mysqli::poll

mysqli_poll

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

mysqli::poll -- mysqli_poll — Poll connections

Description

Object-oriented style

public static function mysqli::poll(
    ?array &$read,
    ?array &$error,
    array &$reject,
    int $seconds,
    int $microseconds = 0
): int|false

Procedural style

function mysqli_poll(
    ?array &$read,
    ?array &$error,
    array &$reject,
    int $seconds,
    int $microseconds = 0
): int|false

Poll connections. The method can be used as static.

Note:

Available only with mysqlnd.

Parameters

read

List of connections to check for outstanding results that can be read.

error
List of connections on which an error occurred, for example, query failure or lost connection.
reject
List of connections rejected because no pending asynchronous query exists to poll.
seconds

Maximum number of seconds to wait, must be non-negative.

microseconds

Maximum number of microseconds to wait, must be non-negative.

Return Values

Returns number of ready connections upon success, false otherwise.

Errors/Exceptions

A ValueError is thrown when neither the read nor error arguments are passed.

Changelog

Version Description
8.3.0 Now throws a ValueError exception when neither the read nor error arguments are passed.

Examples

Example #1 A mysqli_poll() example

<?php
$link1 = mysqli_connect();
$link1->query("SELECT 'test'", MYSQLI_ASYNC);
$all_links = array($link1);
$processed = 0;
do {
    $links = $errors = $reject = array();
    foreach ($all_links as $link) {
        $links[] = $errors[] = $reject[] = $link;
    }
    if (!mysqli_poll($links, $errors, $reject, 1)) {
        continue;
    }
    foreach ($links as $link) {
        if ($result = $link->reap_async_query()) {
            print_r($result->fetch_row());
            if (is_object($result))
                mysqli_free_result($result);
        } else die(sprintf("MySQLi Error: %s", mysqli_error($link)));
        $processed++;
    }
} while ($processed < count($all_links));
?>

The above example will output:

Array
(
    [0] => test
)

See Also