使用多线程从 PHP 调用 Python 脚本

Question

I'm using PHP to display the Python output in the browser. Since the Python script takes a long time to print the output, The User Interface gets hung till the Python script finishes its execution.

Pthreads for Windows is enabled in PHP for multithreading the shell_exec( ) function which invokes the Python script. Inspite of using Pthreads, the User Interface still gets hung.

Here is the code:

$output_customer_churn_prediction = "";

class WorkerThreads extends Thread {
    private $workerId;

    public function __construct($id)
    {
        $this->workerId = $id;
    }

    public function run()
    {
        sleep(rand(0, 3));
        echo "Worker {$this->workerId} ran" . PHP_EOL;
        $output_customer_churn_prediction = shell_exec('python '.$_SERVER['DOCUMENT_ROOT'].'/analytics/python/neural-net-prediction-customer-attrition.py');
        print_r($output_customer_churn_prediction);
    }
}

$workers[0] = new WorkerThreads(0);
$workers[0]->start();

print_r($output_customer_churn_prediction, true); 

Even with multithreading, the User Interface (generated by PHP) gets hung while invoking the Python Neural Net script.

What could be the reason ?

Answer 1

PHP is caching the Output. You Need to deactivate the Output cache. Then your Browser will not hang.

See ob_flush()