C++ UV_SUCCEEDED_WITHOUT_IOCP函数代码示例

static void uv_tcp_queue_accept(uv_tcp_t* handle, uv_tcp_accept_t* req) {
  uv_loop_t* loop = handle->loop;
  BOOL success;
  DWORD bytes;
  SOCKET accept_socket;
  short family;
  LPFN_ACCEPTEX pAcceptExFamily;

  assert(handle->flags & UV_HANDLE_LISTENING);
  assert(req->accept_socket == INVALID_SOCKET);

  /* choose family and extension function */
  if ((handle->flags & UV_HANDLE_IPV6) != 0) {
    family = AF_INET6;
    pAcceptExFamily = pAcceptEx6;
  } else {
    family = AF_INET;
    pAcceptExFamily = pAcceptEx;
  }

  /* Open a socket for the accepted connection. */
  accept_socket = socket(family, SOCK_STREAM, 0);
  if (accept_socket == INVALID_SOCKET) {
    SET_REQ_ERROR(req, WSAGetLastError());
    uv_insert_pending_req(loop, (uv_req_t*)req);
    handle->reqs_pending++;
    return;
  }

  /* Prepare the overlapped structure. */
  memset(&(req->overlapped), 0, sizeof(req->overlapped));

  success = pAcceptExFamily(handle->socket,
                          accept_socket,
                          (void*)req->accept_buffer,
                          0,
                          sizeof(struct sockaddr_storage),
                          sizeof(struct sockaddr_storage),
                          &bytes,
                          &req->overlapped);

  if (UV_SUCCEEDED_WITHOUT_IOCP(success)) {
    /* Process the req without IOCP. */
    req->accept_socket = accept_socket;
    handle->reqs_pending++;
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(success)) {
    /* The req will be processed with IOCP. */
    req->accept_socket = accept_socket;
    handle->reqs_pending++;
  } else {
    /* Make this req pending reporting an error. */
    SET_REQ_ERROR(req, WSAGetLastError());
    uv_insert_pending_req(loop, (uv_req_t*)req);
    handle->reqs_pending++;
    /* Destroy the preallocated client socket. */
    closesocket(accept_socket);
  }
}

int uv_tcp_write(uv_loop_t* loop, uv_write_t* req, uv_tcp_t* handle,
    uv_buf_t bufs[], int bufcnt, uv_write_cb cb) {
  int result;
  DWORD bytes;

  uv_req_init(loop, (uv_req_t*) req);
  req->type = UV_WRITE;
  req->handle = (uv_stream_t*) handle;
  req->cb = cb;
  memset(&req->overlapped, 0, sizeof(req->overlapped));

  /* Prepare the overlapped structure. */
  memset(&(req->overlapped), 0, sizeof(req->overlapped));
  if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
    req->event_handle = CreateEvent(NULL, 0, 0, NULL);
    if (!req->event_handle) {
      uv_fatal_error(GetLastError(), "CreateEvent");
    }
    req->overlapped.hEvent = (HANDLE) ((ULONG_PTR) req->event_handle | 1);
    req->wait_handle = INVALID_HANDLE_VALUE;
  }

  result = WSASend(handle->socket,
                   (WSABUF*)bufs,
                   bufcnt,
                   &bytes,
                   0,
                   &req->overlapped,
                   NULL);

  if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
    /* Request completed immediately. */
    req->queued_bytes = 0;
    handle->reqs_pending++;
    handle->write_reqs_pending++;
    REGISTER_HANDLE_REQ(loop, handle, req);
    uv_insert_pending_req(loop, (uv_req_t*) req);
  } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
    /* Request queued by the kernel. */
    req->queued_bytes = uv_count_bufs(bufs, bufcnt);
    handle->reqs_pending++;
    handle->write_reqs_pending++;
    REGISTER_HANDLE_REQ(loop, handle, req);
    handle->write_queue_size += req->queued_bytes;
    if (handle->flags & UV_HANDLE_EMULATE_IOCP &&
        !RegisterWaitForSingleObject(&req->wait_handle,
          req->event_handle, post_write_completion, (void*) req,
          INFINITE, WT_EXECUTEINWAITTHREAD | WT_EXECUTEONLYONCE)) {
      SET_REQ_ERROR(req, GetLastError());
      uv_insert_pending_req(loop, (uv_req_t*)req);
    }
  } else {
    /* Send failed due to an error. */
    uv__set_sys_error(loop, WSAGetLastError());
    return -1;
  }

