January 2013 | The Old New Thing

The somewhat misguided question of whether MapViewOfFile or WriteProcessMemory is faster

Raymond Chen January 31, 2013 Jan 31, 2013 01/31/13

A customer asked, "Which is faster for copying data from one process to another; MapViewOfFile or WriteProcessMemory?" This is one of those "Huh?"-type questions, where the customer has solved half of a problem and is looking for help with the other half, the half that makes no sense. First of all, the question is...

Why doesn’t HeapValidate detect corruption in the managed heap?

Raymond Chen January 30, 2013 Jan 30, 2013 01/30/13

A customer had a program that was corrupting the managed heap by p/invoking incorrectly. The problem didn't show up until the next garbage collection pass, at which point the CLR got all freaked-out-like. "According to Knowledge Base article 286470, the GFlags tool is supposed to catch heap corruption, but it doesn't catch squat." Depending...

Poisoning your own DNS for fun and profit

Raymond Chen January 29, 2013 Jan 29, 2013 01/29/13

When you type a phrase into the Windows Vista Start menu's search box and click Search the Internet, then the Start menu hands the query off to your default Internet search provider. Or at least that's what the Illuminati would have you believe. A customer reported that when they typed a phrase into the Search box and clicked Search the ...

Please hold your head perfectly still while you write up that memo

Raymond Chen January 28, 2013 Jan 28, 2013 01/28/13

I dreamed that the original Volkswagen Beetle factory was so cramped that the office workers had to move their desks to the factory floor, with heavy equipment swinging around just inches from their faces. To prevent serious injuries, a template passed through every so often to make sure nothing was out of place...

Finding a printer, and then creating a shortcut to that printer

Raymond Chen January 28, 2013 Jan 28, 2013 01/28/13

Today's "Little Program" does two things: It looks for a printer in the Printers folder, and then once it finds it, it creates a shortcut to that printer. As is common with "Little Programs", I don't bother with error checking. I'll leave you to do that. Second part first, since it is handy on its own: Creating a shortcut to an arbitrary ...

When you have a SAFEARRAY, you need to know what it is a SAFEARRAY of

Raymond Chen January 25, 2013 Jan 25, 2013 01/25/13

A customer had a problem with SAFEARRAY, or more specifically, with CComSafeArray. CComSafeArray<VARIANT> sa; GetAwesomeArray(&sa); LONG lb = sa.GetLowerBound(); LONG ub = sa.GetUpperBound(); for (LONG i = lb; i <= ub; i++) { CComVariant item = sa.GetAt(i); ... use the item ... } The GetAt method returns a VARIANT&, ...

STRICT_TYPED_ITEMIDS is the shell namespace version of the STRICT macro used by USER and GDI

Raymond Chen January 24, 2013 Jan 24, 2013 01/24/13

Starting with the Windows Vista PlatformSDK, defining the symbol STRICT_TYPED_ITEMIDS before including shell header files changes declarations that previously had simply used ITEMIDLIST now use one of various types which are more clear about what type of ID list is being used. Think of it as the STRICT macro for the shell...

Eliot Chang’s list of things Asians hate

Raymond Chen January 23, 2013 Jan 23, 2013 01/23/13

Where are you really from?

Why was WHEEL_DELTA chosen to be 120 instead of a much more convenient value like 100 or even 10?

Raymond Chen January 23, 2013 Jan 23, 2013 01/23/13

We saw some time ago that the nominal mouse wheel amount for one click (known as a "detent") is specified by the constant WHEEL_DELTA, which has the value 120. Why 120? Why not a much more convenient number like 100, or even 10? Because the value 120 made it easier to create higher-resolution mouse wheels. As noted in the ...

Heads-up: Phone scammers pretending to be JPMorgan Chase MasterCard security

Raymond Chen January 22, 2013 Jan 22, 2013 01/22/13

Recently, a round of phone scammers have been dialing through our area with a caller-ID of (000) 000-0000, which should already raise suspicions. When you answer, a synthesized voice says that they are calling from JPMorgan Chase MasterCard security. They claim that your credit card has been disabled due to suspicious activity, and in order ...

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