Tuesday, 28 September 2010

C# .net method call performance

I’ve recently been in a conversation with another dev about a code base and had an alarming exchange regarding method calls and performance.

Alarming because he claimed that the reason that the methods in the system were so long was because someone higher in the dev chain 'tech lead' or 'architect' had claimed that it was expensive to make method calls???

I’ve seen my fair share of long methods, awful things that destroy reuse, developer productivity, and introduce many, many tangled bugs. These usually evolve because the devs are under pressure to get things out of the door on tight schedules, or by inexperienced devs who unfortunately don’t know much better. Personally I like to try and keep my methods short <20 lines, to keep to the principal that a method should only do one thing, do it clearly and well (so its easy to read, understand and change), you know all the usual stuff. But I’ve never seen the justification for long methods to be because of performance...

so i thought what is this performance gain of long methods? After googling around I didn’t find anything (if you do let me know) so i wrote a program.

Essentially it consisted of 2 loops, one to do a simple calculation in line and one to call a method to do the same calculation.

for (int i = 0; i < LoopCount; i++ )

for (int i = 0; i < LoopCount; i++ )

i took timings before and after each loop and recorded the results

LoopCount= 100000000
elapsed time = 234.447 milliseconds
elapsed time = 640.8218 milliseconds
Method call loop took 406.3748 millisecs longer than inline loop for 100000000 calls
Thats a cost of 0.0000041 millisecs per method call

i wasn’t sure about the results so i decided to run it again, this time with ten billion iterations of the loop, these performance penalties must show up with that many calls.

LoopCount= 1000000000
elapsed time = 2250.6912 milliseconds
elapsed time = 6376.9584 milliseconds
Method call loop took 4126.2672 millisecs longer than inline loop for 1000000000 calls
Thats a cost of 0.0000041 millisecs per method call

its quite conclusive, method calls don’t really add up to all that much overhead, as we all expected.

Sunday, 12 September 2010

Azure Learnings

A few months ago I played with Azure, experimented with all the storage options (table, queue, blobs) web and worker roles, made things interact and generally got to know what was possible, not possible and how to do things. It was interesting, i gave a few presentations to the company I was contracted to at the time but in the end it was all just exploration, they were never going to take it up (they own lots of their own hardware, i mean Lots, and besides in my view there are issues with going to Azure as a solution for that enterprise problem), also I didn't see any use for it in my own personal projects.

I had a MSDN account which at the time entitled me to 750 compute hours a month (a compute hour is just a measure of how long your roles have been deployed in the cloud), and was careful with my deployments, always take test deployments down to minimise the total compute hours.

Anyway two problems:

1st. I didnt check my subscription(why would i?) it turned out i had the basic "starter" subscription (50 free compute hours) not the MSDN package (750 free hours).

2nd. I did a demo and someone wanted to use it afterwards so i left it up (one web role and one worker role) and then forgot about it... opps. To add to my woes my hotmail account is not my primary email account so the billing was not coming to me, i only just found it when I happened to be on hotmail.

To cut a long story short I got charged £50 + £120 + £120 for the honour of having my dummy website sat doing nothing on the azure application fabric... I;ve since talked to Microsoft and cancelled my azure account, i see no need for it, I'm not going to use it any time soon, and wanted to make double sure all my web instances were gone. but after talking to them i have got last months money back, better than nothing but still... i guess it was my fault for not checking my package, my running instances and my email, stupid boy.

Morale of the story to all you perspective Azure developers out there, check your subscriptions, and always take down your test deployments, always.

Wednesday, 1 September 2010

Site creation with google sites

Just been through the process of setting up a new website http://sites.google.com/site/stangerphotography/ new picasa site and new flickr account http://www.flickr.com/photos/oliverstanger/ for my brother who is setting up a photography business.

It was actually quite easy to do once you get used to navigating your way around the site and the wysiwyg editors. Managed to fully set up google analytics and web master tools also.

Now I just need to make sure my brother updates his content.