PHP Multiprocess

calculate.php

<?php

ini_set('memory_limit','512M');
CONST WORKER_POOL = 3;
CONST INPUT_FILE = 'in.txt';
CONST OUTPUT_FILE = 'out.txt';
CONST PROCESS_DESCRIPTORS = [0 => ['pipe', 'r'], 1 => ['pipe', 'w'], 2 => ['file', 'error.log', 'a']];

$workers = [];
$pipes = [];
$inputFile = fopen(INPUT_FILE, 'r');
stream_set_blocking($inputFile, false);
$lineNumber = 0;

for ($index = 0; $index < WORKER_POOL; $index++) {
    $pipes[$index] = [];
    $workers[] = proc_open('php worker.php', PROCESS_DESCRIPTORS, $pipes[$index]);
}


while(!feof($inputFile)) {
    $line = fgets($inputFile);
    fwrite($pipes[$lineNumber % WORKER_POOL][0], $line);
    $lineNumber++;
}
fclose($inputFile);

for ($index = 0; $index < WORKER_POOL; $index++) {
    fclose($pipes[$index][0]);
}

$outputFile = fopen(OUTPUT_FILE, 'w');
stream_set_blocking($outputFile, false);
$lineNumber = 0;
while (!feof($pipes[$lineNumber % WORKER_POOL][1])) {
    $result = fgets($pipes[$lineNumber % WORKER_POOL][1]);
    fputs($outputFile, $result);
    $lineNumber++;
}
fclose($outputFile);

for ($index = 0; $index < WORKER_POOL; $index++) {
    fclose($pipes[$index][1]);
}


for($index = 0; $index < WORKER_POOL; $index++) {
    proc_close($workers[$index]);
}

in.txt

3388,-4200,2042,-3204
2456,-894,594,549
-3765,-146,-968,2616
1188,-1772,3479,-4172
1934,-4371,-488,1721
554,623,1720,-4633
-1613,-3469,301,-2528
3966,1576,2185,4581
-2621,-3078,-4622,2417
-1389,4472,-1285,-820
2091,3747,3154,-1553
3284,3728,4825,-3244
1319,170,-1078,-1469
-3263,4695,4641,-4579
-3436,-3944,4466,-1294
-221,3980,-449,-3068
1405,34,-3125,2053
1583,3739,2403,-1706
-3138,1898,-1617,988
4574,813,3396,-3294
3344,-2274,1581,-1766
193,-1344,2938,817
-373,-1177,-3421,-4162
-4645,2099,1869,-4788
-4249,-1111,-4596,-1210
-3567,2990,3499,-2116
3404,-3959,4769,-1588
2832,-2985,-864,4092
-3643,-1170,-1515,3340
343,-446,1144,3444
-736,-1237,-4073,2005
-3065,981,-968,-2744
1369,1704,2229,-3305
3635,1589,-4265,-3433
-682,-1504,-304,-607
-3662,4475,4230,-998
1367,-36,-3382,-1596

worker.php

<?php

ini_set('memory_limit','512M');
$input = fopen('php://stdin', 'r');
while (!feof($input)) {
    $line = fgets($input);
    if (strlen($line) > 0) {
        $numbers = explode(',', preg_replace('~[\r\n]+~', '', $line));
        $result = round(sqrt(pow(/**/(int)$numbers[2] - (int)$numbers[0], 2) + pow((int)$numbers[3] - (int)$numbers[1],2)), 2);
        echo $result . "\n";
    }
}
fclose($input);