How to externalize function for parallel processing in PHP - php

Question

I am going to play with parallel processing in PHP. https://www.php.net/manual/en/book.parallel.php
I could make something very basic to understand the main concept.
Here is where I am :
<?php
for ($i = 0; $i < 7; $i++) {
$runtime = new \parallel\Runtime();
$runtimes[] = $runtime;
echo "starting thread $i from main thread" . PHP_EOL;
$future = $runtime->run(function($i){
$nbtot = 0;
echo "I am thread $i " . PHP_EOL;
for ($j = 0; $j < 5; $j++) {
echo "thread $i in loop $j " . PHP_EOL;
$nbsec = rand(0, 10);
$nbtot = $nbtot + $nbsec;
sleep($nbsec);
}
return array($i, $nbtot); //returning an array to the main thread
}, array($i)); //passing argument to the closure
$futures[] = $future;
}
$ct = count($futures);
while ( $ct > 0 ) {
echo "$ct active threads" . PHP_EOL;
foreach ($futures as $key => $future) {
if ($future->done()) {
print_r($future->value());
unset($futures[$key]);
}
}
sleep(2);
$ct = count($futures);
}
?>
For maintenance purpose, I would like to put the code of the function (closure) in another file. I guess that \parallel\bootstrap is made for it, but I can't figure out how to make it work. What should I change my current code ? and what should I place in the other file ?

Answer 1

After some hard time and the support of Joe Watkins, here is the answer I was looking for :
<?php
\parallel\bootstrap('test_threads_inc.php');
for ($i = 0; $i < 7; $i++) {
echo "starting thread $i from main thread" . PHP_EOL;
$futures[] = \parallel\run(function($a) {return myfunction($a);}, array($i)); //passing argument to the closure
}
$ct = count($futures);
while ( $ct > 0 ) {
echo "$ct active threads" . PHP_EOL;
foreach ($futures as $key => $future) {
if ($future->done()) {
print_r($future->value());
unset($futures[$key]);
}
}
sleep(2);
$ct = count($futures);
}
?>
and test_threads_inc.php :
<?php
function myfunction($i) {
$nbtot = 0;
echo "I am thread $i " . PHP_EOL;
for ($j = 0; $j < 5; $j++) {
echo "thread $i in loop $j " . PHP_EOL;
$nbsec = rand(0, 10);
$nbtot = $nbtot + $nbsec;
sleep($nbsec);
}
return array($i, $nbtot); //returning an array to the main thread
}
?>

Answer 2

I wrote this include file test_inc.php :
<?php
$myworker = function($i){
...
return array($i, $nbtot); //returning an array to the main thread
}
?>
and then include it at the beginning of main script : include('test_inc.php');. I could replace the function description by the variable just like this :
$future = $runtime->run($myworker, array($i));

Answer 3

It's possible to work with class inside the Closure function. For that, you need to use require_once inside the function to include them. It's probably possible to include the require_once outside the Closure function if you use a bootstrap