Showing tag results for Code

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...

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 p...

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 ca...

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 sub...

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 contain...

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 docume...

A customer had a rather strange request. "Is there a way to be notified when the user uninstalls any program from Programs and Features (formerly known as Add and Remove Programs)?" They didn't explain what they wanted to do this for, and we immediately got suspicious. It sounds like the customer is trying to do something user-hostile, like seeing...

Today's Little Program solves the following problem: Consider a two-dimensional board, tall and narrow. Into the board are nailed a number of horizontal obstacles. Place a water faucet at the top of the board and turn it on. The water will dribble down, and when it hits an obstacle, some of the water will go left and some will go right. The goal...

Some time ago, I gave a scripting solution to the problem of obtaining the computer manufacturer and model. But what if you want to do this from C++? I could translate the script into C++, or I could just point you to Creating a WMI Application Using C++ in MSDN. In particular, one of the WMI C++ Sample Applications does exactly what you want:...

A customer reported that the message was not working. Specifically, they sent the message to a window, and they can plainly see that the window is rendering with a particular font, yet the message returns 0. Why isn't the window returning the correct font handle? The and messages are not mandatory. A window may choose to support them, or it ma...