The parallel\Future class

(0.8.0)

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

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

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