c# - List/Collection blocked until its filled -

i trying achieve easy describe, cannot find how.

i want blocked until list has @ least 1 element. let's have 2 workers.

collection c; 

worker 1:

while(true) {   var element = c.waitoneelement();   // stuff element } 

worker 2:

// slow stuff c.add(element); 

this done using semaphores, i'm wondering if there built-in class allows kind of stuff.

thanks

edit: alternatively, map callback "element added" event, don't think exists.

you can read such collections here http://www.albahari.com/threading/part5.aspx#_concurrent_collections

and heres code snippet page might

   public class pcqueue : idisposable     {       blockingcollection<action> _taskq = new blockingcollection<action>();        public pcqueue (int workercount)       {         // create , start separate task each consumer:         (int = 0; < workercount; i++)           task.factory.startnew (consume);       }        public void dispose() { _taskq.completeadding(); }        public void enqueuetask (action action) { _taskq.add (action); }        void consume()       {         // sequence we’re enumerating block when no elements         // available , end when completeadding called.          foreach (action action in _taskq.getconsumingenumerable())           action();     // perform task.       }     } 

notice consume method blocks until theres item in collection.