How many of haven’t received unwanted LinkedIn invites from people that claim to know you, been colleagues and you haven’t even heard of?
Like… so :
or like so :
Don’t be fooled, they’re just trying to get their recruitment bonus. The right choice? The “REPORT SPAM” button up above. Press it. They deserve it. The correct way would have been a private message but it’s more useful for the recruiters to add a new contact since they may need to contact him/her again.
What do you think this piece of code will output?
class Program
{
static void Main(string[] args)
{
Console.WriteLine(GetValue() == (object)true);
Console.WriteLine(object.Equals(GetValue(), true));
}
static object GetValue()
{
return true;
}
}
I won’t be like others and ask you not to run the code. Run the code if you feel like it. I’ll wait here.
…
Back already? Surprised?
I surely have been.. I’ve found a piece of code similar to this as I was cleaning up code in our repository. You have a method that is required to return object (as in System.Object) and you want to check if, unboxed, it holds the value of true (or not).
Why exactly does
GetValue() == (object)true
return false considering that GetValue() returns always a true value? Well… because you are comparing two instances of a System.Object and the ‘==’ operator is coded in a way that uses the ReferenceEquals (and not Equals) method on System.Object.
The author could have unboxed it to a local variable and do the check after but the speed of coding is so much important for some of us.. Thank you ReSharper for pointing this to us and fixing a potentially subtle bug.
I had a rough experience a few days ago while trying to book a flight for my upcoming holiday. I … no, we, chose TAROM (site link here).
What happened, in short, I started to book the flight, filled-in all the flight details, got to the point where I need to provide the billing details (card number etc.), pressed next and then… “session expired, please start over again”. For a moment I checked my bank account. Sure enough they took the money and offered me just an error. No email, no nothing.
After 1 hour and something, I finally got to customer service representative who manually issued the tickets which couldn’t have been issued by the site. (Meanwhile I found out how hard is to cancel a payment from your bank to a rogue vendor).
In the end things got fixed but a bitter taste persists towards this TAROM operator. Anyway I tried to understand what went wrong in the process, IT-wise and this is what happened, I think :
From this short analysis a few WTFs have emerged :
Having had to put up with Romanian services for the last three decades I’ve learnt that the most probable reason for these WTFs is this :
Leaving the funny thing aside I suppose the ‘architects’ that built TAROM’s site (hope the plane doesn’t crash like the site) thought that it’s better to have the money in the bag and then see if all else went ok… or maybe they thought of a situation where many people would try to book few tickets? Or who knows…
What do you think dear reader?
Have you been testing code speed like this?
var start = DateTime.Now;
int i;
for(i = 0; i < 1000; i++)
{
DoSomething();
}
var stop = DateTime.Now;
var total = stop - start;
var timePerIteration = total.Ticks / i;
Or maybe you’ve found the Stopwatch class and been happy with its superior time precision?
Better, I’d say, but I’ve quite had it. Plus I needed to benchmark a local website and needed to test parallel requests (something similar to ab – ApacheBench)
What does a programmer in such a case? Writes his own tools! 
That’s how BenchmarkNET appeared. Using BenchmarkNET you can write the same thing as above only much shorter and with a better timing precision :
var result = Benchmark.Sequentially(() => DoSomething(), 1000);
Neat? That’s not all. The result can easily printed out to a console or inspected with a debugger :
Benchmarking an HTTP operation over 10 parallel threads, 100 times for each thread?
var dl2 = Benchmark.Parallel(new BenchmarkParams<WebClient>(c => c.DownloadString("http://localhost/"), 100), 10, () => new WebClient());
The project has been published as open source (LGPL license) on CodePlex. You can discuss it, file bugs, or even contribute to it.
Have fun and if you test it out, please leave some feedback!
Later edit : It seems some people already dig it 
TL;DR version :
Upon a curiosity of mine I found out that WCF with basicHttpBinding can be easily beaten (performance-wise) by plain-old ASP.NET even if stripped down of transactions, reliability, security etc. (1500 req/sec vs 800 req/sec)
Also SQL Server Express can handle 1300 inserts per second easily and up to 4300 queries per second just as well. This on a 6+ million rows table and stored on the hard disk not in RAM.
Long version :
A few days ago I was thinking how I implemented a certain web service a few years ago, a few employers ago. Although it was quite fast and efficient it wasn’t scalable. I, then, thought how I should have implemented it.
The web service had to receive an incoming (public) HTTP request, check for a visitor cookie. If there was a visitor-identifying cookie it would check against a data store (in-memory dictionary at that time) to see if that visitor answered.
It was about inviting visitors of certain sites to an on-line survey. A new visitor would be presented with a pop-up box having a “yes”, a “no” and “X” (close) button.
The business rules stated that if the visitor answered yes, the answer would be stored, the pop-up would close and then a new tab/window would appear with the survey. If the visitor answered no, then the same things would happen except opening the survey. If the visitor closed the pop-up, the next time the pop-up would appear again. If the visitor closed three times the pop-up then (s)he wouldn’t be bothered anymore with the invitation.
Saturday, November 26th, there will be a session of presentations at Microsoft’s Bucharest Headquarters.
Free entrance, drinks and lunch on the house.
The event agenda :
I will be presenting WCF Streaming at 11:00. But I assure you the other presentations will be just as interesting as this!
Come and join us and you won’t regret it! But first register at the event site first! Only 22 seats available at the time of the writing.
Hope to see you there!.
Developing that small WCF presentation that I was talking about earlier, I got stumped on trying to get the local path. The server needs to access the App_Data folder to handle uploads and downloads but it needs the base path for that.
No, you don’t get HttpContext (HttpContext.Current is null) although the service is bound over basicHttpBinding.
Luckily I’ve found via StackOverflow that there is HostingEnvironment.ApplicationPhysicalPath which will help you.
Therefore a simple
public class Service : IService
{
private readonly string _dataFolder;
public Service()
{
_dataFolder = Path.Combine(HostingEnvironment.ApplicationPhysicalPath, "App_Data");
}
}
.. will suffice.
I am preparing a small talk & demo on WCF streaming and I’ve tried a lot of things to get it started and working (the practical demo).
I was trying to showcase uploading and downloading large files, in an async manner with progress report and so on.
Turns out I get an exception, with HTTP code 400 Bad request no matter what I’ve tried :
What was the issue? Well the damn development server (code named Cassini) !!! It seems another guy had the same issue, reported on StackOverflow and I was lucky to find it in the large WCF pile.
Running the same server project on the new IIS Express or plain old IIS makes it work.
Hope this will help someone too.. At all costs avoid Cassini (“ASP.NET Development Server”). This is not the first issue that this damn server introduces and surely not the last. I hope Visual Studi vNext will NOT include it anymore and will ship with IIS Express only.
Today as I was inspecting why some condition was evaluated to true instead of false I found out a strange thing. The code is something like :
var someList = new List<Person>();
if (someList.All(v => v.Age > 18))
{
Console.WriteLine("All are 18 or older.");
}
else
{
Console.WriteLine("At least one is less than 18.");
}
I was expecting that in case of an empty collection the All method would return false. But it doesn’t. The “All are 18 or older.” string would be printed.
In my case one more simple condition solved this issue :
if (someList.Any() && someList.All(v => v.Age > 18))
After this I read the manual (RTFM) and according to MSDN (in a community comment however) :
It’s important to note that Enumerable.All() returns true for empty sequences
So it’s a “doh” moment for me.
Watch out for this in your code.
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