In this article, we will discuss the mysqli_poll() function in PHP, which is used to poll connections.

Introduction to the mysqli_poll() function

The mysqli_poll() function is a built-in function in PHP that is used to poll connections. This function can be used to check if there is any data available on a connection before reading from it. The mysqli_poll() function can be used in conjunction with non-blocking I/O to make your application more responsive.

How to use the mysqli_poll() function

Using the mysqli_poll() function is straightforward. Here's an example:

$mysqli = new mysqli("localhost", "username", "password", "database");

if ($mysqli->connect_errno) {
    echo "Failed to connect to MySQL: " . $mysqli->connect_error;

$links = [$mysqli];
$processed = 0;
do {
    $links_ready = mysqli_poll($links, 10);
    if ($links_ready !== false) {
        foreach ($links_ready as $link) {
            if ($result = $link->reap_async_query()) {
                // process the result set
            } else {
                // handle the error
} while ($processed < count($links));


In this example, we first create a new MySQLi object using the mysqli() constructor. We then check if the connection was successful using the connect_errno property. If the connection was successful, we create an array of links that we want to poll, which contains only the $mysqli object. We then enter a loop that continues until all links have been processed. Inside the loop, we call mysqli_poll() with the array of links and a timeout value of 10 milliseconds. If there is data available on one or more of the links, mysqli_poll() returns an array of links that are ready to be processed. We then loop through the links that are ready to be processed and call the reap_async_query() method on each link to retrieve any data that is available. Finally, we increment the $processed counter and repeat the loop until all links have been processed.


In conclusion, the mysqli_poll() function is a powerful tool for polling connections in PHP. By understanding how to use the function, you can make your application more responsive and efficient when working with MySQL databases.

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