PHP mysqli: poll() function
mysqli_poll function / mysqli::poll
The mysqli_poll function / mysqli::poll — Poll connections
Syntax:
Object oriented style
public static int mysqli::poll ( array &$read , array &$error , array &$reject , int $sec [, int $usec ] )
Procedural style
int mysqli_poll ( array &$read , array &$error , array &$reject , int $sec [, int $usec ] )
Parameter:
| Name | Description |
|---|---|
| read | List of connections to check for outstanding results that can be read. |
| error | List of connections on which an error occured, for example, query failure or lost connection. |
| reject | List of connections rejected because no asynchronous query has been run on for which the function could poll results. |
| sec | Maximum number of seconds to wait, must be non-negative. |
| usec | Maximum number of seconds to wait, must be non-negative. |
Usage: Procedural style
mysqli_poll(connection);
Parameter:
| Name | Description | Required/Optional |
|---|---|---|
| connection | Specifies the MySQL connection to use | Required |
Return value:
Returns number of ready connections upon success, FALSE otherwise.
Version: PHP 5, PHP 7
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($all_links));
?>
See also
PHP: Tips of the Day
Di?erence between __CLASS__, get_class() and get_called_class()
__CLASS__ magic constant returns the same result as get_class() function called without parameters and they both return the name of the class where it was defined (i.e. where you wrote the function call/constant name ).
In contrast, get_class($this) and get_called_class() functions call, will both return the name of the actual class which was instantiated:
Example:
<?php
class Definition_Class {
public function say(){
echo '__CLASS__ value: ' . __CLASS__ . "\n";
echo 'get_called_class() value: ' . get_called_class() . "\n";
echo 'get_class($this) value: ' . get_class($this) . "\n";
echo 'get_class() value: ' . get_class() . "\n";
}
}
class Actual_Class extends Definition_Class {}
$c = new Actual_Class();
$c->say();
Output:
__CLASS__ value: Definition_Class get_called_class() value: Actual_Class get_class($this) value: Actual_Class get_class() value: Definition_Class
- Weekly Trends
- Java Basic Programming Exercises
- SQL Subqueries
- Adventureworks Database Exercises
- C# Sharp Basic Exercises
- SQL COUNT() with distinct
- JavaScript String Exercises
- JavaScript HTML Form Validation
- Java Collection Exercises
- SQL COUNT() function
- SQL Inner Join
- JavaScript functions Exercises
- Python Tutorial
- Python Array Exercises
- SQL Cross Join
- C# Sharp Array Exercises
We are closing our Disqus commenting system for some maintenanace issues. You may write to us at reach[at]yahoo[dot]com or visit us at Facebook