PHP - PTHREAD Worker Threads not executing concurrently - php

Question

I am working on improving a process in php so I resorted into using multithreading using Worker to manage my threads. But the threads in the worker executes one after the other not concurrently.
This is my sample code
namespace App\Engine\Threads\ThreadClass;
class StatePaperAttendancePDFThread extends \Threaded
{
private $write_folder_name;
private $center_code;
private $paper_id;
private $title;
public function __construct($write_folder_name, $center_code, $paper_id, $title)
{
$this->write_folder_name = $write_folder_name;
$this->center_code = $center_code;
$this->paper_id = $paper_id;
$this->title = $title;
}
public function run(){
echo " Retrieving paper attendance ".$this->center_code." ".$this->paper_id." ".\Thread::getCurrentThreadId()." ".date("H:i:s:u").PHP_EOL;
$artisan = 'C:/xampp/htdocs/attendance/artisan';
$cmd = "php $artisan attendancereport:center $this->write_folder_name $this->center_code $this->paper_id $this->title";
$return = exec($cmd, $output, $return_var);
echo $return;
}
}
foreach ($centers as $i=>$center){
$center_code = $center->getCenterCode();
$thread = new StatePaperAttendancePDFThread($folder_name, $center_code, $paper_id, $title);
$worker->stack($thread);
}
$worker->start(PTHREADS_INHERIT_ALL ^ PTHREADS_INHERIT_CLASSES);
$worker->shutdown();
but when I monitor it from the CLI using the time been printed I can see that none of the threads starts together. They all starts with some seconds interval
Please what am I missing

Answer 1

I was able to solve my problem by creating a customized Thread Pool Executor as below. Please I am open to suggestions and Improvement
class ThreadPoolExecutor{
private $poolSize;
private $threadPool;
private $done = false;
private $workingThreads;
public function __construct($poolSize, array $threadPool)
{
$this->poolSize = $poolSize;
$this->threadPool = $threadPool;
}
public function execute()
{
$this->parametersOk();
try {
while (!empty($this->threadPool)) {
$this->extractThreads();
foreach ($this->workingThreads as $thread) {
$thread->start(PTHREADS_INHERIT_ALL ^ PTHREADS_INHERIT_CLASSES);
}
foreach ($this->workingThreads as $thread) {
$thread->join();
}
}
$this->done = true;
} catch (\Exception $ex) {
var_dump($ex->getMessage());
}
}
private function parametersOk()
{
if (!is_array($this->threadPool))
throw new \RuntimeException("threadPool expected to be an array of threads");
if (count($this->threadPool) <= 0)
throw new \RuntimeException("expected at least an element in threadPool");
foreach ($this->threadPool as $thread) {
if (!is_subclass_of($thread, \Thread::class, false)) {
throw new \RuntimeException(" an element of threadPool does not extend class \\Thread");
}
}
if ($this->poolSize > count($this->threadPool)) {
throw new \RuntimeException("The number of threads set to execute can not be greater than the threadPool");
}
return true;
}
private function extractThreads()
{
$this->workingThreads = [];
$this->workingThreads = array_slice($this->threadPool, 0, $this->poolSize);
for ($i = 0; $i < count($this->workingThreads); $i++) {
array_shift($this->threadPool);
}
}
public function isDone()
{
return $this->done;
}
}
I will appreciate any addition or correction to this.