StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POCurious Performance difference between returning a value or returning through an Action<T> parameter
text
Body
copied!<p>I was curious to see what the performance differences between returning a value from a method, or returning it through an Action parameter. </p> <p>There is a somewhat related question to this <a href="https://stackoverflow.com/questions/2082735/performance-of-calling-delegates-vs-methods">Performance of calling delegates vs methods</a></p> <p>But for the life of me I can't explain why returning a value would be ~30% slower than calling a delegate to return the value. Is the .net Jitter (not compiler..) in-lining my simple delegate (I didn't think it did that)? </p> <pre><code>class Program { static void Main(string[] args) { Stopwatch sw = new Stopwatch(); sw.Start(); A aa = new A(); long l = 0; for( int i = 0; i < 100000000; i++ ) { aa.DoSomething( i - 1, i, r => l += r ); } sw.Stop(); Trace.WriteLine( sw.ElapsedMilliseconds + " : " + l ); sw.Reset(); sw.Start(); l = 0; for( int i = 0; i < 100000000; i++ ) { l += aa.DoSomething2( i - 1, i ); } sw.Stop(); Trace.WriteLine( sw.ElapsedMilliseconds + " : " + l ); } } class A { private B bb = new B(); public void DoSomething( int a, int b, Action<long> result ) { bb.Add( a,b, result ); } public long DoSomething2( int a, int b ) { return bb.Add2( a,b ); } } class B { public void Add( int a, int b, Action<long> result ) { result( a + b ); } public long Add2( int i, int i1 ) { return i + i1; } } </code></pre>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload