You can achieve the equivalent of the mysql_list_processes() function for MySQLi in php using:
function mysqli_list_processes(){
$query = "SHOW PROCESSLIST";
if ($res =$this->mysqli->query($query)){
while ($row = $res->fetch_assoc()) $recs[$i++] = $row;
$res->close();
return $recs;
} else {
return false;
}
}