  return 0;
}

int uv__tcp_connect6(uv_connect_t* req,
                     uv_tcp_t* handle,
                     struct sockaddr_in6 address,
                     uv_connect_cb cb) {
  uv_loop_t* loop = handle->loop;
  int addrsize = sizeof(struct sockaddr_in6);
  BOOL success;
  DWORD bytes;

  if (!uv_allow_ipv6) {
    uv__set_sys_error(loop, WSAEAFNOSUPPORT);
    return -1;
  }

  if (handle->flags & UV_HANDLE_BIND_ERROR) {
    uv__set_sys_error(loop, handle->bind_error);
    return -1;
  }

  if (!(handle->flags & UV_HANDLE_BOUND) &&
      uv_tcp_bind6(handle, uv_addr_ip6_any_) < 0)
    return -1;

  if (!handle->func_connectex) {
    if(!uv_get_connectex_function(handle->socket, &handle->func_connectex)) {
      uv__set_sys_error(loop, WSAEAFNOSUPPORT);
      return -1;
    }
  }

  uv_req_init(loop, (uv_req_t*) req);
  req->type = UV_CONNECT;
  req->handle = (uv_stream_t*) handle;
  req->cb = cb;
  memset(&req->overlapped, 0, sizeof(req->overlapped));

  success = handle->func_connectex(handle->socket,
                                   (struct sockaddr*) &address,
                                   addrsize,
                                   NULL,
                                   0,
                                   &bytes,
                                   &req->overlapped);

  if (UV_SUCCEEDED_WITHOUT_IOCP(success)) {
    handle->reqs_pending++;
    uv_ref(loop);
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(success)) {
    handle->reqs_pending++;
    uv_ref(loop);
  } else {
    uv__set_sys_error(loop, WSAGetLastError());
    return -1;
  }

  return 0;
}

int uv__tcp_connect(uv_connect_t* req,
                    uv_tcp_t* handle,
                    struct sockaddr_in address,
                    uv_connect_cb cb) {
  uv_loop_t* loop = handle->loop;
  int addrsize = sizeof(struct sockaddr_in);
  BOOL success;
  DWORD bytes;
  int err;

  if (handle->flags & UV_HANDLE_BIND_ERROR) {
    return handle->bind_error;
  }

  if (!(handle->flags & UV_HANDLE_BOUND)) {
    err = uv_tcp_bind(handle, uv_addr_ip4_any_);
    if (err)
      return err;
  }

  if (!handle->func_connectex) {
    if (!uv_get_connectex_function(handle->socket, &handle->func_connectex)) {
      return WSAEAFNOSUPPORT;
    }
  }

  uv_req_init(loop, (uv_req_t*) req);
  req->type = UV_CONNECT;
  req->handle = (uv_stream_t*) handle;
  req->cb = cb;
  memset(&req->overlapped, 0, sizeof(req->overlapped));

  success = handle->func_connectex(handle->socket,
                                   (struct sockaddr*) &address,
                                   addrsize,
                                   NULL,
                                   0,
                                   &bytes,
                                   &req->overlapped);

  if (UV_SUCCEEDED_WITHOUT_IOCP(success)) {
    /* Process the req without IOCP. */
    handle->reqs_pending++;
    REGISTER_HANDLE_REQ(loop, handle, req);
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(success)) {
    /* The req will be processed with IOCP. */
    handle->reqs_pending++;
    REGISTER_HANDLE_REQ(loop, handle, req);
  } else {
    return WSAGetLastError();
  }

  return 0;
}

static void uv_tcp_queue_read(uv_loop_t* loop, uv_tcp_t* handle) {
  uv_read_t* req;
  uv_buf_t buf;
  int result;
  DWORD bytes, flags;

  assert(handle->flags & UV_HANDLE_READING);
  assert(!(handle->flags & UV_HANDLE_READ_PENDING));

  req = &handle->read_req;
  memset(&req->overlapped, 0, sizeof(req->overlapped));

