stream_set_timeout never works no matter how low the timeout

Question

In PHP, I'm opening a stream, writing to it and then reading from it. I want to set a timeout on the reading of the stream but no matter how low I set this (0 microseconds, 10 microseconds) the meta data never shows "timed_out"!

Relevant code:

//open the socket
if ( $fp = fsockopen( gethostbyname(host), port, $errno, $errstr, $timeout ) ) {

    //Send command to the host
    if ( fwrite( $fp, $requestCommand ) ) {
        //Set timeout and blocking
        stream_set_blocking( $fp, FALSE );
        stream_set_timeout( $fp, 0, 10 ); 

        //Check for timeout
        $info = stream_get_meta_data( $fp );
        echo $info[ 'timed_out' ];

        //Read and check for timeout
        while ( !$info['timed_out'] && !feof( $fp ) ) {
            $response .= fread( $fp, 4096 );

            //Get meta data (which has timeout info)
            $info = stream_get_meta_data( $fp );
        }
    }
} 

What am I doing wrong?

Answer 1

The key I found is the stream_set_blocking($fp, TRUE ).

If FALSE, then $status['timed_out'] seems to not have any practical effect. TRUE [PHP default] works.