The Old New Thing

Changing a window class affects all windows which belong to that class

February 27, 2006 Feb 27, 2006 02/27/06

Raymond Chen

Sometimes you need to state the obvious, and that's fine. You can learn a lot from the obvious. For example, the first topic in my PDC talk consisted of simply stating the obvious. Occasionally, when you state the obvious, you have to follow up by stating the obvious. When I pointed out that the effect of SetCursor lasts only until the next...

Enumerating threads in a process

February 23, 2006 Feb 23, 2006 02/23/06

Raymond Chen

The tool helper library is sort of the black sheep of Win32. It grew out of the 16-bit TOOLHELP library, which provided services for system debugging tools to do things like take stack traces and enumerate all the memory in the system. The original incarnation of Win32 didn't incorporate it; it wasn't until Windows 95 that a 32-bit ...

The performance cost of reading a registry key

February 22, 2006 Feb 22, 2006 02/22/06

Raymond Chen

The registry is a convenient place to record persistent cross-process data in a uniform and multi-thread-safe manner. It roams with the user if you store it in HKEY_CURRENT_USER, and individual keys can be secured (even on systems that use FAT, which doesn't otherwise support security). But that doesn't mean that it's free. The cost of ...

In pursuit of the message queue

February 21, 2006 Feb 21, 2006 02/21/06

Raymond Chen

In 16-bit Windows, every thread (or "task" as it was called then) had a message queue, end of story. In the transition to 32-bit Windows, this model broke down because Win32 introduced the concepts of "worker threads" and "console applications", neither of which had much need for messaging. Creating a queue for every thread in the system would...