Server script starts many times when using Swoole 6

[nguyenhothanhtam0709]

Issue:
I ran a simple http server script using swoole 6 and SWOOLE_THREAD mode, the prinft show many times in console but it only shows 1 time in SWOOLE_PROCESS mode. It seems like this script run 1 time for each worker thread. Is this an expected behaviour or not?

1. What did you do? If possible, provide a simple script for reproducing the error.

I ran this script with Swoole 6

<?php

require_once __DIR__ . '/../vendor/autoload.php';

use Swoole\Constant;
use Swoole\Http\Request;
use Swoole\Http\Response;
use Swoole\Http\Server;
use Workerman\Events\Swoole;

$server = new Server('0.0.0.0', 3001, SWOOLE_THREAD);
$server->set([
    'hook_flags' => SWOOLE_HOOK_ALL,
    'enable_coroutine' => true,
    'task_enable_coroutine' => true,
    'debug_mode' => true,
    'display_errors' => true,
    'enable_preemptive_scheduler' => true,
    'worker_num' => 4,
    'reactor_num' => 2,
    'task_worker_num' => 2
]);

$server->on(Constant::EVENT_WORKER_START, function () {
    $pid = getmypid();
    printf("Worker start on $pid\n");
});

$server->on('Task', function ($server, $task) {});

$server->on('request', function (Request $request, Response $response) {
    $response->end("OK");
});

$pid = getmypid();
printf("[thread] Server started at http://0.0.0.0:$server->port on process {$pid}\n");
$server->start();

2. What did you expect to see?

Line _[thread] Server started at _ shows only 1 time.

3. What did you see instead?

Line _[thread] Server started at _ shows only 8 times.

4. What version of Swoole are you using (show your php --ri swoole)?

swoole

Swoole => enabled
Author => Swoole Team <[email protected]>
Version => 6.0.0
Built => Dec 25 2024 10:41:50
coroutine => enabled with boost asm context
epoll => enabled
eventfd => enabled
thread => enabled
signalfd => enabled
cpu_affinity => enabled
spinlock => enabled
rwlock => enabled
openssl => OpenSSL 3.0.2 15 Mar 2022
dtls => enabled
http2 => enabled
json => enabled
pcre => enabled
zlib => 1.2.11
brotli => E16777225/D16777225
mutex_timedlock => enabled
pthread_barrier => enabled
futex => enabled

Directive => Local Value => Master Value
swoole.enable_library => On => On
swoole.enable_fiber_mock => Off => Off
swoole.enable_preemptive_scheduler => Off => Off
swoole.display_errors => On => On
swoole.use_shortname => On => On
swoole.unixsock_buffer_size => 8388608 => 8388608

5. What is your machine environment used (show your uname -a & php -v & gcc -v) ?

uname -a

Linux PF4GRXXV 6.8.0-49-generic #49~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Nov  6 17:42:15 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

php -v

PHP 8.4.2 (cli) (built: Dec 25 2024 09:55:31) (ZTS)
Copyright (c) The PHP Group
Zend Engine v4.4.2, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.2, Copyright (c), by Zend Technologies

gcc -v

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 11.4.0-1ubuntu1~22.04' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-11-XeT9lY/gcc-11-11.4.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-XeT9lY/gcc-11-11.4.0/debian/tmp-gcn/usr --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04)

[matyhtf]

This is as expected. Unlike processes, multithreading in PHP operates differently because of the thorough isolation enforced by PHP's ZTS (Zend Thread Safety). As a result, child threads cannot inherit any resources from the parent thread, meaning each worker thread runs in a brand new VM environment.

The code segment containing new Server in a child thread will be re-executed within its own context.

There are two key configurations related to SWOOLE_THREAD:

• The bootstrap option allows you to set an entry file for worker threads; by default, it uses the index.php file specified when running php-cli.
• The init_arguments option enables the creation of resources that can be passed as parameters to worker threads. These thread parameters can be accessed within worker threads using the Thread::getArguments() method.

[nguyenhothanhtam0709]

@matyhtf , thank you for your explanation.