  /*
   * Preallocate a read buffer if the number of active streams is below
   * the threshold.
  */
  if (active_tcp_streams < uv_active_tcp_streams_threshold) {
    handle->flags &= ~UV_HANDLE_ZERO_READ;
    handle->read_buffer = handle->alloc_cb((uv_handle_t*) handle, 65536);
    assert(handle->read_buffer.len > 0);
    buf = handle->read_buffer;
  } else {
    handle->flags |= UV_HANDLE_ZERO_READ;
    buf.base = (char*) &uv_zero_;
    buf.len = 0;
  }

  flags = 0;
  result = WSARecv(handle->socket,
                   (WSABUF*)&buf,
                   1,
                   &bytes,
                   &flags,
                   &req->overlapped,
                   NULL);

  if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
    /* Process the req without IOCP. */
    handle->flags |= UV_HANDLE_READ_PENDING;
    req->overlapped.InternalHigh = bytes;
    handle->reqs_pending++;
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
    /* The req will be processed with IOCP. */
    handle->flags |= UV_HANDLE_READ_PENDING;
    handle->reqs_pending++;
  } else {
    /* Make this req pending reporting an error. */
    SET_REQ_ERROR(req, WSAGetLastError());
    uv_insert_pending_req(loop, (uv_req_t*)req);
    handle->reqs_pending++;
  }
}

int uv_tcp_connect6(uv_connect_t* req, uv_tcp_t* handle,
    struct sockaddr_in6 address, uv_connect_cb cb) {
  int addrsize = sizeof(struct sockaddr_in6);
  BOOL success;
  DWORD bytes;

  if (!uv_allow_ipv6) {
    uv_new_sys_error(WSAEAFNOSUPPORT);
    return -1;
  }

  if (handle->flags & UV_HANDLE_BIND_ERROR) {
    LOOP->last_error = handle->error;
    return -1;
  }

  if (address.sin6_family != AF_INET6) {
    uv_set_sys_error(WSAEFAULT);
    return -1;
  }

  if (!(handle->flags & UV_HANDLE_BOUND) &&
      uv_tcp_bind6(handle, uv_addr_ip6_any_) < 0)
    return -1;

  uv_req_init((uv_req_t*) req);
  req->type = UV_CONNECT;
  req->handle = (uv_stream_t*) handle;
  req->cb = cb;
  memset(&req->overlapped, 0, sizeof(req->overlapped));

  success = pConnectEx6(handle->socket,
                       (struct sockaddr*) &address,
                       addrsize,
                       NULL,
                       0,
                       &bytes,
                       &req->overlapped);

  if (UV_SUCCEEDED_WITHOUT_IOCP(success)) {
    handle->reqs_pending++;
    uv_insert_pending_req((uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(success)) {
    handle->reqs_pending++;
  } else {
    uv_set_sys_error(WSAGetLastError());
    return -1;
  }

  return 0;
}

int uv_tcp_write(uv_loop_t* loop, uv_write_t* req, uv_tcp_t* handle,
    uv_buf_t bufs[], int bufcnt, uv_write_cb cb) {
  int result;
  DWORD bytes;

  if (!(handle->flags & UV_HANDLE_CONNECTION)) {
    uv__set_sys_error(loop, WSAEINVAL);
    return -1;
  }

  if (handle->flags & UV_HANDLE_SHUTTING) {
    uv__set_sys_error(loop, WSAESHUTDOWN);
    return -1;
  }

  uv_req_init(loop, (uv_req_t*) req);
  req->type = UV_WRITE;
  req->handle = (uv_stream_t*) handle;
  req->cb = cb;
  memset(&req->overlapped, 0, sizeof(req->overlapped));

  result = WSASend(handle->socket,
                   (WSABUF*)bufs,
                   bufcnt,
                   &bytes,
                   0,
                   &req->overlapped,
                   NULL);

  if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
    /* Request completed immediately. */
    req->queued_bytes = 0;
    handle->reqs_pending++;
    handle->write_reqs_pending++;
    uv_insert_pending_req(loop, (uv_req_t*) req);
  } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
    /* Request queued by the kernel. */
    req->queued_bytes = uv_count_bufs(bufs, bufcnt);
    handle->reqs_pending++;
    handle->write_reqs_pending++;
    handle->write_queue_size += req->queued_bytes;
  } else {
    /* Send failed due to an error. */
    uv__set_sys_error(loop, WSAGetLastError());
    return -1;
  }

