September 2009 | The Old New Thing

2009 Q3 link clearance: Microsoft blogger edition

Raymond ChenSeptember 30, 2009Sep 30, 200909/30/09

It's that time again: Sending some link love to my colleagues.

Why do messages posted by PostThreadMessage disappear?

Raymond ChenSeptember 30, 2009Sep 30, 200909/30/09

The only thread message you can meaningfully post to a thread displaying UI is WM_NULL, and even then, it's only because you want to wake up the message loop for some reason. A common problem I see is people who use PostThreadMessage to talk to a thread that is displaying UI and then wonder why the message never arrives. Oh, the message arri

Microspeak: Net net

Raymond ChenSeptember 29, 2009Sep 29, 200909/29/09

In finance, the net is the total after you have cancelled positive values against negative values. For example, if you took in $30 and paid out $20, then your net is $10. In Microspeak, this term has moved into project planning and has undergone redoubling, so it's not just net; it's net net. The doubling of the word was probably added to cre

Why doesn't Explorer have an interface for creating hard links?

Raymond ChenSeptember 28, 2009Sep 28, 200909/28/09

Nick asks why Explorer doesn't have UI for creating hard links. Heck, while you're at it, why not ask "Why doesn't Explorer have a UI for hex-editing a file?" Remember, all features start out with minus 100 points. Explorer is not under any obligation to expose every last NTFS feature, and it's certainly not going to help to expose an NTFS

The ways people mess up IUnknown::QueryInterface, episode 2

Raymond ChenSeptember 25, 2009Sep 25, 200909/25/09

Sadly, I get to add another entry to The ways people mess up IUnknown::QueryInterface: Blindly responding to everything. Some people are just too eager to please. No matter what the interface is, they say, "Sure, we do that!" Furthermore, no matter what you ask for, they always return the same interface. Even if it's not what you a

Don't panic, it's just H1N1

Raymond ChenSeptember 24, 2009Sep 24, 200909/24/09

The media simply can't resist a good panic story, even when there is no panic to be found. On the Media interviews sociology professor Eric Klinenberg on what happens when the media ask you to talk about the nonexistent widespread panic over H1N1. Klinenberg says to the reporter, effectively, "There is no panic." Undaunted by the lack of

When people ask for security holes as features: Privileged execution

Raymond ChenSeptember 24, 2009Sep 24, 200909/24/09

A customer wanted to know if there was a way to execute privileged instructions without having to write a driver. "I just need to execute a few instructions, and writing a driver would be overkill since it's only three instructions. Is there a way I can execute these privileged instructions without a driver?" The whole point of having a clas

The COM marshaller uses the COM task allocator to allocate and free memory

Raymond ChenSeptember 23, 2009Sep 23, 200909/23/09

It should be second nature to you that the code which allocates memory and the code which frees memory need to use the same allocator. Most of the time, you think of it as "If you allocate memory, you need to free it with the corresponding mechanism," but this sentence works in the reverse direction as well: If you hand memory to a function t

We’ve got your hotel surrounded (on one side) (and not even the entire side)

Raymond ChenSeptember 23, 2009Sep 23, 200909/23/09

A local hotel advertises itself like so: Surrounding the hotel are popular Seattle attractions such as Pike Place Market, the Space Needle, Safeco Park, home of baseball's Seattle Mariners, and Qwest Field, home of football's Seattle Seahawks, all just a short drive away. Okay, first, it's Safeco Field, not Safeco Park. Mind you, I've miss

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