How to synchronize access to private members of a javascript object

javascript synchronized members
Shailesh Vaishampayan picture Shailesh Vaishampayan · Jun 9, 2012 · Viewed 15.9k times · Source

I have a Javascript object created as follows:

var ccStatTracker = (function (){
  ccmap:{
    "1":["1","2","3","4"],
    "2":["4","5"];       
  }

  return {
    modifyCCMap: function (){
      // Code which takes following actions: 
      // - adds/removes keys.
      // - modifies arrays stored as values against the keys in the map.  
    }  
  }
)();

I have a DHTMLXGrid component which displays grid in the form of rows and columns. When I edit any cell in the grid, "onEditCell" event is called. Now, I want to call ccStatTracker.modifyCCMap() from an event handler function attached to "onEditCell" event. As I go on modifying the cells, this event will be called asynchronously which will in turn call a function "modifyCCMap" which will modify private member "CCMap" of my Javascript object. So the latest state of my CCMap as seen by two calls might be different right? So what is the best way to handle this? Is there something as "Synchronized" in Javascript as in Java?

Please help me as it will determine the approach we want to take for implementing this.

Answer

Tomasz Nurkiewicz picture Tomasz Nurkiewicz · Jun 9, 2012

JavaScript is single-threaded (s aside for a moment), nothing happens asynchronously (or everything for that matter) - all code: event handlers, timeouts, callbacks, etc. - run in the same thread, one after another.

Thus you don't need any synchronization in JavaScript. Any given piece of code in JavaScript is guaranteed to be executed by only a single thread. How cool is that?

See also

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