Fake threads in PHP

Why?

simple usage
no need any PHP extension

Install

The best way to install is using Composer:, _(*1)

$ composer require besanek/threads:@dev

Usage

Basic

It's simple!, _(*2)

use Besanek\Threads;

// ...
$executable = new Threads\Executables\PhpExecutable('path/to/script.php');
$job = new Threads\Job($executable);
$job->run();

You can write your own Executable that provides you running bash scripts, native apllications, inline PHP code and whatever you want. Just implement the Besanek\Threads\IExecutable interface., _(*3)

Let's work with the job

Sometimes we read output and sometimes we need write some imput, _(*4)

$executable = new Threads\Executables\PhpExecutable('path/to/repeat.php');
$job = new Threads\Job($executable);
$job->run();
$job->write('Hello');
echo $job->read(); //Hello;

WARNING! The subscript runs in other process, so there can be latency at writing and reading. In this case is not guaranteed that read() return 'Hello'. That occurs if subscript is slower than current script. The solution is waiting cycle like this. ```php while(empty($output = $job->read())) {}, _(*5)


### It's OK or NOT?

How to react to end of the subscript? Callbacks!

```php
$ok = function () { echo "OK" };
$fail = function () { echo "FAIL" };
$job = new Threads\Job($executable, $ok, $fail);

To both callback are passed 3 parameters. stdout, stderr and exitcode., _(*6)

$ok = function ($stdout) { echo $stdout };
$fail = function ($stdout, $stderr, $exitcode) {
    echo "FAILS with exitcode: " . $exitcode . " and error: " . $stderr;
};

NOTE: Callbacks are processed in the method isDone() witch is by default called on an object destructor. It can be too late. If you need process the callback sooner. Run the method isDone() manualy. Ideally in a waiting cycle in case of a subscript is still running. ```php while($job->isDone() === false) {}, _(*7)


### At the end is here management

Imagine, you need resize thousand of pictures. It's ideal for threads! But, if I creates thousand of subprocesses, I wastes all sources on my machine. Is there solution?

**Yes!** `Besanek\Threads\Runner`.

You can add set of jobs and limit the number of threads.

```php
$images = // do some black magic

$runner = new Threads\Runner(50); //Max 50 subprocess
foreach($images as $image) {
    $arguments = '-size=1000x1000 -output output/path/' . $image->name . '--source '.$image->path;
    $executable = new Threads\Executables\PhpExecutable('path/to/resize.php', $arguments);
    $job = new Threads\Job($executable);
    $runner->addJob($job);
    $runner->process();
}

INFO: Method process() has one argument, wich determines whether a queue of jobs are done completely. So if you calling process(true) the whole queue is gradually runned, but it block main process while all jobs aren't done. This is by default called in destructor of runner., _(*8)

WARNING! Only in process() method are jobs runned and finished. So if you forget call it, jobs are waiting till end of script., _(*9)