(0.8.0)
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());
?>
以上例程的输出类似于：
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";
?>
以上例程的输出类似于：
in child .................................................. leaving child parent continues