Question

This seems like a basic question, but Google has not helped me… How do I do basic thread locking in C#.NET WPF? In my fairly simple user application, I have multiple threads performing time-intensive operations that save their results into one common data structure or read from this common data structure. I’d like to be able to lock() and unlock() around access to this data structure to maintain thread safety. However, there are many different places in my code that I access this data structure from, not just one. What .NET objects are used to implement this locking?

Answer 1

try this:

public static class LockHolder
{
    public static object Lock = new object();
}

then, in your code, use:

lock(LockHolder.Lock)
{
    //your safe code
}

http://msdn.microsoft.com/en-us/library/c5kehkcz(v=vs.71).aspx

I guess a little more info may be helpful. IIRC, the lock(object o) is basicly a macro that will be expanded by the compiler and then restrict access to your safe code, which is what you’d expect. What isn’t necessarily obvious is that any object o can be a lock, and each o is needed for each safe lock. if I have

object a = new object();
object b = new object();

and perform a lock(a) then that will not prevent access to something with a lock(b) around it. Most code samples show a lock(this) which will lock to the current instance of the particular class, which is not what you want if you need a global lock and have multiple instances of that class running around.