The Old New Thing
Practical development throughout the evolution of Windows.
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If you want to set a thread's apartment model via Thread.CurrentThread.ApartmentState, you need to act quickly
Welcome to CLR Week 2014. Don't worry, it'll be over in a few days. A customer wanted to know why their was displaying the infamous Current thread must be set to single thread apartment (STA) mode before OLE calls can be made error. "Even though we set the to , the apartment state is still . Curiously, if we put the above code in a standalone test program, it works fine." The problem is that the customer is changing the apartment state too late. On the first call to unmanaged code, the runtime calls CoInitializeEx to initialize the COM apartment as either an MTA or an STA apartment. You can...
The case of the orphaned LpdrLoaderLock critical section
A customer found that under heavy load, their application would occasionally hang. Debugging the hang shows that everybody was waiting for the critical section. The catch was that the critical section was reported as locked, but the owner thread did not exist. How can a critical section be owned by thread that no longer exists? There are two ways this can happen. One is that there is a bug in the code that manages the critical section such that there is some code path that takes the critical section but forgets to release it. This is unlikely to be the case for the loader lock (since a lot of really smart ...
The latest technologies in plaintext editing: NotepadConf
On November 13, 2014 November 14, 2014, Saint Paul, Minnesota will be the home to NotepadConf, which bills itself as "the premier technology conference for Notepad.exe users and text enthusiasts." I'm still not sure whom Microsoft will send to the conference, but maybe that person could give a talk on how you can use Notepad to take down the entire Internet. Update: The conference has been rescheduled to Friday the 14th.
Since clean-up functions can't fail, you have to soldier on
Clean-up functions can't fail, so what do you do if you encounter a failure in your clean-up function? You have to keep cleaning up. Some people like to follow this pattern for error checking: And some like to put it inside a cute flow control macro like or even Whatever floats your boat. But you have to be careful if using this pattern in a clean-up function, because you might end up not actually cleaning up. For example: What if there is an error disconnecting the doodad? (Maybe you got because the doodad lives on a remote server which crashed.) The cleanup code treats this as an error and...
Why does Explorer say "File too large" for my custom file system, when the problem has nothing to do with the file being too large (heck it's not even a file)
When Explorer copies files around, it doesn't really know what the maximum file size supported by any file system happens to be. (That information is not reported by .) So it guesses. If the file system name is or , then Explorer assumes that the maximum file size is 4GB − 1. Also, if a file operation fails with the error , and Explorer can't figure out why the parameter is invalid, it assumes that the reason is that the file has exceeded the maximum allowed file size. Why does Explorer map "invalid parameter" to "file size too large"? Because some file systems use to report that a file is too large in...
Microspeak: 1 – 1 is not zero
In his reddit AMA, Joe Belfiore wrote i have regular 1-1 meetings with my counterparts in Office, Skype, Xbox. The little bit of jargon there is 1-1 meeting. This is an abbreviation for one-on-one meeting, a common business practice wherein two people, typically a manager and a direct report, have a face-to-face meeting with no one else present. In the case Joe used, the meeting is not between a manager and a direct report but between two peers. The term is also abbreviated 1:1, which like 1 − 1 also looks like a bit of mathematical nonsense. But it's not zero or one. It's just an abbreviation for bu...
Enumerating the ways of choosing teams in a group of players
Suppose you have a bunch of people, and you want to break them up into m teams of size n. (Therefore you have a total of nm people.) Today's Little Program will enumerate the ways this can be done. Formally, let's say that you have a collection of size nm, and you want to enumerate the ways of partitioning the collection into m subsets, each subset of size n. The order of elements within each subset does not matter, and the order of the subsets doesn't matter. That's saying that a team of Alice and Bob is the same as a team of Bob and Alice, and Alice-Bob versus Charlie-David is the same as Charlie-David versu...
Before claiming that a function doesn't work, you should check what you're passing to it and what it returns
Before claiming that a function doesn't work, you should check what you're passing to it and what it returns, because it may be that the function is behaving just fine and the problem is elsewhere. The function does not appear to support directories with Unicode characters in their names. The correct directory name is obtained if it contains only ASCII characters in its name, but it truncates the string at the first non-ASCII character. If you step through the code in the debugger, you'll see that the function is working just fine. The buffer is filled with the current directory, including the non-ASC...
What is the strange garbage-looking string in the "command" value of a static verb?
A customer from a major software vendor asked, "What is the significance of the value that can be found under . It appears to be a copy of the default value, but with the program name replaced with apparent garbage. We've seen this both with Microsoft products as well as products by other companies. There is no mention of this value in the documentation on static verbs." The customer didn't explain why they were interested in this particular registry value. Maybe they thought it was enabling some super magical powers, and they wanted to get in on that action. (If that was the case, then they failed to noti...