在线程中存储闭包失败

Question

I'm trying to use a closure as a callback once a thread is done running. However I'm running into what seems to be a limit/failure of PHP or the pthread extension.

My dev stack is running on Win7 x64 with PHP 5.5.3 x86 TS, pthread version 0.44.

The following code works :

class Test
{
    public $callbackVar;
}

$test = new Test();

$callbackVar = function()
{
    echo "Callback var invoked.";
};

$test->callbackVar = $callbackVar;
$test->callbackVar->__invoke();

But as soon as I derive Test from Thread, running the script gives an error :

class Test extends Thread
{
    public $callbackVar;
    public function run() { }
}

$test = new Test();

$callbackVar = function()
{
    echo "Callback var invoked.";
};

$test->callbackVar = $callbackVar;
// assert() returns true
assert($test->callbackVar === null);
$test->callbackVar->__invoke();   

With the following output

Fatal error: Call to a member function __invoke() on a non-object

Anyone ever had this issue ? Any possible workaround ? I'd rather not use eval if possible... I've tried many workarounds, such as rewrapping into another closure, using a ReflectionFunction, ... nothing cuts it.

Answer 1

Zend does not allow you to serialize closure objects.

So it's not something you should try to work around, possibly at some time in the future Zend will allow serialization of Closures, pthreads will not require changes at that time.

You'll just have to do it the old fashioned way ...