php tcp udp 通信

 /**
     * udp收发包
     * @param $ip
     * @param $port
     * @param $timeout
     * @return int 0-成功，非0-失败（具体参考类头部错误码常量定义）
     */
    private function udpSocket($ip, $port, $timeout)
    {
        $time = microtime(true);
        $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);

        if (false === $sock) {
            return self::UDL_SOCKET_CREATE_FAILED; // socket创建失败
        }

        if (!socket_set_nonblock($sock)) {
            return self::UDL_SOCKET_SET_NONBLOCK_FAILED; // 设置socket非阻塞失败
        }

        $len = strlen($this->mUdlRequestBuf);
        if (socket_sendto($sock, $this->mUdlRequestBuf, $len, 0x100, $ip, $port) != $len) {
            return self::UDL_SOCKET_SEND_FAILED; // socket发送失败
        }

        if (0 == $timeout) {
            return self::UDL_SUCCESS; // 无回包的情况，返回成功
        }

        $read = array($sock);
        $second = floor($timeout);
        $usecond = ($timeout - $second) * 1000000;
        $ret = socket_select($read, $write, $except, $second, $usecond);

        if (FALSE === $ret) {
            return self::UDL_SOCKET_RECEIVE_FAILED; // 收包失败
        } elseif ($ret != 1) {
            return self::UDL_SOCKET_SELECT_TIMEOUT; // 收包超时
        }

        $out = null;
        while (true) {
            if (microtime(true) - $time > $timeout) {
                return self::UDL_SOCKET_TIMEOUT; // 收包超时
            }

            // 32k：32768 = 1024 * 32
            $outLen = @socket_recvfrom($sock, $out, 32768, 0, $host, $port);
            if (!($outLen > 0 && $out != '')) {
                continue;
            }

            $list = unpack('Nseq', substr($out, 9, 4));
            $seq = $list['seq'];

            if ($seq !== $this->mSeq) {
                continue;
            }

            $this->mUdlResponseBuf = $out;

            return self::UDL_SUCCESS;
        }
    }

    /**
     * udp收发包
     * @param $ip
     * @param $port
     * @param $timeout
     * @return int 0-成功，非0-失败（具体参考类头部错误码常量定义）
     */
    private function tcpSocket($ip, $port, $timeout)
    {
        $time = microtime(true);
        $sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

        if (false === $sock) {
            return self::UDL_SOCKET_CREATE_FAILED; // socket创建失败
        }

        if (!socket_connect($sock, $ip, $port)) {
            return self::UDL_SOCKET_CONNECT_FAILED;
        }

        $len = strlen($this->mUdlRequestBuf);
        if (socket_write($sock, $this->mUdlRequestBuf, $len) != $len) {
            return self::UDL_SOCKET_SEND_FAILED;
        }

        $read = array($sock);
        $ret = socket_select($read, $write = null, $except = null, $timeout);

        if (false === $ret) {
            return self::UDL_SOCKET_RECEIVE_FAILED;
        } elseif ($ret != 1) {
            return self::UDL_SOCKET_SELECT_TIMEOUT;
        }

        $totalLen = 0;
        while (true) {
            if (microtime(true) - $time > $timeout) {
                return self::UDL_SOCKET_TIMEOUT; // 收包超时
            }

            //读取最多32M的数据
            $data = socket_read($sock, self::SOCKET_TCP_MAX_PCK_SIZE, PHP_BINARY_READ);

            if (empty($data)) {
                // 已经断开连接
                return self::UDL_SOCKET_CLOSED;
            } else {
                //第一个包
                if ($this->mUdlResponseBuf === null) {
                    $this->mUdlResponseBuf = $data;

                    //在这里从第一个包中获取总包长
                    $list = unpack('Nlen', substr($data, 1, 4));
                    $totalLen = $list['len'];
                } else {
                    $this->mUdlResponseBuf .= $data;
                }

                //check if all package is receved
                if (strlen($this->mUdlResponseBuf) >= $totalLen) {
                    return self::UDL_SUCCESS;
                }
            }
        }
    }

    /**
     * 打包、收发包、解包
     * @param $ip
     * @param $port
     * @param int $timeout
     * @return int
     */
    private function sendAndReceive($ip, $port, $timeout = 2, $socketMode)
    {
        try {
            $this->serialize();

            if ($socketMode === self::SOCKET_MODE_UDP) {
                $r = $this->udpSocket($ip, $port, $timeout);
            } else {
                $r = $this->tcpSocket($ip, $port, $timeout);
            }

            if ($r !== self::UDL_SUCCESS) {
                return $r;
            }

            $this->unserialize();
        } catch (Exception $e) {
            return self::UDL_FAILED;
        }

        return self::UDL_SUCCESS;
    }