parallel
PHP Manual

The parallel\Future class

Futures

A Future represents the return value or uncaught exception from a task, and exposes an API for cancellation.

Example #1 Example showing Future as return value

<?php
$runtime = new \parallel\Runtime;
$future  = $runtime->run(function(){
    return "World";
});
printf("Hello %s\n", $future->value());
?>

The above example will output something similar to:

Hello World

The behaviour of a future also allows it to be used as a simple synchronization point even where the task does not return a value explicitly.

Example #2 Example showing Future as synchronization point

<?php
$runtime = new \parallel\Runtime;
$future  = $runtime->run(function(){
    echo "in child ";
    for ($i = 0; $i < 500; $i++) {
        if ($i % 10 == 0) {
            echo ".";
        }
    }
    echo " leaving child";
});

$future->value();
echo "\nparent continues\n";
?>

The above example will output something similar to:

in child .................................................. leaving child
parent continues

Class synopsis

parallel\Future
final class parallel\Future {
/* Resolution */
public mixed value()
/* State */
public bool cancelled()
public bool done()
/* Cancellation */
public bool cancel()
}
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