  return 0;
}

int uv_tcp_connect(uv_connect_t* req, uv_tcp_t* handle,
    struct sockaddr_in address, uv_connect_cb cb) {
  uv_loop_t* loop = handle->loop;
  int addrsize = sizeof(struct sockaddr_in);
  BOOL success;
  DWORD bytes;

  if (handle->flags & UV_HANDLE_BIND_ERROR) {
    loop->last_error = handle->bind_error;
    return -1;
  }

  if (address.sin_family != AF_INET) {
    uv_set_sys_error(loop, WSAEFAULT);
    return -1;
  }

  if (!(handle->flags & UV_HANDLE_BOUND) &&
      uv_tcp_bind(handle, uv_addr_ip4_any_) < 0)
    return -1;

  uv_req_init(loop, (uv_req_t*) req);
  req->type = UV_CONNECT;
  req->handle = (uv_stream_t*) handle;
  req->cb = cb;
  memset(&req->overlapped, 0, sizeof(req->overlapped));

  success = pConnectEx(handle->socket,
                       (struct sockaddr*) &address,
                       addrsize,
                       NULL,
                       0,
                       &bytes,
                       &req->overlapped);

  if (UV_SUCCEEDED_WITHOUT_IOCP(success)) {
    /* Process the req without IOCP. */
    handle->reqs_pending++;
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(success)) {
    /* The req will be processed with IOCP. */
    handle->reqs_pending++;
  } else {
    uv_set_sys_error(loop, WSAGetLastError());
    return -1;
  }

  return 0;
}

static int uv__send(uv_udp_send_t* req,
                    uv_udp_t* handle,
                    const uv_buf_t bufs[],
                    unsigned int nbufs,
                    const struct sockaddr* addr,
                    unsigned int addrlen,
                    uv_udp_send_cb cb) {
  uv_loop_t* loop = handle->loop;
  DWORD result, bytes;

  uv_req_init(loop, (uv_req_t*) req);
  req->type = UV_UDP_SEND;
  req->handle = handle;
  req->cb = cb;
  memset(&req->u.io.overlapped, 0, sizeof(req->u.io.overlapped));

  result = WSASendTo(handle->socket,
                     (WSABUF*)bufs,
                     nbufs,
                     &bytes,
                     0,
                     addr,
                     addrlen,
                     &req->u.io.overlapped,
                     NULL);

  if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
    /* Request completed immediately. */
    req->u.io.queued_bytes = 0;
    handle->reqs_pending++;
    handle->send_queue_size += req->u.io.queued_bytes;
    handle->send_queue_count++;
    REGISTER_HANDLE_REQ(loop, handle, req);
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
    /* Request queued by the kernel. */
    req->u.io.queued_bytes = uv__count_bufs(bufs, nbufs);
    handle->reqs_pending++;
    handle->send_queue_size += req->u.io.queued_bytes;
    handle->send_queue_count++;
    REGISTER_HANDLE_REQ(loop, handle, req);
  } else {
    /* Send failed due to an error. */
    return WSAGetLastError();
  }

  return 0;
}

static void uv_udp_queue_recv(uv_loop_t* loop, uv_udp_t* handle) {
  uv_req_t* req;
  uv_buf_t buf;
  DWORD bytes, flags;
  int result;

  assert(handle->flags & UV_HANDLE_READING);
  assert(!(handle->flags & UV_HANDLE_READ_PENDING));

  req = &handle->recv_req;
  memset(&req->u.io.overlapped, 0, sizeof(req->u.io.overlapped));
  handle->flags |= UV_HANDLE_ZERO_READ;
  buf.base = "";
  buf.len = 0;
  flags = MSG_PEEK;

  result = handle->func_wsarecv(handle->socket,
                                (WSABUF*) &buf,
                                1,
                                &bytes,
                                &flags,
                                &req->u.io.overlapped,
                                NULL);

