December 2018

2018 year-end link clearance

Raymond Chen December 31, 2018 Dec 31, 2018 12/31/18

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The case of the orphaned critical section despite being managed by an RAII type

Raymond Chen December 28, 2018 Dec 28, 2018 12/28/18

Some time ago, I was enlisted to help debug an elusive deadlock. Studying a sampling of process memory dumps led to the conclusion that a critical section had been orphaned. Sometimes, the thread that owned the critical section had already exited, but sometimes the thread was still running, but it was running code completely unrelated to the ...

<CODE>SHOpenRegStream</CODE> does not mix with smart pointers

`SHOpenRegStream` does not mix with smart pointers

Raymond Chen December 27, 2018 Dec 27, 2018 12/27/18

Some time ago, I noted that CoGetInterfaceAndReleaseStream does not mix with smart pointers because it performs an IUnknown::Release of its interface parameter, which messes up all the bookkeeping because smart pointers expect that they are the ones which will perform the Release. The other half of the problem is ...

Don’t forget: std::pair does lexicographical ordering, so you don’t have to

Raymond Chen December 26, 2018 Dec 26, 2018 12/26/18

A feature perhaps not as widely known as I thought is that the std::pair type performs lexicographical ordering, so you don't have to. First, we try to find the component in our list of required versions. If it's not found, then the component has no version requirements, and we say, "Sure, it's supported!" (This is just an example. Maybe you ...

How do I save the results of a file search in Explorer? Not the query itself, but the results

Raymond Chen December 25, 2018 Dec 25, 2018 12/25/18

Say you perform a file/folder search in Explorer and you get the results. How do you save the results? That is, save the list of files that were found. This is not the same as saving the query, which you can do by going to the Search tab and selecting 💾 Save search. To save the results, you can select all of them, say with the &#...

Random internal Windows terminology: IDW, Razzle, and their forgotten partners IDS and Dazzle

Raymond Chen December 24, 2018 Dec 24, 2018 12/24/18

In the Windows team, you'll see the term IDW. You don't see it much in the outside world, though. Here's an ISO image called 6.0.5383.1.1.WindowsSDK_Vista_idw.DVD.Rel.img, so it does get out once in a while. (You can see the file name if you expand the Installation Instructions section.) It also appears on this Web page about performance tips ...

On the attempts to resurrect Space Cadet Pinball

Raymond Chen December 21, 2018 Dec 21, 2018 12/21/18

Since the unfortunate demise of Space Cadet Pinball, there have been occasional efforts to resurrect the popular game. Space Cadet Pinball was not originally written by Microsoft, but was rather obtained via licensing from a company then-known as Cinematronics. This means that there are restrictions on what can be done with the program, as ...

In 16-bit Windows, some per-process data structures were really per-data segment

Raymond Chen December 20, 2018 Dec 20, 2018 12/20/18

In 16-bit Windows, one of the things you did at the start of your program (or more accurately, which the runtime did for you before calling your WinMain) was call the LocalInit function. This function initialized your local heap. When a process started, it was given a data segment, which it could use for whatever purpose it liked. This ...

It rather involved being on the other side of this airtight hatchway: Hanging the loader

Raymond Chen December 19, 2018 Dec 19, 2018 12/19/18

A security vulnerability report pointed out that a malicious file can cause the module loader to enter an infinite loop, thereby causing a denial of service on the process doing the loading. This was by itself not interesting. After all, if you have managed to get the system to attempt to load your DLL, and you want to use it to cause a ...

How come Explorer reports higher disk space used on my volume than my third party disk space tool?

Raymond Chen December 18, 2018 Dec 18, 2018 12/18/18

When you view the properties of a volume in Explorer, it reports (among other things) disk space used and disk space remaining. You find that you're running low on disk space, so you want to look for big files that could be archived and deleted, and you run a disk space tool, but that tool reports disk usage less than what Explorer reports. ...

The Old New Thing

December 2018 - The Old New Thing