用 Event 扩展来实现一个支持并发处理的Socket服务器

<?php 
// 使用pcntl实现，只能指定固定进程数去处理，性能不高
/*
$sock = stream_socket_server("tcp://127.0.0.1:8080", $errno, $errstr);
$pids = [];

for ($i=0; $i<10; $i++) {
    $pid = pcntl_fork();
    $pids[] = $pid;
    
    if ($pid == 0) {
        for ( ; ; ) {
            $conn = stream_socket_accept($sock);
            $write_buffer = "HTTP/1.0 200 OK\r\nServer: my_server\r\nContent-Type: text/html; charset=utf-8\r\n\r\nhello!world";
            fwrite($conn, $write_buffer);
            fclose($conn);
        }
        
        exit(0);
    }
    
}

foreach ($pids as $pid) {
    pcntl_waitpid($pid, $status);
}
*/

function daemon() {
    umask(0);
    
    if (pcntl_fork()) {
        exit(0);
    }
    
    posix_setsid();
    
    if (pcntl_fork()) {
        exit(0);
    }
}

// 守护进程
daemon();

$fd = stream_socket_server("tcp://127.0.0.1:8080", $errno, $errstr);
stream_set_blocking($fd, 0);
$eventBase = new EventBase();

$event = new Event($eventBase, $fd, Event::READ | Event::PERSIST, function ($fd) use (&$eventBase) {
    $conn = stream_socket_accept($fd);

    fwrite($conn, "HTTP/1.0 200 OK\r\nContent-Length: 2\r\n\r\nHi");
    fclose($conn);
}, $fd);

$event->add();
$eventBase->loop();