chrome extension chrome.storage how to do a lot of get and set the same time and avoid race condition?

I get an object from chrome.storage.local.get and then I want to update that object by using chrome.storage.local.set in the callback.

If the callback is executed multiple times a race condition happens. What can I do to avoid this?

I know it can be resolved by jQuery.defer, but is there any method to do an atomic update? Or any suggestions to improve my code?

Below is a very simple example:

chrome.tabs.onCreated.addListener(function(tab){//a lot of at the same time
    //just test
    chrome.storage.local.get(null, function(items) {
            if(!items.test){
                items.test=[];
            }
            items.test.push(something);
            chrome.storage.local.set(items,function(){});
            console.log('a'+JSON.stringify(items));
        });    
});

One solution is to use localStorage in combination with chrome.storage.

You can use localStorage for all the frequent get and set from your listener. Setting and getting localStorage is synchronous/blocking so there is no need to worry about race conditions.

You can then decide some idle time/event to sync localStorage with chrome.storage.

This would work assuming that the user will be using this extension at one computer at any one time.