  if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
    /* Process the req without IOCP. */
    handle->flags |= UV_HANDLE_READ_PENDING;
    req->u.io.overlapped.InternalHigh = bytes;
    handle->reqs_pending++;
    uv_insert_pending_req(loop, req);
  } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
    /* The req will be processed with IOCP. */
    handle->flags |= UV_HANDLE_READ_PENDING;
    handle->reqs_pending++;
  } else {
    /* Make this req pending reporting an error. */
    SET_REQ_ERROR(req, WSAGetLastError());
    uv_insert_pending_req(loop, req);
    handle->reqs_pending++;
  }
}

static int uv__udp_send(uv_udp_send_t* req, uv_udp_t* handle, uv_buf_t bufs[],
    int bufcnt, struct sockaddr* addr, int addr_len, uv_udp_send_cb cb) {
  uv_loop_t* loop = handle->loop;
  DWORD result, bytes;

  uv_req_init(loop, (uv_req_t*) req);
  req->type = UV_UDP_SEND;
  req->handle = handle;
  req->cb = cb;
  memset(&req->overlapped, 0, sizeof(req->overlapped));

  result = WSASendTo(handle->socket,
                     (WSABUF*)bufs,
                     bufcnt,
                     &bytes,
                     0,
                     addr,
                     addr_len,
                     &req->overlapped,
                     NULL);

  if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
    /* Request completed immediately. */
    req->queued_bytes = 0;
    handle->reqs_pending++;
    uv_ref(loop);
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
    /* Request queued by the kernel. */
    req->queued_bytes = uv_count_bufs(bufs, bufcnt);
    handle->reqs_pending++;
    uv_ref(loop);
  } else {
    /* Send failed due to an error. */
    uv__set_sys_error(loop, WSAGetLastError());
    return -1;
  }

  return 0;
}

static void uv_udp_queue_recv(uv_loop_t* loop, uv_udp_t* handle) {
  uv_req_t* req;
  uv_buf_t buf;
  DWORD bytes, flags;
  int result;

  assert(handle->flags & UV_HANDLE_READING);
  assert(!(handle->flags & UV_HANDLE_READ_PENDING));

  req = &handle->recv_req;
  memset(&req->u.io.overlapped, 0, sizeof(req->u.io.overlapped));

  /*
   * Preallocate a read buffer if the number of active streams is below
   * the threshold.
  */
  if (loop->active_udp_streams < uv_active_udp_streams_threshold) {
    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);
    if (handle->recv_buffer.base == NULL || handle->recv_buffer.len == 0) {
      handle->recv_cb(handle, UV_ENOBUFS, &handle->recv_buffer, NULL, 0);
      return;
    }
    assert(handle->recv_buffer.base != NULL);

    buf = handle->recv_buffer;
    memset(&handle->recv_from, 0, sizeof handle->recv_from);
    handle->recv_from_len = sizeof handle->recv_from;
    flags = 0;

    result = handle->func_wsarecvfrom(handle->socket,
                                      (WSABUF*) &buf,
                                      1,
                                      &bytes,
                                      &flags,
                                      (struct sockaddr*) &handle->recv_from,
                                      &handle->recv_from_len,
                                      &req->u.io.overlapped,
                                      NULL);

    if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
      /* Process the req without IOCP. */
      handle->flags |= UV_HANDLE_READ_PENDING;
      req->u.io.overlapped.InternalHigh = bytes;
      handle->reqs_pending++;
      uv_insert_pending_req(loop, req);
    } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
      /* The req will be processed with IOCP. */
      handle->flags |= UV_HANDLE_READ_PENDING;
      handle->reqs_pending++;
    } else {
      /* Make this req pending reporting an error. */
      SET_REQ_ERROR(req, WSAGetLastError());
      uv_insert_pending_req(loop, req);
      handle->reqs_pending++;
    }

