How to get a value from a running action?

Question

I have a case looks like this: Here is my controller code:

//example controller:

public function runAction() {
    // a example code that run a long time
    $count = 0;
    while (true) {
        $count = $count + 1;
        Mage::register('testcount', $count);
        sleep(3);
    }

}

public function viewAction() {
    echo Mage::registry("testcount");
}

I want to view $count while "runAction" is running by using viewAction. But the viewAction loads forever. Any solution for me?

Answer 1

You could use the cache storage for this:

Set cache value:

Mage::app()->saveCache($count, 'my_counter', array(), 86400);

Read the cache:

Mage::app()->loadCache('my_counter')

Clear cache:

Mage::app()->removeCache('my_counter')

Answer 2

Mage::registry("testcount") will expire when your current request ends. Use the session to persist values.

In addition to Marius' catch of the while loop never ending - the reason your controller viewAction never returns is most likely due to filesystem session locks. If you have a long-running request it turns out that while your filesystem session file is locked, other processes cannot access it. Try switching your session type to DB or to Memcached/APC.

See below for more information about this phenomenon:

Long Running Admin Page Requests Blocking Other Requests

Answer 3

There is something wrong with your code.
First of all runAction will (try) run forever because of while(true), and second of all you will get an error because of this: Mage::register('testcount', $count);. The first time it works, the second time will give you an error because there is already a value in the registry for testcount.
On an other view, Mage::register() and Mage::registry() do not keep values between requests. This is just a way to set and get values 'globaly' in the same request. For passing values between requests use the session. Or write the value in a file.