pthreads
PHP Manual

The Volatile class

(PECL pthreads >= 3.0.0)

Introduction

The Volatile class is new to pthreads v3. Its introduction is a consequence of the new immutability semantics of Threaded members of Threaded classes. The Volatile class enables for mutability of its Threaded members, and is also used to store PHP arrays in Threaded contexts.

Class synopsis

Volatile extends Threaded implements Collectable , Traversable {
/* Inherited methods */
public array Threaded::chunk ( int $size , bool $preserve )
public int Threaded::count ( void )
public bool Threaded::extend ( string $class )
public Threaded Threaded::from ( Closure $run [, Closure $construct [, array $args ]] )
public array Threaded::getTerminationInfo ( void )
public bool Threaded::isRunning ( void )
public bool Threaded::isTerminated ( void )
public bool Threaded::isWaiting ( void )
public bool Threaded::lock ( void )
public bool Threaded::merge ( mixed $from [, bool $overwrite ] )
public bool Threaded::notify ( void )
public bool Threaded::notifyOne ( void )
public bool Threaded::pop ( void )
public void Threaded::run ( void )
public mixed Threaded::shift ( void )
public mixed Threaded::synchronized ( Closure $block [, mixed $... ] )
public bool Threaded::unlock ( void )
public bool Threaded::wait ([ int $timeout ] )
}

Examples

Example #1 New immutability semantics of Threaded

<?php

class Task extends Threaded
{
    public function 
__construct()
    {
        
$this->data = new Threaded();

        
// attempt to overwrite a Threaded property of a Threaded class (invalid)
        
$this->data = new StdClass();
    }
}

var_dump((new Task())->data);

The above example will output something similar to:

RuntimeException: Threaded members previously set to Threaded objects are immutable, cannot overwrite data in %s:%d

Example #2 Volatile use-case

<?php

class Task extends Volatile
{
    public function 
__construct()
    {
        
$this->data = new Threaded();

        
// attempt to overwrite a Threaded property of a Volatile class (valid)
        
$this->data = new StdClass();
    }
}

var_dump((new Task())->data);

The above example will output something similar to:

object(stdClass)#3 (0) {
}

pthreads
PHP Manual