C# Breaking larger method into two threads

If I have a large method that is composed of two small methods:

public int LargeMethod() 
{ 
int result = 0; 
result += Small开发者_Python百科MethodA(); 
result += SmallMethodB(); 
}

Both small methods block my program for atleast 2 seconds and I believe it will really be better for performance if I let the two methods run in their own threads.

Can you please suggest a programming model?

---

If you are using .NET 4 you can use tasks

public int LargeMethod()
{
    int result = 0;
    Task<int> t1 = new Task<int>(SmallMethodA);
    Task<int> t2 = new Task<int>(SmallMethodB);
    t1.Start();
    t2.Start();
    result += t1.Result;
    result += t2.Result;
    return result;
}

---

Read this Task Parallel Library for more information's and here you have solution:

Task<int>[] taskArray = new Task<int>[]
   {
       Task<int>.Factory.StartNew(() => SmallMethodA()),
       Task.Factory.StartNew(() => SmallMethodB()),           
   };

int result = 0;
for (int i = 0; i < taskArray.Length; i++)
{
    result += taskArray[i].Result;
}

---

CLR2:

• You can define delegates for the methods, create an instance of the delegate and use the "BeginInvoke/EndInvoke" methods.
• Use the "ThreadPool" to "EnqueueWorkerItem"
• Use System.Thread to create a new Thread and start your method on it.

CLR4:

• Use the task library
• revert tot CLR2 patterns

Hope this helps,

ps; Your looking at the 'Parallel Block' pattern.

---

If the operations are short, I would probably put the calls to them into anonymous methods that are executed using the ThreadPool, paired with using the Interlocked class for updating the result variable.

---

How about Tasks? Untested code below...

Task<int> t1 = new Task<int>(() => return SmallMethodA());
Task<int> t2 = t1.ContinueWith((t) => return t.Result + SmallMethodB());
t1.Start();

Of course you could just wrap up both SmallMethodA and SmallMethodB within a single task. If you're writing to the UI afterwards, be sure to use a ContinueWith task that runs on the current thread context.

---

I like Albin Sunnanbo's answer (http://stackoverflow.com/questions/4303605/c-breaking-larger-method-into-two-threads/4303662#4303662)

but then with just 1 fork to make it just a bit quicker and less verbose:

public int LargeMethod()
{    
    var t1 = new Task<int>(SmallMethodA);
    t1.Start();
    int result = SmallMethodB();    
    result += t1.Result;    
    return result;
}

Edit even less like this:

public int LargeMethod()
    {    
        var t1 = new Task<int>.Factory.StartNew(SmallMethodA);
        return SmallMethodB() + t1.Result;
    }

GJ