The Old New Thing
Practical development throughout the evolution of Windows.
Latest posts
When someone proposes marriage, bear in mind that there is a question that needs to be answered
A colleague of mine was at a restaurant, and he spotted a young couple at the next table. The woman fawned over a classic diamond engagement ring, and when she put it on her finger, he decided that it was safe to ask them about it. They had gotten engaged earlier that day, and the man told the story of the proposal, up to the point where he asked her to marry him. My colleague then turned to the woman and teasingly asked, "And what did you say?" The woman chuckled, then suddenly her eyes opened wide with the realization that she had skipped over this important technical detail. She became dead serious and very...
Debugging: Diagnosing why malloc is failing
A customer had some code which was experiencing memory allocation failures when calling (which maps to ). The function returns , and reports . However, there was still plenty of memory free: The customer was continuing their investigation but was looking for some pointers since the bug took a day to emerge. Could it be heap fragmentation? (The program is uses the regular C runtime heap and does not enable the low-fragmentation heap.) One of the suggestions was to run the VMMap utility to see if the problem was exhaustion of virtual address space. And lo and behold, that was indeed the cause. The code had ...
When something gets added to a queue, it takes time for it to come out the front of the queue
SendInput puts it at the end.
The heavy metal umlaut encroaches into Seattle real estate
The heavy metal umlaut is creeping into Seattle real estate. I submit for your consideration the condominium known as Bleü. I can't even tell what language they are trying to pretend to be. There are other properties in Seattle with dots, but at least the dots aren't gratuitous. Hotel Ändra in Belltown takes its name from the Swedish word meaning to change. (The hotel is consistent with its use of the dots, but outsiders frequently omit them, changing the hotel's name to Andra, which means "Others".) Hjärta Condos takes its name from the Swedish word meaning heart. Hjärta is in the Ballar...
What is this extra thread in my process?
A customer liaison asked: After applying Service Pack 2 to Windows Server 2003, my customer found that a simple MFC application (just using the template, no customization) has two threads when it is supposed to have only one. After five minutes, one of the threads exits. This doesn't happen on Windows Server 2003 RTM or Windows Server 2003 Service Pack 1. Here is a stack trace of the extra thread: The parameters to seem to be consistent with . Assuming that's the case, the parameters are Can you explain what the purpose of this thread is? Did this behavior change as a result of the update? ...
Microspeak: Party, in various forms
To use with abandon.
Excuses I learned from babies
I was visiting a friend of mine, and his young daughter was being unusually cranky. He explained, "Oh, she's teething." I filed that away as an excuse I could use the next time I felt cranky. "Sorry about that. I'm teething." Here's another excuse you might want to use: "No, I'm not drunk. I simply lost interest in remaining upright."
Execute a file as if it were a program, even though its extension is not EXE
Today's Little Program executes a file as if it were a program, even though its extension is not EXE. The idea here is to prevent somebody from running your program by accident, so you give it an extension like . This is great for preventing somebody from running the program by mistake, but how do you do it on purpose? We're merely using the member of the structure to force the file to be interpreted as the type we specify, overriding the default type inference code.
VirtualLock locks your memory into the working set, even if your threads are blocked
Today, a correction to an earlier article on . When you lock memory with , it will remain locked even if all your threads are blocked. As noted in the Follow-up section at the end of the referenced article, the behavior of the operating system never changed. Virtually-locked pages were never unlocked in practice. What changed is that an implementation detail was elevated to contract. The intention when was originally designed was that virtually-locked pages were potentially unlockable if the application is not running. However, the memory manager folks never got around to implementing that part. At some point,...