  } else {
    handle->flags |= UV_HANDLE_ZERO_READ;

    buf.base = (char*) uv_zero_;
    buf.len = 0;
    flags = MSG_PEEK;

    result = handle->func_wsarecv(handle->socket,
                                  (WSABUF*) &buf,
                                  1,
                                  &bytes,
                                  &flags,
                                  &req->u.io.overlapped,
                                  NULL);

    if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
      /* Process the req without IOCP. */
      handle->flags |= UV_HANDLE_READ_PENDING;
      req->u.io.overlapped.InternalHigh = bytes;
      handle->reqs_pending++;
      uv_insert_pending_req(loop, req);
    } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
      /* The req will be processed with IOCP. */
      handle->flags |= UV_HANDLE_READ_PENDING;
      handle->reqs_pending++;
    } else {
      /* Make this req pending reporting an error. */
      SET_REQ_ERROR(req, WSAGetLastError());
      uv_insert_pending_req(loop, req);
      handle->reqs_pending++;
    }
  }
}

static void uv_tcp_queue_read(uv_loop_t* loop, uv_tcp_t* handle) {
  uv_read_t* req;
  uv_buf_t buf;
  int result;
  DWORD bytes, flags;

  assert(handle->flags & UV_HANDLE_READING);
  assert(!(handle->flags & UV_HANDLE_READ_PENDING));

  req = &handle->read_req;
  memset(&req->overlapped, 0, sizeof(req->overlapped));

  /*
   * Preallocate a read buffer if the number of active streams is below
   * the threshold.
  */
  if (loop->active_tcp_streams < uv_active_tcp_streams_threshold) {
    handle->flags &= ~UV_HANDLE_ZERO_READ;
    handle->alloc_cb((uv_handle_t*) handle, 65536, &handle->read_buffer);
    if (handle->read_buffer.len == 0) {
      handle->read_cb((uv_stream_t*) handle, UV_ENOBUFS, &handle->read_buffer);
      return;
    }
    assert(handle->read_buffer.base != NULL);
    buf = handle->read_buffer;
  } else {
    handle->flags |= UV_HANDLE_ZERO_READ;
    buf.base = (char*) &uv_zero_;
    buf.len = 0;
  }

  /* Prepare the overlapped structure. */
  memset(&(req->overlapped), 0, sizeof(req->overlapped));
  if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
    assert(req->event_handle);
    req->overlapped.hEvent = (HANDLE) ((DWORD) req->event_handle | 1);
  }

  flags = 0;
  result = WSARecv(handle->socket,
                   (WSABUF*)&buf,
                   1,
                   &bytes,
                   &flags,
                   &req->overlapped,
                   NULL);

  if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
    /* Process the req without IOCP. */
    handle->flags |= UV_HANDLE_READ_PENDING;
    req->overlapped.InternalHigh = bytes;
    handle->reqs_pending++;
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
    /* The req will be processed with IOCP. */
    handle->flags |= UV_HANDLE_READ_PENDING;
    handle->reqs_pending++;
    if (handle->flags & UV_HANDLE_EMULATE_IOCP &&
        req->wait_handle == INVALID_HANDLE_VALUE &&
        !pRegisterWaitForSingleObject(&req->wait_handle,
          req->event_handle, post_completion, (void*) req,
          INFINITE, WT_EXECUTEINWAITTHREAD)) {
      SET_REQ_ERROR(req, GetLastError());
      uv_insert_pending_req(loop, (uv_req_t*)req);
    }
  } else {
    /* Make this req pending reporting an error. */
    SET_REQ_ERROR(req, WSAGetLastError());
    uv_insert_pending_req(loop, (uv_req_t*)req);
    handle->reqs_pending++;
  }
}

static void uv_tcp_queue_accept(uv_tcp_t* handle, uv_tcp_accept_t* req) {
  uv_loop_t* loop = handle->loop;
  BOOL success;
  DWORD bytes;
  SOCKET accept_socket;
  short family;

  assert(handle->flags & UV_HANDLE_LISTENING);
  assert(req->accept_socket == INVALID_SOCKET);

  /* choose family and extension function */
  if (handle->flags & UV_HANDLE_IPV6) {
    family = AF_INET6;
  } else {
    family = AF_INET;
  }

  /* Open a socket for the accepted connection. */
  accept_socket = socket(family, SOCK_STREAM, 0);
  if (accept_socket == INVALID_SOCKET) {
    SET_REQ_ERROR(req, WSAGetLastError());
    uv_insert_pending_req(loop, (uv_req_t*)req);
    handle->reqs_pending++;
    return;
  }

