Parallel.php

<?php
//montecarlo
const N = 1000000000;

/*$counter = 0;
for($i=0;$i<N;$i++){
    $x = mt_rand() / mt_getrandmax();
    $y = mt_rand() / mt_getrandmax();
    if(($x**2 + $y**2)**2 < 1) $counter++;
}
$pi = 4*$counter/N;
var_dump($pi);*/


$runtime1 = new \parallel\Runtime;
$runtime2 = new \parallel\Runtime;
$runtime3 = new \parallel\Runtime;
$runtime4 = new \parallel\Runtime;

$future1 = $runtime1->run(function(){
    $N = 1000000000;
    $counter = 0;
    for($i=0;$i<($N/4);$i++){
        $x = mt_rand() / mt_getrandmax();
        $y = mt_rand() / mt_getrandmax();
        if(($x**2 + $y**2)**2 < 1) $counter++;
    }
    return $counter;
});

$future2 = $runtime2->run(function(){
    $counter = 0;
    $N = 1000000000;
    for($i=($N/4);$i<($N/4)*2;$i++){
        $x = mt_rand() / mt_getrandmax();
        $y = mt_rand() / mt_getrandmax();
        if(($x**2 + $y**2)**2 < 1) $counter++;
    }
    return $counter;
});

$future3 = $runtime3->run(function(){
    $counter = 0;
    $N = 1000000000;
    for($i=($N/4)*2;$i<($N/4)*3;$i++){
        $x = mt_rand() / mt_getrandmax();
        $y = mt_rand() / mt_getrandmax();
        if(($x**2 + $y**2)**2 < 1) $counter++;
    }
    return $counter;
});

$future4 = $runtime4->run(function(){
    $counter = 0;
    $N = 1000000000;
    for($i=($N/4)*3;$i<$N;$i++){
        $x = mt_rand() / mt_getrandmax();
        $y = mt_rand() / mt_getrandmax();
        if(($x**2 + $y**2)**2 < 1) $counter++;
    }
    return $counter;
});

$c = $future1->value() + $future2->value() + $future3->value() + $future4->value();
$pi = 4*$c/N;
var_dump($pi);


class ParallelFor {

    public function __construct(Closure $fun, int $count, int $max_parallel){
        $this->func = $func;
        if($count < $max_parallel){
            echo 'count < max_parallel', PHP_EOL;
            return;
        }
        $this->count = $count;
        $this->max_parallel = $max_parallel;

        $runtimes = [];
        for($i=0;$i<$max_parallel;$i++){
            $runtime = ParallelFactory::create();
            $runtime->run(function() use ($func, $i, $count, $max_parallel){
                for($j=($count/$max_parallel)*$i;$j<($count/$max_parallel)*($i+1);$j++){
                    $func();
                }
            });
        }
    }

    public function getFunction(){
        return $this->func;
    }

    public function getMaxParallel(){
        return $this->max_parallel;
    }
}


class ParallelFactory {

    public static function create(){
        return new \parallel\Runtime;
    }

}