Why does the second client from the same IP address have a 20 second timeout before displaying the page?

Question

Edit:

I changed the name from "Why can't the second client access the page until the first call ends?" to "Why does the second client from the same IP address have a 20 second timeout before displaying the page?". Thus, until all changes are changed,

---

here are 2 urls: /homeand /sleep.

/home displays the home page

/sleep sleeps 10 seconds

---

I have 2 clients:

Client 1 : /sleep→ 10 seconds waiting

Client 1 : /sleep, Client 2 : /home→ 1 client waits 10 seconds, Client 2 Instant Download page.

1: /sleep, 2: /sleep → 1 10 , 2 20 .

---

? ?

- , - .

:

$fileHandler = fopen('process.lock', 'w');
$hasLock = flock($fileHandler, LOCK_EX | LOCK_NB);
if (!$hasLock) {
    return('already running'); // it never goes here.
}

for ($i = 0; $i < 10; ++$i) {
    echo nl2br("$i" . PHP_EOL);
    ob_flush();
    flush();
    sleep(1);
}

flock($fileHandler, LOCK_UN);
fclose($fileHandler);

. , " " 20 . , for, " " 2, 20 .

, .

Edit2

, , Apache PHP, , :

1 /sleep:

public function sleep() {
    // this is the endpoint of http://127.0.0.1/sleep
    sleep(300);
}

, 2 :

public function sleep() {
    // this is the endpoint of http://127.0.0.1/sleep
    die('hello');
}

5 ( ), 20 hello.

Edit3

1: 127.0.0.1/sleep → 10

2: 192.168.0.10/sleep → 10

, IP. ?

Answer 1

PHP, flock() . , , fopen.

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: PHP flock() Windows vs Linux