  /* Make the socket non-inheritable */
  if (!SetHandleInformation((HANDLE) accept_socket, HANDLE_FLAG_INHERIT, 0)) {
    SET_REQ_ERROR(req, GetLastError());
    uv_insert_pending_req(loop, (uv_req_t*)req);
    handle->reqs_pending++;
    closesocket(accept_socket);
    return;
  }

  /* Prepare the overlapped structure. */
  memset(&(req->overlapped), 0, sizeof(req->overlapped));
  if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
    req->overlapped.hEvent = (HANDLE) ((DWORD) req->event_handle | 1); 
  }

  success = handle->func_acceptex(handle->socket,
                                  accept_socket,
                                  (void*)req->accept_buffer,
                                  0,
                                  sizeof(struct sockaddr_storage),
                                  sizeof(struct sockaddr_storage),
                                  &bytes,
                                  &req->overlapped);

  if (UV_SUCCEEDED_WITHOUT_IOCP(success)) {
    /* Process the req without IOCP. */
    req->accept_socket = accept_socket;
    handle->reqs_pending++;
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(success)) {
    /* The req will be processed with IOCP. */
    req->accept_socket = accept_socket;
    handle->reqs_pending++;
    if (handle->flags & UV_HANDLE_EMULATE_IOCP &&
        req->wait_handle == INVALID_HANDLE_VALUE &&
        !pRegisterWaitForSingleObject(&req->wait_handle,
          req->event_handle, post_completion, (void*) req,
          INFINITE, WT_EXECUTEINWAITTHREAD)) {
      SET_REQ_ERROR(req, GetLastError());
      uv_insert_pending_req(loop, (uv_req_t*)req);
      handle->reqs_pending++;
      return;
    }
  } else {
    /* Make this req pending reporting an error. */
    SET_REQ_ERROR(req, WSAGetLastError());
    uv_insert_pending_req(loop, (uv_req_t*)req);
    handle->reqs_pending++;
    /* Destroy the preallocated client socket. */
    closesocket(accept_socket);
    /* Destroy the event handle */
    if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
      CloseHandle(req->overlapped.hEvent);
      req->event_handle = NULL;
    }
  }
}

static int uv_tcp_try_connect(uv_connect_t* req,
                              uv_tcp_t* handle,
                              const struct sockaddr* addr,
                              unsigned int addrlen,
                              uv_connect_cb cb) {
  uv_loop_t* loop = handle->loop;
  const struct sockaddr* bind_addr;
  struct sockaddr_storage converted;
  BOOL success;
  DWORD bytes;
  int err;

  err = uv__convert_to_localhost_if_unspecified(addr, &converted);
  if (err)
    return err;

  if (handle->delayed_error) {
    return handle->delayed_error;
  }

  if (!(handle->flags & UV_HANDLE_BOUND)) {
    if (addrlen == sizeof(uv_addr_ip4_any_)) {
      bind_addr = (const struct sockaddr*) &uv_addr_ip4_any_;
    } else if (addrlen == sizeof(uv_addr_ip6_any_)) {
      bind_addr = (const struct sockaddr*) &uv_addr_ip6_any_;
    } else {
      abort();
    }
    err = uv_tcp_try_bind(handle, bind_addr, addrlen, 0);
    if (err)
      return err;
    if (handle->delayed_error)
      return handle->delayed_error;
  }

  if (!handle->tcp.conn.func_connectex) {
    if (!uv_get_connectex_function(handle->socket, &handle->tcp.conn.func_connectex)) {
      return WSAEAFNOSUPPORT;
    }
  }

  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));

  success = handle->tcp.conn.func_connectex(handle->socket,
                                            (const struct sockaddr*) &converted,
                                            addrlen,
                                            NULL,
                                            0,
                                            &bytes,
                                            &req->u.io.overlapped);

  if (UV_SUCCEEDED_WITHOUT_IOCP(success)) {
    /* Process the req without IOCP. */
    handle->reqs_pending++;
    REGISTER_HANDLE_REQ(loop, handle, req);
    uv_insert_pending_req(loop, (uv_req_t*)req);
  } else if (UV_SUCCEEDED_WITH_IOCP(success)) {
    /* The req will be processed with IOCP. */
    handle->reqs_pending++;
    REGISTER_HANDLE_REQ(loop, handle, req);
  } else {
    return WSAGetLastError();
  }

  return 0;
}