public function receive()
    {
        $nFeedbackTupleLen = self::TIME_BINARY_SIZE + self::TOKEN_LENGTH_BINARY_SIZE + self::DEVICE_BINARY_SIZE;

        $this->_aFeedback = array();
        $sBuffer = '';
        while (!feof($this->_hSocket)) {
            $this->_log('INFO: Reading...');
            $sBuffer .= $sCurrBuffer = fread($this->_hSocket, 8192);
            $nCurrBufferLen = strlen($sCurrBuffer);
            if ($nCurrBufferLen > 0) {
                $this->_log("INFO: {$nCurrBufferLen} bytes read.");
            }
            unset($sCurrBuffer, $nCurrBufferLen);

            $nBufferLen = strlen($sBuffer);
            if ($nBufferLen >= $nFeedbackTupleLen) {
                $nFeedbackTuples = floor($nBufferLen / $nFeedbackTupleLen);
                for ($i = 0; $i < $nFeedbackTuples; $i++) {
                    $sFeedbackTuple = substr($sBuffer, 0, $nFeedbackTupleLen);
                    $sBuffer = substr($sBuffer, $nFeedbackTupleLen);
                    $this->_aFeedback[] = $aFeedback = $this->_parseBinaryTuple($sFeedbackTuple);
                    $this->_log(sprintf("INFO: New feedback tuple: timestamp=%d (%s), tokenLength=%d, deviceToken=%s.",
                        $aFeedback['timestamp'], date('Y-m-d H:i:s', $aFeedback['timestamp']),
                        $aFeedback['tokenLength'], $aFeedback['deviceToken']
                    ));
                    unset($aFeedback);
                }
            }

            $read = array($this->_hSocket);
            $null = NULL;
            $nChangedStreams = stream_select($read, $null, $null, 0, $this->_nSocketSelectTimeout);
            if ($nChangedStreams === false) {
                $this->_log('WARNING: Unable to wait for a stream availability.');
                break;
            }
        }
        return $this->_aFeedback;
    }

    /**
     * Parses binary tuples.
     *
     * @param  $sBinaryTuple @type string A binary tuple to parse.
     * @return @type array Array with timestamp, tokenLength and deviceToken keys.
     */
    protected function _parseBinaryTuple($sBinaryTuple)
    {
        return unpack('Ntimestamp/ntokenLength/H*deviceToken', $sBinaryTuple);
    }