Question

I am trying to assess the performance of a program I’m writing.

I have a method:

public double FooBar(ClassA firstArg, EnumType secondArg)
{
    [...]

If I check the Function Details in the VS Performace Analyser for FooBar I can see that the method accounts for 14% of the total time (inclusive), and that 10% is spent in the body of the method itself. The thing that I cannot understand is that it looks like 6.5% of the total time (both inclusive and exclusive) is spent in the open brace of this method; it is actually the most time-consuming line in the code (as exclusive time concerns).

The method is not overriding any other method. The profiling is done in Debug configuration using sampling, the run last about 150s and that 6.5% correspond to more than 3000 samples out of a total of 48000.

Can someone explain me what it is happening in this line and if there is a way to improve that behaviour?

Answer 1

In the first open curly braces of the method is shown the amount of time spent for method initialization.

During the method initialization, the local variables are allocated and initialized.
Be aware that all the local variables of the method are initialized before the execution also if are declared in the middle of the body.

In order to reduce the initialization time try moving local variables to the heap or, if they are only used sometimes (like variables inside an if branch or after a return), extract the piece of code that uses them to another method.