How to use

recvfrom

method

in

libcore.io.IoBridge

private void doRecv(DatagramPacket pack, int flags) throws IOException {
  IoBridge.recvfrom(false, fd, pack.getData(), pack.getOffset(), pack.getLength(), flags, pack, isNativeConnected);
  if (isNativeConnected) {
    updatePacketRecvAddress(pack);
  }
}

/**
 * For PlainSocketInputStream.
 */
private int read(byte[] buffer, int offset, int byteCount) throws IOException {
  if (byteCount == 0) {
    return 0;
  }
  Arrays.checkOffsetAndCount(buffer.length, offset, byteCount);
  if (shutdownInput) {
    return -1;
  }
  int readCount = IoBridge.recvfrom(true, fd, buffer, offset, byteCount, 0, null, false);
  // Return of zero bytes for a blocking socket means a timeout occurred
  if (readCount == 0) {
    throw new SocketTimeoutException();
  }
  // Return of -1 indicates the peer was closed
  if (readCount == -1) {
    shutdownInput = true;
  }
  return readCount;
}

private SocketAddress receiveDirectImpl(ByteBuffer target, boolean loop) throws IOException {
  SocketAddress retAddr = null;
  DatagramPacket receivePacket = new DatagramPacket(EmptyArray.BYTE, 0);
  int oldposition = target.position();
  int received = 0;
  do {
    received = IoBridge.recvfrom(false, fd, target, 0, receivePacket, isConnected());
    if (receivePacket != null && receivePacket.getAddress() != null) {
      // copy the data of received packet
      if (received > 0) {
        target.position(oldposition + received);
      }
      retAddr = receivePacket.getSocketAddress();
      break;
    }
  } while (loop);
  return retAddr;
}

private SocketAddress receiveImpl(ByteBuffer target, boolean loop) throws IOException {
  SocketAddress retAddr = null;
  DatagramPacket receivePacket;
  int oldposition = target.position();
  int received = 0;
  // TODO: disallow mapped buffers and lose this conditional?
  if (target.hasArray()) {
    receivePacket = new DatagramPacket(target.array(), target.position() + target.arrayOffset(), target.remaining());
  } else {
    receivePacket = new DatagramPacket(new byte[target.remaining()], target.remaining());
  }
  do {
    received = IoBridge.recvfrom(false, fd, receivePacket.getData(), receivePacket.getOffset(), receivePacket.getLength(), 0, receivePacket, isConnected());
    if (receivePacket != null && receivePacket.getAddress() != null) {
      if (received > 0) {
        if (target.hasArray()) {
          target.position(oldposition + received);
        } else {
          // copy the data of received packet
          target.put(receivePacket.getData(), 0, received);
        }
      }
      retAddr = receivePacket.getSocketAddress();
      break;
    }
  } while (loop);
  return retAddr;
}

private int readImpl(ByteBuffer dst) throws IOException {
  synchronized (readLock) {
    int readCount = 0;
    try {
      if (isBlocking()) {
        begin();
      }
      readCount = IoBridge.recvfrom(true, fd, dst, 0, null, false);
      if (readCount > 0) {
        dst.position(dst.position() + readCount);
      }
    } finally {
      if (isBlocking()) {
        end(readCount > 0);
      }
    }
    return readCount;
  }
}

private int readImpl(ByteBuffer dst) throws IOException {
  synchronized (readLock) {
    int readCount = 0;
    try {
      begin();
      readCount = IoBridge.recvfrom(false, fd, dst, 0, null, isConnected());
    } catch (InterruptedIOException e) {
      // InterruptedIOException will be thrown when timeout.
      return 0;
    } finally {
      end(readCount > 0);
    }
    return readCount;
  }
}

private void doRecv(DatagramPacket pack, int flags) throws IOException {
  IoBridge.recvfrom(false, fd, pack.getData(), pack.getOffset(), pack.getLength(), flags, pack, isNativeConnected);
  if (isNativeConnected) {
    updatePacketRecvAddress(pack);
  }
}

private void doRecv(DatagramPacket pack, int flags) throws IOException {
  IoBridge.recvfrom(false, fd, pack.getData(), pack.getOffset(), pack.getLength(), flags, pack, isNativeConnected);
  if (isNativeConnected) {
    updatePacketRecvAddress(pack);
  }
}

private void doRecv(DatagramPacket pack, int flags) throws IOException {
  IoBridge.recvfrom(false, fd, pack.getData(), pack.getOffset(), pack.getLength(), flags, pack, isNativeConnected);
  if (isNativeConnected) {
    updatePacketRecvAddress(pack);
  }
}

