Question

I have three methods that I call to do some number crunching that are as follows

results.LeftFront.CalcAi();  
results.RightFront.CalcAi();  
results.RearSuspension.CalcAi(geom, vehDef.Geometry.LTa.TaStiffness, vehDef.Geometry.RTa.TaStiffness);

Each of the functions is independent of each other and can be computed in parallel with no dead locks.
What is the easiest way to compute these in parallel without the containing method finishing until all three are done?

Answer 1

See the TPL documentation. They list this sample:

Parallel.Invoke(() => DoSomeWork(), () => DoSomeOtherWork());

So in your case this should just work:

Parallel.Invoke(
    () => results.LeftFront.CalcAi(),
    () => results.RightFront.CalcAi(),
    () => results.RearSuspension.CalcAi(geom, 
                                        vehDef.Geometry.LTa.TaStiffness, 
                                        vehDef.Geometry.RTa.TaStiffness));

EDIT: The call returns after all actions have finished executing. Invoke() is does not guarantee that they will indeed run in parallel, nor does it guarantee the order in which the actions execute.