    /* Initialize slow poll specific fields. */
+    handle->flags |= UV_HANDLE_POLL_SLOW;
+  }
+
+  /* Intialize 2 poll reqs. */
+  handle->submitted_events_1 = 0;
+  uv_req_init(loop, (uv_req_t*) &(handle->poll_req_1));
+  handle->poll_req_1.type = UV_POLL_REQ;
+  handle->poll_req_1.data = handle;
+
+  handle->submitted_events_2 = 0;
+  uv_req_init(loop, (uv_req_t*) &(handle->poll_req_2));
+  handle->poll_req_2.type = UV_POLL_REQ;
+  handle->poll_req_2.data = handle;
+
+  uv_ref(loop);
+
+  loop->counters.handle_init++;
+  loop->counters.poll_init++;
+
+  return 0;
+}
+
+
+int uv_poll_start(uv_poll_t* handle, int events, uv_poll_cb cb) {
+  if (!(handle->flags & UV_HANDLE_POLL_SLOW)) {
+    if (uv__fast_poll_set(handle->loop, handle, events) < 0)
+      return -1;
+  } else {
+    if (uv__slow_poll_set(handle->loop, handle, events) < 0)
+      return -1;
+  }
+
+  handle->poll_cb = cb;
+  return 0;
+}
+
+
+int uv_poll_stop(uv_poll_t* handle) {
+  if (!(handle->flags & UV_HANDLE_POLL_SLOW)) {
+    return uv__fast_poll_set(handle->loop, handle, 0);
+  } else {
+    return uv__slow_poll_set(handle->loop, handle, 0);
+  }
+}
+
+
+void uv_process_poll_req(uv_loop_t* loop, uv_poll_t* handle, uv_req_t* req) {
+  if (!(handle->flags & UV_HANDLE_POLL_SLOW)) {
+    uv__fast_poll_process_poll_req(loop, handle, req);
+  } else {
+    uv__slow_poll_process_poll_req(loop, handle, req);
+  }
+}
+
+
+void uv_poll_close(uv_loop_t* loop, uv_poll_t* handle) {
+  if (!(handle->flags & UV_HANDLE_POLL_SLOW)) {
+    uv__fast_poll_close(loop, handle);
+  } else {
+    uv__slow_poll_close(loop, handle);
+  }
+}
+
+
+void uv_poll_endgame(uv_loop_t* loop, uv_poll_t* handle) {
+  assert(handle->flags & UV_HANDLE_CLOSING);
+  assert(!(handle->flags & UV_HANDLE_CLOSED));
+
+  assert(handle->submitted_events_1 == 0);
+  assert(handle->submitted_events_2 == 0);
+
+  handle->flags |= UV_HANDLE_CLOSED;
+
+  if (handle->close_cb) {
+    handle->close_cb((uv_handle_t*)handle);
+  }
+
+  uv_unref(loop);
+}

src/win/req.c

@@ -135,6 +135,10 @@ void uv_process_reqs(uv_loop_t* loop) {
         uv_process_async_wakeup_req(loop, (uv_async_t*) req->data, req);
         break;
 
+      case UV_POLL_REQ:
+        uv_process_poll_req(loop, (uv_poll_t*) req->data, req);
+        break;
+
       case UV_ARES_EVENT_REQ:
         uv_process_ares_event_req(loop, (uv_ares_action_t*) req->data, req);
         break;

uv.gyp

@@ -145,6 +145,7 @@
             'src/win/loop-watcher.c',
             'src/win/pipe.c',
             'src/win/thread.c',
+            'src/win/poll.c',
             'src/win/process.c',
             'src/win/req.c',
             'src/win/stream.c',