private void doRecv(DatagramPacket pack, int flags) throws IOException {
  IoBridge.recvfrom(false, fd, pack.getData(), pack.getOffset(), pack.getLength(), flags, pack, isNativeConnected);
  if (isNativeConnected) {
    updatePacketRecvAddress(pack);
  }
}

private void doRecv(DatagramPacket pack, int flags) throws IOException {
  IoBridge.recvfrom(false, fd, pack.getData(), pack.getOffset(), pack.getLength(), flags, pack, isNativeConnected);
  if (isNativeConnected) {
    updatePacketRecvAddress(pack);
  }
}

private SocketAddress receiveDirectImpl(ByteBuffer target, boolean loop) throws IOException {
  SocketAddress retAddr = null;
  DatagramPacket receivePacket = new DatagramPacket(EmptyArray.BYTE, 0);
  int oldposition = target.position();
  int received = 0;
  do {
    received = IoBridge.recvfrom(false, fd, target, 0, receivePacket, isConnected());
    if (receivePacket != null && receivePacket.getAddress() != null) {
      // copy the data of received packet
      if (received > 0) {
        target.position(oldposition + received);
      }
      retAddr = receivePacket.getSocketAddress();
      break;
    }
  } while (loop);
  return retAddr;
}

private void doRecv(DatagramPacket pack, int flags) throws IOException {
  IoBridge.recvfrom(false, fd, pack.getData(), pack.getOffset(), pack.getLength(), flags, pack, isNativeConnected);
  if (isNativeConnected) {
    updatePacketRecvAddress(pack);
  }
}

private int readImpl(ByteBuffer dst) throws IOException {
  synchronized (readLock) {
    int readCount = 0;
    try {
      if (isBlocking()) {
        begin();
      }
      readCount = IoBridge.recvfrom(true, fd, dst, 0, null, false);
      if (readCount > 0) {
        dst.position(dst.position() + readCount);
      }
    } finally {
      if (isBlocking()) {
        end(readCount > 0);
      }
    }
    return readCount;
  }
}

private int readImpl(ByteBuffer dst) throws IOException {
  synchronized (readLock) {
    int readCount = 0;
    try {
      if (isBlocking()) {
        begin();
      }
      readCount = IoBridge.recvfrom(true, fd, dst, 0, null, false);
      if (readCount > 0) {
        dst.position(dst.position() + readCount);
      }
    } finally {
      if (isBlocking()) {
        end(readCount > 0);
      }
    }
    return readCount;
  }
}

private int readImpl(ByteBuffer dst) throws IOException {
  synchronized (readLock) {
    int readCount = 0;
    try {
      begin();
      readCount = IoBridge.recvfrom(false, fd, dst, 0, null, isConnected());
    } catch (InterruptedIOException e) {
      // InterruptedIOException will be thrown when timeout.
      return 0;
    } finally {
      end(readCount > 0);
    }
    return readCount;
  }
}

private int readImpl(ByteBuffer dst) throws IOException {
  synchronized (readLock) {
    int readCount = 0;
    try {
      begin();
      readCount = IoBridge.recvfrom(false, fd, dst, 0, null, isConnected());
    } catch (InterruptedIOException e) {
      // InterruptedIOException will be thrown when timeout.
      return 0;
    } finally {
      end(readCount > 0);
    }
    return readCount;
  }
}

private int readImpl(ByteBuffer dst) throws IOException {
  synchronized (readLock) {
    int readCount = 0;
    try {
      begin();
      readCount = IoBridge.recvfrom(false, fd, dst, 0, null, isConnected());
    } catch (InterruptedIOException e) {
      // InterruptedIOException will be thrown when timeout.
      return 0;
    } finally {
      end(readCount > 0);
    }
    return readCount;
  }
}

private int readImpl(ByteBuffer dst) throws IOException {
  synchronized (readLock) {
    int readCount = 0;
    try {
      begin();
      readCount = IoBridge.recvfrom(false, fd, dst, 0, null, isConnected());
    } catch (InterruptedIOException e) {
      // InterruptedIOException will be thrown when timeout.
      return 0;
    } finally {
      end(readCount > 0);
    }
    return readCount;
  }
}

private int readImpl(ByteBuffer dst) throws IOException {
  synchronized (readLock) {
    int readCount = 0;
    try {
      begin();
      readCount = IoBridge.recvfrom(false, fd, dst, 0, null, isConnected());
    } catch (InterruptedIOException e) {
      // InterruptedIOException will be thrown when timeout.
      return 0;
    } finally {
      end(readCount > 0);
    }
    return readCount;
  }
}