PHP Decode

--TEST--
proc_open() with IO socketpairs
--FILE--
<?php

function poll($pipe, $read = true)
{
    $r = ($read == true) ? [$pipe] : null;
    $w = ($read == false) ? [$pipe] : null;
    $e = null;

    if (!stream_select($r, $w, $e, null)) {
        throw new \Error("Select failed");
    }
}

function read_pipe($pipe): string
{
    poll($pipe);

    if (false === ($chunk = @fread($pipe, 8192))) {
        throw new Error("Failed to read: " . (error_get_last()['message'] ?? 'N/A'));
    }

    return $chunk;
}

function write_pipe($pipe, $data)
{
    poll($pipe, false);

    if (false == @fwrite($pipe, $data)) {
        throw new Error("Failed to write: " . (error_get_last()['message'] ?? 'N/A'));
    }
}

$cmd = [
    getenv("TEST_PHP_EXECUTABLE"),
    __DIR__ . '/proc_open_sockets2.inc'
];

$spec = [
    ['socket'],
    ['socket']
];

$proc = proc_open($cmd, $spec, $pipes);

foreach ($pipes as $pipe) {
    var_dump(stream_set_blocking($pipe, false));
}

printf("STDOUT << %s\n", read_pipe($pipes[1]));
printf("STDOUT << %s\n", read_pipe($pipes[1]));

write_pipe($pipes[0], 'done');
fclose($pipes[0]);

printf("STDOUT << %s\n", read_pipe($pipes[1]));

?>
--EXPECT--
bool(true)
bool(true)
STDOUT << hello
STDOUT << world
STDOUT << DONE