starboard/shared/win32/socket_is_connected.cc

// Copyright 2017 The Cobalt Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "starboard/common/socket.h"

#include <winsock2.h>

#include "starboard/common/log.h"
#include "starboard/shared/win32/socket_internal.h"

bool SbSocketIsConnected(SbSocket socket) {
  if (!SbSocketIsValid(socket)) {
    return false;
  }

  SB_DCHECK(socket->socket_handle != INVALID_SOCKET);

  // To tell if it is really connected, we peek a byte from the stream. We
  // should get a byte back, or an EAGAIN/EWOULDBLOCK telling us the socket is
  // waiting for data.
  char c;
  const int result = recv(socket->socket_handle, &c, 1, MSG_PEEK);
  if (result == 0) {
    // If the connection is closed, the return value is 0.
    return false;
  }

  const int last_error = WSAGetLastError();
  return (result > 0 || last_error == WSAEWOULDBLOCK);
}