CODEWITHSUNDEEP
c#multithreading
Alxandr
Alxandr

Reputation: 12423

C# thread dispatching in console app

I'm jusing Jurassic javascript compiler to run javascript in my C# application. Now, jurassic isn't thread-safe, and I call functions (in javascript) from threads all over the place, which I figured wasn't that smart. What I could do was ofcause just to create a simple lock on the javscript-engine, however, what I want is a programming model similar to the one you have when working with a GUI thread in WPF or WinForms. So, I spawned a thread, and created my javascript-engine inside that thread, and what I would like is that no other threads are allowed to edit the objects created in that thread (which will just be the javascript-engine and all the js-objectes). And then, to call js-code from other thread I'd like to use a dispatcher, or something similar, to make the js-thread run the code.

Is this possible in C#?

Upvotes: 1

Views: 2011

Answers (2)

Chris Hannon
Chris Hannon

Reputation: 4134

It doesn't quite answer your question but you may want to take a look at this MSDN article. It talks about the approach that WPF took with their objects and the Dispatcher model, as well as the Dispatcher, DispatcherObject and DispatcherSynchronizationContext classes.

What they recommend for individual objects is to inherit from DispatcherObject (which may not be feasible for your situation) and call the inherited VerifyAccess() method on public access.

public class ThreadOwnedObject : DispatcherObject
{
    private string field;
    public string ExposedProperty
    {
        get { return field; }
        set
        {
            VerifyAccess(); 
            field = value;
        }
    }
}

And the invocation would use the inbuilt Dispatcher.

ThreadOwnedObject ownedInstance = new ThreadOwnedObject();
ownedInstance.Dispatcher.Invoke(new Action(() => ownedInstance.ExposedProperty = "foo"));

Alternately, if that or the DispatcherSynchronizationContext in the article doesn't fit your needs, I imagine that you could probably create a mechanism that mimics the DispatcherObject by holding onto the Thread.CurrentThread.ManagedThreadId when an object is created and perform checks against that value for every exposed access. Beyond that or an equivalent, I don't think that there's a built-in mechanism that will associate a random object with a given thread.

Upvotes: 2

Josh C.
Josh C.

Reputation: 4363

I'm not quite sure what you are asking, but I'll try to help anyway.

Can you use a semaphore to lock the thread running the javascript engine? Even if you don't use the Semaphore class, you could use a boolean or "lock" keyword to protect the code block with the executing engine. The objects produced by that thread could be hidden by the class with the engine until you are ready. You could also expose a method in that class that would allow code injection or object fetching from behind the protected code.

Upvotes: 0

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